Techno-economic Analysis and Carbon Footprint Accounting for Industrial CO<sub>2</sub> Electrolysis Systems
Tianqi Gao, Baokai Xia, Kang Yang, Di Li, Tianye Shao, Sheng Chen, Qiang Li, Jingjing Duan
Abstract
Currently, CO 2 electrolysis technologies are widely investigated in the laboratory, while pilot-scale applications are absence. To promote its industrialization, herein, we establish a complete workflow of the CO 2 electrolysis system and carry out a techno-economic analysis (TEA) of four main products: formic acid, carbon monoxide, ethanol, and ethylene. In the current scenario, the levelized cost of formic acid and carbon monoxide is $0.468/kg and $0.449/kg, respectively, which rivals conventional methods (formic acid, $0.683/kg; carbon monoxide, $0.6/kg), while that of ethanol and ethylene is not yet competitive. To improve the economic feasibility of multicarbon products, improved faradaic efficiency of the solo product and reduced cell voltage and electricity prices should be achieved. In particular, the production process of the most economically efficient product formic acid has been optimized using heat-pump-assisted pressure swing distillation (HPA-PSD) to reduce its separation energy consumption. Significantly, on the basis of carbon footprint accounting, a carbon-negative effect could be achieved by coupling the formic acid production from CO 2 electrolysis with concentrating solar power.