Enhanced hydrogen production from cornstalk by dark- and photo-fermentation with diluted alkali-cellulase two-step hydrolysis

• DOI: 10.1016/j.ijhydene.2015.07.062
• Publication Date: 2015-08-01T07:16:33Z
• Authors: Honghui Yang; Bofang Shi; Hongyu Ma; Liejin Guo
• Keywords: Enzymatic Hydrolysis; Reducing sugar

Abstract The effect of a two-step cornstalk pretreating process, NaOH delignification followed by enzymolysis with cellulase and hemicellase, on dark- and photo-fermentative H 2 production was studied. A five-factor and five-level orthogonal experimental array was designed and conducted to study the effect of NaOH concentration (0–1%), hydrolysis time (0–3 h), hydrolysis temperature (98–126 °C), cellulase (0–18 IU/g-cornstalk) and hemicellulase dosage (0–2400 IU/g-cornstalk) on pretreatment efficiency determined by H 2 production. With NaOH 0.75%, hydrolysis temperature 108 °C, hydrolysis time 0.5 h, cellulase dosage 12 IU/g-CS and hemicellulase 2400 IU/g-CS, a maximum reducing sugar yield of 0.56 ± 0.03 g/g-CS and maximum H 2 yield of 163.1 mL-H 2 /g-cornstalk were obtained under dark-fermentation, and a maximum H 2 yield of 339.5 mL-H 2 /g-cornstalk was obtained under photo-fermentation. According to the results, the significance of the five parameters on H 2 production was listed in high-to-low order as: NaOH concentration, cellulase dosage, hydrolysis temperature, hemicellulase and hydrolysis time. The effect of the alkaline delignification on pretreatment efficiency and the future efforts on improving H 2 production from agricultural wastes were also discussed.