title: Low temperature calcium hydroxide treatment enhances anaerobic methane production from (extruded) biomass.
abstract: Ca(OH)2 treatment was applied to enhance methane yield. Different alkali concentration, incubation temperature and duration were evaluated for their effect on methane production and COD conversion efficiency from (non-)extruded biomass during mesophilic anaerobic digestion at lab-scale. An optimum Ca(OH)2 pretreatment for grass is found at 7.5% lime loading at 10°C for 20h (37.3% surplus), while mild (50°C) and high temperatures perform sub-optimal. Ca(OH)2 post-treatment after fast extrusion gives an additional surplus compared to extruded material of 15.2% (grass), 11.2% (maize straw) and 8.2% (sprout stem) regarding methane production. COD conversion improves accordingly, with additional improvements of 10.3% (grass), 9.0% (maize straw) and 6.8% (sprout stem) by Ca(OH)2 post-treatment. Therefore, Ca(OH)2 pretreatment and post-treatment at low temperature generate an additional effect regarding methane production and COD conversion efficiency. Fast extrusion gives a higher energy efficiency ratio compared to slow extrusion.
authors.affiliation: Ghent University Campus Kortrijk, Department of Industrial Biological Science, Graaf K. de Goedelaan 5, 8500 Kortrijk, Belgium; Ghent University, Department of Biochemical and Microbial Technology, Laboratory of Microbial Ecology and Technology (LabMET), Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Way Cern
authors.initials: WC
authors.lastname: Khor
authors.affiliation: Ghent University, Department of Biochemical and Microbial Technology, Laboratory of Microbial Ecology and Technology (LabMET), Coupure Links 653, 9000 Gent, Belgium.
authors.forename: Korneel
authors.initials: K
authors.lastname: Rabaey
authors.affiliation: Ghent University Campus Kortrijk, Department of Industrial Biological Science, Graaf K. de Goedelaan 5, 8500 Kortrijk, Belgium. Electronic address: Han.Vervaeren@UGent.be.
authors.forename: Han
authors.initials: H
authors.lastname: Vervaeren
mesh_terms: D000693:Anaerobiosis; D056804:Biofuels; D018533:Biomass; D001709:Biotechnology; D002126:Calcium Hydroxide / Q000737:chemistry*; D007700:Kinetics; D008697:Methane / Q000737:chemistry / Q000378:metabolism*; D006109:Poaceae / Q000737:chemistry / Q000378:metabolism; D013696:Temperature
chemical_list: D056804:Biofuels; D008697:Methane; D002126:Calcium Hydroxide
keywords: Anaerobic digestion; Calcium hydroxide; Energetic assessment; Extrusion; Pretreatment