University of Illinois Chicago engineers have devised a method for producing ammonia, termed lithium-mediated ammonia synthesis, that meets sustainability targets. Unlike traditional methods involving high temperatures and pressures, this process involves nitrogen gas combining with lithium and hydrogen atoms in a regenerative and low-temperature reaction, according to an April 1 press release. By efficiently orchestrating this reaction, the team, led by Meenesh Singh, achieves high energy efficiency and cost-effectiveness, aiming to produce ammonia at $450 per ton, 60% cheaper than previous methods.
"There are two loops that happen. One is regeneration of the hydrogen source and second is the regeneration of the lithium," said Singh, associate professor of chemical engineering at UIC, in the press release. "There is a symphony in this reaction due to the cyclic process. What we did was understand this symphony in a better way and try to modulate it in a very efficient way, so that we can create a resonance and make it move faster."
The process demonstrates high selectivity, minimizing the unwanted production of hydrogen gas. These advancements could meet Department of Energy standards for large-scale ammonia production. Additionally, the process could contribute to hydrogen fuel goals by offering a safe and economical means of hydrogen transport through ammonia.
"You want hydrogen to be generated, transported and delivered to hydrogen pumping stations, where hydrogen can be fed to the cars. But it's very dangerous," Singh said. "Ammonia could function as a carrier of hydrogen. It's very cheap and safe to transport, and at the destination, you can convert ammonia back to hydrogen."
Currently, the scientists are partnering with the General Ammonia Co. to pilot and scale up their lithium-mediated ammonia synthesis process at a plant in the Chicago area. UIC's Office of Technology Management has filed a patent for the process.