Bio-hydrogen and biomass-supported palladium catalyst for energy production and waste-minimisation

Abstract

The project objective was to advance the development of the H2 economy by improving biological H2 production in a sustainable way. Pseudo-continuous H2 production was achieved with improved efficiency, via the bacterial fermentation of sugars in a dual-bioreactor (‘upstream system’) comprising a dark fermentation coupled to a photofermentation. Excess biomass from the upstream system was used to recover palladium from solution, producing ‘palladised biomass’ (Bio-Pd(0)), which was useful in the construction of bioinorganic catalytic anodes for the electricity generation from bio-H2 using a polymer electrolyte membrane fuel cell (‘downstream system’). Furthermore, the catalytic usefulness of Bio-Pd(0) was confirmed in several reactions in comparison with other palladised biomasses and with Pd(0) made chemically.

The upstream modules: Escherichia coli dark fermentation and Rhodobacter sphaeroides photofermentation, were investigated and developed separately, before coupling the two stages by the novel application of electrodialysis (accelerated membrane separation). The biorecovery and testing of palladium bionanocatalyst are described, before the production of fuel cell catalyst using waste biomass. The technical challenges and potential benefits of biohydrogen production are discussed and contrasted with those of competing biofuel technologies.