Pilot-Scale CO2 Electrolysis Enables a Semi-empirical Electrolyzer Model

Carbon dioxide (CO2) electrolysispoweredwith renewableelectricity can help close the carbon cycle by converting emissionsinto chemicals and fuels. Two key advancements are required to bridgethe technological gaps for industrial implementation: pilot plantdemonstrations with detailed performance data; and chemical engineeringprocess models built and tested with lab- and pilot-scale data. Here,we develop a semi-empirical electrolyzer model in Aspen Custom Modelerwhich is trained on a 5 cm(2) lab-scale CO2 electrolyzer.We then scale to a pilot-scale 800 cm(2) single cell and10 x 800 cm(2) stack and use the results to validatethe model; at 100 mA cm(-2), the model can predictsix of seven cell performance metrics within 16% absolute error andthree of five stack metrics within 11% absolute error. With the combinationof the electrolyzer model and the pilot-scale data, this work providesthe prerequisites for further scaling of CO2 electrolysis.

Automated summary

Carbon dioxide electrolysispowered with renewable electricity is a promising method for converting emissions into valuable chemicals and fuels. However, there are technological gaps that need to be addressed before industrial implementation, including pilot plant demonstrations and the development of accurate process models. In this study, a semi-empirical electrolyzer model was developed and validated using lab- and pilot-scale data. The results showed that the model can accurately predict the performance metrics of the electrolyzer, providing a foundation for further scaling of CO2 electrolysis.