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 degrees 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. (C) 2015 Elsevier Ltd. All rights reserved.