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

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.