Stoichiometry evaluation of biohydrogen production from various carbohydrates

In this paper, biochemical hydrogen potential (BHP) tests were conducted to investigate H₂ production from different substrate with acid-treated anaerobic digested sludge at the mesophilic range. The sludge was collected from an anaerobic digester and was subjected to sulfuric acid pretreatments at pH 3 for 24 h. The effects of substrate type (glucose, fructose, and sucrose as carbon source) were investigated in batch experiments. Results showed that substrate degradation rate for all of the substrates was up 95 % and the electron equivalent balance showed good closure for glucose and sucrose. Batch experiments showed that the maximum molar hydrogen yield with glucose, fructose, and sucrose was 3.27, 3.16, and 6.46 mol H₂/mol of substrate. The maximum cumulative biohydrogen production was 1552, 1487, and 1366 mL and maximum hydrogen production rate was 308, 279, and 275 mL/h for glucose, sucrose, and fructose, respectively. The experimental results suggest that the formation of hydrogen associates with the main aqueous products, i.e., acetate butyrate.