title: Improvement of biogas production from orange peel waste by leaching of limonene.
abstract: Limonene is present in orange peel wastes and is known as an antimicrobial agent, which impedes biogas production when digesting the peels. In this work, pretreatment of the peels to remove limonene under mild condition was proposed by leaching of limonene using hexane as solvent. The pretreatments were carried out with homogenized or chopped orange peel at 20-40°C with orange peel waste and hexane ratio (w/v) ranging from 1 : 2 to 1 : 12 for 10 to 300 min. The pretreated peels were then digested in batch reactors for 33 days. The highest biogas production was achieved by treating chopped orange peel waste and hexane ratio of 12 : 1 at 20°C for 10 min corresponding to more than threefold increase of biogas production from 0.061 to 0.217 m(3) methane/kg VS. The solvent recovery was 90% using vacuum filtration and needs further separation using evaporation. The hexane residue in the peel had a negative impact on biogas production as shown by 28.6% reduction of methane and lower methane production of pretreated orange peel waste in semicontinuous digestion system compared to that of untreated peel.
authors: Swedish Centre for Resource Recovery, University of Borås, Allégatan 1, 50190 Borås, Sweden.
authors: Rachma
authors: R
authors: Wikandari
authors: Department Chemical and Biological Engineering, Chalmers University of Technology, 41296 Gothenburg, Sweden.
authors: Huong
authors: H
authors: Nguyen
authors: Department of Food and Agricultural Product Technology, Faculty of Agricultural Technology, Universitas Gadjah Mada, Bulaksumur, Yogyakarta 55281, Indonesia.
authors: Ria
authors: R
authors: Millati
authors: Department Chemical and Biological Engineering, Chalmers University of Technology, 41296 Gothenburg, Sweden.
authors: Claes
authors: C
authors: Niklasson
authors: Swedish Centre for Resource Recovery, University of Borås, Allégatan 1, 50190 Borås, Sweden.
authors: Mohammad J
authors: MJ
authors: Taherzadeh
mesh_terms: D056804:Biofuels; D032084:Citrus sinensis / Q000737:chemistry*; D053138:Cyclohexenes / Q000737:chemistry*; D006586:Hexanes / Q000737:chemistry; D000077222:Limonene; D017744:Medical Waste Disposal / Q000379:methods*; D008697:Methane; D013729:Terpenes / Q000737:chemistry*
chemical_list: D056804:Biofuels; D053138:Cyclohexenes; D006586:Hexanes; D017744:Medical Waste Disposal; D013729:Terpenes; D000077222:Limonene; D008697:Methane