Effect of alkaline pretreatment on photo-fermentative hydrogen production from giant reed: Comparison of NaOH and Ca(OH).

Giant reed was the first time used for photo-fermentative hydrogen production with HAU-M1 bacteria. Effects of NaOH and Ca(OH) pretreatments of giant reed on structural changes, enzymatic digestibility, hydrogen production, and energy conversion efficiency were evaluated. Compared to Ca(OH) pretreatment, NaOH pretreatment removed more dry matter and lignin at the same loading. The highest glucose yield (44.9%) of NaOH pretreatment was 1.74-fold higher than that of Ca(OH) pretreatment. 20% NaOH pretreated giant reed biomass achieved the highest hydrogen yield (98.3 mL/g TS), which was 20% and 70% higher than the highest level of Ca(OH) pretreated (20% Ca(OH)) and untreated giant reed, respectively. Only giant reed biomass pretreated with 20% NaOH resulted in a significant (p < 0.05) increase (25%) in energy conversion efficiency.