A comparison study between liquid- and vapor-fed anode zero-gap bioelectrolysis cells

Improving microbial electrosynthesis could be one solution for transitioning towards sustainable chemical production, offering a pathway to convert CO ₂ into valuable commodities from renewable energy sources. Therefore, we examined the performance differences between liquid- and vapor-fed anode zero-gap bioelectrochemical cells for electromethanogenesis, utilizing a membrane electrode assembly to enhance mass and ohmic transport. Focusing on CH ₄ and H ₂ production, we compared two ion-exchange membranes with the liquid-fed anode system and selected the best performing ion-exchange membrane for the vapor-fed anode system. Liquid-fed anode systems did not show significant differences in volumetric CH₄ production rates compared to vapor-fed anode systems, although the latter demonstrated advantages in reducing electrocatalyst degradation and maintaining stable cell voltages. The research underscores the need for further optimization to address performance losses and suggests potential for industrial applications of microbial electrosynthesis, highlighting the importance of catalyst protection.