What is Plasma-assisted ammonia synthesis from flue gas?
Ammonia (NH3) is a critically important industrial chemical mainly used to manufacture fertilizers. Presently, ammonia is produced primarily via the highly energy-intensive Haber-Bosch (H-B) process, which requires extreme operating conditions of 450–600 °C and 150–300 atm and must be executed at very large scales in order to maximize efficiency. It also utilizes H2 and N2 as feedstocks, each of which must first be produced in separate energy-intensive processes. ACT has proposed a novel reaction mechanism utilizing non-thermal plasmas to produce ammonia directly from cheap, greenhouse gas feedstocks, via the following reaction:
3CH4 + 3CO2 + 30N2 → 4NH3 + 6CO +28N2.
This reaction uses natural gas (CH4) and inexpensive flue gas (CO2 + N2) to produce two valuable chemical products: ammonia (NH3), and carbon monoxide (CO). Using non-thermal plasma, the reaction can be carried out at very mild operating conditions, which would enable decentralized ammonia production. Additionally, the process can be easily turned on and off with no compression or preheating requirements, allowing operators to take advantage of low-cost electricity produced via renewable sources when it is available.
DOE Project Spotlight
Under a Department of Energy SBIR Phase I Project “Plasma-Catalysis for Ammonia Production” (Award Number DE-SC0020924), ACT seeks to develop this novel reaction such that it may be implemented in a commercial capacity, to capitalize on its unique benefits. Through the Phase I project, ACT was able to achieve promising efficiencies and product yields. Laboratory experiments conducted using feedstocks containing CH4, CO2, and N2 demonstrated product yields (by volume) are as follows:
- 2.3 vol. % yield of ammonia (NH3, extent of reaction = 7.8 %)
- 23 vol. % yield of carbon monoxide (CO)
- 24 vol. % yield of hydrogen (H2)