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Nitrogen is an essential
element for all life on our planet. Without it, amino acids cannot be
produced in plants and animals. Although the universe is abundant in
nitrogen and the Earth's atmosphere is over 78% triple-bonded nitrogen as
N2, its availability in the soil is limited. Why can't we get it from the
air when we breath? Great question! Indeed, the triple-bonds make N2 in
the air very stable and unusable when we breath it in. The only way to
obtain it is through the earth where bacteria, manure, and synthetic
chemical processes infuse the soil with nitrogen so that it can be
utilized in plants and later consumed by animals.
Before synthetic fertilizer production, nitrogen in the soil has primarily been fixed by special bacteria - tiny microbes that have their own internal biological chemical plants that break apart the triple-bonds of the N2 molecules in the air. From here, they produce different nitrogen containing compounds like nitrates and nitrites that plants can utilize through their roots to create different proteins for structure and metabolic processes. Indeed, this is how we humans get nitrogen in our bodies: either by consuming plants with the nitrogen compounds, or from consuming animals which have eaten plants prior. Because it takes a lot of energy to breaks apart the N2 triple-bonds in the atmosphere, naturally the amount of nitrogen in the soil that can be used by plants and animals puts a natural limit on life in the biosphere. Humans are a creative species, and it wasn't long ago, in geologic terms, when humans learned the putting manure on soil after harvests, help the next generation of crops to grow. We know why now, too. When we harvest plants, the plants slowly leech out the nitrogen naturally "fixed" within the soil by bacteria. Over time, the nitrogen becomes depleted and plants can no longer grow - again, because they need nitrogen for growth. Manure, which is high in nitrogen compounds, (historically from ruminant animals, pigs, or chickens), was spread over the soil after a harvest to help replenish the lost nitrogen. Although using manure as a fertilizer for growing consistent crops has a long history, eventually people found better ways to increase crop yields. Guano, which is a concentrated petrified bird manure, was mined in the 1800s on islands in the South Pacific. Natural nitrogen containing compounds like potassium nitrate and caliche, or sodium nitrate were also mined and utilized. Caliche found in northern Chile and Bolivia became a valuable resource shipped to Europe and the United States. The War of the Pacific in the late 1800s between Chile and an alliance between Peru and Bolivia was, in part, centered around the crucial and valuable Caliche resource. The quest for a better alternative moved along in parallel with the use of different fertilizers and the War of the Pacific. Finding a way to produce a synthetic nitrogen-containing compound for agricultural use was a kind of "Holy Grail" of chemistry in the 19th and 20th centuries. Many different methods were developed to produce usable nitrogen out of the air, and some of them were successful. In the end, it was a Prussian (modern day Germany) man named Fritz Haber who developed an efficient process in a lab to produce anhydrous ammonia, or NH3, using high temperature and pressure, hydrogen, and nitrogen. He later teamed up with Carl Bosch and Alwin Mittasch at the Prussian chemical company BASF. It was here where they successfully scaled up the process and began to produce large amounts of ammonia, first at a plant in Oppau, and later at another plant in Leuna. The process would later be known as the Haber-Bosch process. The Haber-Bosch process is not very complex, even though the road to master it was difficult. The process combines hydrogen with nitrogen at high temperatures and pressures over a metal catalyst - typically iron based or ruthenium based. Because the reaction of hydrogen and nitrogen is exothermic, the waste heat can be re-used reducing the overall energy needs. Thus, the entire process can run at around 90% efficient when at the proper temperature. On the contrary, the hydrogen input into the Haber-Bosch process is much more energy intensive. Today, most of the hydrogen used to create ammonia comes from natural gas, where it is first run through a separate process called steam-methane reforming and a subsequent water-gas shift reaction. This process essentially separates out the hydrogen from the CH4 natural gas compound. Not only is this process energy intensive, but obtaining and moving the natural gas has become an increasingly more energy intensive process because of the transportation, storage, and procurement (namely natural gas fracking) involved. Currently, the Haber-Bosch process almost entirely uses natural gas for its hydrogen input. Overall, the Haber-Bosch process uses about 3 - 5% of the world's natural gas every year, and about 1 - 2% of the world's energy. These numbers highlight how reliant the Haber-Bosch process is on natural gas. The nitrogen input to the Haber-Bosch comes by way of air separation units often utilizing a method known as fractional distillation. This process is not very energy intensive and hence, it is of less concern from an improvement standpoint. Because the Haber-Bosch process is efficient and reliable, the gains from improving the process are more negligible. The improvements need to be made with the decomposition of the hydrogen from compounds. There are limitations on the thermal physics and required energy to break hydrogen molecular bonds. Even so, there is research currently underway on this front. The other opportunity is looking at the hydrogen compound supply. The majority of hydrogen used in the Haber-Bosch right now comes from natural gas. We see this as a major issue. Total natural gas supplies are not known fully and the easy-access deposits are now limited. What the US has access to now, particularly the natural gas shale deposits, require a lot of water, energy, and toxic lubricants to extract. The long-term environmental effects of this invasive extraction process are not fully known, but we aren't enthusiastic of the outcome. A better option is to procure the hydrogen from a resource we know is much more abundant and we know it does not interfere with the carbon cycle. That resource is water. Using the process of industrial electrolysis, hydrogen can be decomposed from H2O with a comparable amount of energy as steam methane reforming process used for the decomposition of CH4. Even better, we don't need to extract, transport, store, or buy the water like we would if we used natural gas. We can use the Ogallala aquifer where our ammonia production plants will be. Not only is this recourse abundant, local, and cheap, but it does not interfere with the carbon cycle like using CH4 does. To obtain the hydrogen needed for the production of ammonia, we will used electrolysis. To power the industrial electrolyzers, we will use off-grid wind and solar power. This is the next step un in the chain that is decoupled from centralization, carbon, utilities and the regulations that govern them, and the elaborate transportation chain that adds costs, logistics and waste to the ammonia industry. In short, we will start with 10 small-scale ammonia production plants, each averaging 10 ton/day of ammonia sold directly to farmers within a 200 mile radius. For those who need it, we will take care of all storage and transportation within our existing resource network. These plants will be strategically located across the Midwest to utilize the best water, solar and wind resources. They will deliver high quality, inexpensive, local ammonia for food producers and other consumers who want to be part of a better, cleaner, and more reliable ammonia system - horizon to horizon. |
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