title: The type of ion selective membrane determines stability and production levels of microbial electrosynthesis.
abstract: Microbial electrosynthesis (MES) can enable electricity-driven bioproduction from CO2. Several membrane types such as anion exchange, cation exchange, and bipolar membranes (AEM/CEM/BPM) can be used to separate the anodic oxidation from the biocathodic reduction. The impact of the membrane type on MES has not yet been studied. Therefore we compared the three membranes for MES of acetic acid. The reactor with AEM enabled in situ recovery of acetic acid. This extraction led to a 32% higher production rate and efficiency compared to the systems that did not include product recovery, as product inhibition was likely occurring. Besides H+/OH-, mainly HCO3-contributed to charge balancing. Due to water displacement across the membrane, the product concentration in the AEM reactor (9g/L) did not exceed the concentration in the CEM reactor (10.5g/L). Overall this comparison shows that the membrane type in MES can be critical towards a stable and efficient process.
authors.affiliation: Center for Microbial Ecology & Technology (CMET), Ghent University, Coupure Links 653, B-9000 Gent, Belgium.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Gildemyn
authors.affiliation: Center for Microbial Ecology & Technology (CMET), Ghent University, Coupure Links 653, B-9000 Gent, Belgium.
authors.forename: Kristof
authors.initials: K
authors.lastname: Verbeeck
authors.affiliation: Center for Microbial Ecology & Technology (CMET), Ghent University, Coupure Links 653, B-9000 Gent, Belgium.
authors.forename: Robbe
authors.initials: R
authors.lastname: Jansen
authors.affiliation: Center for Microbial Ecology & Technology (CMET), Ghent University, Coupure Links 653, B-9000 Gent, Belgium. Electronic address: Korneel.Rabaey@UGent.be.
authors.forename: Korneel
authors.initials: K
authors.lastname: Rabaey
mesh_terms: D000085:Acetates / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D001639:Bicarbonates / Q000032:analysis; D001674:Bioelectric Energy Sources / Q000382:microbiology*; D019149:Bioreactors; D004553:Electric Conductivity; D004560:Electricity; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008567:Membranes, Artificial; D010084:Oxidation-Reduction
chemical_list: D000085:Acetates; D001639:Bicarbonates; D007477:Ions; D008567:Membranes, Artificial
keywords: Biocathode; Bioproduction; Carbon dioxide; Ion exchange membrane; Microbial electrocatalysis