title: Biomethanization of orange peel waste.
abstract: Recent research has demonstrated that orange peel waste is a potentially valuable resource that can be developed into high value products such as methane. Following a pre-treatment to extract D-limonene, the anaerobic digestion of orange peel waste was evaluated at laboratory and pilot scale under mesophilic and thermophilic conditions. D-limonene removals of 70% were reached with pre-treatment. The results showed the convenience of thermophilic conditions for treating this waste as the methane production rate and biodegradability were higher than at mesophilic temperature. At pilot scale, a thermophilic continuously stirred-tank reactor working in semi-continuous mode was employed. The OLR was found to be in the range of 1.20-3.67 kg COD/m(3) d; the most appropriate range for working under stable conditions at SRT of 25 d. The methane yield coefficient was found to be 0.27-0.29 L(STP)CH(4)/g added COD and the biodegradability 84-90% under these conditions. However, acidification occurred at the highest OLR.
authors.affiliation: Departamento de Química Inorgánica e Ingeniería Química, Facultad de Ciencias, Universidad de Córdoba, Campus Universitario de Rabanales, Edificio C-3, Ctra Madrid-Cádiz, km 396, 14071 Córdoba, Spain. iq2masam@uco.es
authors.forename: M A
authors.initials: MA
authors.lastname: Martín
authors.forename: J A
authors.initials: JA
authors.lastname: Siles
authors.forename: A F
authors.initials: AF
authors.lastname: Chica
authors.forename: A
authors.initials: A
authors.lastname: Martín
mesh_terms: D000143:Acids / Q000737:chemistry; D000468:Alkalies / Q000737:chemistry; D001673:Biodegradation, Environmental; D056804:Biofuels / Q000032:analysis*; D001709:Biotechnology / Q000379:methods*; D032084:Citrus sinensis / Q000737:chemistry*; D053138:Cyclohexenes / Q000302:isolation & purification; D057168:Distillation; D006863:Hydrogen-Ion Concentration; D000077222:Limonene; D008697:Methane / Q000096:biosynthesis*; D010865:Pilot Projects; D012722:Sewage / Q000382:microbiology; D013696:Temperature; D013729:Terpenes / Q000302:isolation & purification; D013997:Time Factors; D014835:Volatilization; D014866:Waste Products / Q000032:analysis*
chemical_list: D000143:Acids; D000468:Alkalies; D056804:Biofuels; D053138:Cyclohexenes; D012722:Sewage; D013729:Terpenes; D014866:Waste Products; D000077222:Limonene; D008697:Methane