Temperature and pH are key factors that have significant effects on the anaerobic fermentation process. Hence, in this study, a combined bio-hydrogen and bio-methane production process over a range of initial pH and temperature was evaluated. Corn stover was taken as substrate, bio-hydrogen and bio-methane yield, biogas composition and energy conversion efficiency were analyzed. Results showed that the highest hydrogen yield of 69.02 +/- 1.75 mL/g VS was obtained with fermentation conditions at initial pH 8 and 35 degrees C, and the highest methane yield of 249.36 +/- 9.81 mL/g VS was obtained from the photofermentation effluent at initial pH 6 and 30 degrees C. Highest hydrogen and methane contents in the produced biogas were 14.42% and 46.46%, respectively. Furthermore, the highest energy conversion efficiency of 48.83% was obtained with fermentation condition at pH 6 and 30 degrees C. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.