Hydrogen production from Brewer's spent grain hydrolysate by dark fermentation

Abstract

The aim of this study was to evaluate the production of H2 by dark fermentation of brewer's spent grain (BSG) hydrolysate. The process was evaluated under different conditions of temperature, initial pH, and inoculum ratio. The maximum cumulative H2 production (PH2), H2 production rate (RH2), and H2 yield (YH2) was 4160 mL/L of working volume, 760 mL/L.h, and 5154.26 mL/gglucose cons, respectively. The assay with initial pH 7.5, inoculum 30%, and 35 °C, resulted in the highest PH2, and assay with initial pH 7.5, inoculum 30%, and 45 °C resulted in the highest RH2 and YH2. It is observed that PH2 and RH2 were statistically influenced by the initial pH, showing the negative effect of low pH. The initial concentration of furfural (<0.0047 g/L) and 5-(hydroxymethyl)furfural (<0.0220 g/L) were low. Therefore, BSG hydrolysate would be a suitable substrate for dark fermentative H2 production.