Ok, I didn’t actually clear this challenge with the Nobel Committee, but I think we could convince them. Nobels were awarded early in the 20th century when German scientists Fritz Haber and Carl Bosch made the sequential advances that made it possible to make synthetic nitrogen fertilizer from the nitrogen gas that makes up ~80% of the atmosphere. Without their contributions we could not have improved the lives of billions of people, and we could never have fed the increase in world population that has occurred since their work. Of course that comes with the environmental issues I’ve been discussing in my previous posts. I’m not forgetting that there are changes that need to be made in the way we farm to make nitrogen use more efficient and to prevent water pollution issues.
The Carbon Footprint of Fertilizer Issue
The other thing that would be good to address is the “carbon footprint” of running Haber-Bosch. For every pound of ammonia that is synthesized, about 3.7 pounds of carbon dioxide is generated (mainly through the use of natural gas to generate hydrogen). That means to fertilize an acre of corn at 120 pounds of nitrogen, there are carbon dioxide emissions that are the equivalent of ~20 gallons of diesel. That works out to 1.59 billion gallon equivalents for just the US corn crop – some serious carbon emissions (I’ve already posted about why Organic fertilizers are not the solution here).
What This Invention Could Mean
Here is where our future Nobel Laureate comes in: animal manure, municipal sewage, woody debris and other waste streams can be turned into energy through a variety of methods (anaerobic digestion for methane, pyrolysis for syngas or bio-oil, burning for electricity…). What if you could use that energy to run the Haber-Bosch process? Today the nitrogen fertilizer for the world is made in very large facilities that mostly use natural gas. I’m sure you could never achieve comparable efficiency on a small scale, but the cost difference could be offset with something like carbon credits or some other form of subsidy.
What would be even better would to to invent a system that can run on a very small scale to take waste sources of various types and generate nitrogen fertilizer for subsistence farmers in Africa and elsewhere. In this case, the system would also have to take the ammonia and turn it into something like urea (hey, chemists and engineers are very resourceful, right?)
I’m definitely not the first to suggest this, but I honestly don’t know whether this is feasible. I usually try to blog about things I know more about, but I’m hoping that there are some chemical engineers or other specialists out there that can tell me if this is even something worth talking about. Maybe you know one and could ask them.
So if you are someone knowledgeable about this tell me whether this makes sense. Thanks!
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Nobel Medal image from Jonathunder