Biochemical methane potential of two-phase olive mill solid waste: Influence of thermal pretreatment on the process kinetics

• Published in: Bioresource technology 2013-07, Vol.140, p.249-255
• Main Authors: Rincón, B., Bujalance, L., Fermoso, F.G., Martín, A., Borja, R.
• Format: Article
• Language: English
• Subjects: Anaerobiosis; Applied sciences; Biochemical methane potential (BMP); Biochemistry; Biological and medical sciences; Biological Oxygen Demand Analysis; Bioreactors - microbiology; Biotechnology - methods; Cellulose - analysis; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Industrial Waste; Kinetics; Lignin - analysis; Methane; Methane - metabolism; Mills; Models, Chemical; Olea - chemistry; Olive mill solid waste (OMSW); Olives; Oxygen demand; Pollution; Polysaccharides - analysis; Pretreatment; Solid Waste; Solid wastes; Temperature; Thermal pretreatment; Volatilization; Wastes
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.04.090

•COD solubilisation of 42% was obtained for OMSW treated at 120 and 180°C (180min).•Two different stages were observed in the biochemical methane potential tests.•First-order exponential and sigmoidal models were used for the 1st and 2nd stage.•No pretreatment influence on the kinetic constant of the first-stage was observed.•OMSW pretreated at 180°C-180min was the fastest BMP during the second phase. The effect of thermal pretreatment on two-phase olive mill solid waste was evaluated by chemical oxygen demand solubilisation and biochemical methane potential (BMP) tests. Temperatures of 100, 120, 160 and 180°C were applied during 60, 120 and 180min for each temperature studied. The highest chemical oxygen demand solubilisation after pretreatment (42%) was found for 120 and 180°C during 180min in both cases. These two conditions were selected for the BMP tests. BMP tests showed two different stages: a first exponential stage and a sigmoidal zone after a lag period. No influence of the pretreatment was observed on the kinetic constant of the first-stage. Clear difference was observed in the maximum methane production rate of the second stage, 76.8mL CH4/(g VSday) was achieved after pretreatment at 180°C (180min), value 22% and 40% higher than that obtained for the untreated and pretreated OMSW at 120°C, respectively.