title: Feasibility of hydrogen production from ripened fruits by a combined two-stage (dark/dark) fermentation system.
abstract: Anaerobic fermentation for hydrogen (H2) production was studied in a two-stage fermentation system fed with different ripened fruit feedstocks (apple, pear, and grape). Among the feedstocks, ripened apple was the most efficient substrate for cumulative H2 production (4463.7 mL-H2 L(-1)-culture) with a maximum H2 yield (2.2 mol H2 mol(-1) glucose) in the first stage at a hydraulic retention time (HRT) of 18 h. The additional cumulative biohydrogen (3337.4 mL-H2 L(-1)-culture) was produced in the second stage with the reused residual substrate from the first stage. The major byproducts in this study were butyrate, acetate, and ethanol, and butyrate was dominant among them in all test runs. During the two-stage system, the energy efficiency (H(2) conversion) obtained from mixed ripened fruits (RF) increased from 4.6% (in the first stage) to 15.5% (in the second stage), which indicated the energy efficiency can be improved by combined hydrogen production process. The RF could be used as substrates for biohydrogen fermentation in a two-stage (dark/dark) fermentation system.
authors.affiliation: Department of Environmental Engineering, Yonsei University, Wonju, Gangwon-Do 220-710, South Korea.
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Hwang
authors.forename: Jeong-A
authors.initials: JA
authors.lastname: Choi
authors.forename: Reda A I
authors.initials: RA
authors.lastname: Abou-Shanab
authors.forename: Booki
authors.initials: B
authors.lastname: Min
authors.forename: Hocheol
authors.initials: H
authors.lastname: Song
authors.forename: Yongje
authors.initials: Y
authors.lastname: Kim
authors.forename: Eung Seok
authors.initials: ES
authors.lastname: Lee
authors.forename: Byong-Hun
authors.initials: BH
authors.lastname: Jeon
mesh_terms: D001709:Biotechnology / Q000379:methods*; D050260:Carbohydrate Metabolism; D003624:Darkness; D004736:Energy-Generating Resources; D000431:Ethanol / Q000032:analysis; D005232:Fatty Acids, Volatile / Q000032:analysis; D005240:Feasibility Studies; D005285:Fermentation; D005638:Fruit / Q000737:chemistry* / Q000254:growth & development*; D006859:Hydrogen / Q000032:analysis*; D012722:Sewage / Q000737:chemistry; D013997:Time Factors; D014866:Waste Products / Q000032:analysis
chemical_list: D005232:Fatty Acids, Volatile; D012722:Sewage; D014866:Waste Products; D000431:Ethanol; D006859:Hydrogen