Techno-Economic Evaluation of Green NH₃ Production by Integrating Current-Assisted Reaction and Ionic Liquid Absorption

Abstract

In this work, an ammonia (NH 3 ) synthesis loop under mild conditions (595 K and 20 bar) was constructed, including a current-assisted reaction unit and a separation unit based on ionic liquid absorption. ASPEN Plus was used to simulate the NH 3 synthesis loop with a capacity of 20,000 tons per year, where the reactor was a customized model. Based on the simulation results, the techno-economic evaluation of a miniaturized green NH 3 production plant was carried out, with hydrogen from water electrolysis and nitrogen from pressure swing adsorption. The levelized cost of ammonia (LCOA) in the reaction-absorption (RXN-ABS) process was obtained to be 838.81 $ t NH3 −1 . The LCOA in the RXN-ABS process is 18.56% and 10.09% lower than the reported reaction-condensation (RXN-CON) and reaction-adsorption (RXN-ADS) processes, respectively. If the revenue from oxygen sales is taken into account, the RXN-ABS process can achieve an after-tax return of 34.72%. As the price of renewable electricity decreases to 0.024 $ kWh −1 and electricity consumption of water electrolysis decreases to 5.58 kWh kg NH3 −1 , the LCOA in the RXN-ABS process can be lower than the selling price of NH 3 . The new NH 3 synthesis loop has better economy and safety, which promotes the popularization of the distributed NH 3 production technology.