title: Improvement of hydrogen production via ethanol-type fermentation in an anaerobic down-flow structured bed reactor.
abstract: Although a novel anaerobic down-flow structured bed reactor has shown feasibility and stable performance for a long-term compared to other anaerobic fixed bed systems for continuous hydrogen production, the volumetric rates and yields have so far been too low. In order to improve the performance, an operation strategy was applied by organic loading rate (OLR) variation (12-96 g COD L(-1) d(-1)). Different volumetric hydrogen rates, and yields at the same OLR indicated that the system was mainly driven by the specific organic load (SOL). When SOL was kept between 3.8 and 6.2 g sucrose g(-1) VSS d(-1), the volumetric rates raised from 0.1 to 8.9 L H2 L(-1) d(-1), and the yields were stable around 2.0 mol H2 mol(-1) converted sucrose. Furthermore, hydrogen was produced mainly via ethanol-type fermentation, reaching a total energy conversion rate of 23.40 kJ h(-1) L(-1) based on both hydrogen and ethanol production.
authors.affiliation: Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium; Laboratory of Biological Processes, Center for Research, Development and Innovation in Environmental Engineering, São Carlos School of Engineering, University of São Paulo, João Dagnone Ave. 1100, Santa Angelina, 13563-120 São Carlos, São Paulo, Brazil. Electronic address: pilaranzola@gmail.com.
authors.forename: Mélida del Pilar
authors.initials: Mdel P
authors.lastname: Anzola-Rojas
authors.affiliation: Laboratory of Biological Processes, Center for Research, Development and Innovation in Environmental Engineering, São Carlos School of Engineering, University of São Paulo, João Dagnone Ave. 1100, Santa Angelina, 13563-120 São Carlos, São Paulo, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Zaiat
authors.affiliation: Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium.
authors.forename: Heleen
authors.initials: H
authors.lastname: De Wever
mesh_terms: D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism*; D056804:Biofuels; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D001709:Biotechnology / Q000379:methods*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D006859:Hydrogen / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D012212:Rheology; D012995:Solubility; D013395:Sucrose / Q000378:metabolism; D013997:Time Factors
chemical_list: D056804:Biofuels; D000431:Ethanol; D013395:Sucrose; D006859:Hydrogen
keywords: Biohydrogen; Fixed-bed anaerobic reactor; Soluble fermentation products; Specific organic load; Substrate concentration