EGSB REACTOR PERFORMANCE ON HYDROGEN PRODUCTION FROM SUGARCANE JUICE

The present study evaluated the effect of hydraulic retention time (HRT) (24 to 1 h) on hydrogen production from a mixed culture in mesophilic expanded granular sludge bed reactors (ESGB) (30 ± 1 °C) using sugarcane juice in concentrations of 5, 10 and 15 g L-1 in EGSB-5, EGSB-10 and EGSB-15, respectively. Maximum hydrogen production rates (HPR) were observed by decreasing the HRT to: 1 h in EGSB5 (290 mL h-1 L-1); 1 h at EGSB10 (798 mL h-1 L-1); and 2 h in EGSB15 (2183 mL h-1 L-1). Results indicate that EGSB, a high rate reactor, can be operated under high organic loading rates (OLR), since maximum hydrogen yield (HY) was observed in EGSB15 for the highest OLR applied (1.46 mol H2 mol-1 sucrose in OLR 182.9 kg sucrose m-3 day-1). Possible H2 consumption was observed because of homoacetogenesis, with maximum acetic acid of 59.0%, 50.0% and 25.0% for EGSB5, EGSB10 and EGSB15, respectively. Overall, the decrease in HRT from 24 to 1 h improved HPR, indicating that the sugarcane juice can be a feasible alternative for H2 production on full scale.