Many of us here today, unbeknownst, owe our existence to something pervasive and ubiquitous. No, I’m not referring to the golden arches. But yes, this something has quite a lot to do with the golden arches. Potatoes, wheat, corn, soy and other crops used as ingredients in our beloved Happy Meals, all grow on scales impossible a century ago. Industrial scale agriculture has not been enabled because we landed on the moon, nor because we’ve put more seeds into the ground. By some estimates, without industrial scale fertilizer, the amount of arable land on the planet would supply, at most, enough calories, in the form of crops and feed for animals, to sustain a population of around 4 billion. Yet, here we are today approaching 7 billion, looking more and more like a happy little “McVirus with shoes,” [channeling Bill Hicks, Rant in E Minor].
Without the synthesis of synthetic ammonia in the early 20th century through a process developed by Fritz Haber and Carl Bosch (Germany), the population of the planet would have likely leveled off around 4 billion. Before this process was realized, the issue for agriculture had always been usable nitrogen. Nitrogen is essentially the limiting factor for plant growth. All plants need nitrogen, yet even though the atmosphere is over 75% nitrogen, plants cannot use it unless it is readily absorbable. The nitrogen in the air is N2, triple bonded, and very stable. Generally, plants cannot break this triple bond because it requires a lot of energy. Manure, urine and nitrates like saltpeter have traditionally been used as plant fertilizer, but they have been historically and relatively in short supply. All of these contain nitrogen that is accessible to plants and helps them grow. Since our bodies also need nitrogen for growth, (we have it in our cells and DNA), then we too are limited in growth by the amount of usable nitrogen. As you may have concluded, we cannot obtain usable nitrogen from breathing. It stays inert. We breathe it in, and then breathe it out as N2.
The Haber-Bosch process, scaled up before World War I by BASF under the direction of Carl Bosch, has penetrated every corner of the planet. It is estimated that the process uses 1-2% of the world’s energy each year. It is also estimated that the process currently sustains about one third of the planet’s population. The process produces ammonia (NH3), a form of nitrogen that can be used by our beloved crops as fertilizer. This fertilizer, often in the form of anhydrous ammonia or urea, is used for more than just our McCrops and feed for our McCows. Fertilizer use is ubiquitous for crop growing.
The production of ammonia involves two inputs – nitrogen and hydrogen. The nitrogen comes from the air, concentrated with an air separation unit. The hydrogen comes from natural gas, which is mostly methane. Steam methane reforming, (SMR) is the process of reacting methane with high temperature, high pressure water to produce carbon monoxide and hydrogen. The carbon monoxide is then reacted with more water at high temperatures and high pressures, called a water-gas shift reaction, to produce more hydrogen and carbon dioxide. The carbon dioxide goes into the atmosphere and causes little baby polar bears to drown in the Arctic. 3-5% of the world’s natural gas is used as feedstock for ammonia production. 90% of ammonia production uses natural gas as a hydrogen feedstock. Oil and coal are not the only fossil fuels that have permeated every nook and cranny. Natural Gas is at the party too. In essence our transportation needs, electricity needs and caloric needs every day, are directly tied to the consumption of fossil fuels.
On a lighter note, let’s rebel against fossil fuels! It’s easy, just eat tree bark, stop using electricity and walk everywhere! Oh yeah, and stop wearing clothes too.
As we all know, or at least some of us know, fossil fuels will someday be gone. Sooner, I think than many people believe. What is to be done, with the world in such a predicament? One option is to produce the hydrogen feedstock for ammonia production with electrolysis. Electrolysis produces hydrogen with electricity and water as the input. If the electricity is clean and cheap, the hydrogen is clean and competitive in the market. There is also research being done with solid state ammonia synthesis (SSAS) cells. These cells combine both the hydrogen production from water with the ammonia synthesis reaction in one cell. The production cost savings could be substantial. At some point, something along these lines will have to be done if we still want to enjoy our beloved McRibs and McNuggets.
*Disclaimer- I don’t eat or promote the eating of McDonald’s food. It’s ok if you do.