2024 AIChE Annual Meeting

Anhydrous Polybenzimidazole-Based CO2 Electrolysis Using Computational Fluid Dynamics

CO2 electrolysis has become an increasingly well studied method of using captured CO2 from the atmosphere as a source of popular chemical feedstocks.1 Additionally, it can be more time- and cost-efficient to model CO2 electrolysis using computational fluid dynamics (CFD) before applying the calculated predictions to a lab setting. Current CO2 electrolysis simulations use a NafionTM brand proton exchange membrane (PEM) and a liquid flow model2, but this research investigates using a polybenzimidazole (PBI) membrane in a gas phase model. This membrane’s ability to function in high-temperature, anhydrous environments3 makes it a promising next step in the area of CO2 electrolysis due to its possible increased efficiency. Furthermore, a gas phase simulation could allow for faster diffusion rates and less overpotential than a multiphase model4. Using Star-CCM+ as the CFD software, a geometry and meshing based on an actual, densified and 24-hour reimbibed, PBI electrolyzer cell were developed. Then, parameters from previous models3,5, the literature6, given constants, and prediction calculations were input into the simulation. The electrolyzer’s performance in terms of species concentration distribution, potential distribution, current density distribution, temperature distribution, and pressure distribution were plotted and analyzed, as well as its polarization curves. Using this data, experiment design and predictions in the lab setting can become more precise; in return, lab results can be used to create a more accurate model for CO2 electrolysis.

References:

  1. CO2 Electrolyzers. Colin P. O’Brien, Rui Kai Miao, Ali Shayesteh Zeraati, Geonhui Lee, Edward H. Sargent, and
    David Sinton Chemical Reviews 2024 124 (7), 3648-3693 DOI: 10.1021/acs.chemrev.3c00206.
  2. Lin, S., Zhao, S., Dou, H., Wei, G., Li, Y., Gao, S., Gao, J., & He, Y. (2024). Mass‐transfer mechanism of Nafion
    proton‐exchange membranes in fuel cells—a review. Energy Technology, 12(6).
    https://doi.org/10.1002/ente.202400164.
  3. Likit-anurak, K., Karki, I., Howard, B. I., Murdock, L., Mukhin, N., Brannon, J., Hepstall, A., Young, B.,
    Shimpalee, S., Benicewicz, B., & Meekins, B. (2023). Polybenzimidazole membranes as Nafion
    replacement in aqueous HCl electrolyzers. ACS Applied Energy Materials, 6(10), 5429–5434.
    https://doi.org/10.1021/acsaem.3c00522.
  4. Hou, P., Wang, X., Wang, Z., & Kang, P. (2018). Gas phase electrolysis of carbon dioxide to carbon monoxide
    using nickel nitride as the carbon enrichment catalyst. ACS Applied Materials & Interfaces,
    10(44), 38024–38031. https://doi.org/10.1021/acsami.8b11942
  5. Star-CCM+ PEM Fuel Cell tutorial.
  6. Pérez-Rodríguez, S., Barreras, F., Pastor, E., & Lázaro, M. J. (2016). Electrochemical reactors for CO 2
    reduction: From acid media to gas phase. International Journal of Hydrogen Energy, 41(43), 19756–
    19765. https://doi.org/10.1016/j.ijhydene.2016.06.130.