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

The aim of this study was to evaluate the production of H 2 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 H 2 production (P H2), H 2 production rate (R H2), and H 2 yield (Y H2) was 4160 mL/L of working volume, 760 mL/L.h, and 5154.26 mL/g glucose cons , respectively. The assay with initial pH 7.5, inoculum 30%, and 35 °C, resulted in the highest P H2 , and assay with initial pH 7.5, inoculum 30%, and 45 °C resulted in the highest R H2 and Y H2. It is observed that P H2 and R H2 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 H 2 production. [Display omitted] • The highest H 2 production obtained from the BSG hydrolysate was 4160 mL H2 /L. • The H 2 production was better than other studies found in the literature using BSG. • The initial pH was the variable with the greatest statistical influence. • Furfural and 5-HMF concentrations in BSG hydrolysate did not inhibit H 2 production. [ABSTRACT FROM AUTHOR]