Techno-economic assessment of plasma-driven air oxidation coupled with electroreduction synthesis of ammonia
Lei Xiao, Shiyong Mou, Xiaoyu Lin, Keying Wu, Siyuan Liu, Weidong Dai, Weiping Yang, Chiyao Tang, Chang Long, Fan Dong
Abstract
Recently, the plasma-driven air oxidation coupled with electrocatalytic NO x reduction reaction (pAO-eNO x RR) technology for sustained NH 3 synthesis displays the promise in tackling the high energy-consumption and carbon-emission associated with the Haber-Bosch process. Here, a technical and economic assessment of pAO-eNO x RR technology is comprehensively undertaken to determine its feasibility as a potential substitute for the Haber-Bosch process. The technical assessment suggests that, in terms of both environmental impact and energy efficiency, N 2 -NO-NH 3 and N 2 -NO 2 − -NH 3 are presently the most effective pathways. The deep analysis of the current state-of-the-art technological performance indicates that the pAO-eNO x RR technology is competitive with commercial processes in achieving large-scale NH 3 synthesis. However, lower energy efficiency of pAO-eNO x RR technology leads to high electricity costs that surpass the current market price of NH 3 . Subsequently, we conducted a comprehensive analysis which reveals that, for the economic viability of NH 3 synthesis, an energy efficiency in the range of 33.8–38.6% must be attained. The expenses associated with plasma equipment, electrolyzer, catalysts, and NH 3 distillation also contribute significantly to the economic burden. The further development of pAO-eNO x RR technology should be centered around advancements in plasma catalysts, electrocatalysts, reactors, as well as the exploration for energy-efficient cathode-anode synergistic catalytic systems. Schematic diagram of plasma-driven air oxidation coupled with electrocatalytic NO x reduction reaction technology for sustained NH 3 synthesis. • The pAO-eNO x RR technology displays the promise for sustained NH 3 synthesis. • The pAO-eNO x RR technology is competitive with commercial processes in achieving large-scale NH 3 synthesis. • The following objective is to decrease the energy consumption in the pAO-NO x RR to 1.5 MJ mol N −1 . • Progresses in plasma catalysts, electrocatalysts, reactors, and cathode-anode systems will promote the pAO-eNO x RR technology.