Continuous hydrogen production by dark fermentation in a foam SiC ceramic packed up-flow anaerobic sludge blanket reactor.

Biohydrogen generation using anaerobic sludge from a sewage treatment plant is a promising strategy for converting waste into renewable energy. The porous foam SiC ceramic structured packing was used as a support in the up-flow anaerobic sludge blanket (UASB) reactor to enhance the biohydrogen yield. Using glucose as the major carbon source, the SiC-UASB reactor was continuously operated under the organic loading rates (OLR) between 30 and 90 g_glucose/L · d at a hydraulic retention time (HRT) of 4 h. The maximum hydrogen production rate (5.24 L/L · d) and hydrogen content (50 %) were obtained at 60 g_glucose/L · d OLR. It demonstrated that the reaction of fermentation was predominated by the butyric acid pathway. The employment of SiC packings resulted in quick startup (∼5 days) and high efficiency of hydrogen production. The buffering capacity and the cell culture immobilization ability of the UASB reactor were obviously improved by the application of SiC packings, which increased the feasibility of scale-up of the continuous biohydrogen production system. [ABSTRACT FROM AUTHOR]