Principle and perspectives of hydrogen production through biocatalyzed electrolysis

Biocatalyzed electrolysis is a novel biological hydrogen production process with the potential to efficiently convert a wide range of dissolved organic materials in wastewaters. Even substrates formerly regarded to be unsuitable for hydrogen production due to the endothermic nature of the involved conversion reactions can be converted with this technology. Biocatalyzed electrolysis achieves this by utilizing electrochemically active micro-organisms that are capable of generating electrical current from the oxidation of organic matter. When this biological anode is coupled to a proton reducing cathode by means of a power supply, hydrogen is generated. In the biocatalyzed electrolysis experiments presented in this article acetate is used as a model compound. In theory, biocatalyzed electrolysis of acetate requires applied voltages that can be as low as 0.14V, while hydrogen production by means of conventional water electrolysis, in practice, requires applied voltages well above 1.6V. At an applied voltage of 0.5V the biocatalyzed electrolysis setup used in this study, produces approximately 0.02m3 H2/m3 reactor liquid volume/day from acetate at an overall efficiency of 53±3.5