A kinetics-mass transport model for CO2 electroreduction reactor to investigate performance limitation factors

Abstract

Modeling of CO2 electroreduction reactor (CO2ECR) is highly demanded for rapid design of industrial processes, while facing challenges in practical applications. Herein, a kinetics-mass transport model is proposed, which can well balance the competition between HCOO– produce and H2 evolution, and be easily integrated into Aspen HYSYS as a user defined module for CO2ECR process design. By considering both cathode potential and CO2 concentration in flow channel, optimal regions of the key parameters can be simulated to achieve high efficiency of CO2 electroreduction, i.e., about 80 % for both HCOO– Faraday efficiency and CO2 conversion with slightly compressed pure CO2 feedstock of 300 kPa. By increasing anode flow rates, the lean streams with H2 concentration of around 50% achieve nearly the maximum H2 utilization, which is attractive due to the possible reduction of purification cost.