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Analysis of the mechanisms of bioelectrochemical methane production by mixed cultures
Author(s) -
van EertenJansen Mieke C. A. A.,
Jansen Nina C.,
Plugge Caroline M.,
de Wilde Vinnie,
Buisman Cees J. N.,
ter Heijne Annemiek
Publication year - 2015
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.4413
Subject(s) - methane , hydrogen production , cathode , chemistry , formate , hydrogen , electrochemistry , inorganic chemistry , electron transfer , electrode , chemical engineering , catalysis , photochemistry , organic chemistry , engineering
BACKGROUND In a methane‐producing bioelectrochemical system ( BES ) microorganisms grow on an electrode and catalyse the conversion of CO 2 and electricity into methane. Theoretically, methane can be produced bioelectrochemically from CO 2 via direct electron transfer or indirectly via hydrogen, acetate or formate. Understanding the electron transfer mechanisms could give insight into methods to steer the process towards higher rate. RESULTS In this study, the electron transfer mechanisms of bioelectrochemical methane production by mixed cultures were investigated. At a cathode potential of −0.7 V vs. normal hydrogen electrode ( NHE ), average current density was 2.9 A m −2 cathode and average methane production rate was 1.8 mole e − eq m −2 cathode per day (5.2 L CH 4 m −2 cathode per day). Methane was primarily produced indirectly via hydrogen and acetate. Methods to steer towards bioelectrochemical hydrogen and acetate production to further improve the performance of a methane‐producing BES are discussed. CONCLUSION At cathode potentials equal to or lower than −0.7 V vs. NHE and using mixed cultures, methane was primarily produced indirectly via hydrogen and acetate. (Bio)electrochemical hydrogen and acetate production rate could be increased by optimizing the cathode design and by enriching the microbial community. Consequently, the production rate of CO 2 ‐neutral methane in a BES could be increased. © 2014 Society of Chemical Industry