Biohydrogen production from pretreated corn cobs

In this study, the co-fermentability of four different pretreated corn cob streams at different mixing ratios was assessed. The four streams, denoted DP, DS, HP, and HS, were: two dilute acid pretreatment comprising one purge and one squeeze and two high pressure autohydrolysis comprising one purge and one squeeze. The “Purge” stream was taken from the steam percolation reactor during cooling and the “Squeeze” stream was recovered from the cooked biomass with a pressing step. In addition, the impact of furfural and 5-hydroxymethylfurfural (HMF) on biohydrogen production potential was evaluated. The DP:DS mix at 50:50 by volume achieved the maximum H2 yield of 265 (mL/gCOD sugars consumed). Furfural at concentrations of 0.21–1.09 g/L had no impact on H2 production rates and yields and HMF was below the inhibitory threshold of 0.14 g/L. A positive correlation was observed between the monomeric-to-polymeric sugars ratio and H2 production rates and yields.