title: Coal-packed methane biofilter for mitigation of green house gas emissions from coal mine ventilation air.
abstract: Methane emitted by coal mine ventilation air (MVA) is a significant greenhouse gas. A mitigation strategy is the oxidation of methane to carbon dioxide, which is approximately twenty-one times less effective at global warming than methane on a mass-basis. The low non-combustible methane concentrations at high MVA flow rates call for a catalytic strategy of oxidation. A laboratory-scale coal-packed biofilter was designed and partially removed methane from humidified air at flow rates between 0.2 and 2.4 L min-1 at 30°C with nutrient solution added every three days. Methane oxidation was catalysed by a complex community of naturally-occurring microorganisms, with the most abundant member being identified by 16S rRNA gene sequence as belonging to the methanotrophic genus Methylocystis. Additional inoculation with a laboratory-grown culture of Methylosinus sporium, as investigated in a parallel run, only enhanced methane consumption during the initial 12 weeks. The greatest level of methane removal of 27.2±0.66 g methane m-3 empty bed h-1 was attained for the non-inoculated system, which was equivalent to removing 19.7±2.9% methane from an inlet concentration of 1% v/v at an inlet gas flow rate of 1.6 L min-1 (2.4 min empty bed residence time). These results show that low-cost coal packing holds promising potential as a suitable growth surface and contains methanotrophic microorganisms for the catalytic oxidative removal of methane.
authors.affiliation: School of Chemical Engineering, The University of New South Wales, Sydney, Australia.
authors.forename: Hendy
authors.initials: H
authors.lastname: Limbri
authors.affiliation: School of Chemical Engineering, The University of New South Wales, Sydney, Australia.
authors.forename: Cindy
authors.initials: C
authors.lastname: Gunawan
authors.affiliation: School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia; Centre for Marine Bio-Innovation, The University of New South Wales, Sydney, Australia.
authors.forename: Torsten
authors.initials: T
authors.lastname: Thomas
authors.affiliation: School of Chemical Engineering, The University of New South Wales, Sydney, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Smith
authors.affiliation: School of Chemical Engineering, The University of New South Wales, Sydney, Australia.
authors.forename: Jason
authors.initials: J
authors.lastname: Scott
authors.affiliation: School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia.
authors.forename: Bettina
authors.initials: B
authors.lastname: Rosche
mesh_terms: D000393:Air Pollutants / Q000302:isolation & purification / Q000378:metabolism; D001673:Biodegradation, Environmental; D002245:Carbon Dioxide / Q000378:metabolism; D003031:Coal; D005374:Filtration / Q000379:methods*; D017752:Greenhouse Effect; D008697:Methane / Q000302:isolation & purification* / Q000378:metabolism*; D020581:Methylosinus / Q000378:metabolism*; D010084:Oxidation-Reduction; D014691:Ventilation
chemical_list: D000393:Air Pollutants; D003031:Coal; D002245:Carbon Dioxide; D008697:Methane
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