title: Influence of the gas-liquid flow configuration in the absorption column on photosynthetic biogas upgrading in algal-bacterial photobioreactors.
abstract: The potential of an algal-bacterial system consisting of a high rate algal pond (HRAP) interconnected to an absorption column (AC) via recirculation of the cultivation broth for the upgrading of biogas and digestate was investigated. The influence of the gas-liquid flow configuration in the AC on the photosynthetic biogas upgrading process was assessed. AC operation in a co-current configuration enabled to maintain a biomass productivity of 15gm-2d-1, while during counter-current operation biomass productivity decreased to 8.7±0.5gm-2d-1as a result of trace metal limitation. A bio-methane composition complying with most international regulatory limits for injection into natural gas grids was obtained regardless of the gas-liquid flow configuration. Furthermore, the influence of the recycling liquid to biogas flowrate (L/G) ratio on bio-methane quality was assessed under both operational configurations obtaining the best composition at an L/G ratio of 0.5 and co-current flow operation.
authors.affiliation: Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n., Valladolid 47011, Spain.
authors.forename: Alma
authors.initials: A
authors.lastname: Toledo-Cervantes
authors.affiliation: Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n., Valladolid 47011, Spain.
authors.forename: Cindy
authors.initials: C
authors.lastname: Madrid-Chirinos
authors.affiliation: Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n., Valladolid 47011, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Cantera
authors.affiliation: Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n., Valladolid 47011, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Lebrero
authors.affiliation: Department of Chemical Engineering and Environmental Technology, University of Valladolid, Dr. Mergelina s/n., Valladolid 47011, Spain. Electronic address: mutora@iq.uva.es.
authors.forename: Raúl
authors.initials: R
authors.lastname: Muñoz
mesh_terms: D056804:Biofuels; D018533:Biomass; D001709:Biotechnology / Q000295:instrumentation* / Q000379:methods; D002708:Chlorella / Q000502:physiology; D000460:Chlorophyta / Q000502:physiology; D004867:Equipment Design; D008697:Methane / Q000096:biosynthesis*; D058433:Photobioreactors / Q000382:microbiology; D010788:Photosynthesis; D061005:Ponds
chemical_list: D056804:Biofuels; D008697:Methane
keywords: Algal-bacterial photobioreactor; Bio-methane; Biogas upgrading; Digestate; Nutrients recovery