Biohydrogen production from autoclaved fruit and vegetable wastes by dry fermentation under thermophilic condition

Dark fermentative hydrogen production from organic waste is an attractive technique that simultaneously treats waste along with generation of renewable fuel. In this study, a relative new technology named dark dry fermentation was tested in a 55-L reactor to treat fruit and vegetable waste (FVW) along with simultaneous generation of biohydrogen. To understand the effect of autoclaving as a pretreatment method on FVW for subsequent biohydrogen production, two independent experiments were performed; one with autoclaved waste (experiment I) and another by using non autoclaved waste (experiment II). From the analyses, it was found that maximum hydrogen % obtained for experiment I was 41% (v/v%) whereas, for experiment II was 21%. In terms of total hydrogen produced, around 30% higher production was observed with experiment I compared to experiment II. The hydrogen yields for experiment I and experiment II were respectively, 27.19 and 20.81 NmL H2/gVS (VS = volatile solid added), and the metabolites (VFAs) preferentially produced were acetic acid and iso-butyric acid.