Thermophilic bio-hydrogen production from corn-bran residue pretreated by calcined-lime mud from papermaking process

•Corn-bran residue (CBR) is an attractive, low-cost feedstock for H2 production.•CLMP pretreatment favored the H2 evolution from CBR.•CLMP disintegrated and gelatinized the crystalline construct of CBR.•Maximum H2 yield of 338.91 ml/g-VS was obtained after CLMP (10 g/L) treatment.•CLMP pretreatment is an alternative approach to improve cellulosic H2 production.

This study investigated the use of calcined-lime mud from papermaking process (CLMP) pretreatment to improve fermentative hydrogen yields from corn-bran residue (CBR). CBR samples were pretreated with different concentrations (0–15 g/L) of CLMP at 55 °C for 48 h, prior to the thermophilic fermentation with heat-treated anaerobic sludge inoculum. The maximum hydrogen yield (MHY) of 338.91 ml/g-VS was produced from the CBR pretreated with 10 g/L CLMP, with the corresponding lag-phase time of 8.24 h. Hydrogen yield increments increased from 27.76% to 48.07%, compared to the control. The CLMP hydrolyzed more cellulose, which provided adequate substrates for hydrogen production.