title: Biohydrogen production from microalgal biomass: energy requirement, CO2 emissions and scale-up scenarios.
abstract: This paper presents a life cycle inventory of biohydrogen production by Clostridium butyricum through the fermentation of the whole Scenedesmus obliquus biomass. The main purpose of this work was to determine the energy consumption and CO2 emissions during the production of hydrogen. This was accomplished through the fermentation of the microalgal biomass cultivated in an outdoor raceway pond and the preparation of the inoculum and culture media. The scale-up scenarios are discussed aiming for a potential application to a fuel cell hybrid taxi fleet. The H2 yield obtained was 7.3 g H2/kg of S. obliquus dried biomass. The results show that the production of biohydrogen required 71-100 MJ/MJ(H2) and emitted about 5-6 kg CO2/MJ(H2). Other studies and production technologies were taken into account to discuss an eventual process scale-up. Increased production rates of microalgal biomass and biohydrogen are necessary for bioH2 to become competitive with conventional production pathways.
authors.affiliation: IDMEC, Instituto Superior Técnico, Technical University of Lisbon, Lisbon, Portugal. filipa.ferreira@ist.utl.pt
authors.forename: Ana F
authors.initials: AF
authors.lastname: Ferreira
authors.forename: Joana
authors.initials: J
authors.lastname: Ortigueira
authors.forename: Luís
authors.initials: L
authors.lastname: Alves
authors.forename: Luísa
authors.initials: L
authors.lastname: Gouveia
authors.forename: Patrícia
authors.initials: P
authors.lastname: Moura
authors.forename: Carla
authors.initials: C
authors.lastname: Silva
mesh_terms: D056804:Biofuels / Q000032:analysis*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D002245:Carbon Dioxide / Q000032:analysis*; D005285:Fermentation; D006859:Hydrogen / Q000378:metabolism*; D058086:Microalgae / Q000378:metabolism*; D013816:Thermodynamics
chemical_list: D056804:Biofuels; D002245:Carbon Dioxide; D006859:Hydrogen
keywords: Biohydrogen; CO(2) emissions; Energy consumption; Scale-up scenarios; Scenedesmus obliquus