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Launch HN: Prometheus (YC W19) – Remove CO2 from Air and Turn It into Gasoline
1250 points by rmcginnis on May 6, 2019 | hide | past | favorite | 565 comments
Hi HN! I’m Rob, Founder of Prometheus. We’re removing CO2 from the air and turning it gasoline, diesel, and jet fuel. Since we use zero-carbon electricity from sources like solar and wind to make our fuel, there are no net CO2 emissions when you use it.

An article about us came up on HN recently and people seemed interested (https://news.ycombinator.com/item?id=19792412), so we thought it would be good to try to answer some of the questions we saw there and try to dive in some more to any questions that follow!

The only inputs to make the fuel are CO2 and water (both from the air) and electricity. The only outputs are fuel and oxygen. One way to think about it is that making fuel is reverse combustion. The process isn’t super efficient (we expect 50-60% overall efficiency at maturity), but it turns out that doesn’t matter as long as the electricity is zero carbon and low cost. If the cost of our equipment is also low, then we believe we can not only make zero carbon fuel, but actually compete on price with fossil fuel.

We’re not the first to make fuel from the air - in fact Google, Audi, Carbon Engineering, Global Thermostat, Climeworks, and labs at universities and national labs have all done it before us. What no one has been able to do so far is do it at a low enough cost to compete with fossil fuel.

The thing that’s new about what we’re doing is that we have gotten rid of all the thermal processes normally used, and instead use a process that uses only electricity (no natural gas, etc) and does it at room temperature. This is a big deal for both capital cost and for being truly carbon zero. We can use inexpensive materials, which keeps our cost low, and can start up and shut down quickly, which allows us to run intermittently, matching the intermittent nature of many renewable energy sources. We can also only run when the power is at the price we want.

Digging in to some more details, we absorb CO2 and water vapor from the air into an aqueous electrolyte. We then react the CO2 in the water with a copper catalyst to directly make alcohols like ethanol, butanol, propanol, etc. Both of these things have been done by many others and the science is known. Normally at this point one would have to use a thermal process (distillation) to get the fuel out of the water, and this is expensive and makes the economics really hard to get right. We don’t have to do this step thermally though, because we have a carbon nanotube membrane that replaces it, extracting the alcohols from water in a single step at room temperature. This makes a huge difference in cost. The last step is that we up-convert the alcohols to gasoline, diesel, and jet fuel. This last step is also well known and we can actually buy this step from others.

The carbon nanotube membrane that makes this all work is the product of 6 years at my previous startup, Mattershift. I was developing it for desalination and water purification. About 3 years ago I realized it could do this job, but it wasn’t clear that a startup could raise money for such an ambitious effort, especially one linked to a political issue (unfortunately) like climate change. When I saw the YC request for startups in carbon removal, I knew that the timing was right, and I founded Prometheus to do it.

Please let me know if you have more questions or feedback. I’ll do my best to answer any questions, but please excuse if I’m not able to go too far into details like our piping and instrumentation design, or other really specific things we wouldn’t want to help competitors with.

Thanks!




A few questions from a chemistry major

1. why extract from the air when you can just put a device on the smokestack of an existing coal or natural gas plant? The higher CO2 density of the effluent will make things more efficient. 2. Your key innovation isn't the part where you pull CO2 out of the air; it's the nanotube-based reverse osmosis process for separating ethanol from water. This process could just as easily be applied to other fields. For example, bioethanol production similarly requires a very expensive distillation step to extract pure ethanol from the fermentation medium. Making that step more efficient would be much simpler than reinventing the entire supply chain around carbon dioxide extraction and subsequent reduction to ethanol.


> why extract from the air when you can just put a device on the smokestack of an existing coal or natural gas plant?

So you have spare available energy you can use to run the converter, and you also have a demand for energy that you're satisfying using a hydrocarbon powered generator. Why not reduce your hydrocarbon use in the first place, by substituting in the energy you were going to use in the converter? That seems to me to be an awful lot more efficient.

IMHO this technology really comes into it's own when you have available spare renewable energy, and want to find a way to store it in a dense, portable and easily reusable form. I think it's best thought of as a competitor to battery storage, but with the added benefit of extracting atmospheric CO2.


"why extract from the air when you can just put a device on the smokestack of an existing coal or natural gas plant? "

The process uses clean electricity to reverse the CO2. I suspect here we have a timing issue. When the sun shines, the gas plant will be idle, and that's when the spare electricity is available is used to reverse the process.

And the physical position - the gas plant is likely to be where the sun shines less.

As ever we have a storage buffer problem.


That storage buffer problem leads to one possibility. (excuse my english!)

I think there are really two major business cases for Prometheus. One is in earning back carbon offsets (reducing net CO2 production from a polluting source) while producing a valuable byproduct. The other is as a way to ethically and profitably use local excess energy to create that same byproduct.

I think it makes sense for the Prometheus apparatus to be paired with electrical load balancers (aka industrial battery banks) built for renewable energy. Allow me to expand:

1. Renewable sources like solar collect electric energy on an inconsistent basis.

2. Depending on local energy demands (a factory, the neighboring town, etc.), the grid will either use or store the electric energy. Storage for large businesses and nations nowadays occurs through industrial battery banks (i.e. BYD's).

3. Usually, those who use battery capacity battery stored energy can be used before conditions are right for collection again. However, if local energy demands less than can be stored and used in the next collection cycle, that "buffered" energy is wasted.

This is a prime use for that wasted energy. I imagine it only becomes viable at scale. And there is one other issue to address...

Companies like BYD who do national-scale renewable grid storage usually undershoot the amount of battery storage they provide because over-storing is costly (the energy isn't used or is distributed less efficiently and the batteries incur both capital, installation, and maintenance costs).

If Prometheus reaches cost effectiveness, a renewables/storage company could start over-providing energy generation and battery storage and pair it with CO2 factoring to a) reduce costs associated with wasted energy b) earn carbon offsets for large companies and c) create valuable byproducts.


The co2 could be stored underground? I guess that could deal with the timing issue at least?


You're mostly right, in that a timing issue could be resolved through a temporary storage unit, though probably wouldn't have to put it underground.

Likewise, batteries/capacitors/whatever would probably be set up on the electricity. A plant design would seem to want to control the flow rates of both.

Overall, the parent comment's unlikely to be correct in its speculation that the reason for open-air capture is related to timing issues.


You'd have to separate pump and store it, when electricity is expensive.

I suspect the advantage of this system is that is doesn't need pure co2 to work


And if you were storing CO2 I suspect the first question is how do we liquify it. So the advantage fades away.

edit: You'd probably want to store the electricity on-site instead for this. At least if there's no CO2 to consume you can be in the electricity storage business.


We want to replace fossil fuels with renewable fuels, at the largest possible scale, over 300 billion gallons of fuel per year. Point sources of CO2 and biofuels can't scale to this level.


But first you have to cross the valley of death. Elsewhere you refer to having to limit capital spending, wouldn't getting CO2 from a 3rd party instead of building a massive air capture facility do that? Everything I've seen says that its cheaper to capture from a point source than from the atmosphere, why would you make your costs higher than they need to be? You can of course build air capture down the road but I'd guess that you'd want to get off the ground as easily as possible.


Yes, we're actually agnostic on CO2 source. To get to scale we'll need to use CO2 from direct air capture, but we could by the collection from someone else.


I can completely see the logic. If this only works for point sources it may not scale sufficiently to be viable long term. So that capability needs to be proved out early in order to demonstrate it's long term value to investors.


how many point sources do you need to make atmospheric extraction viable? i'm thinking it's like a million


> 1. why extract from the air when you can just put a device on the smokestack of an existing coal or natural gas plant? The higher CO2 density of the effluent will make things more efficient.

That was my big question, too. Asked and got a response here:

https://news.ycombinator.com/item?id=19844578


But then, why to use solar energy to convert CO2 into fuel when you can convert the solar energy into electricity directly and remove the need for the fossil fuel based power plants?


This question is probably answered literally more than a hundred times in this comments section!

We have a huge fleet of cars, trucks, planes and ships that are all very carbon-positive. We also have a huge amount of existing infrastructure for delivering fuel to these things.

Sure, cars and trucks could go electric, but large airliners probably never can, and it's difficult for ships. But even for cars it will take decades to fully transition to electric. An economically viable, carbon neutral fuel that could be brought to market and scaled up quickly would be a huge win for the transition. Especially if it's cleaner burning (no/very low sulfur, aromatics etc.).


The unit economics around this are by no means perfect but the BIG point here that should probably be in all caps is that fact that the thermal process is displaced by the use of electricity. We could argue on what is used to generate said electricity, but that is beside the point since this innovation opens up many more possibilities than are stated here. We could also argue about the comparative cost of produced energy vs conventional fossil, but lets not forget that those same arguments were used during the early commercialization of solar energy.

In my opinion, the conversion process should stop at the creation of alcohols which can then be used as additives in E-85 gasoline for example, or in other chemical applications that have a less direct and immediate carbon impact on the environment.

I also think this innovation has a larger impact if it were used to bring existing generators of emissions closer to being carbon neutral. It also reduces the burden of being cost efficient on Day 1 since the carbon intensity of large emission generators is already a cost they'd be glad to mitigate or get rid of (esp if the process generates a valuable by-product). Imagine power plant stack exhausts channeled through this technology, or if were miniaturized and made a standard part of every fossil fuel combustion engine...we could all be buying gasoline and selling ethanol before you can say Prometheus.


>I also think this innovation has a larger impact if it were used to bring existing generators of emissions closer to being carbon neutral. It also reduces the burden of being cost efficient on Day 1 since the carbon intensity of large emission generators is already a cost they'd be glad to mitigate or get rid of

I can't follow this argument. What exactly are you proposing? His process still has a ~50% efficiency-loss, so even using all energy generated from fossil generators would only mitigate a maximum of 50% emissions (even ignoring all other efficiency losses here). And that obviously would be stupid. That energy is generated for a purpose.

The whole point of his process is to use solar/renewable/carbonfree energy to reverse carbon emissions. It would always be more efficient to just use less electricity/energy in other situations.


In its base form this technology is mining a resource - carbon. Would you rather mine in areas of low or high atmospheric intensity? Would you rather capture it where you fund the whole operation yourself, or where someone else (existing polluters) is willing to pay you to take it out of the air because there is a regulatory cost to them putting said carbon in the air?

Maybe i should have been clearer. I wasn't suggesting using the energy from a fossil plant to power this, but co-locating it to areas where there might be more environmental and cost incentives to do so.

As i said in my earlier post, arguments on cost/efficiency are beside the point. The huge deal here is the use of electricity (of any form including all the advances to come in the future...solar cells in space, nuclear fusion etc), to remove CO2 from the atmosphere. One can now envision a future (regardless of cost or efficiency today) where we can sustainably keep the earth whole.


I imagine the only places you can realistic install this technology is next to hydro dams/large wind farms where you can get very cheap electricity at certain times, and there are likely no hydrocarbon plants in these areas.

I'm not sure it's reasonable to install this in a coal plant and try to source cheap solar from hundreds of miles away to power it (if that were possible, why would the coal plant be active? It can't compete with the energy you're using to scrub it)


So we bleed energy off a hydrocarbon fueled generator system that produces CO2, to power a machine for capturing CO2 to create hydrocarbon fuels. That seems a little pointless.

The advantage of this system is you can use excess renewable energy sources to mitigate hydrocarbon energy generators. If you are running a hydrocarbon powered system, don't use energy to power this capture system at the same time. That's madness. Better to use that energy to reduce your use of hydrocarbons in the first place.


That is not what I was suggesting.


You said:

>Imagine power plant stack exhausts channeled through this technology

What's I'm saying is, if you have spare energy available to power the converter, you're better off reducing the hydrocarbon power plant output and replacing that output with your 'spare' energy supply. Doing so would be dramatically more efficient.

The only case this doesn't apply is if there is no way to substitute your spare available energy for the output of the hydrocarbon plant, but I can't think of such a situation, at industrial scale, off the top of my head.


Ok, I understand where you're coming from, and its a logical argument. However, a lot of fossil generators (esp coal) are baseload plants that stay running for system reliability. They might stay running during off-peak hours when the output is barely needed, just to ensure availability during on-peak hours. In those cases, you can't tweak output to match variable renewable energy output.


Thermal heat is low grade compared to electricity.


If this new process is working at scale, it has huge potential. I just wonder whether this process is covered by a patent or not. Might be a huge risk if not. If so, I wouldn't be surprised when the new process is named after the inventor. Much like the Haber-Bosch process.


Or we could just run engines on alcohol.


Jet fuel has about double the energy density of ethanol. Running planes on ethanol would severely curtail their range.


I'm skeptical, but fascinated by what you're doing.

It sounds like all of the steps of your process are known, except:

1. CO2 fixation uses only electricity - no natural gas or other fossil fuels. It works at room temperature.

2. Distillation of the immediate products (alcohols) is not necessary. A carbon nanotube membrane solves the problem at room temperature through reverse osmosis.

Correct?

If so, then why target fuels rather than alcohol production directly? Burning gasoline puts the CO2 right back into the atmosphere, which seems like a half measure.

Why not focus on delivering CO2-negative organic feedstocks instead and possibly tap into the carbon credits market?

Edit: another question. How much flexibility/control does your process give over the kinds of alcohols you produce? For example, can you select for long chain alcohols over short? Saturated vs. unsaturated? Cyclic vs acyclic? Aromatic? Mono- vs oligohydroxylated hydrocarbons. Primary, secondary, tertiary? etc.


We could use the alcohols as fuels directly (in flex fuel vehicles), but this wouldn't address the much larger market for gasoline. It's a simple and inexpensive upgrade, so makes sense to do it. We will definitely take advantage of carbon credits, tax incentives, etc too!


If the alcohol upgrade to gasoline makes sense technically and economically for you, why is it not commonly done with (presumably much cheaper and extant in great volume) industrial alcohol today?


Actors are not necessarily as rational as Econ 101 would have us believe. Incomplete information, misinformation and advertisement distort the market. As well as monopolistic practices.

A lot of conspiracy theories are paranoid, but the propaganda machine of the oil industry is very real and managed to incite a lot of economically counter-productive policies.


He said "inexpensive", not "economical". The whole process isn't economical yet. Perhaps conversion is more economical with their particlar sorts of alcohol though.


Understood, although eventually it has to become "economical" or it doesn't fly.

My point was, you can view the alcohols as a feedstock for the gasoline production, and given that, you might just stream in large quantities of already-produced and cheap grain ethanol etc. from Indiana.


It is more likely that polluting methods (net non-zero) will be forced to become uneconomical.


Ethanol mixed fuel is common in a lot of places.


I might have misunderstood your point, but I believe alcohol is commonly used as a fuel in Brazil, where most cars are capable of using it directly.


Organic feedstocks (non-fuel), although smaller isn't exactly a tiny market. Depending on how much control you have over the fixation process you might be able to tap into some high-value alcohol markets. That's the main reason I added the follow-up to the original questions.

In other words, the flow of material would look like:

CO2 -> polymers, drugs, and other useful solid materials

There would be no [product] -> CO2 step at the end. It cuts out the re-release of CO2 and eliminates a dependence on petroleum.


I believe that as long as we have a huge worldwide oil / diesel / gasoline infrastructure in place, from transport to refining to distribution to combustion, it makes a lot of sense to build reasonably-efficient carbon-neutral mechanisms to plug into that infrastructure.

In other words, for the next handful of decades, the worldwide fleet of cars, trucks, generators, boats, etc. are going to be burning carbon that comes from somewhere. Products like this provide a carbon-neutral means of supplying that demand.

It's like working on a huge existing codebase, but at much larger scale, and with geopolitics. People are working on rebuilding it all from scratch, but iterating within the existing infrastructure could also deliver huge wins.

And, if we somehow found ourselves in a world in which carbon-neutral petrochemicals were the norm, well, we can always generate a surplus and sequester that surplus, right?


If I am allowed to daydream freely, a huge fusion reactor with a gasoline pipeline flowing from it, is (in my mind) a beautiful thing.


Ultimately anything we make now with petroleum feedstocks could be made from CO2 mined from the air instead. Gasoline and other transportation fuels is a logical first step, but we don't need to stop there. Agreed!


I think one has to look at this from a business minded point of view. One way of doing that is going for what could be an immense market.


Hi Rob. I'm CTO of a company that generates electricity from waste heat at industrial facilities. Pipeline compressor stations often generate 35MWth+ in waste heat, which we can use at about 20% efficiency to generate electricity.

Many pipeline compressor stations are not anywhere close to distribution lines so just merrily pump this heat up their stack. Especially with new pipelines where companies are battling (legitimate) environmental concerns, there is no reason they would not install your tech, powered by a heat recovery system, on every single proposed compressor station on the line.

We have actually modeled it with negative operating costs (using technology from one of your competitors) and think we could get the pipeline companies or the government (we're in Canada) to pay for it even in the face of bad economics. If your system is a step change in effectiveness from those systems, it could be a game-changer in this market.

Let me know if you'd like to explore this a bit. My email is in my profile.


> Pipeline compressor stations often generate 35MWth+ in waste heat, which we can use at about 20% efficiency to generate electricity.

Can the waste heat be used for distillation instead? To heat up the fuel/water mix to separate the two cleanly?

It would seem to me that the future of "waste heat" is to actually utilize the heat, instead of powering a relatively inefficient heat-engine. Perhaps instead of 20% efficiency, you get closer to 100% efficiency since all you'd be doing is running the fuel-water mix to the heat-source to evaporate the fuel out (I presume anyway, I'm no chemist)


Your instincts are excellent: using heat directly is always and everywhere better than turning it into a fungible commodity like electricity, only to convert that electrical energy to some other form later. (Creating liquid fuel is no different in this regard.)

The reality is that there's almost never a practical direct use of the heat at the facility where it is created. It is too low quality for the onsite processes. Economizers and Regenerators are two common pieces of equipment that suck out what heat can be used - what's left is too low temperature for whatever they're making onsite.

Sometimes there's an opportunity to broker a deal between two adjacent facilities, where one can use the heat that the other considers waste. But those are rare.

Happy to talk about this until you wished you'd never asked. Feel free to email.


re: waste heat, I've been thinking forever that someone must capture this. I've generally assumed the economics don't work out or no one has cracked it outside of scenarios like regenerative braking. We waste so much energy that we could capture and put back to use.


Regen braking doesn’t use waste heat. It converts mechanical energy back to electrical.


And in so doing, reduces waste heat due to friction, which is likely what the parent commenter meant.


Some say it doubles the lifespan of brake pads.


> We waste so much energy that we could capture and put back to use.

The biggest current waste of energy is residential heating. We take high quality energy in the form of natural gas and fuel oil and use it to produce low quality heat.

Co-gen systems burn fuel to generate electricity and use the waste heat for heating buildings.


Something like 55-60% of the thermal energy created by burning fossil fuels is currently wasted.


It’s kind of ironic that cars and power plants work hard on getting rid of that energy.


Modern power plants work hard at getting every last bit of that energy before it escapes. Current Combined Cycle plants, that generate steam from the exhaust of a gas turbine, are currently getting over 60% efficiency.


One must be a bit careful there. 60% efficiency based on the LOWER heating value of natural gas. That ignores the heat available from condensing the water of combustion. Coal plants typically use the higher heating value when computing efficiency, which does reflect the latent heat of vaporization of that water.


I know ICE engines use turbochargers to "recapture" the energy. Exhaust can be used to power the intake fan, which can increase air-pressure available to the engine's intake.


Turbocharged engined still need a ton of cooling but yes I think they are more efficient overall .


You could certainly do this, using distillation or the thermal processes Carbon Engineering is doing, and it could be worth pursuing, from a business opportunity perspective. We're focused on an implementation that can scale to >300 B gallons per year, so are pursuing an electricity only path.


Thanks. If the scale is lacking, I get it. But to be clear, I’m talking about a series of 10MW electrical power plants each with 95% capacity factor.

Using your number downthread of 60kW/gallon, that translates to about 1.4 million gallons per station per annum - even with dozens of stations per line, a couple of orders of magnitude less than your target opportunity of 300B gallons+.

Would you be willing to expand a bit on your opportunity target of 300B+ gallons/year? My understanding is that the US production of gasoline in 2018 was about 142 billion gallons, so I certainly misunderstand something.


To put this number in perspective: 300B gallons of gasoline is an amount of carbon equivalent to all of the CO2 in the air above all of the earth's land area, up to an altitude of about 80 feet.

If you can pull that off, I'll be impressed; but it seems like a very aggressive target.


It's about half of global annual gasoline consumption. It's going to be hard, but worth it to try.


I don't have anything new to add, other than to say - this is a very well written startup pitch. I'm in awe of how clearly you've laid out the opportunity.


The only thing I have to add here is that a random stranger from the internet is rooting for you. This post sounds awesome and has all the makings of a classic American success story. Good luck!


It's almost surreal reading through the comments in this thread. I'm so used to the internet being a constant wave of negativity and hatred of everyone, especially in recent years.

This thread is such a nice break from that, feels so refreshing. I don't know anything about this process but I hope it works out.


I concur. This is really great news about a great product. I only have supportive feedback and no complaints. It carbon neutral and it’s competitive. It’s one of the pieces to the puzzle solving pollution and GHGs in the atmosphere.


I hope this startup does well and can get this tech widespread across developed and developing countries. It’ll mean we can be carbon efficient with our existing ICE cars.


Thanks!


If you really think the underlying economic problem with electrochemical CO2 to alcohols as fuel is the separation at the end you are in for a world of (economic) hurt. Not that improving the aforementioned separation isn't useful or valuable, its just not the lynch pin.

Take a really hard look at your economics, in particular throughput and capital amortization (which scales proportionally to uptime!). Good comparison industries are chlor-alkali, fuel cell, and water-electrolyzer. Aqueous Cu catalyzed CO2 reduction - even if you are best in class for FY and efficiency and durability - have atrocious current densities, diffusion limited, by the standards of anything considered commercializeable.


The separation itself is not the only thing that makes the economics favorable. It's important that changing the separation makes the process electricity only overall, and this is a big deal. We can run intermittently, allowing low renewable power costs, and since there is no pressure or heat in the system, we can use inexpensive components. When the capex is low, it allows for a lot of other things to not be ideal starting out. Current densities aren't going to be as high as water splitting electrolyzers or aluminum production, for example, but that's ok in this context.


Electricity costs more than heat, as a rule. (electricity = heat at pretty much 100% efficiency)

Intermittent operation blows up CAPEX costs.

There's no heat in the system until you start dumping electricity into the resistive heating of your cells - you won't ever be able to run at scale at room temperature. A gallon of gas per second unit - something nicely sized for intermittent operation at a gas station - would need to vent approximately 120 megawatts of heat.

Current densities are 1-2 OOM lower than water electrolyzer.

Cell CAPEX isn't nearly as catalyst dependent as the daily 'We've invented a replacement for platinum in fuel cells' papers would make you believe. Nafion, balance of hardware, and assembly man-hours are $$$.

I've been where you are (more or less): beware the superficially justifiable assumptions.


It's true that running part of the time is not as good as running continuously, but if the capital is low enough, it's ok to start out running intermittently until we get to the point where we have low cost dedicated power and can have a higher uptime.

We will have to shed heat from the system to the environment, but that can be done passively.

Current densities are likely going to be substantially lower, but our capital costs are also going to be much lower. We don't need to operate at 30 bar for example, nor further compress our product.

Our capital costs aren't magic, they're just good enough in balance with everything else.


Hook to nuclear and hydro electricity and you can get your uptime much higher while remaining carbon free. That should give you a good 2x boost on capex at least.


Building nuclear plants to save on electrolyzer capital cost is not a good idea at all. Penny wise, pound foolish.


Hook to existing plants to help them load follow where intermittent renewables are at high capacity.


If you base yourself in QC you'll have access to cheap and 100% green hydro electricy 24/7.


I hope you are wrong, but realistically I fear you are correct. It is easy to show something works in the lab, hard to make it work in the real world.


How could the math possibly work out on this? If a gallon of gas holds 33.70 kWh of energy, and you can get cheap electricity for $0.1/kWh, you're looking at $3.37/gallon if you have a magical process that converts with 100% efficiency. Even if you hit your efficiency goal, which would be impressive, who is paying $7/gallon for gas? Just buy an electric car. This can only possibly be useful when all of the oil is gone and there is no other alternative, right?


We expect a gallon of gasoline to require approx. 60 kWh of electrical energy. If the price of that electricity is below 5 cents, the economics work. If the price is lower, the efficiency of the conversion could also be lower if that optimized other costs (like capital). Electricity is routinely below 5 cents now at utility scale (wholesale), which is where we will want to be.


60 kWh capacity EV will get you (realisticaly) 200 miles.

A gallon of petrol - 40 miles (realistcally and using UK gallon).

According to Tesla their charging is 92% efficient so reduce that 200 to 184 miles.

Your process is 4.5 times less efficient than just putting that electricity into the EV? Is that right?

If so - and your process is carbon neutral (big if) - what's the point in a future where EVs dominate?


In the long term, electric vehicles may indeed replace ICE cars. That would be awesome. One way to see what we're doing is to make sure the path to that future is good. We can't burn fossil fuels while we wait to replace the existing vehicle fleet with electric cars. By using zero carbon we make sure that we are solving the problem right away.


You might want to focus on jet fuel, since we don't know how to make batteries with sufficient energy density for long range flights and don't know if such energy density will ever become possible.

It might also be worth looking at where airplanes tanker fuel, that is to say, carry more fuel than they need for their current leg because refueling at the next stop would be difficult or expensive. Apparently a lot of that currently happens on short flights to small islands; while I hope Wright Electric and/or the EViation Alice will eventually take over that market, in the short term that's a market that might be willing to pay a bit more for liquid fuel made from air plus local solar panels.

Fuel oil that can be burned in combined cycle power plants in the winter may also be valuable for dealing with seasonal imbalances in demand vs renewable generation that lithium ion batteries can't cost effectively balance.


> what's the point in a future where EVs dominate?

EVs won't dominate some important uses for a long time, e.g. aviation and marine shipping.


4.5 is not so much. Gasoline is very energy dense, stores well (especially synthetic) and transports well. This is great - gas will be around for a long time to come - if we can shift the source of it to something better, I'm all for it.


1. Airplanes and boats will still need gas for a while 2. We’ll need to suck carbon out of the atmosphere anyway. So a process like this will be necessary, even if in the end the product needn’t be turned back into gasoline. This will be costly, but it’s the price we pay for all of the fuel we burn currently.


Aircraft and cargo ships simply can't use batteries.


Ah, that certainly explains it. I'm still highly skeptical of how widespread this will ever be, since electric cars will become even more compelling as electricity costs decrease, but you've convinced me to not dismiss this completely as impractical. Thanks for the context.


Batteries still are the main issue with electric cars. The range, charging time and battery life are getting better but still don't match hydrocarbons.

It's just a great storage mechanism.

Storage is also a big issue when it comes to renewables. You could take in carbon in areas with lots of sun and ship the fuel to areas not well suited for solar generation.

This really would be a game changer for lowing the net carbon output.

This also means you could solve one of the big problems in the power grid, peak generation. Use the extra capacity during off peak hours to generate fuel that is later used to fire up power stations to supply peak demand.


But liquids fuels like ethanol are used for MANY more things than just transport – plus the cost of fossil fuels can only go up on any reasonable timeline.


Intermittent renewable energy like wind also drives cost really low sometimes. This could be an alternative to grid-based storage of electricity. Comparison of capital cost and loss and value of the byproduct would be interesting.


No the economics does not work, if you include the "externalities" of that gallon of gas. You are continually creating waste heat and carbon emissions, while using naive reasoning based on Gas Buddy prices.


Solar is already down to $0.065/kWh for industrial applications [1]. That's $3.90/gallon at today's prices, and solar prices continue to fall.

The DOE's 2020 targets came three years ahead of schedule. Their 2030 target is $0.04/kWh [2], which would work out to $2.40/gallon. Mix in the fact that a bunch of countries (and US states) have implemented carbon taxes and you've got yourself a good long term investment.

[1] http://solarcellcentral.com/cost_page.html [2] https://www.energy.gov/eere/solar/articles/2020-utility-scal...


Do those figures include gas taxes? Don't those make up a large part of the price at the pump?


In the US, gas taxes are low (I think I pay 15 cents per gallon tax on a total of $2.50 per gallon).

Taxes are low as here in the US (a) many people hate taxes and (b) with such a low population density, commerce is very reliant on road vehicles. So raising taxes has an outsized impact on commerce.


California has higher gas taxes. Our gas is currently about $3.70 a gallon where I live.


$4.29 for premium yesterday in oakland.


About that in parts of Seattle as well. Which is low given a few year rolling average. We should expect gasoline prices to rise, and fast. So anything that starts to look into economically viable options at $7-10/gallon is worth checking into now in a startup phase.


There have been 15 year solar power purchase agreements signed already for $0.025/kWh [1].

Assuming they get to 50% efficiency, that's $1.69/gallon.

Sounds crazy low, but I hope it's true.

[1] https://www.utilitydive.com/news/texas-muni-signs-cheap-sola...


Yes, and that's just until now. Anyone want to bet that we've hit rock bottom in terms of prices, efficiencies, and economies of scale? Or are we going to see another 10x? 0.17$/gallon. 20x?, 0.09$/gallon (rounding up because I'm lazy).

My view is that is more a question of when than if and that the point where it stops mattering relative to the comparison to fossil fuels depending on your point may already be quite near or even in the past.

Some places are still getting expensive solar, some places are bidding at 0.025/kwh. It doesn't really matter. What matters is what the bids will be ten years or so from now, which is when realistically this could start becoming operational at a meaningful scale.

It's 2019. Ramping up production for something like this takes some time. A decade can fly by for a startup like this. Doing the math with 2019 prices and efficiencies means you get a very conservative view of what would be possible now with today's level of technology at today's scale.

However, an investor needs to look a decade ahead. Or longer and assign some probabilities to likely outcomes. The outcome where there's no progress whatsoever in making clean energy tech better in the next ten years seems unlikely. So, betting on < 1$/gallon as a feasible goal in 1-2 decades seems like a reasonable bet. If the rest of the technology works as advertised (room temperature synthesis and extraction of alcohols) and the technology can be scaled at reasonable cost, that ought to be basically a money printing machine. The lower that price drops, the better. As long as oil remains the primary source, you can pocket the difference as profit.


At industrial scales, you can buy electricity much cheaper than $0.1/kWh if you locate your facility in the right place. For example, hydroelectric power near a large dam can cost as little as $0.02 to $0.05/kWh.


I believe they’re looking for very cheap electric rates. Excess wind or solar power the grid doesn’t want could certainly be cheap. Or college dorms.


> who is paying $7/gallon for gas?

Today's price for standard gasoline here in the Netherlands is 1.83 EUR/litre, which is currently equivalent to 7.75 USD/gallon.


It would not make sense today, but in 10 to 15 years, with climate regulations, having a carbon neutral jet fuel might start making a lot of sense.


Yup. We could tax extraction rather than fuel purchase. (or only tax fuels that are extracted rather than captured, or tax the latter less, or..)


I expect I'll see new battery powered aircraft before I see today's aircraft powered by kerosene synthesized from water and carbon dioxide in the air. And we'll probably see more rail/car before then since the massive cost increase on airline tickets from this will destroy the industry.


As the other reply pointed out, without a huge(like 5x) improvement in energy density (specific energy, actually) of batteries, this is physically impossible. Even with improvements, it would still be inefficient as batteries don't lose mass as they are used up - airliners can't even land with full fuel, they have to use it up, or dump it in an emergency situation.

Using a process like this would essentially make the fuel simply a much better battery for airplanes than our batteries today.


There is a good chance we will make jet fuel in the next 2-3 years. There appears to be a lot of demand for it. We're starting with gasoline because it's a much bigger market / impact, but it's not that hard to make jet fuel too.


And if synthesizing jet fuel turns out to be viable, I could easily see governments 10–20 years from now requiring airlines to use it, the way they are for automobiles.


Battery powered aircrafts would require huge jumps in electrical storage. There are no signs of them becoming a reality any time soon. Not to mention the complete replacement of old planes is going to be very very slow.

I don't understand your rail/car replacing flying argument. There are no signs that flying is going to get so expensive that people would rather pay for it with so much of their time.


>> who is paying $7/gallon for gas

A lot of people in the world. And Americans would pay close to that without subsidies + rising gas prices.


In the UK, a gallon of Petrol is currently about $7.97 (about £1.20/litre).


who is paying $7/gallon for gas?

In the UK, people pay approx $6 per gallon for gasoline.


https://www.globalpetrolprices.com/New-Zealand/gasoline_pric...

If you change that chart to USD and Gallons you'll find this around the cost of gasoline in New Zealand.


For comparison, in Sydney, Australia, as of this morning, basic unleaded 91 octane fuel is about AUD 1.35 / litre at best. Which is USD 0.94 at today's exchange rate. Just under USD 4 / US gallon.

Of that, AUD 0.41 is federal fuel excise, and AUD 0.12 is GST.


Don't forget that UK Gallons are not the same as US Gallons 1 Imperial Gallon = 1.2 US Gallons


In France current prices are around 7$/gallon (1.6€/L)


$7/gallon is the approximate price in Scandinavia. It's not a completely alien price.


In Quebec our electricity can be lower than 0.05$ CAD/kWh (3.28¢/kWh based on the Rate L [1]). Our courrent lowest price is 1.384$ CAD/L. So considering that 1L would be 8.9 kWh. So all it would need is an efficiency of 33% to be profitable with an electricity cost of 0.05$ CAD/kWh. That's excluding any tax incentive to do so or any deal made with HydroQuebec to use excess power.

[1] http://www.hydroquebec.com/business/customer-space/rates/rat...


> Just buy an electric car.

China’s EV goal is 20% of new vehicle sales by 2025. That is to say, 80% of sales in 2025 will still be gas. (So will the 100 million gas vehicles sold in China between now and then). We are a long ways away from not needing this tech.


Don't skate to where the puck is, skate to where the puck is going to be.

Electric cars can't compete against gasoline cars until the price hits about $6/gallon. And considering that crude prices are relatively low, but gas in CA is almost $4/gallon in the Bay Area, it doesn't take much time for normal rates to hit $6/gallon in the next 10 years or so.

At that price, it becomes more economic and that's the time frame probably what they're targeting as well.


What? They compete today with significantly lower fuel cost. You see 100+ mpge on every electric car I know of today, you're looking at half-1/3 the per mile cost in an electric car. That more than makes up for the higher upfront cost over the lifetime of the vehicle, with cars you can go buy right now, today.


And that doesn't even take into account the superior UX.


I don't know why you got down voted on this. My experience of EV vs ICE (sometimes in the same vehicle - daily driving in a Prius plug-in) agrees entirely with your comment: the lovely EV experience of linear, quiet acceleration is so pleasant compared to driving a petrol car, even an automatic. And my Prius in EV mode isn't even a that great an electric experience compared to that of an i3 or 2018 Leaf.


ICE cars cant compete with convenience of: * not needing to refuel * less maintenance needed * not spewing particulates in air etc (if you care about what you breathe)


* not needing to refuel

no, we're taking Soothing30MinuteRelaxingBreaksAt200MileIntervalsAwesomeHappy™ brought to you by Tesla™ instead


I don't know about you. I've driven the last 5 months / 5,000 miles without using a Supercharger once, except for the first day I took delivery just to try it out.

It's there when I need it for the long road trip. But daily life is effectively refueling-free.

What percentage of round-trips are under 200 miles? NHTS recorded the distance from ~750,000 car trips in 2009 and found the 95th percentile is 30 miles, and the 99th percentile is 70 miles. Somewhere on the order of 1 in 1,000 trips needs a Supercharger stop along the way.

[1] - https://nhts.ornl.gov/vehicle-trips


I go on vacation a few times a year. Renting a car just for that is more expensive than extra cost of fuel. Not to mention most rental cars won't let me use my truck as a truck (putting rock in the back damages the bed, and a trailer is right out - both things I do only a couple times a year but I still own a truck for just those few times).

IF this is as good as they claim I don't see electric cars as worth it as a first car. They are slightly cheaper for an in-town only commuter car, but the downsides of electric cars (expensive battery replacement, limited range without long recharge times) are something that fans hate to acknowledge. Note that I said first car, once you have decided to have a second car electric is probably better.


Battery replacement is not really a factor under any kind of "normal" use. One Tesla owner driving for Tesloop was able to burn out a battery after extensively (exclusively) Supercharging from low charge to 95-100% charge after about 350,000 miles. Maintenance cost over that time was calculated as $0.05/mile. [1]

With V3 Supercharging, you can drop in with your Model 3 at 15% and be at 80% in 24 minutes. In my road trip experience, that's barely enough time for everyone to use the bathroom and pick out a beverage. [2]

[1] - https://www.tesloop.com/blog/2018/7/16/tesloops-tesla-model-...

[2] - https://twitter.com/privater/status/1103567772301193216/phot...


Interesting stats on the battery replacement, but if my family/youth groups/etc. routinely took 20+ minutes for a gas station bio break, there'd be words. Especially if we had to do it every 150 miles (80-15%).


I go both ways on that one. On the one hand I want to get there. On the other hand my doctor wants me to get out and take a 10 minute walk every hour anyway.


Also worth mentioning that 65% of the LR Model 3 is over 200 miles.

So if you are starting the day with 95% charge, and ending the day plugged in at your destination with 15% charge, that means you can travel about 450 miles with just one ~20 minute stop to charge along the way.

How is that not fast enough? The only issue is if you can't plug in at your destination. Maybe in that case you have breakfast near the next Supercharge on your route.

Yes, it is something you might have to think about for a minute. The guidance software will map out Supercharging stops for you.


How long are you waiting in line to get a chance to charge? I've been driving with my friend with a Tesla and he visited 2 places before giving up because the line was too long.


I wouldn’t know, I’ve only gone the one time.

I do expect that they will figure out a reservation system which tracks and queues vehicles en route, like an air traffic controller, to cut down on inefficient ad hoc queueing at the location.

It would be super fun to program such a system, backend and front. Even more so as the cars become increasingly autonomous.

For now at least you can click on the map and see live how many chargers are in use.


Bizarre comment. Being able to quickly refuel is one of the key advantages internal combustion engines have over electrics.


Depending on your assumptions.

For day to day use EV doesn't need trips for gas station to refuel - so you actually save time.

For long trips - yes.


But nobody makes trips to the gas station to refuel. Re-fueling is something that's done on the way at a convenient gas bar, and typically takes only 2–3 minutes.


I’m very skeptical about 2-3 minutes. Maybe if you disregard lost momentum and don’t keep track of your mileage or wait for a receipt or have to go around once or twice to find a spot or...

Because I keep track of my mileage and have to carefully babysit the process (likes to overflow) I’d say I lose at least 10 minutes every time I get gas, and that’s every 130 miles or so.


Well, the speed depends entirely on how fast the pump is. Some are faster than others, but I never have to wait for a spot, and printing a receipt takes 5 seconds. Maybe diesel pumps are faster? I sometimes use the truck pumps at freeway service centres, and it comes out like a firehose.

Only 130 miles? Is that normal? My car can easily go 600 miles on a 15 gallon tank (diesel), but I've had it for so long I don't remember what other cars are like.

Now I'm curious how long it actually takes. Next time I fill up I'll time it.


No, 130 is definitely not normal. Theoretically I can go 200, which itself is pretty terrible, but my fuel pump sensor is shot and I just prefer to play it safe.


This is accurate in my experience. Pay at pump takes ~2.5 minutes for the whole process. I note mileage and reset OBC when I do this - included in the time. I typically buy around 50 L.


But A small Gas station can refuel several cars in that 10 mins


If the ev car companies got their shit together, they could have used swappable battery packs.

You can wait around for 12h to charge, or you can turn in your cores and pay for 100% capacity batts now. And the swap would be quicker than standing around filling up a tank.

But no. Each ev is different and proprietary. The chargers aren't even the same.


I mean the battery technology for EV companies is their special sauce. If they are all the same that takes away their differentiator. I agree it would be better for customers but it's understandable why that isn't something they want to do.


Much like swappable batteries in a smartphone, there are tradeoffs to such a scheme. And an electrical “pump” is vastly simpler to implement than something that would allow swapping out a car-sized battery.

https://www.greencarreports.com/news/1090933_standardized-el...


Swapping an EV battery is like swapping an ICE transmission. You can do it if you have a car lift and a scissor jack to drop it.


Sure, but one can argue that a EV could be designed/optimized for faster battery replacement. While it would still need at least a forklift to move the batteries, I believe the time needed for battery swapping could be greatly reduced with a proper design.


I’d much rather have an EV optimized for efficiency, battery endurance, etc. given that battery swaps would only really be useful for long distance road trips.

But you’d still need to have expensive batteries in stock on location, technicians and equipment. I can’t see that ever being done at scale.


Tesla did that for a while. They abandoned the plan. Batteries are big and heavy. It turns out to be far more important that engineers have the ability to fit them around the other parts (suspension...) than the ability to swap a standard battery.


Yep, the batteries are ridiculously heavy and they’re used as structural elements in the car.

So swapping batteries is hard to do, and unnecessary for most drives. Sure, you’d want to be able to swap batteries in five minutes like pumping gas. But who’s going to ship batteries out to the middle of Kansas, build infrastructure, and pay technicians just for people on a road trip who want to swap batteries?


> gas in CA is almost $4/gallon in the Bay Area

And the national average (today) is $2.95, you might as well compare Hawaii and Alaska which are also economic islands.

>it doesn't take much time for normal rates to hit $6/gallon in the next 10 years or so.

The national average 10 years ago was $2.45, which is $2.90 accounting for inflation. The only way gas hits $6 is if we have a second Great Inflation or massive political changes in the United States and abroad.


That's very US centric though. It's already much higher where I live (Vancouver, just minutes from the US border): $1.70 CAD/L ~= $4.80 USD/gal. I don't think $6 is far off at all in many locations.


Gas is currently about 1.56€/liter ($6.6 per gallon) in Finland.


That doesn't make it an economic island by any means. This is simply due to regulations that virtually only affect gas prices.

By that measure, Florida or Oregon would be economic islands due to their anomalous taxes.


This is really cool! I hope that you can rise above the comments of the "this isn't good enough" or "zero carbon or bust" crowd. This type of innovation is what we need to move the needle in a realistic manner and that helps to build on the infrastructure that we already have in place.

I'm excited to see what comes of this in the coming years!


I'm conflicted. This is clearly better than what we have but I was really hoping for a carbon negative future. I hope projects like this are a stepping stone and not a handbrake on progress.


Wouldn’t this help carbon negativity eventually? The world can just pay to sequester fuel produced this way, and bring concentrations down to preindustrial levels.


This does not displace a carbon negative future. And zero minus current emissions is still a negative number.


If it breaks our dependency on fossil fuels then I'm all for it.


Ye on reflection and reading more comments from the founder I'm tentatively positive on this. Localised air pollution from burning of fuels and globally elevated co2 levels are two distinct problems. Solving one is already a big step in the right direction.


Precisely! Replacing all gasoline and diesel engines, if that's even possible, will take decades. We need something other than fossil fuels for them in the mean time.


Thanks!


Would you be willing to share vague details of your roadmap?

Specifically; How many barrels of ready to burn gasoline are you outputting per day in 6 months? 1 year? 3 years?

The fact that the general fuel is going to be sold and re-burned means this is at best carbon neutral, so from a cynical environmentalist point of view, what's the point? This can't help anyone unless you pump the synth-gas into the ground and sequester it, but that isn't VC-backed viable.

If you are using some sort of membrane to pull out distillates without heat, why wouldn't you just sell that to existing petro-chemical companies for their distillation processes? What non-thermal-energy related benefits come with this membrane?

The poster gave important information in another thread: 60kWh per gallon of gas, aiming for ~5 cents per kWh, ~$3.00 per gallon into distribution channels. That makes it instantly cheaper than petrol in, at minimum, the UK


...the general fuel is going to be sold and re-burned means this is at best carbon neutral, so from a cynical environmentalist point of view, what's the point? This can't help anyone unless you pump the synth-gas into the ground and sequester it...

The status quo today is that we are removing carbon from the ground and putting it into the air. This replaces those fuels that currently come out of the ground. It's still a big win, even if it's technically only carbon neutral.

Even electric vehicles aren't carbon neutral, because they're mostly charged by coal power.

Also: you suggest the synth-gas should be pumped into the ground. What would be the point of converting the carbon dioxide to alcohol to gasoline and spending electricity to do it? At a minimum you could just pump at the alcohol stage.


An EV makes several times the motion from the same energy input.

> Even electric vehicles aren't carbon neutral, because they're mostly charged by coal power.Even electric vehicles aren't carbon neutral, because they're mostly charged by coal power.

Is thus an invalid/irrelevant argument.

I can get excited about jet fuel however, since battery powered planes are considerably less practical than their traditional counter parts with the current technology.


This is a completely accurate comment. Why is it downvoted?

I assume the company is operating in the US. In the US only 27% of electricity is from coal and falling. https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...

And in California (where nearly half of the US's electric vehicles reside--with EVs achieving a nearly 8% market share last year among light vehicles), it's MUCH less than that. There's only a single, tiny 63MW coal co-generation plant in the state, so coal power is less than 1% of California electricity.

> Even electric vehicles aren't carbon neutral, because they're mostly charged by coal power.

Additionally, it's absurd to compare two consumers of electricity, both of which are flexible with respect to time of consumption, and just arbitrarily say one is mostly coal power (which is false) and the other isn't.

We definitely need carbon neutral or even carbon negative industrial processes. I kind of question the logic of going for fuels versus more valuable non-fuel feedstocks, however. A maybe 50% efficient conversion of electricity to alcohols with a typical 20% energy conversion of fuels to mechanical power gives you about an order of magnitude less efficiency than battery-electric.

And if you ARE insistent on making carbon neutral fuels: Makes more sense to focus on things that are super hard to electrify, like long-haul aircraft and transoceanic shipping and maybe heating fuels for the far north (where air source heat pumps lose their effectiveness in January).

But I'm glad an electrochemical process is being developed, here. Electrolysis and related processes are much preferable, IMHO, than the more common thermal processes.


If this process were to only make transoceanic shipping carbon neutral it would be well worth it.


Except fuel oil used in shipping is like $1 per gallon or something similarly low.


That said, for bulk low-quality fuel needs like shipping they could reduce costs by skipping the upcycling stage and just burning the alcohol.


California electricity is only 1% coal. 52% is natural gas and 40% is carbon-free. https://en.wikipedia.org/wiki/Energy_in_California. Most growth is in renewables.


The world is bigger than just California, and I thought that SV startups target "world dominance" by default :)


Most advanced economies are phasing out coal. Worldwide it's less than 30% of power generation.

Also, fuel is fairly transportable. You can produce the fuel wherever renewable electricity is most available, and sell it worldwide. The economics are comparable to aluminum, where a large fraction of the world's supply is produced adjacent to geothermal power stations. https://en.wikipedia.org/wiki/Economy_of_Iceland#Aluminium


>What would be the point of converting the carbon dioxide to alcohol to gasoline and spending electricity to do it? At a minimum you could just pump at the alcohol stage.

Sounds like a great idea! My general point is that zero carbon energy sources like wind and solar are at least mildly zero sum, and creating brand new load on them would likely just result in capacity moving over to other producers like natural gas and coal.

I guess I don't understand why YC is throwing money at this because I'm not confident there's profitability on the horizon, unless they nail down mind bogglingly large scale of production of aviation fuel,

Meanwhile, if San Fran is looking to dump money on (IMO) nebulous and green projects, give me money and I'll plant 100k trees


We'll need a lot more wind and solar, so Prometheus will drive the expansion of these. We'll start out taking intermittent power that's low cost (wind at midnight, for example), but will soon have resources built for us to expand. This will be good for displacing other fossil fuel use (other than transportation), as we will be increasing the availability of renewable power, and also solving the problem of being able to use the excess (we can be seen as a kind of grid storage).


So the plan is to only use excess renewable energy that otherwise wouldn't get produced and consumed? If not wouldn't you be a net carbon generator, as you would be burning fossil fuels and releasing carbon in order to capture a lesser amount of carbon in your process?

What steps are in place to prevent the process from displacing other renewable use? Take the fact that it is less than 100% efficient to store renewable energy as gasoline. Others might make more efficient use of this renewable energy by immediately using it to displace fossil fuels, with no or lower storage losses. Under this scenario Prometheus is again a net carbon generator. (edit: The same dilemma is faced by any other type of storage.)

It strikes me that Prometheus will come into its own if it can guarantee that it doesn't displace more efficient users. This will happen when fossil fuel usage becomes negligible or we (as a society) come up with a sophisticated energy scheduling algorithm that can take account of efficiency.

It comes back to that fact that whilst it is green to replace fossil with renewable energy, it's even greener if we can increase efficiency and avoid consuming that energy in the first place.

Don't get me wrong, correctly used it's a great thing you are doing.


Allocating commodity resources efficiently is what capitalist economies are actually pretty good at.

A couple of scenarios where this is ideal:

1. Located close to intermittent renewable generation that is already hooked up to the grid, especially in places like California where intermittent renewables can already push generation beyond load at peak times and result in near zero or negative prices, this can soak up electricity usefully in a way that displaces other carbon emitting fuel.

2. Deployed along with intermittent renewables in the most optimal places for generation, where connection to the grid is impossible, inefficient, or will simply take time. This can soak up the most efficient possible generation of deployable renewables which would make otherwise uneconomical utility scale deployment viable.

Both of these are scenarios that our capitalist market system should work well to optimize for assuming the electricity->fuel technology reaches suitable efficiency (and not before then).


Wouldn't you have to really be paying above market rates to "drive" the expansion of renewables? Any thoughts about essentially building/running your own renewable power facilities?


Renewable power plants are not reliable producers of power. When they produce power they are the cheapest, so utilities would love to have more - but they need a backup plan for when renewable power isn't running which they have complex management schemes to deal with. Expansion of renewable energy it limited more by the power companies willingness to buy it than by ability to install more (though that is of course an issue as well).

If they can scale their process quickly (not just on-off, but to levels in between) the power company will be happy to give them a substantial discount. They can probably get power for $.03/kwh - windmills are about $.02 for profit so that is plenty of profit to pay for transmission infrastructure. Of course they have to agree to how quickly they can change their production.

This assumes they can turn off completely at 5pm when everyone gets home and jumps in the shower needing hot water. Then go to full production as they go to bed while the wind blows the best. Then drop down overnight. Then scaling up again as the sun comes up. In the late afternoon as the sun is hot they scale down to account for air conditioning. Of course they may as well shut down for maintenance in December (Christmas lights). If they can pull this off renewable energy can scale grow to be much better while taking more power plants offline. That is a big if though.


We will just have to agree to a purchase power agreement (PPA), and others will build the renewable power plants for us. We will be going for very large scale, so will help to drive electricty prices down from where they are now. There is a lot of competition to build renewable power plants.


Not sure how in the last 10 years after the last gas shock that people have forgotten the petroleum is a finite resource that we are going through rapidly. If you read E&P announcements and various P2/P3 reserve estimates of existing resources and measure those against daily global consumption it is pretty alarming. Presuming stable petroleum input prices may not be a reasonable assumption.


If we replace fossil gasoline with renewable gasoline, that reduces CO2 emissions. Our gasoline will be zero carbon, and may actually be certified as slightly negative, as we will not be emitting CO2 from drilling and refining as fossil fuels do. If we replace all liquid fuels now made from oil with fuels made from air mining of CO2, it could reduce emissions by approx. 10 gigatons per year. That is huge.

The membrane will definitely replace distillation in a number of industries, but the most exiting thing to do with it is to replace fossil transportation fuel with renewable fuel.


>If we replace fossil gasoline with renewable gasoline, that reduces CO2 emissions

Nitpick: It will leave carbon emissions unchanged, but may reduce the amount added to the carbon cycle.

What kind of production quantity are you looking at? Small batch aviation fuel for a niche "green" airline? Every semi truck on the road in America? The neighbor kid's go-kart?

You give an "efficiency" of 60ish %, but I don't know how to interpret that. How many megajoules (or kilowatts) are required to produce a gallon of 86 rated gasoline?


We are going for the whole gasoline, jet fuel, and diesel market. The 100% efficient energy content of gasoline is approx. 34 kWh/ gallon. At 60% efficiency in converting renewable electricity to chemical energy, that would be approx. 57 kWh/gal.


Seems like France would love to have this technology to replace imported fuels, and the political problems that go with them, with fully-local nuclear-powered hydrocarbon production.


Please think twice about diesel - NOX is a killer. On the other hand, I expect particle emissions to be much lower with your fuel.


Much lower particle emissions is what we expect. Also no benzene, sulfur, or aromatics. Despite diesel's drawbacks, I'd rather offer zero carbon diesel as long as people are still using it.


You are certainly aware of this, but synthetic fuel is perfect for military applications and for backup generators and such, because there is no biofouling or degradation. Also wasn't the USAF testing bio jet fuel? Your product is superior on all technical points and just as good if not better on the environment.


The main thing that's turned me positive on "e-fuels" is that there's such a huge amount of petroleum that's used today in applications where we basically have no other options.

Think stuff like big jets, or container ships. If you sit down and crunch the numbers for any non-carbon energy carrier, you either end up sinking the ship or with a fuel tank twice the size of the cargo.


The problem with e-fuels for jets is that a majority of the climate forcing comes from the high altitude water vapor in the exhaust, not actually the CO2. EDIT: I should point out here you COULD actually make an e-fuel without hydrogen and thus without water vapor as a combustion product. Carbon monoxide, for instance. The energy density is much lower, but it is sufficient. HOWEVER, there are obvious safety concerns with CO fuel that basically makes that a non-starter. Another option is a fuel cell that condenses the water output and stores it for periodic (possibly lower altitude) discharge in liquid form.

But I agree container ships would be a good application of this. Container ships also have pretty high efficiency internal combustion engines (about 50%), meaning there's less advantage in electrification there than for land vehicles which often have 15-25% efficient engines. And it allows low particulates, which is one of the main forcing regulations on shipping powertrains nowadays, without the overhead of cryogenic LNG.

However, container ships use ridiculously cheap bunker fuel instead of highly refined gasoline.


CO2 seems much worse pollutant than water long term, because it stays in the air. Water at high altitudes condenses, reflects some radiation back to space and then falls back down.


At high altitude, the water stays up long enough and has such a huge impact that even its long term averaged impact is greater than the CO2.


Could you give a source for that? My understanding after some search is that effect of high-altitude water is hard to evaluate. I agree that at high altitudes contrails may evaporate and the water then may not fall down... Is it possible that jet exhaust water vapor accumulates in stratosphere? That would be terrible.


It is hard to evaluate, but of course being hard to evaluate does not mean it's not a real thing.

The effect (not counting contrails) is about double the effect of CO2 emissions alone. Including contrails, it may be even higher. There are mitigation strategies to deal with these non-CO2 radiative forcing effects, though it's very complicated.

Good article: https://www.carbonbrief.org/explainer-challenge-tackling-avi...


Thanks. That article refers to paper doi:10.1016/j.atmosenv.2009.04.044

https://elib.dlr.de/68051/1/fugl-2010-4648.pdf

which says

> At pressures greater than 500 hPa (i.e. below roughly 6 km), the forcing [of water vapor] is assumed to be negligible

So flying below 6km would help a lot for impact of water vapor. However, given this was not yet acted upon, IPCC is probably right that

> the effect of water vapour emissions is likely to be a significant, or even the dominant, contributor to their climate forcing.

This is even worse given the projections of aviation expansion. Right now the water does not seem to be a big problem and it could stay that way - water lifetimes even in stratosphere is counted in years, as opposed to centuries for CO2 - but if aviation expands, then it becomes more serious than CO2.


I have been completely unaware of this effect. Could you provide me with a source where I can read up on this?


Good overview: https://www.carbonbrief.org/explainer-challenge-tackling-avi...


Plastics! Zero-carbon plastics would be great. Pull CO2 from the air, mix with water and wind/solar elec and product bags, phones etc!


Absolutely. A friend of mine founded a company to produce carbon-net-zero biodegradable plastics. Their seed round went well, and making great progress, and are currently raising a series A. If anyone's interested in learning more, email me steven.buss@gmail.com.


The thought is kind of horrifying, but you could even make it a closed process - send your old phone to the factory, where it's burned to produce the plastics for your new phone.


That would open up a pretty good avenue for "recycling" then, and could possibly reduce waste plastic in the environment


As I learned today in another thread [1], the only problem would be that plastic is usually doped with additional elements that I assume we would somehow have to deal with when burning it.

[1] https://news.ycombinator.com/item?id=19845427


Why is this horrifying? Is there some part of this I'm missing here?


It just feels wrong to burn this stuff as part of an established cycle.


Well, every barrel of their stuff that is burned is one that wasn't sucked from the ground and put into the carbon cycle. So as long as it doesn't depress the price of gas much and cause consumption to increase, I'd take a bit of a less cynical view towards it.


Personally: Carbon negative aims are admirable, but idealistic. Carbon neutrality is in many cases much more feasible and makes a massive impact in an industry that is currently overwhelmingly carbon positive. By argument of historical trends to future trends replacing a carbon positive market with carbon neutrality at the end of the day is removing carbon from the air that would otherwise have ended up there.


> is at best carbon neutral, so from a cynical environmentalist point of view, what's the point?

This doesn't make sense to me? Wouldn't even the most cynical environmentalist agree that carbon neutral is much preferable to carbon positive?


> The fact that the general fuel is going to be sold and re-burned means this is at best carbon neutral, so from a cynical environmentalist point of view, what's the point?

It's meant to replace a carbon-emitting process (burning gasoline made from fossil fuels) with a carbon-neutral process. The replacement process is not carbon-neutral.


It can be seen as an energy storage technology for renewables.


Interesting timing of Derek's Lowe's post on "In the pipeline".[1]

There are government levers (subsidies, tax breaks, carbon use taxes and so on) that can change the economic landscape, but the paper estimates that you’d need electrochemical efficiencies of at least 60% and electricity available at 4 cents/kilowatt-hr or better to make these ideas profitable (with the usual 30-year-amortization assumption about the plants themselves). How close are we? Many of the processes are currently in the 40-50% efficiency range, and need further scale-up work: within sight, but not there yet. And renewable electricity costs vary a great deal by region. The best cases are getting down around that figure, though, and continuing to improve.

[1]https://blogs.sciencemag.org/pipeline/archives/2019/05/06/sw...


Yes, that data is from a recent Science review article: https://science.sciencemag.org/content/364/6438/eaav3506

I think the timing on this effort is right, from a cost of renewable power perspective, as well from a growing consensus that it is very close to being achieved. Hope to prove that soon!


How quickly could you pull CO2 out of the air if you were scaled up to make full use of a typical nuclear reactor for the electricity? If you just stored the output of that process rather than refining it into gasoline, diesel, or jet fuel, how would that product compare in cost to drilled oil in the same state?

My thinking here is that creating gasoline and selling it for immediate use is at best carbon neutral, and at worst delaying the replacement of that gasoline-burning equipment with an all-electric version. But if your focus was on replenishing raw oil reserves for future (hopefully mostly non-burning) use, you'll be removing CO2 from the atmosphere. To do it at significant scale requires a lot of energy, and a nuclear reactor is much better at providing that level of energy than other zero-carbon sources. The trade-off is nuclear waste, but that's much more containable than the waste from non-zero-carbon energy producers for equivalent amounts of energy. Eventually it could be reprocessed to extract more energy from it as well, until the radioactivity is used up.


As a person with a background in Environmental Studies, a c o2 to fuel conversion technology such as this sounds revolutionary! I am most curious about the fundementals.

Can you give us more specifics on the process such as;

1. What is the scale of the operation? Does this process need to be done at a large scale to work out economically? 2. Take a Boeing 737 for example which has a fuel capacity of ~6,875 Gallons. How much would it cost to build a C02 refinery that could produce that much fuel daily?

3. How much does it cost at a small scale? Say you have a miminal viable product that can refine 100 gallons of gasoline per day. What is the cost of that production in USD?

4.How many KWh of electricity would be required to refine 1 gallon of fuel using your current prototype?

I would love to hear / see data your numbers.

Thanks, 01


The smallest scale at which we can operate profitably is probably in the 100,000 gallon/year range, although that could go down over time. We will make modular, mobile systems that don't have to be very big to be profitable. One shipping container will likely be able to do 100,000 gal/yr for example.

The electricity required will be approx. 60 kWh/gallon.


60 kWh is about 200 mi of range in a gen 2 Chevy Volt, while a gallon of gasoline is worth about 40 miles. Just trying to put the efficiency in context using something I'm familiar with.


That shipping container model would be ideal for remote villages in Alaska! Making fuel locally would be so much more energy efficient!


"60kWh/gallon" -- is that gallon of gasoline? Or ethanol? Or CO2?

If you know the figures off-hand (to save me doing the chemistry), how much water and CO2 is required to produce the gallon of output?


Gasoline. Each metric ton of CO2 corresponds to approx. 113 gallons of gasoline. The amount of water is approx. 1:1 by volume.


Very rough calculation:

* 60 kWh / gallon of gasoline * 100,000 gallons / year * = 6 GWh / year * = 3.5 MW solar array (from on-line calculator) * ~ 18,000 m^2 of solar panels (500W, 1.9m * 1.3m) (roughly 3 football fields of solar panels).


Not to be flippant; but doesn't that seem like a surprisingly small installation for ~273 gallons a day?


Can you talk a bit about the waste-water left over? Assuming it's non-potable, what does the disposal path look like? How much of such water is there at scale, e.g., water-per gallon of petro-product? Thanks, sounds awsome.


There is no waste. The only inputs are water, CO2, and electricity. The only outputs are fuel and oxygen.


With respect, that answer skirts the question of what happens to the water.

You said you're using the nanotube membrane to separate petro products from the water. What do you do with the water left over? What state is the water in when the process is complete? Potable? In need of treatment by traditional water treatment facilities?


I think you're asking a different question from the one being responded to (and the one being responded to is more obvious to me): I will try to help this conversation by restating the questions, both of you should correct me if I've misread this.

Your question is, in the distillation step, the nanotube membrane separates fuel from water, leaving some amount of water; what happens to that water in the process?

The question that was answered was, what happens to waste water? For which the answer is that there is no water "left over", and so the question of what happens to it is ill-defined because it doesn't exist.

So I guess what is happening is that any water left in the aqueous electrolyte can continue to be used in the process indefinitely, and there is no point at which the water becomes waste water? That all the water collected from the air gets broken up into hydrogen (in the fuel) and oxygen (waste product, sent into the atmosphere) and the amount of water in the aqueous electrolyte doesn't grow?


Correct!


Thanks for confirming, though what if the ingested air/vapor/carbon mixture has a consistently higher than required water-vapor/co2 ratio? Or is that a non-issue?


If the inputs are truly CO2 and electricity, and 100% gets converted to usable hydrocarbons, then there's no waste water; the catalyst and water remain behind.

Assuming some water is lost due to electrolysis, you can top it off over time.

If the catalyst breaks down, or some undesired reaction limits efficiency (i.e. generation of perioxide or other undesired chemicals that degrade or react with the membrane, electrodes, catalyst, etc) then I think there might be some treatment or maintenance necessary.

However, none of this sounds remotely as bad as the treatment needed in the production of petrochemicals or lithium batteries or recycling.


There is no water left either—you forgot that oxygen is also produced.


I wasn't really sure how much of the o2 generated came from the co2 and how much came from the water. Either way, I don't see "waste water" to be as big an issue as the earlier posts i was replying to did.


The water becomes the fuel. The hydrogen combines with the carbon in CO2 to form hydrocarbons, while the oxygen combines with itself to form molecular oxygen.


I would think so, but the founder says: we have a carbon nanotube membrane that replaces it, extracting the alcohols from water

This implies there is still water there. Maybe it was poor phrasing, and all of the water is consumed, but that isn't what is stated.


If water is an input and not an output, that implies it's consumed, not left over.


Yes, one of the things that gets glossed over many times in this field (I used to do research in artificial photosynthesis) is that water gets consumed to create the fuel, and is released as vapor from every engine's exhaust. So to generate 10 million barrels requires about 10 millions barrels of pure water, per day, to satiate the US.


Yes, water is turned into fuel and oxygen. In most places the water can be obtained from moisture in the air (there is much more water than CO2 in air, and we are already mining the air, so we can get both). In the process the fuel is separated from the water, which remains in the reactor, and is topped off as it is used to make the fuel. No waste water.


Somewhat tangential, but does your crystal ball show when we will start seeing carbon nanotube desalination tech making it into the real world?


His startup was supposed to start shipping it last year...


I would think so, but the founder says: we have a carbon nanotube membrane that replaces it [distillation], extracting the alcohols from water

This implies there is still water there. Maybe it was poor phrasing, and all of the water is consumed, but that isn't what is stated.


I think the water that is still there after distillation will just be used for more distillation, it just hasn't been consumed yet, it isn't a waste product.


What about dust, pollens, etc, from the air? Is there a maintenance requirement to clean filters or something? Does the efficiency of ingesting the water vapour and CO2 decrease over time until maintenance is performed?


We'll want to filter our air, yes. This means replacing filters, etc, which factors into the maintenance costs.


What about the device itself, its lifetime, and the resources used to build it?


We expect a long lifetime (approx. 20 years or more), assuming modest maintenance costs. The capital is actually pretty inexpensive for a room temperature, unpressurized, electricity only system, so this helps mitigate longevity risks.


So, the goal is carbon-neutral gasoline.

Short term, I suppose your target is feel-good gas burning vehicles. Longer term, do you envision this technology being used for clean(er) + carbon neutral municipal power generation, or is the fuel type just wrong for that?

I ask because a stop-gap can easily become permanent, and it'd be unfortunate to continue dumping particulates (pm2.5/10), smog, etc into the air in major cities. One huge benefit of electric vehicles is you can make power where population is scarce, and use it where the population is. You don't get that with burner vehicles.


In the near term, we will remove the damage caused by fossil fuel use. Our fuel will burn much cleaner, so that's also helpful. In the medium to long term, cars will switch to electric, but now we'll have enough time to do that. As that happens, Prometheus will roll out new products made from CO2, like carbon negative building materials, etc. It's important to look not only at the end goal, but also the path!


> cars will switch to electric

Even once cars are all electric, I can’t see gas turbine engines in planes, trains and ships being replaced in a hurry.

And rockets are never going to be electric. I assume you can make RP-1 with this process.

I can imagine hydrocarbons being produced where electricity is cheap and practical, and being shipped to where it is expensive and impractical.

In theory if it was efficient enough, you could even use it to store electricity, (e.g. in the summer) and burn it again in the winter.


> Even once cars are all electric, I can’t see gas turbine engines in planes, trains and ships being replaced in a hurry.

Of course most (non-electric) train engines use Diesel-electric propulsion (https://en.wikipedia.org/wiki/Diesel%E2%80%93electric_transm...). That's mostly because of the flat torque curve of the electric motor. Some ships do too.

I'm not sure why you think that battery-electric train engines or ships aren't going to happen. There is a lot of room for batteries on vehicles like that!


A fun usage of dimensional analysis:

Fuel capacity of a diesel electric locomotive: 6200 gallons

Energy density of diesel fuel: 40kWh/gal

Total energy capacity of full fuel load: 248 megawatt hours

Tesla battery pack weight: 540kg

Tesla energy capacity: 85kWh

Weight of equivalent battery pack for a diesel locomotive:

248 MWh / (85 kWh / 540 kg) = 1575 metric tons

Weight of a diesel locomotive: 196 metric tons

So you'd roughly 10x the weight of a locomotive by trying to make it run on batteries, leaving aside the challenges of actually trying to charge those batteries.

Another fun fact: that locomotive can run flat out at max power for 2.2 days without refueling.


Of course, while it's neither easy, nor cheap, that train does not need to have any batteries in order to run on electricity. Much of the UK's rail network is either electrified or in the process of being electrified.

The side effect of not needing to use energy to haul your energy source around is pretty cool, too.


Why will your fuel burn cleaner? Soot and NOx are fundamental to the combustion process. I guess you have no sulfur, which is worth something.


Gasoline and hydrocarbons in general are mixtures of many different kinds of chemicals, and not 'pure' to some degree (the refinement process purifies to some extent).

If this process produces a specific hydrocarbon or class of hydrocarbon, it is feasible that common byproducts of combustion will not appear with their fuels.


Different molecules burn differently. They might not be able to stop NOx, but they can make a fuel burns cleaner in an engine. We already know how to make those molecules, but it isn't practical to make gasoline that way for normal use (read 3x the price of pump gas)


The perfect is the enemy of the good.

We have a carbon problem now, that is causing real damage now. We shouldn't be turning our noses up at "stopgap" just because it doesn't do everything we can dream of doing.


Absolutely.

I do not question the sanity of carbon neutral gasoline. Esp aviation fuel and rockets.

I was suggesting carbon neutral gas plants which can power electric fleets, as a way to also reduce pollution.


My most immediate question (after others you already answered in this thread) is about getting enough CO2.

When you start absorbing CO2 from the air, won't the CO2 in the neighborhood be depleted very quickly? And I'm assuming you can't pump enormous amounts of air either for various reasons (noise, energy usage, other environmental issues). Of course there's wind to bring more CO2, but I'm curious about your computations.


This won't be a limiting factor. It won't be stagnant air, and the diffusion rate for gases is high.


CCS: large amounts of high quality concentrated CO2 from gas fired electricity can be stored underground https://en.m.wikipedia.org/wiki/Carbon_capture_and_storage

And when power prices are low and the gas fired plant is turned off, you have a transmission system right there ready to deliver power.


They're looking at cheap off-peak electricity sources, one of which is excess wind power at night, so they're likely to be operating when the wind is blowing anyway.

(Not that they need it - gas diffusion is fast - but it's a cute synergy.)


Don't you just need to open a window and wait a few seconds to desaturate a room where too many people breathe ?


Doesn't matter, air is a fluid, so diffusion works in your favor.


Yes, but does it work fast enough?


You can figure that out: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2389....


This is really cool, I have a two questions the last one maybe a bit sillier than the first:

- I'm not a chemist, maybe you said this implicitly, but roughly at what rate would this capture a kilogram of carbon?

- Why did you choose the name 'Prometheus' the titan who created man, gave us fire, and as punishment for the latter part, had his liver eaten out by a vulture every day for eternity?


First question - each ton of CO2 captured is equivalent to approx. 113 gallons of renewable gasoline. If we replace all fossil gasoline in the US, for example, that's approx. 140 billion gallons, equivalent to approx. 1.2 Gigatons of CO2. You can more than double that for the world. If we include all liquid fuels (including heating), it's larger still. It's a hugely significant CO2 emissions reduction.

Second question - I chose Prometheus because the story is that he gave us fire, and we have a responsibility to use it well. So far, not so good, but now we can do better. I imagine him saying "here's fire, don't screw it up".


I believe you misread the first question. It wasn't asking for the numbers on the conversion from CO2 to gasoline; it was asking about the rate at which you remove CO2 from the air.

What's the expected total removal per year in, say, your first, fifth, or tenth years of operation?


Assuming that the generated gasoline is used, there's ultimately nothing removed from the air.

It does reduce or eliminate the need to source gasoline from "fossil" sources however.


He wasn't quite punished for eternity, just for a very long time until Hercules set him free. Not sure what that means for the company, but if I worked there I wouldn't want to be the company's equivalent of the liver.


> had...for eternity

Has?


If nothing else it would be a great technology for solar and wind plants to employ on-site to convert excess power into fuel that could drive standby turbine generators for the times there is no sun or wind.

Giant batteries are a pretty easy to beat cost and maintenance wise.


So if this is basically eliminating the traditional "distillation" phase by using the membrane, do you envision a day when I can dip your membrane in my beer and then poor off some moon shine?


Yes, you could do that now!


Well then, I'd like to place an order for all of them.

On a serious note though, that does present a novel use for these membranes within that industry. I imagine that optimizing the distillation phase for lower energy use and/or the possibility of distinct flavor characteristics that might coincide with alternate distillation techniques could be very compelling. Freeze-distillation has its own unique characteristics, I'd be surprised if this didn't also have some of its own.


I've been super curious about alternatives to the Sabatier reaction. Nice work!

Maybe I'd encourage you to think of yourself less as a fuel company and more as a chemical precursor one. Outside of combustion, there are a ton of other use cases in need of synthetic pathways.


Thanks! We are also going to make carbon negative building materials to remove CO2 that has already been emitted. Really anything now made from petroleum is potentially replaceable with air mined CO2 and renewable electricity. Will start with gasoline.


Automatic factory on Mars?


You could make a lot of stuff from the CO2 in the Martian atmosphere, for sure!


Not a chemist, but as far as I understand the process you're using to process the CO2 also needs water or at least some other source of hydrogen? Where would you get that from on Mars? (Sure, there is water on Mars but not in the atmosphere.)


Most likely subsurface ice


> we expect 50-60% overall efficiency at maturity

What efficiency are you at now and what happens to your startup if you never reach that "maybe too optimistic" 50-60% goal?


We will know what our starting efficiency is before next year, when we start to produce and sell fuel. Anything above 25% works economically, and that has already been demonstrated.


USNRL have achieved ~50-60% efficiency using similar technology -- though sourcing from seawater rather than air.


That's gold, considering where solar cells efficiency are now (mature industry!!)!!


How small can you scale it? Net energy metering for small-scale solar is not particularly widespread, and the terms are getting progressively less favorable over time. If you can make an inexpensive unit to turn a few kW of excess production for a few hours a day into fuel at 50% efficiency, you might be able to sell it in some markets. Think of it as a 25% round-trip efficiency battery with immense capacity that can supply winter heat or vehicle power.

edit: for some applications like this, alcohol might be a better end point than gasoline.


Our current prototype is the size of a refrigerator. One of the cool things about our tech is that it can work well at small scale. We don't have to get to a billion dollar plant to get the economics right. We could make a system to fit in your garage and make fuel at home. This isn't our focus right now because we want to solve the problem of CO2 emissions from fuel, so need to scale as fast as possible. That's the commodity gasoline market.


Still, "refrigerator-that-produces-fuel" would probably be a hit with those interested in living off the grid. Just an idea for a side market.


Possibly, a licensing play? May be a way to inject capital to get to the larger problem?


If brewing alcohol, ethanol would probably be ruled out to avoid legal issues in many places.


What's your Energy Returned on Energy Invested (EROEI) on that?

Specifically, this means if you took the gasoline you made from this and put it into an efficient generator how much electricity would you get out of it vs how much electricity you put into it to make it in the first place? This would be very useful in comparing this technology to biodiesel as a method of carbon sequestration for example. Biodiesel has other problems too such as using arable land and depleting topsoil. This comparison would make a nice slide in your deck.


I think you're making an incorrect comparison. This is basically an energy storage system. What you could do is compare the EROI of the energy source that provided it (say wind-energy) and factor in the process efficiency and compare that with the extraction of a specific fossil fuel.


CO2 only accounts for 0.04% of the atmosphere, guess you need to concentrate or isolate it before pump into your solution, also gas solubility in water is low, so you might need to reduce temperature or change air pressure to increase CO2 solubility. I just read Haber-Bosch process today, looks like your process could be similar.

You mentioned use nanotube to extract alcohol, is this process similar to chromatography? Do your nanotube's half-life long and stable, and the production now is in industrial scale and low-cost?


Appreciate you're sharing some of these details (thank you). I have been thinking about this same basic idea but with hydrogen and fuel cells but will need to evaluate the merits of electricity -> gasoline vs. electricity -> hydrogen.

Being able to work with existing infrastructure and vehicles and other components designed to work with gas is a huge advantage. And of course the simpler storage of gas vs. hydrogen is nice too.

In terms of efficiency we can do a little back of envelope calcualtions. Prometheus converts electricity to gas at 60 kWh a gallon (33.7 kWh) or about 56% efficient. Hydrogen production via electrolysis comes in at between 44.5 - 55 kWh/kg-H2 (I've seen a wide range of estimates) for a kg of Hydrogen (33 kWh) so about 60-70% efficient.

Of course then there's the reverse process of burning gas or using a fuel cell for electricity production. The Toyota Mirai gets about 68 miles per kg of hydrogen and the roughly equivalent Toyota Camry hybrid gets about 52 mpg.

So boiling this down (if I got this right and my data is good):

Gas method: 60kWh -> 1 gallon of gas -> 52 miles = .86 miles / kWh Hydrogen method: 55 kWh -> 1 kg of h2 -> 68 miles = 1.23 miles / kWh

Of course this ignores all the challenges to building the hydrogen infrastructure, public fear (warranted or not) about hydrogen, capital costs of both systems, etc. It's also likely the hydrogen conversion gets more efficient than the 55kWh to product 1kg but wanted to keep this conservative.


I synthetic fuels are a temporary solution for cars. If you are changing car infrastructure, IMO it makes most sense to switch over to electricity (highest efficiency and you can use electrical car batteries to stabilize the grid).

Synthetic fuels will make most sense for aviation (higher energy density compared to hydrogen), (possibly) shipping and as a transitional fuel for transport to reduce our emissions.

Synthetic fuels could also be a solution for seasonal storage.


How sensitive is the systems to airborne sodium chloride if located near salty bodies of water? I would assume that colocation with nuclear power would be ideal and many nuclear plants are next to salty bodies of water.

Being an energy auditor in my early career in the energy sector, I'm very interested in seeing such systems implemented to balance system loads during off peak times which will make Nuclear (safe and well designed) more cost effective.


I am a proponent of nuclear, but wouldn't use of extra energy during off peak times apply to renewables even more so?

Unless there are massive improvements in efficiency and cost-effectiveness of storage, adapting usage to production of intermittent sources seems like it would maximize yield and minimize investment costs.


Are you using anything to do with those nano-spike catalysts? Was one of the first things that came to mind when I read the pitch. - https://www.popularmechanics.com/science/green-tech/intervie...


Not using nanospikes, but there are many proven heterogeneous catalysts now that can do the same job. Can't elaborate here, sorry!


Yayy, a mystery. I like mysteries. Could you elaborate on where you could elaborate?


The best catalyst for CO2 conversion is copper. There are papers that have done an exhaustive analysis of alternative metals, and copper comes out on top everytime. Adding it to other materials like carbon or other metals in a heterogeneous material can help with Faradaic efficiencies. We are less concerned with Faradaic efficiencies than overall efficiencies and costs, which leads us to different optimizations than academic labs pursue - they typically want very high specificity. We don't care as long as it burns in an engine well :)


Think I got it, your aim is going to be whatever gives you the overall highest specific energy of the outputs for a given combined cost of inputs, rather than any chasing purity of chemical, as they can all be used. That's presumably the rest of industry's problem and it is already setup for that.

edit - also, thank you very much for taking the time to reply to my blatant attempt to work out exactly what you are up to, I really appreciate it. Is a subject I find fascinating.


In spring and early summer, electricity prices in the PNW go negative due to hydropower minimum flows and wind power subsidies.[0] You said capex is low, so setup a bunch and be prepared to get paid to make fuel!

[0] https://www.eia.gov/todayinenergy/detail.php?id=5110


We will definitely take free power whenever possible!


How is this different from what the US Navy has been trying to accomplish with turning seawater into Jet fuel? I know that they are extracting CO2 from the water instead of the air, but I believe the last I heard they had large inefficiency issues. And for them they plenty of power from their onboard reactor.


Google X did a project to remove CO2 from seawater and turn it into fuel. It was called project Foghorn: https://x.company/projects/foghorn/

They couldn't get the economics right, but did succeed in making fuel. Their tech lead is an advisor of ours and is excited to get there this time!


What’s your perspective on naval applications in general? It seems like an obvious first step. Resupplying carrier groups at sea requires a much more expensive supply chain than the one that runs to your local gas station. The Navy might even pay a small premium for the strategic advantage of not having to rely upon vulnerable oilers to keep their planes flying.


Hello Rob, thanks for the post! Has your company performed an energy return on energy invested (EROI) accounting for your process? Few companies provide comprehensive and transparent EROI and/or CO2 emissions accounting for their product(s). I know you explained that the inputs are low-carbon; however (1) “renewable” energy is still anywhere from 10-50 gram CO2 per kWh (effectively), and (2) the CO2-intensity of your capital equipment can be depreciated over the useful lifespan of said equipment and allocated to each effective unit of energy generated (kWh or gallon?). I’m genuinely excited about your technology; your low capital costs, inexpensive materials, flexible/intermittent operations, and hopefully low maintenance cost — all sound very promising.


Interesting proposition. 1. Why would your process be more cost effective and/or efficient than the commercially available processes for alcohol production? Surely if the magic sauce is the nanotube alcohol/water separation then conventional alcohol sources from fermentation will start using it at some point and will be able to produce same fuel but cheaper and/or more efficient. Maybe you can show that [photosynthesis -> organic matter -> fermentation] is less efficient than your process using renewables as input?

2. Why use CO2 from Air? At 400ppm, there is 500 times less CO2 in air than in any powerplant exhaust, so using the same state of the art separation, for the same throughput, your equipment should be ~500 larger? That seems like a capex waste.


The cost of the agricultural feedstocks to biofuels are not easy to reduce further, whereas renewable electricity is getting less expensive and likely has much further to go. I think CO2 to fuel will have a decisive cost advantage over biofuels.

The reason to use direct air capture rather that going for higher concentration point sources is one of scale. We want to produce fuel at scales much larger than can be accommodated by any other means that capture from the air.


Why not go for the higher concentrations now? Why not target agricultural ethanol plants now? I grant that long term they are limited, but why not use them now?

Higher CO2 concentration seems like it ought to make your initial testing easier.

Likewise, if you are really more cost effective than distillation all the existing ethanol plants would love to replace their boilers with your system. It seems like a simple way to get a small cash infusion selling to them. They can convert their ethanol to gasoline as well, and have infrastructure in place.

What I'm saying is don't bite off more than you can chew. If any piece works now push it while getting the others working.


Maybe they need to quickly scale up because of VC backing and thus a requirement for a high return on the investment?


I'd imagine retrofitting power plants to process their exhaust is itself an extremely expensive process.

Maybe they could setup their devices around plants anyways tho.


I hope Prometheus becomes successful. As an interesting side effect - its success may render the need for electric vehicles less acute and maybe even not so critical at all. Especially given the not so environment friendly battery manufacturing process.

In a sense, Prometheus is a competitor to Tesla.


> turns out that doesn’t matter as long as the electricity is zero carbon and low cost. If the cost of our equipment is also low, then we believe we can not only make zero carbon fuel, but actually compete on price with fossil fuel.

That's a lot of "if". How close are you to that?

If you plan to sell to car users, how do you plan to compete with electric cars, that can get about 8x the use out of the electricity (and don't have most of the many issues of combustion engines).

Am I missing something really obvious? Is transport through cable for direct consumption prohibitively expensive from the energy sources you're planning to use? Do fuel cells change the calculation? What's the advantage? Potentially take over a rapidly dying market?


There are lots of current uses of fuel besides short-transit automobiles.

Large sea shipping, aircraft, and rockets will continue to use fuel for a long time.


Congrats. Thats awesome.

Just guessing that real estate is going to be a consideration for this venture. Where (geographically) do you plan on operating? Is there any advantage to doing this in areas like Los Angeles/ Mexico City that naturally trap automobile emissions?


The best location is one that gives us access to the lowest electricity price. The CO2 and water are in air almost everywhere (in a desert environment the water is harder to get from the air, but CO2 is evenly distributed). We will be next to utility scale wind, solar, and other renewable sources.


Is the percentage of carbon in those areas significantly higher so that it makes a difference? I would be inclined to believe that being in an area closer to electric plants and/or where real estate is cheaper would make a bigger difference.

Or even having multiple points of capture across a geographical area.


The Navy would be highly interested in this, as they've had a project in the works for years (via NRL) to create jet fuel from seawater. They're basically 25% efficient right now, and the physical size of the device vs the output is quite prohibitive... But the advantage of making jet fuel on the carrier itself for the planes, by using onboard nuclear vs having to dispatch and maintain a fueling fleet is quite attractive even at this efficiency.

Short summary here: https://youtu.be/ikt1oOnoKGg


A compilation of references going back over 50 years, at USNRL, MIT, and Brookhaven NL.

https://old.reddit.com/r/dredmorbius/comments/28nqoz/electri...


Most naval ships also use jet fuel these days, interestingly enough. A carrier that synthesizes its own jet fuel can also refuel its own escorts.


So you are competing with batteries? I suppose batteries have much higher roundtrip efficiency, but maybe there are other advantages to your technology, like being able to rely on combustion engine cars?


The energy density of gas makes it incredibly useful for storage and transportation as well. For example, Tesla's 50MWh battery installation in Australia has the same energy as only 1,500 gallons of gasoline. (It's not an apples to apples comparison, I just wanted to give an example of a "large" battery installation.)

Obviously there are lots of benefits of batteries over gas, but being able to load up a standard 10,000 gallon tanker truck with 300MWh of energy and drive it anywhere there's a road is something batteries simply can't do.


Sure, but how useful is the energy density in practice? 1. Very soon all new cars will be electric anyway (because that is better for other reasons) 2. I’m assuming range will not be an issue, almost all private driving is very local, so most cars don’t benefit from long range, as long as it’s easy to get long range vehicles when you need them. And of course trucks etc will need to be long range. 3. Driving a truckload of energy is cool but how useful is it? We can already deliver more energy than that instantly through the grid, and most populated places on earth are on the grid now so it seems like a niche use case.


Yup, exactly. You can fit the entire battery installation in 5.5 cubic meters! A fairly small closet, even (1.4x1.5x2.5 meters for example, 4.5 x 5 x 8 feet) could fit the entire battery plant, which is huge by comparison.


The main advantage of renewable gasoline over batteries is that we can decarbonize the existing vehicle fleet without replacing it. Also, the very high energy density of gasoline, diesel, and jet fuel will make sense for a long time in Jet aircraft, long haul trucks, and ocean container ships, for example.


> we can decarbonize the existing vehicle fleet without replacing it.

Put that way, it's a huge improvement and avoids having to electrify entire fleets first.


Now for aircraft I can see how it makes sense, but anything ground based could easily be electrified.

Another thing, will this synthetic diesel burn cleanly like hydrogen or do they need to add lots of nasty stuff?


The very high density is in hydrogen - actually.


And the best way to store hydrogen is to attach it to carbon atoms.


Their sweet spot is specific energy density of the fuel source. The higher the requirement, the better off you are from not having to carry around your oxidizer.


You've elsewhere quoted 60 kWh per gallon of renewable gasoline. The US consumed 391.40 million gallons per day on average in 2018 [1], and concurrently had generation capacity for 1.153 billion kWh per day from non-hydroelectric renewable sources [2]. That suggests that full replacement of current gasoline usage would require ~23.48 billion kWh per day, which far outpaces what is currently available.

Of course any replacement of fossil fuels is a great goal, but just curious where you see this going at scale, if it were wildly successful? It seems like if you or others were able to scale this up massively, you'd run into unit economics issues as demand for the required renewable electricity outpaced supply, raising the price.

[1] https://www.eia.gov/tools/faqs/faq.php?id=23&t=10 [2] https://www.eia.gov/outlooks/steo/report/electricity.php


To replace all gasoline in the US, it will require a substantial increase in renewable power plants. We estimate it will cost approx. $1T to build that capacity, although the cost could go down as it is done. To put that in context, the amount invested in shale fracking in an 8 year period between 2010 and 2018 was approx. $0.7 T, so not as crazy as it sounds. https://www.iea.org/newsroom/news/2018/july/investment-analy...


Thanks - that makes a lot of sense. I suppose the same issue exists with a large scale up of electric vehicles, so your interests would dovetail with other parties there and hopefully collectively spur grown in renewable generation capacity.


The real question should be: How much improvement over time in the efficiency of this process could be expected? 1.1x? 2x? 10x? 100x?

Every new technology goes through a refinement cycle where costs & resources are reduced, and I would assume the same is possible here.


We will likely make improvements primarily in capex, power costs, and transportation to lower our cost of producing fuel. Fundamental thermodynamics and overpotential limits will hold our efficiency to some cap, likely 75% or lower. We could try to push higher than 60%, but there will be an optimum for capex vs opex that will probably not favor the highest possible efficiencies.


Presumably they would make gains in efficiency, but only to a point - if a gallon of gasoline contains 34 kWh of energy you'll always need at least that much to create one, and at 60 kWh/gal now they aren't that far off.


What happens with the gasoline after it’s made? Does it get burnt again? I’m guessing the energy released from burning that gasoline must necessarily be less than the energy used in creating it. Then the net is going back to square one with regards to CO2, but with a net loss of renewable energy?

I may well be off the mark here, so would appreciate it if someone could tell me what I’m missing.


I think the idea is that you're powering traditional combustion engines with a fuel generated with green power. It may be more wasteful of that green electricity than a new EV charging from the grid would be but you didn't have to build and buy a new thing and it's kind of fine to waste renewable energy if the economics works out because it's renewable.

So it's effectively a way to convert your ICE car into a zero-emission EV by using that fuel.


The energy content of the gasoline is less than the energy used to make it (only 50-60% efficiency), but the CO2 released is the same as the CO2 used. So the energy efficiency is low, but the net CO2 emission is still zero.


Is your device small enough that it could be placed to filter the exhaust emissions from a fuel burning car and reinsert the newly created gasoline into its fuel tank?


powered by what? It would only make sense if there was a carbon free cheap power source you could use to charge it - if you just take it from the car battery you're wasting fuel as it's only ~50% efficient


In order to have a pure output of oxygen and fuel from CO2 and water, don't you need a pure source of CO2 and a very clean source of water?

Could you provide some more detail on how these inputs are obtained? How much CO2 are you able to extract over a day? Do the input rates suffer from depleting the accessible CO2 from the local airspace in the same way that plants do?


Hi Rob, Great idea! I have ton of questions:

1) If you hope to target low cost renewable power, will you be operating intermittently at peak production, or around the clock?

2) Does negative pricing of power factor in to your business model?

3) Do you think your process could economically compete in the market for grid energy storage? I so, how does the costs and efficiency compare to other methods?


We are designing our systems to run intermittently, to match the intermittent availability of renewable power. The capital cost of our systems is expected to be low enough for us to run profitably even if we are only operating 50% of the time. We expect we will get very low electricity prices because of this, and even negative pricing some times. We are not positioning ourselves as grid storage, but having our systems on the grid will balance demand for renewables, allowing more to be deployed, which is a similar service. If we can get paid for demand response, we won't turn it down!


Are you in direct competition with Carbon Engineering from BC, Canada?


Yes indeed.


Get to keep current infrastructure, engines, powerplants etc? Check!

Get the probability of gasoline with carbon neutrality? Check!

What an exciting technology!


*portability Darn autocorrect


Thanks!


Incredible pitch, I wish you luck. This would be an amazing alternative to batteries in areas where there would otherwise be renewable over-capacity. While it appears less efficient, it is transportable and easy to store.

Please keep us all updated on how it goes, I'm sure you will see a lot of excitement about what you are doing.


Thanks, will do!


Hello Rob, thanks for the post. I studied with Chichilnisky before founding, and have reviewed Thermostat. Has your company performed an energy return on energy invested (EROI) accounting for your process? Few companies (engaged in fossil fuels, renewables, or CCS) provide a comprehensive EROI and/or CO2 emissions accounting for their products. I know you explained that the inputs are low-carbon; however (1) “renewable” energy is still anywhere from 10-50 gram CO2 per kWh (effectively), and (2) the CO2 intensity of your capital equipment can be depreciated over the useful lifespan of said equipment and then allocated to each effective unit of energy (kWh? or Gallon?). I’m genuinely excited about your technology; your low capital costs, cheap materials, intermittent operations, and hopefully low maintenance cost all sound very promising.


By law, gasoline gets cut with ethanol, degrading engine performance. If I buy gas from you guys will it be legal to put 100% gasoline into my engine? If so that's a "killer app," (so to speak) for people who care about their engines, even if it is more expensive in early development stages.


Why do you say ethanol degrades performance? Ethanol is an anti-knocking agent when added to gasoline, so it actually enables higher performance.


It degrades energy density of the fuel (by volume).

In other words, today's gasoline in US takes you 4% less distance than gasoline from 70s.

It also creates problems with internal corrosion (which is why it is not used in aircraft fuels), though modern auto engines are designed to deal with that (and are more expensive because of that, too).


Sure, the energy density is a bit lower, but that's not really what people mean when they talk about "performance". "High-performance cars" don't usually refer to cars that can go a long distance on a tank.


Your engine has to be designed for it. It's a niche market I know, but some engines aren't. (Not every gasoline engine is in a car after all.)


It's likely we will be exempt from ethanol blending requirements, as this would increase the carbon intensity of our fuel.


Only seven states have laws mandating gasahol. Gas stations in all other states are just using it for profit.


Long term we need to do this and then pump the resulting alcohol back underground or in some other reservoir where it can be more or less permanently removed from the environment. Basically we've built up an enormous energy debt from carbon that we need to repay to avoid cooking the Earth to death.


Great work! If this really works at scale distributed around the globe, fuming lots of CO2 into the atmosphere maybe wasn't a bad idea after all. Since we thus distributed it evenly around the globe, it can be harvested back anywhere. Say goodbye to pipelines (in the far future).


I don't know nearly enough about the science to comment on that, so I'm just going to assume you can do this. Would your ultimate model just be to sell to gas stations? Create your own? Create a consumer product small and simple enough for people to put it in their home?

This is really cool!


Hello Rob, thanks for the post! Has your company performed an energy return on energy invested (EROI) accounting for your process? Few companies if any provide a comprehensive EROI and/or CO2 emissions accounting for their product(s). I know you explained that the inputs are low-carbon; however (1) “renewable” energy is still anywhere from 10-50 gram CO2 per kWh (effectively), and (2) the CO2 intensity of your capital equipment can be depreciated over the useful lifespan and then allocated to each effective unit of energy (kWh or Gallon?). I’m genuinely excited about your technology; your low capital costs, inexpensive materials, intermittent operations, and hopefully low maintenance costs all sound very promising.


Thanks! We haven't done a unique analysis yet, but here is a paper that does a good overview of energy balances and efficiencies for CO2 to fuels and products. In their separations discussion you can see why distillation of alcohols is not favorable. A membrane approach is approx. 6x better, but until the CNT membrane was shown to do this job, there was no practical way to do the separation at this efficiency.

https://www.cell.com/joule/fulltext/S2542-4351(18)30042-4


> we absorb CO2 and water vapor from the air into an aqueous electrolyte....to get the fuel out of the water...we have a carbon nanotube membrane

Considering the partial pressure of CO2 in the atmosphere is miniscule, the eventual concentration of the product will also be very low. And because the water molecule is the smallest, you will not be extracting fuel from the solution, but rather extracting water until the fuel concentration is sufficient. Together, this implies that the energy expended in separation must be high, and therefore the process must be inefficient. Is this correct, or have I made a bad assumption somewhere?


Why open-air capture?

I mean, it's typically much cheaper to capture CO2 from concentrated streams, such as the flue gases from coal-fired power plants. So why accomplish the same CO2 mitigation at higher cost by getting it from open-air capture?


We want to get to >300 B gallons per year of gasoline, and only direct air capture will scale to that level.


Yeah, but your capture system will have to be insanely massive. Have you estimated how much air you’ll have to churn through? What risks are there to local fauna? You’ll have to collocate these all over the world.


Even in the long term, it seems like you'd want to grab CO2 from point-sources. Sure you might need to also grab CO2 from open-air if you reach such a scale, but even at that point open-air would just be a supplement rather than the sole source (unless there's a reason to favor open-air exclusively?).

So why start with open-air capture? Just seems weird to burn cash on a more expensive way of accomplishing the same goal.


It takes time to integrate technology with existing utilities or businesses, rather than just renting a building and opening a window.

I agree, they're going for the harder problem, but it's also the most scalable solution.


> I agree, they're going for the harder problem, but it's also the most scalable solution.

It's not really harder, just more expensive.

When major point-sources give off CO2, it's more concentrated. Once it gets into the atmosphere, the entropy goes up, and that entropy cost must be repaid to capture it again. Technical challenges aside, it's still another cost to be paid, making it more expensive.

I think people like the idea of open-air capture because it's just so easy to imagine. I'd guess that it's also easier to pitch to non-technical investors, largely because it sounds so elegant in its simplicity. I just don't see how it makes much technical or business sense, beyond that sex appeal -- which, to be fair, I can appreciate having its own uses.

Honestly, I'm skeptical that a robust analysis of the economics would yield a favorable conclusion. But the market isn't entirely rational, and I can imagine a strategy that sacrifices a measure of fiscal viability for sex appeal potentially profiting for it -- I'm guessing most when pitching to investors, but potentially when pitching to policy makers and the general public?

Which I think is what I find so interesting here. I mean, this doesn't look like a technically optimal strategy to me, but perhaps that isn't necessarily a bad thing?

This is, say that they optimize the plan in a fiscal sense -- would it still get funding from investors? Would people still want to buy into it as hard? Would the HackerNews thread still have so many positive comments?


Investors financed total nonsense such as solar roads. You don't need to be efficient to get VC money, particularly nowadays with loads of free cash from the central banks and low interest rates.


I don't see how that will economically make sense long term. Burn coal to yield co2 + water + electricity, then use electricity to convert the co2 + water into oil? I assume it's more efficient to directly convert coil to oil: https://en.wikipedia.org/wiki/Coal_liquefaction

What they're doing makes more sense to my intuition. "Mine" (excess) co2 from the atmosphere, using a cleaner source of electricity.


That's what makes this so interesting!

I mean, if open-air capture is used, it's mostly just a higher cost -- switching to capture from point-sources should make it more efficient. But then it seems to demolish folks' evaluation of the proposal itself.

I suspect that it's that "mining CO2 from the atmosphere" concept that, when we talk about open-air capture, makes it feel like a closed-loop process. But when we talk about capture from point-sources, it seems to feel less like a closed-loop process, leading to a loss of that intuitive feeling you'd mentioned above.


So what happens to the gasoline afterward? This seems only useful if you bury it underground in an attempt to reverse climate change. If you just use it for fuel, then is this anything other than a really inefficient electric car?


You could stop extracting oil from underground and just keep the existing quantities of CO2 that currently exist. This would allow a "green" application of all the existing engines (think ships) and many situations where going full electric may be impractical.


I have high hopes for desalination with graphene or nanotubes, so I hope when Prometheus is up and running, you look into it again. I'd love to know what happens in your nanotube filters. I read somewhere that water can be ballistic in certain nanotubes, with zero resistance, so I wonder if you stumbled upon something amazing. You must be thinking about other uses. Too many comments here belabor the obvious, which you must get all the time, so kudos for sticking with it and overcoming resistance. It's cool that we don't ever have to run out of gasoline.


Is it possible to take the stuff from the air and store it in wood? If it was you could sell "CO2 storage furniture". This would make your business model green green.

I cannot find the reference but I remember that a chemists organisation was years ago suggesting one should buy furniture/wood products. (This certainly sounds adventurous and I might not remember this correctly.) Certain types of wood come from controlled wood growing/farming, and those trees grow quite fast. So the bottom line was that they suggested to consider Wood a natural CO2 sink.


Good idea, we could even give it a name like "tree" and we could scale it up to something like a "forest"


Thank you. :D I was thinking that one could additionally enrich the wood. Being a porous material this shouldn't be too difficult, although probably one should watch out that inflammability doesn't increase.


> Is it possible to take the stuff from the air and store it in wood?

Yes it is, it's called "forestry".


Are you going to open a few "carbon neutral" gas stations? It might be great for publicity and marketing to open a few in dense urban areas with high gas prices (like LA and SF). Look at what the Apple and Tesla stores did for those companies. You could probably also charge gas prices higher than average by attracting the environmental crowd who would be willing to pay extra to fill their Priuses with carbon neutral gas. This would also work well as initially your supply will be small and still scaling up the process.


I would actually argue that they'd be better off competing on price, rather than raising it (if at all possible and sustainable.) That way even the "but it doesn't run on gas" nuts would have no excuse not to get this instead.


Competing on price is the plan. It's a commodity, so the only way to replace fossil fuel is to take market share by competing on price.


We'll start out using other's pumps, and then move into making/selling fuel making systems themselves. I don't see us buying gas stations.


This sounds amazing, thank you for sharing and for answering so many questions.

I know that you focus is on scale, so you're not likely to pursue this, but the prospect of a fridge sized fuel generator seems like a wonderful stop-gap for the existing ICE cars.

Having one in your garage that produces fuel from rooftop solar panels when there is excess generated, and then not having to worry about transporting the fuel or going to a petrol station sounds like a wonderful future while we transition to EV.

Really looking forward to hearing how this plays out, good luck.


I still don't see any theoretical proof that your carbon nanotubes are going to do this job more efficiently.

If they do, will they need any replacement? Are they reusable? How low the reuse cost can be?


There should be a peer review article with this data by the end of the summer. Mattershift, the company that makes the membranes, got a DOE RAPID grant to get bench and pilot data for this: https://www.aiche.org/rapid/news/08-27-2018/rapid-manufactur...

The membranes are robust and should have a long life in this application.


I was excited to see the article and the response to this post is really heartening. I will echo other comments by saying that your HN pitch is well-written.

I do have a question: in conventional capture processes, the step that makes the process cost-prohibitive is regenerating the absorbent or adsorbent because it is so energy-intensive. You say above that CO2 (and water vapour) is absorbed by an aqueous electrolyte. How do you separate the CO2 from the electrolyte solution?


The CO2 is absorbed in the electrolyte, and that's where we use it in the catalysis process. It is turned into fuel within the electrolyte, then we extract that fuel from it.


Does your 60kWh/gallon gasoline quote include the energy needed for airflow to hit the production scale you expect? This is a significant cost and is why https://www.nature.com/articles/s41467-019-09685-x#ref-CR33 proposes integration with A/C systems.


How do we apply for jobs at this company. I’m sure people would like to contribute to such a good cause! Put the internet to work for you!


Rob -- doing something (somewhat) similar using plastic as an input (instead of co2) and getting oil as an output.

You mentioned you can compete with fossil fuels on (electricicity cost) that would be very dependent on where you operate (where the energy is cheapest). I suspect these would be the same places that bitcoin miners operate out from (and for the same reasons). Is this true ?

Thanks!


Yes, we could probably just generate a map of where aluminum smelters and bitcoin miners operate to give us our short list of early sites.


I read in the Bloomberg article that the machine itself hasn't yet created "enough gasoline to power his Golf even a single mile". I assume you've already made enough to power an engine in the separate steps? How long before you think you'd be able to make a video taking gas from the machine and pouring it into a tank?


We are doing the system shakedown now, and have started making fuel. We'd like to do a demo in the next few months, as long as it doesn't divert us from our timeline. Everything we're doing has been demonstrated separately, including the CNT membrane alcohol extraction, so there isn't really a technical risk here. Everything we need to do now is focused on proving the economics.


Very cool! Thanks for the response, and I wish you all the best.


This is awesome and I couldn't root for you folks more. This is such a great step towards saving the planet!

"What no one has been able to do so far is do it at a low enough cost to compete with fossil fuel." I wish we as a society could properly account for negative externalities in the price of fossil fuel.


So, what's your current fuel output per squaremeter of membrane?

EDIT: read the Bloomberg-report and this reminds me a little bit of the cold-fusion buzz and the occasional kid doing yellow cake in his/her basement. But hey, today there's enough money floating around and why not bet a little ...


This isn’t going to let us electrify the transportation decrypt. Here’s some back of the envelope numbers. An ICE is about 33% efficient at converting chemical energy to kinetic. I don’t know how efficient this process is, but to be generous, I’ll guess 75%. (I could be way off!) Factor in transmission losses of about 2% to the refinery and 5% losses to distribute the fuel, and you get about 6% of the generated electricity making its way to kinetic forward motion. Contrast this with an EV, which has a battery roundtrip efficiency of 99% and motors of around 85-90%. The end result is about 80% of the generated electricity getting used.

Now, I hope we can electrify the transportation sector, but our current generation and transmissions systems are inadequate. I am did he calculations for the state of California, and found that they would need to be roughly doubled in size. An immense undertaking, but a doable one.

However, I do not see us increasing the electricity generation and transmission systems by a factor of 25, which would be required for this technology.


How much control over molecules do you have? Gasoline is a mix of things (which changes based on season). I know today you can buy synthetic diesel (last I checked 3x the price of pump fuel, but it has enough more energy to make the difference between a win/loss in a race).


We have pretty good control, but it's not necessary to make pure substances like only octane, etc. A mix of C4 to C12 hydrocarbons and alcohols that meets the ASTM spec is all we need.


Congratulations. I wish you the best.


Thanks!


How much of what you are doing is "behind closed doors / patented / patent pending"? If there was a list of materials needed to do this on a consumer level, I could see a lot of people wanting to play around with this as a hobby.


Patented, yes. You could do the fuel synthesis in water on a hobby level, and use a thermal still to get something flammable, but you wouldn't be able to use it in an engine. It's pretty fascinating to work on though.


Do you guys not have a landing page / website yet?


https://www.prometheusfuels.com/


This is a cool project! One question though: why is getting rid of thermal processes an improvement? If you're getting electricity from solar, you can get even more thermal energy from solar since the conversion efficiency for capturing heat is much higher.


The cost of solar and wind electricity is low and getting lower. SImilar investments have not been made in renewable heat (like geothermal or solar heat), so they are not as inexpensive. Also, a thermal process needs to run continuously (24/7 if possible), whereas a pure electric process can run intermittently, which is a better fit for the zero carbon energy resources.


I'm thinking of something like http://www.absolicon.com/, concentrating collectors for industrial process heat. Maybe the intermittency is a factor though, you'd need a thermal storage to go along with it.


Can you make vodka out of thin air?


Yes, we have thought about having an "air bar" at events. Downside is we'd have to make sure it was pure ethanol. Gasoline is easier, because it can be a mix of many things that burn. Engines are much less picky than our livers.


You could theoretically sell devices for people to install in their back yards to brew their own fuel? Even assuming, for simplicity, the use of mains power and ethanol fuel.

Edit: already mentioned in the "How small can you scale it?" thread elsewhere.


From what I can see, the catch here is that the process of producing the gas is really slow.


One can get alcohol out of water at room temperature (28 degrees Celsius) by using pressure. Dr. Carl Jung used the distillation under pressure in 1908 to get alcohol out of wine and get alcohol-free wine. Wouldn't the same process work here?


It's possible to do a deep vacuum distillation (and some people do this for moonshine, etc) to get a useable fuel out. Farmers have made their own fuel from time to time doing this. The economics aren't good enough to compete with fossil gasoline though.


How does your expected 50-60% energy efficiency compare to the current energy efficiency of oil extraction? Extraction and especially refinement must be pretty inefficient. How do the end to end costs compare, and why do they fall the way they do?


We expect to be able to compete with fossil fuels on price as we push the price down to get more market share. The process of extracting oil and refining it to gasoline is not inexpensive or easy. By comparison, making fuel on site that doesn't need refining is potentially much less difficult and costly.


At what sort of electricity cost do you expect to produce the fuel at same price as current petrol?

( I am pretty sure even if it was 30% more expensive at Retail consumer will still be willing to paid for Clean Petrol, and that 30% could be your profits. )


If climate change is going to be addressed, fossil fuel prices will need to go up a lot.


At what scale are you going to run the process ? Is it going to be large scale refinery-like production facilities, or could it also be a small unit for storing power in a remote location with plenty of sun but no power lines ?


What would be the longevity and manufacturing costs of this carbon nanotube membrane?

I assume it wouldn't impact the energy accounting itself by much, but I heard nanotubes' main flaw is the inability to manufacture them at scale.


> If the cost of our equipment is also low, then we believe we can not only make zero carbon fuel, but actually compete on price with fossil fuel.

even if it can compete with fossil fuel, do you think it will also be competitive with BEV?


Fuels are used in lots of places besides cars where batteries aren't necessarily viable options.

Large transport ships, airplanes, and rockets all are a long way of from being able to be electric.


Is this something that could be turned into a consumer-scale machine? I understand a lot of the high fuel cost on islands is simply from shipping the fuel there - producing it on site with this tech would be a huge benefit.


Yes, we could definitely do remote location fueling stations, like remote airstrips, etc. Right now we're focused on replacing as much fossil fuel as possible with zero carbon fuel, so that has us focused on the commodity gasoline market. Later we may do small distributed systems as well.


It took me a bit to realize this was unrelated to https://prometheus.io, which is a pretty popular project which is posted about here on HN frequently.


Even if it works you would do it only if it would make enough money. If market changes for some reason and it is not profitable anymore than Planet is screwed up again. There is no easy fix. Only just stop polluting CO2.


Very exciting! I believe these types of approaches will be greatly beneficial in turning the tide of environmental change. However, I am curious about the long (very long) term effects of this technology.

If atmospheric CO2 becomes a resource for the production of goods that do not release the CO2 back into the environment for reuse, would there be a risk of O2 overabundance? If left unchecked it could overcorrect for global warming and usher in an ice age.

I imagine there’s a balance point for CO2 levels and finding and maintaining that balance will be what determines humankind’s success in the long (very long) term.

See, e.g., University of Maryland. "Rise Of Oxygen Caused Earth's Earliest Ice Age." ScienceDaily. ScienceDaily, 7 May 2009. <www.sciencedaily.com/releases/2009/05/090507094218.htm>.


> If left unchecked it could overcorrect for global warming and usher in an ice age.

Human society can live through, and has lived through, glacial periods, all within the current ice age. It hasn't survived through a warning period that ended an ice age. Warming is both more imminent and more dangerous.

That said, consuming CO2 without releasing O2 won't significantly increase the O2 level anyway, because the total CO2 level isn't a significant proportion of the O2 level. Depleting CO2 too far runs a bigger risk of reducing O2 by reducing plant biomass which depends on CO2 and produces O2.

In any case, any risk of reducing CO2 concentration is easily mitigated by ramping up enough fossil-fuel-based energy production to counteract the decrease. CO2 underabundance isn't a problem we have, but it's certainly a problem for which we have (without specific intent) done an excessively good job of developing, proving, and deploying infrastructure to mitigate if necessary.


Seems unlikely that overcorrection would be a problem. By the time we are there, there should be many other options, and there will be plenty of time to prepare.

Right now, it seems the big concern is the next 20-50 years.


>If left unchecked it could overcorrect for global warming and usher in an ice age.

The entire point of being able to control it is that it's not just left unchecked. We'll modify it while studying it, and then when it becomes so routine it's trivial, we'll automate it.


Re: “unchecked”: I was speaking more from an economic perspective, rather than a technical one. If there is a new CO2 sourced product with a long lifetime and the carbon does not return to the atmosphere for a long period, and it is in high global demand, it could open the door to the issues I’m trying to highlight in the original comment.


Can you elaborate on "we use zero-carbon electricity"? How far abstracted from electrical generation are you? What guarantees do you have that your electricity is provided by low/zero-carbon sources?


We're going to take the power at the renewable power plant, so we will be certain that we are getting zero carbon electricity.


Solar panels or wind turbines do emit CO2 (e.g. construction, maintenance). Is the amount of CO2 emitted per kWh negligible compared to what would be captured from the air ? What's the ratio ?


>About 3 years ago I realized it could do this job, but it wasn’t clear that a startup could raise money for such an ambitious effort, especially one linked to a political issue (unfortunately) like climate change.

That is probably true, but unfortunate. FWIW I’m a major skeptic as to the harms of climate change, but I still find your startup very exciting. Whether or not climate change is an issue, having a renewable cost effective way to convert energy into hydrocarbons would be amazing!

I’m curious whether you’re sticking to just focusing on the energy use case or continuing to develop other use cases such as the earlier desalination. There are likely lots of areas in industry where such membrane technology would provide a useful tool in the arsenal of methods to separate chemicals.


I'm focused on Prometheus and turning CO2 to fuel, but my previous company Mattershift will make the membranes available for other uses.


So, lets talk numbers:

Let's assume we have 100W (typically 12V) solar panels in ~1m Square space. How many litres of alcohol/syntfuel will it generate during an (expected) 8hours of 100% power capacity in a day?


That's basically what plants do. So the question becomes: what is the advantage of your system over biofuels?

An obvious one is that you can use electricity from any source (I am thinking nuclear), while plants are solar-only. But since you mentioned solar electricity, I think a side by side comparison of a biofuel producing field and its factory with a solar farm tied to your system could be interesting.

EDIT: In case it isn't clear, my point is not to call you stupid, I assume everyone who wants to extract CO2 from the air also considered plants, and for some reason, found that artificial means are somehow better. The real question is why? For example I know that natural photosynthesis is not very efficient, but there may be other reasons.


How do you measure efficiency ? Is it amount of energy spent to generate equivalent energy worth of gasoline ? ( Will one megawatts solar plant generate about 0.25 gallon gasoline per minute ? )


There are a couple of kinds of efficiency, i.e. Faradaic efficiency vs overall efficiency. We are talking about overall efficiency, which is electrical energy turned into useful chemical energy.


I hope this becomes an immense success. Gives me hope for the future.


Thanks!


Are you having to choose specific production areas to get effective economics for electricity? E.g., are you expecting to have to scale up a plant near cheap electricity like hydro?


I understand you want to make money, but why not open source your work? I'd imagine this would be the right thing to do. I'm sure you could still live a prosperous life.


Leaving aside the questions of cost-effectiveness/carbon neutrality/etc of e.g. corn ethanol, but can your tech potentially also make existing biofuels more efficient?


Yes, the CNT membranes will improve the efficiency of biofuels, but Prometheus won't do that. My previous company Mattershift makes the membranes and will sell them for other uses.


I had read something about using a nano-surface on the electrodes on this process to improve the yield of desired products. Have you considered using similar technology?


How much emissions do you expect from production and disposal of your machines? How big an impact will that have over the entire life cycle of your hardware?


congrats.. what about the name clash with e.g. this? https://prometheus.io/


I am probably extremely naive but I have a feeling I am going to hear a lot about this in the future and that I am witnessing the start of something great.

All the best!


Thanks!


Thank you for the detailed description. I wonder what impact may this technology have on nature. Plants after all need CO2 to exist.

Thank you. I’ll be rooting for you.


There is no risk in terms of taking too much CO2 out of the atmosphere. Over the last couple of hundred years, humans have put several trillion extra tonnes of the stuff in (by burning material sequestered over millions of years). Further, this tech carbon neutral, not carbon negative. The advantage is that when the fuel is used, it's just putting CO2 back into the air that was there before, not adding more.

Hopefully this kind of thing, in addition to switching the electricity grid to zero emissions tech will allow us to halt global warming where it's at.


What are the companies that do the up conversion to final fuel?

Are there any other products remaining after the conversion from alcohols such as propane, butane etc..?


Some of the companies that do upgrading include Vertimass, Gevo, Swedish Biofuels, for example, and there are some methods that are not under patent protection that anyone can use. Basically a catalyst that dehydrates the alcohols and oligomerizes them into longer carbon chains. No other products than a combustible fuel.


How long does the the carbon nanotube membrane last? How many gallons can it produce before it needs replacing? And how much it costs to manufacture?


We expect a long life for the CNT membrane, as it operates on clean internal streams. They are actually not that expensive, so this is a small risk.


I had read a while back of the use of nano-texturing on the electrodes in this process to improve the yield of desired compounds.

Have you considered doing this?


What are the major challenges you have yet to face to make it economically viable?

e.g manufacturing your nano material at scale or obtaining higher efficiency..


There are no limiting factors to us scaling now.


I am curious about the membranes - is the production capacity available to produce them in such massive quantities you'll need?


So is it fair to say that basically your only constraint is the price of your input electricity?


That is the main input. We also have to keep the capital costs low, but that looks good too.


Cool, what do you plan to use for power source? (ie where is the electricity cheap and carbon free?) Can the process be run intermittently?


Love the pitch, keep us up to date. Any place we can sign up to follow along? Google just gives Kubernetes metrics results :)


Can this process be used to make Ethanol at large scale from plant matter? And can it be competitive with fossil fuels?


Correct me if I'm wrong, but planes look like a bad target for this fuel substitute : for 1 kg of CO2 emitted, estimates give a ~2 (or worse, 2.7 - 4) factor of radiative forcing (the potential for climate warming), due to the water vapor released at high altitudes.

You'd have to capture 2 or 3 times more fuel that you'd burn in the sky for this to be "net zero climate", which is a better metric than "net zero carbon".


You seem to be right about the forcing of water being much higher [1], but CO2 has a nasty property as opposed to water: it stays in the atmosphere for much longer and contributes to warming for much longer than the water does. If temperatures get really bad in future, we can limit burning fuels and all the excess water will fall back down to oceans in few years. CO2 won't do such thing as fast. So even if we can't decrease forcing due to aviation burning fuel, it makes sense to make aviation use CO2 neutral fuels to keep the concentration of CO2 low.

[1] https://pubs.acs.org/doi/full/10.1021/es9039693


Contrary to what I said above, it seems the effect of jet exhaust water is more complicated and hard to evaluate... the problem is that unless there is enough water for condensation, water molecule is lighter than oxygen or nitrogen molecule, which means the high altitude vapor isn't likely to fall down quickly.


Thanks for pointing this out. As for the temperature, the rise is already really bad right now, it didn't change the mind of the minority flying...


We think air travel will be dramatically better with zero carbon jet fuel. That doesn't remove all of the impacts, but it's worth doing.


Do you think a long term use case for this tech is as a storage method for energy produced through renewables?


Rob,

I haven't seen anyone else ask this question, but I currently craft my own biodiesel and was wondering if the maker / private owner market would be able get access to buy fuel from this process?

I understand there might be tweaking of engine combustion profiles to make that happen, but I think this is exciting and would love to support by buying some of this amazing fuel without waiting for it at a gas pump...


Very cool, looking at another solution to attack the global plastic waste problem with oil as an output.


How is the scalability of of the extraction process, both in manufacture and operation of the membrane?


Both are highly scalable. The CNT membrane is available in commercial modules now and can scale up further quickly.


For the reasons mentioned below I'm skeptical that this is a solution to the climate problem. However, certain applications such as air travel do not currently have safe viable non-carbon power sources. Even if this is more expensive than fossil fuel, limited amounts of subsidized zero carbon fuel (~1-2% of consumption iirc) can make air travel sustainable.

Best of luck.


Looking for any software engineers?


And if not, what do you need?


Do you factor the carbon that went into producing the solar panels and wind turbines?


Out of interest, how does this differ from companies like LanzaTech?


Lanzatech uses a biological process.


Could this be a superior method for generating methane on mars?


Can normal people (like me :) support the effort of invest?


How is this different from what Opus 12 has developed?


Could you also make a filter that distills liquor?


God allows you to succeed. That would be awesome.


How do the carbon nanotubes do the distillation?


Can you hook a miniaturized-enough version of this device to your exhaust pipe then and have a zero exhaust car that runs on water but is technically a gasoline car?


It did not occur to me that this is linked to politics until you mentioned it. If you feel that is hindering oyu in any way, feel free to skip the mention.


What's YC like as a solo founder?


Sounds like the ubeam "works for very tiny numbers, everything else is a scaling problem" con.


hi rob, would you rather be jonas salk or john d. rockefeller?


i am interested in collaborating at india

9140451991 ashishtewari.ips@gmail.com


The 50-60% efficiency does matter if wind power itself isn't all that green.


I am interested in the idea at india. please contact @9140451991

ashishtewari.ips@gmail.com


you are producing carbon emitting fuel. you process therefore needs to be negative carbon, not neutral.

this will never succeed as a VC funded enterprise.


Well, producing solar panels and such also requires energy input, and these do have limited lifetime. What is the real full-cycle energy conversion ratio is?

Secondly... continuous distillation doesn't necessarily require lots of energy, since a lot of it could be recycled with counterflow heat exchangers and heat pumps instead of plain heaters (i.e. hot output and hot waste are used to heat up input to close to the proper fraction boiling temp, and the output and waste are only slightly warmer than the input mix). It still needs energy input to deal with losses and entropy reduction from mix to separate fractions, but this is also true about using any sort of membrane-based separation.


* producing solar panels and such also requires energy input, and these do have limited lifetime. What is the real full-cycle energy conversion ratio is?

I wonder what this is, too, but a typical 300W panel with 20 year lifespan will generate something like 20MWh over its lifetime. You can't possibly use anywhere near that much energy to manufacture it.


I read something about this a little while ago - if I recall the analysis correctly the energy payback was in the order of 1-2 years for the average (300W or so) panel. Not bad for a 20 year life, but we will need recycling advances in the meantime as we will have so many panels reaching end of life in the next decade.


My personal pet theory is that the energy consumption is more or less equivalent to the price. So as long as the solar panel is not economically viable, it does not provide an energy surplus.

20MWh is not much, it's $500-$3000 worth of energy, depending on taxes and stuff. Can you buy, install, connect, maintain, clean a 300W solar panel for 20 years for this price?

Edit: Also, 20MWh is quite high. That's 9h of perfect sun, each day, the whole 20 years.


Well-placed solar plants have capacity factors of about 20%, so 10MWh. That's worth about $1200 at the retail end of the grid (or $2600 if your local utility has gone bankrupt). At the production end, it costs anywhere from $100 for fully depreciated hydro[1] to $1400 for solar PPAs made by bankrupt utilities[2] to $600 for new solar when you assume an unrealistic cap factor and ignore Chinese subsidies[3] to $240 if you ignore a whole bunch of additional stuff.[4]

1 https://www.eia.gov/electricity/annual/html/epa_08_04.html

2 https://www.spglobal.com/marketintelligence/en/news-insights...

3 https://www.eia.gov/outlooks/archive/aeo18/pdf/electricity_g...

4 https://www.utilitydive.com/news/nv-energy-23-cent-solar-con...


Last time I checked retail prices were around 0.30 to 0.32 $ per Wp for large customers. So your high efficiency, last tech 300 Wp module would be around 100$ including shipping for large orders. Could go up to around 120 to 150 for smaller volumes. Of course, market prices may vary depending on demand and availability.


It's my impression that lifetime is mostly efficiency degradation from UV exposure. If that's true, then it seems that if you have fewer solar hours per day, the panel will just retain its efficiency longer until eventually you reach the same lifetime energy produced. (Until you get to ages where actual weathering of the enclosure etc destroys it, obviously.)


"My personal pet theory is that the energy consumption is more or less equivalent to the price."

This implies that energy is the only input to making PV, which is clearly wrong.

Or maybe you're saying that if we trace back costs into the economy, from the workers, to the grocery stores where they buy their food, to the farmers, etc. etc., it all eventually comes back to energy. In that case the energy return on investment is going to be 1:1 in steady state, which indicates that's not a useful metric either.


> Or maybe you're saying that if we trace back costs into the economy, from the workers, to the grocery stores where they buy their food, to the farmers, etc. etc., it all eventually comes back to energy.

Yes. Of course, this is greatly simplified and I'm not entirely sure where to put capital costs in my theory. But I think I'm not too far off. And of course I'm purely talking about energy, not whether it is environmentally friendly or not.

> In that case the energy return on investment is going to be 1:1 in steady state, which indicates that's not a useful metric either.

I'm not sure what you mean by this. If I pump up a barrel of oil from the ground, I end up with more energy than I started with. Otherwise I would not do this in this first place, because I could not make money.


It means that if you trace economic activity back to the point that it involves energy, ALL economic energy eventually traces back to energy. The EROEI becomes 1, by definition.

Of course this is ludicrous. If you double the energy efficiency of all activities, and cut the energy used in the economy by half, these long chains get longer, but they still end at the energy production, so that '1' doesn't change. What this kind of evaluation misses is the massive multiple counting going on: that displaced energy use is producing value all along the chains, and the longer the chains, the more value each unit of energy produces.


If that were true, the cost of the energy consumed would be equivalent to GDP, and that is not the case.


That a good point. But a huge part of the GDP increase is an increase in efficiency, i.e., you can do more with less energy. A 2019 computer would cost a totally different price in 2009, and would be infeasible expensive in 1999.

But if you compare technologies within one year, the price tag gives you a very good idea how much energy was used for producing each one. Of course, there are scale effects at play, so an R&D cost (energy) might only occur once, but is then distributed within all units produced. This will very well be reflected in the price, once something enter mass market.

The same will happen with photovoltaic cells: They will continue to get cheaper (and more efficient) and at one point it will make economic sense to put them everywhere. And at this point it is clear that they are net energy producers, where currently it is still debatable, at least in more northern regions.


The price of energy in Australia is very expensive. 20MWh is worth approximately $6000-9000 AUD.

So a 3kW system @ about $8k purchase price should return about $50 - 80k gross.

You can lower your efficiency substantially and still offset a substantial expense.


how many watts today is required to produce one liter of fuel using both your membrane and the conventional way requiring distillation? What are your long-term watts/liter targets ?

Maybe a non-membrane version could be attempted that used renewable energy (sunlight) to do the boiling? Certain geographic regions might have the right combination of plentiful sunlight, water, and wind to minimize all these costs?


It will take approx. 60 kWh/gallon of fuel, or just under 16 kWh/Liter. As long as this electricity is from zero carbon sources and is inexpensive enough, it works. Distillation and other thermal processes typically need to burn fossil fuels. The difference between renewable electrical energy only vs using thermal is really more a difference of kind than of degree. It's really hard to do a thermal process that is truly zero carbon, and hard to do it economically as well.


how much energy is spent pulling CO2 out of the air? I know this sounds like a step backward, but perhaps burning plant matter or recycled cardboard might be a more efficient source of CO2? If purifying smoke is cheaper (energy-wise), maybe you could let mother nature extract the CO2 through fast-growing plants, then dry and burn them?


How does this compare with planting trees and harvesting the wood as fuel?


> please excuse if I’m not able to go too far into details like our piping and instrumentation design, or other really specific things we wouldn’t want to help competitors with.

"I'll save the planet and my children only if we get super rich"

Is this peak capitalism ?


Is your supply chain carbon neutral?


The inputs are zero carbon, but there will be life cycle (LCA) impacts in the materials of construction. We'll likely be well in carbon negative territory even including materials, and will do a LCA to verify this when we get a chance.


It's never said explicitly and I couldn't find a question about it, but everyone talks as if we'll need solar input to power this. I assume this means the machine doesn't produce enough fuel to power itself?

At any rate, amazing product. Can I (eventually) buy one of those machines or donate somewhere to make my area CO2 free?


Are you asking if this is a perpetual motion machine?

Edit: Or close enough to perpetual motion that it only requires the occasional replacement of nanotubes and other materials


Please see the sibling thread that asked the same question a few minutes earlier (probably wasn't there when you loaded the page). I replied there: https://news.ycombinator.com/item?id=19844137


Wouldn't producing the necessary fuel to fuel itself lead to an infinite energy source, essentially making this a perpetual energy machine?


Please see the sibling thread that asked the same question a few minutes earlier (probably wasn't there when you loaded the page). I replied there: https://news.ycombinator.com/item?id=19844137


Well of course not. It does not defy the laws of thermodynamics.


Well sure, it would not be a perpetuum mobile. It would take CO2 from the air to turn into fuel, and once it runs out, there is no more fuel to be made. It creates a little CO2 by burning fuel for itself, but if that is less than the amount used for fuel production (that's the scenario where it could power itself), that would be less than it needs to generate the fuel to continue the cycle.

An oil pump can pump enough oil to fuel itself (we don't need solar to power our gasoline industry). And we can eat a plant and have enough energy to cultivate more plants to eat. I would not be surprised if it works the same here.

Edit: I guess the flaw in the logic is that, where there is a lot of energy stored in oil and plants (and plants get it from soil and the sun or so, again something external), this process is the reverse of burning. So if reverse burning costs less fuel than burning, we'd have a perpetuum mobile. Is that it? I'm sorry that this wasn't immediately obvious to me (if that is even the answer), since there are so many other fuel creating and self supporting processes...


No, you cannot extract free energy from air.


My two cents — change your name. Prometheus us too pretentious in my opinion. Also, Prometheus can be pronounced in different ways. Is it pronounced PromEEteus or PrometHeus? And its also ProMeth. :)


Most importantly, Prometheus is a well-known software...https://prometheus.io/


Prometheus is the most popular time-series metrics database and query engine for monitoring. It's really great, highly recommend!


"Google, Audi, Carbon Engineering, Global Thermostat, Climeworks, and labs at universities and national labs have all done it before us. What no one has been able to do so far is do it at a low enough cost to compete with fossil fuel." So Google failed but Prometheus will succeed.

Are you just trying to make a buck in The End Times?

I have no feedback, Mother Earth has, probably a couple of hundreds of them loops... We are screwed.


To make combustible fuel from solar energy is crazy. The cost of such fuel is almost zero from the large oil reserves: the price you see is carefully calculated to maximize profits and to politically permit less efficient suppliers to survive and profit acceptably: but any synfuel business can be wiped out any time. At a point where we are trying for a renewable electric ecosystem, to take its product, and turn it inefficiently back into fuel is ununderstandable. By the way, if electricity is free, please send me some.


> To make combustible fuel from solar energy is crazy. The cost of such fuel is almost zero from the large oil reserves

...if you ignore the costs that exist in the form of environmental externalities, a behavior which is increasingly being recognized as an existential threat to human civilization.


I see, in other words, you have a method of capturing the externality costs, and using them to protect this fledgling enterprise. Look, I understand externalities. I understand 415ppm. I live in Hollywood, FL, and see flooding at high tides, with my own eyes. But the proposition here is to turn solar electricity into combustible fuel. And waste at least half of this energy in practice, because we have some "valuable" investment in fossil fuels infrastructure. Again, are you kidding me?


This can’t work because of Jevon’s paradox [0]. Every barrel of gasoline created by this process just displaces a barrel of fossil gasoline, pushing down the price of gasoline at the margins resulting in increased consumption.

CO2 neutral gasoline can only work if you can get the cost below the marginal cost of production of fossil gasoline such that the oil stays in the ground. This is a massive ask on thermodynamic grounds.

0. https://en.wikipedia.org/wiki/Jevons_paradox


Jevon's paradox only applies because governments subsidize fossil fuels by failing to correct the market failure of their externalities. If they were taxed appropriately to compensate for the damage they do then synthetic hydrocarbon fuels would probably be viable in the cases where batteries are unsuitable because of insufficient energy density (e.g. long-distance aviation).


We heavily tax fuel in Turkey, yet everyone buys petrol powered cars.


No. I think you really need to understand Jevon's paradox. I highly encourage you to do so - once I learned about it so much of the world became clearer.


The price does not need to be below the marginal cost of production of fossil fuel. It only needs to be below the cost of production + the cost of taxes on fossil fuel. I suggest that a taxation level that allows Jevons paradox to occur is too low.


Taxes on fossil fuels just raise the marginal cost of production. They are a totally separate issue from the effect of introducing a new fuel into the market.

Given the amount of down voting I have received basic economics is not popular on HC. Increasing the supply of gasoline will reduce its price which will cause increased demand greater than the original supply. The original example used by Jevon was coal consumption which rose 10 fold as the price halved. If Promethus succeeds they will cause an increase in consumption of fossil fuels (assuming no other changed) as they will lower the price of gasoline increasing its consumption.

The only way that such an approach can work is if they can get the price of gasoline below the cost of production from fossil fuels. While this may be possible, on thermodynamic grounds it is hard to compete with all the stored sunlight in fossil fuels, let alone the sunk costs in the fossil fuel infrastructure.

I am very much in favour of doing something about us burning fossil fuel, but I want us to concentrate on those things that make economic sense. In respect to gasoline that would be electrification of the transport system and better electric storage.

The one thing that would potentially be worth pursuing is not the production of gasoline, but avgas (diesel) as there really is no viable alternative to these for air and sea transport.


>Increasing the supply of gasoline will reduce its price

This is not an inevitability. The state can and does tax things, and I am suggesting that they should tax fossil fuels sufficiently to prevent Jevon's paradox from happening. The correct taxation to prevent the market failure of externalities is not any percentage of the production cost, it's the cost of the harm done. If Jevon's paradox would increase the harm done then tax should increase to prevent this.


There is no need to have some alternative gasoline in order to implement a tax to decrease consumption of gasoline. Just a straight carbon tax would do this. The problem of course has been getting these implemented.

We really should keep the topic of what Prometheus wants to do seperate from other things like carbon taxes.

I think the best bang for our buck would be to just buy the oil before it is pumped out of the ground and leave it there. The producers would stop fighting us doing something about climate change and the increase in gasoline prices would drive the adoption of carbon neutral energy sources.


IMHO this is a waste of time. You are wasting clean energy sources to make dirty ones -- at best a 50-60% loss of energy. And you end up with dirty fuel, that further produces CO2, in which the cycle repeats, with a net loss.

In the near future, cars and trucks will be electric. This is shuffling deckchairs on the titanic. Why not put 100% of your efforts into electric vehicles powered by 100% renewable sources?


If we want to stay below 2 degrees C in warming, we don't have time to replace the existing vehicle fleet (approx. 1.2 billion cars, trucks, buses, etc) with electric vehicles. If we instead replace the fuel, this can be fast enough. Even if all vehicles are electric in the future, this is still the right thing to do now.


My issue is that this is a step in the wrong direction, it is incentivizing the current dirty status quo. Why would anyone replace their dirty engine if they can feel good about by using your 'cleaned' fuel.

I agree we need to do something now, but this is just putting off the inevitable. Re-engineering dirty fuel sources doesn't buy us time to resolve this. It is procrastinating, shuffling titanic deckchairs.

The main advantage of this tech I can see is making 'primary' sourced fuel illegal, 'secondary' sourced fuel like this prohibitively expensive, and forcing everyone to go pure electric engine by economy.


The energy density of batteries is nowhere near as good as oil - the laws of physics limit how good batteries can get (there is some room for improvement, but oil is still better by a large margin).


We need carbon neutral fuel for shipping and aircraft, so that's one huge application. Especially if it's cleaner burning (no sulfur, aromatics etc.).


Like someone said in another comment, you'll still have existing gas-powered vehicles(current cars, jet aircraft, etc.) for some time, and they have to get that gas somewhere. Better from a net zero source than to add to our carbon debt.


Can you elaborate how gasoline is 'dirty' if the outputs were converted back into the fuel via carbon neutral means?

Such technology would make gasoline have no output, since the ouptuts would be reabsorbed. If anything, electric cars, due to the massive environmental damage due to rare earth mineral mining, would be more of an environmental disaster.


Every cycle has a 50% cost in renewable power. This is close to being carbon neutral, but it is not entirely. Its not a closed loop. You have a growing loss every cycle. Its digging yourself deeper every time.


It is not energy neutral, but it is carbon neutral (if the electricity input is from a zero-carbon source).

It sounds like you're suggesting that burning the fuel releases more carbon than was used to produce it, which isn't possible.


Well of course it's not 100% energy efficient. Nothing we do is 100% efficient because we cannot escape the second law of thermodynamics (entropy).


The claim is renewable energy is not carbon neutral? Just to be clear -- you realize carbon can neither be created nor destroyed by any industrial process available to mankind?


To buy an electric car i need £20,000 which I don’t have. Even if I had the money or access to credit, I don’t have a parking space near my house, so I can’t charge the car.

All fixable things, but will take tens of years. Let me use carbon neutral petrol


You have 20.5 years until Petrol cars are outlawed in the UK. Best get saving. Also -- this is no such thing is carbon neutral petrol.


Nothing at all is truly carbon neutral, after all a human took a breath to contemplate it.

The idea and processes behind Prometheus are still very interesting and have implications beyond the short-term focus on carbon footprint. This type of process will likely be needed to manufacture fuel on other planets.


Very promising but I'm going to hold out until I actually see this being applied in places like South Korea, literally suffocating from a combination of both local and foreign smog from Korea's favorite neighbor.

You can't really fault me because we've often seen groundbreaking, extraordinary claims, and very little of it is actually realized. Sort of like how we get news about how somebody found a cure for AIDs or Cancer. Again, not trying to shit on anybody, just practicing good old skepticism, I will believe it when my nephews and nieces in Korea are able to breathe in cleaner air and can play outside without wearing industrial face masks. Until then, fingers crossed and hope this is the real deal.


I totally agree on skepticism. We are working hard to prove our economics. We are targeting selling renewable gasoline from the air for a profit next year. It will be much better for air quality too!


How will this improve the global average of air quality? If you are removing the CO2 from the air then reintroducing it back into the same environment (assuming it is not repurposed in another sector e.g. jet fuel, commercial containers) wont the net effect be the same?

I understand this will concentrate the pollution significantly and may even reduce it in the short term, but wont the average effects be the same?


By "air quality" I believe he is saying that an extra benefit to being carbon neutral is that their fuel combusts more purely than fuel made from crude oil. This means less SOx, NOx, particulates, etc.


It'll improve net air quality (if it works) because our current methods of producing fuels themselves require other 'carbon negative' energy.


Hope the best for you guys, I really do! If realized, this could be too seductive for foreign governments that depend on importation of oil and polluting their air to support export industries. Cleaning up the air AND mining the skies for gasoline? Good deal imho.


Here's what I don't understand - You're taking CO2 out of the atmosphere using renewable energy sources. Thermodynamically, this will take at least as much energy as it took to burn them. You did not mention how energy efficient your energy storage method is right now (50-60% at maturity sounds really optimistic, when plants are only a few %), but, in the short term, while we're still mostly using carbon-based fuels, you're basically diverting renewable energy capacity from consumers. Instead of getting 1kWh of usable energy from a solar panel, they're getting at best 0.5kWh, albeit in a much denser form that's easier to move around for some transportation uses, such as aviation. But, in the short term, you have a net-negative impact.

In the long term, if things keep going where they are going and we end up having to remove carbon from the atmosphere to reverse some effects of global warming, why would we want to convert it into gasoline instead of e.g. just capturing it and storing?

Or is this just a way to generate jet fuel for planes of the future when we'll electrify all of transportation except for flying?


Demonstrated overall conversion efficiencies for CO2 to fuels are already in the 25-50% range, depending on the fuel. We are confident we can get to at least 50% for our process. We will not be taking renewable power away from other uses - in the short term we'll be using marginally useful power (wind at midnight, solar at noon, etc), as we need the power to be low cost, and any time it has higher value uses, it won't be cheap enough. So we are not removing it from other beneficial use. Also, as we scale, we will cause much more solar and wind power to be available as we will be buying a lot of it. In the long term, aviation and shipping are likely to still use liquid fuel, yes.


Thanks for the reply, I get the load balancing part now, I did not think about that.

I was thinking a lot recently about flying and how we could make it work in the (hopefully) greener future. This is definitely a more sensible way of doing it than electric jets, good luck with your company!


Thanks!


How do the unit economics look for using your tech as a battery store and then burning excess fuel for grid energy when demand is high?


One cool thing is that one could build huge power plants in the middle of nowhere, and not worry as much about transmission losses. Oil fields are already typically in the middle of nowhere, and fuel travels and stores easily.


Look at it from an economics standpoint... because of the efficiency loss, energy from this process would always be twice as expensive (or more) than freshly generated renewable electricity. So you'd only want to use it in places where grid electricity is impractical.

Vehicles are the obvious market. It took over a century for electric vehicles to become even remotely practical. But vehicles are necessarily disconnected from the grid.

And even for vehicles, this is only desirable when consumption needs or disconnect times are very high, like aircraft and oceangoing ships. That's because combustion is very wasteful. There are about 33.7 kwh of energy in a gallon of gasoline. A Tesla goes as far on three gallons' worth of energy as a comparable Mercedes goes in ten or more. That's because an electric drivetrain is 3x (or more) more efficient than a combustion one.

So using this process, it could cost 10x as much to operate a fuel-based vehicle as an electric one. You don't want to do that unless you have no other choice.


Probably just the last line? Even still, we can easily build out way more solar than we need so if there remains a need for energy dense carbon fuels then why not?




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