Techno-Economic Assessment of Plasma-driven Air Oxidation Coupled with Electroreduction Synthesis of Ammonia

Recently, the plasma-driven air oxidation coupled with electrocatalytic NO_x reduction reaction (pAO-eNO_xRR) technology for sustained NH₃ 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_xRR 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, N₂-NO-NH₃ and N₂-NO₂^--NH₃ are presently the most effective pathways. The deep analysis of the current state-of-the-art technological performance indicates that the pAO-eNO_xRR technology is competitive with commercial processes in achieving large-scale NH₃ synthesis. However, lower energy efficiency of pAO-eNO_xRR technology leads to the high electricity costs that surpass the current market price of NH₃. Subsequently, we conducted a comprehensive analysis which reveals that, for the economic viability of NH₃ synthesis, an energy efficiency in the range of 33.8-38.6% must be attained. The expenses associated with plasma equipment, electrolyzer, catalysts, and NH₃ distillation also contribute significantly to the economic burden. The further development of pAO-eNO_xRR technology should be centered around advancements in plasma catalysts, electrocatalysts, reactors, as well as the exploration for energy-efficient cathode-anode synergistic catalytic systems.