(435a) Boosting Ammonia Synthesis in NH3-Sieving Inorganic Membrane Reactor
Ammonia is one of the most important and widely produced chemicals worldwide, and a primary ingredient for fertilizer and hydrogen carrier for energy supplying. Currently, owing to the kinetic and thermodynamic restrictions of ammonia synthesis reaction, most of ammonia is produced under conditions of temperature up to 400-500 oC and pressure up to 100-200 bar (Haber-Bosch process), resulting to intensive energy input and accounting for 3% of global energy consumption annually. Although numerous NH3 synthesis catalysts with high activity has been developed recently, but the yield of NH3 is still low. Membrane reactor which can timely and exclusively remove trace amount of NH3 in abundant H2/N2 gas mixture at high temperature and pressure will overcome the thermodynamic restriction and achieve higher NH3 yield, thus, making ammonia synthesis less energy intensive and more affordable. But, it is very difficult to find such a membrane material due to the harsh conditions and small size difference between H2 (0.289 nm) and NH3 (0.26 nm). In this study, we successfully introduce a new type of inorganic membrane which shows NH3-selective/sieving effect. After investigating the NH3/H2/N2 separation performance in detail, NH3 synthesis within membrane reactor was also performed.