The article makes a good point that ammonia is an integral part of our modern world, and it's pretty much impossible to get around it.
However, there are also other places in which ammonia will cost energy. That fertilizer we use ends up in our food which ends up in our sewage. In turn, that excess fertilizer causes algae blooms and environmental damage. Therefore, we need to find ways to remove that waste (Europe already does in many places). Sadly, this costs additional energy.
I worked (very briefly) on a technology that helps reduce that impact, there's a lot of interesting work in this area. Some even uses the ammonia itself as a source of energy.
Just to nitpick for a second, the vast majority of ammonia that moves from fertilizer to algae blooms comes just from farm runoff. Many farms still use flood irrigation and many others end up timing fertilizer right before big rainstorms in the spring. The water runoff is how the ammonia makes it into the water supply, not from the food and then sewage.
Absolutely true, that's why there is a dead zone at the bottom of the mississippi.
However there are literally tons of ammonia flowing out of places with high density and where that high ammonia still ends up in water ways after passing through a sewage system. In particular this has been true in Western Europe, and there are issues in various areas around the country here (Great Lakes, Chesapeake Bay, SF bay is weird so for now we seem to be not as affected on this particular front). In the US human sewage is thought to contribute 11% of the problem and in Europe 25%. Not everything, but surely it'd be nice to solve the problem. Also some of these technologies could be applied to other sources such as manure if treatment standards were imposed on agriculture. Runoff is harder for sure, but there we can maybe look at more targeted application of fertilizers. It helps nobody to pay for fertilizer that ends up in a river and not growing more food.
I was just hearing an Ohio farmer complain that they won't let him spray manure on his fields while the ground is frozen anymore, and he doesn't have sufficient storage to hold all the manure through the winter. What's a poor farmer to do?
Spraying frozen fields is not "fertilizing", it is just dumping manure and letting it wash into the streams. He may as well have been dumping it straight into a stream all winter.
It makes one wonder, is there an 80-20 rule for farmers? Are 20% of them causing 80% of the fertilizer runoff?
One supposes he could invest in an anerobic digester[1] and start turning all that manure into electricity for the grid. Honestly, any farmer not doing this yet is leaving money on the table.
That all depends on how long the payback is, which isn't clear from that reference. Farmers are businessmen, aren't going to do something if it doesn't make financial sense.
However, there are also other places in which ammonia will cost energy. That fertilizer we use ends up in our food which ends up in our sewage. In turn, that excess fertilizer causes algae blooms and environmental damage. Therefore, we need to find ways to remove that waste (Europe already does in many places). Sadly, this costs additional energy.
I worked (very briefly) on a technology that helps reduce that impact, there's a lot of interesting work in this area. Some even uses the ammonia itself as a source of energy.
One process using the ammonia as fuel in a way:
https://en.wikipedia.org/wiki/Anammox
Process I helped get some attention at one point:
http://web.stanford.edu/~cantwell/Recent_publications/Schers...