Enhanced bio-hydrogen production by anaerobic fermentation of apple pomace with enzyme hydrolysis

A series of batch experiments were conducted to investigate the effects of the HCl-pretreated concentrations, enzyme hydrolysis time and temperature, the cellulose dosage, the ultrasonic time and the fermentation substrate concentration on hydrogen (H-2) production from the anaerobic fermentation of apple pomace (AP). The natural mixed microorganisms from river sludge was used as the seed after being boiled for 15 min. A maximum cumulative H-2 yield (CHYm) of 134.04 ml/g total solid (TS) and an average H-2 production rate (AHPR) of 12.00 ml/g TS/h were obtained from the fermentation of the enzyme-hydrolyzed AAP (a AP soaked with 6% ammonia liquor for 24 h) at the substrate concentration of 15 g/L. The optimal enzyme hydrolysis conditions were proposed as follows: AAP with a cellulase dosage of 12.5 mg/g TS at the hydrolysis substrate concentration of 20 g/L after the ultrasonic irradiation for 20 mm was hydrolyzed by the enzyme catalysis at 45 degrees C and initial pH 5.0 for 48 h. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.