title: Simultaneous coproduction of hydrogen and ethanol in anaerobic packed-bed reactors.
abstract: This study evaluated the use of an anaerobic packed-bed reactor for hydrogen production at different hydraulic retention times (HRT) (1-8 h). Two reactors filled with expanded clay and fed with glucose (3136-3875 mg L(-1)) were operated at different total upflow velocities: 0.30 cm s(-1) (R030) and 0.60 cm s(-1) (R060). The effluent pH of the reactors was maintained between 4 and 5 by adding NaHCO3 and HCl solutions. It was observed a maximum hydrogen production rate of 0.92 L H2 h(-1) L(-1) in R030 at HRT of 1 h. Furthermore, the highest hydrogen yield of 2.39 mol H2 mol(-1) glucose was obtained in R060. No clear trend was observed by doubling the upflow velocities at this experiment. High ethanol production was also observed, indicating that the ethanol-pathway prevailed throughout the experiment.
authors.affiliation: Department of Chemical Engineering, Federal University of São Carlos, Washington Luis Road, km 235, 13565-905 São Carlos, SP, Brazil.
authors.forename: Cristiane Marques
authors.initials: CM
authors.lastname: dos Reis
authors.affiliation: Department of Chemical Engineering, Federal University of São Carlos, Washington Luis Road, km 235, 13565-905 São Carlos, SP, Brazil.
authors.forename: Edson Luiz
authors.initials: EL
authors.lastname: Silva
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D000693:Anaerobiosis; D019149:Bioreactors; D000077215:Clay; D000431:Ethanol / Q000138:chemical synthesis*; D005285:Fermentation; D005947:Glucose / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D062065:Wastewater / Q000737:chemistry
chemical_list: D000538:Aluminum Silicates; D000077215:Clay; D000431:Ethanol; D005947:Glucose; D006859:Hydrogen; D062065:Wastewater