Producing ammonia using less energy
JAPAN: Scientists at Tokyo Institute of Technology claim to have developed a means of producing ammonia using only half the energy that existing techniques require.
Widely used in the production of fertiliser, ammonia is also one of the low GWP “natural” refrigerants vital to global efforts to reduce the environmental impact of refrigeration. Its production, however, is energy intensive and, consequently, expensive.
Ammonia is typically produced via the Haber-Bosch process which converts natural gas, LPG or petroleum naphtha into hydrogen gas. A catalyst is then employed to combine the hydrogen with nitrogen to produce ammonia. However, the process requires a high energy input (typically 450ºC) as conventional catalysts lose their effectiveness at 100-200°C. This process is said to contribute to over 3% of global CO2 emissions.
The team at the Tokyo Institute of Technology has developed an improved catalyst by taking the common dehydrating agent calcium hydride and adding fluoride to it. The catalyst is said to facilitate the synthesis of ammonia at 50°C.
At the end of last year, researchers at Rice University’s George R Brown School of Engineering in Houston claimed to have developed an inorganic method to synthesise ammonia by manipulating molybdenum disulfide.