• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.4
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• pp.95-103
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• 2016

The objective of this study was to investigate feasibility of semi-dry anaerobic digestion using dairy cattle manure and to evaluate solidified fuel value of semi-dry anaerobic digestate. To evaluate semi-dry anaerobic digestion using dairy cattle manure, 950 mL bottle type anaerobic reactor was set in the constant temperature room maintained at $35^{\circ}C$. To produce anaerobic digestate for making solidified fuel, acrylic cylindrical anaerobic digester(1,000 mm width ${\times}$ 450 mm height) was set in the constant room temperature to carry out batch test of semi-dry anaerobic digestion using same dairy cattle manure. Moisture content of dairy cattle manure and inoculum solution for anaerobic digestion were 80.64% and 96.83%, respectively. The dairy cattle manure and the inoculum solution was mixed by 1:1 ratio(v/v) for anaerobic digestion. Water content and VS/TS(Volatile Solids/Total Solids) of mixture of substrate and inoculum were 89.74% and 83.35%, respectively. In case of non-inoculated anaerobic digester, the biogas was not produced. By the semi-dry anaerobic digestion, the calorific value of the digestate was reduced by 20% compare to fresh dairy cattle manure. In other hand, ash content increased from 15% to 18.4%. The contents of Cr, Pb, Cd and S of pellet produced from anaerobically digested dairy cattle manure were not against the standard regulation for livestock manure solidified fuel. Therefore, it can be used as fuel that anaerobic digestate produced after semi-dry anaerobic digestion using dairy cattle manure.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.2
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• pp.85-93
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• 2018

Semi-dry anaerobic digestion experiment using dairy cattle manure collected from dairy cattle house was conducted to analyze efficiency of biogas production. As a first experiment, Biochemical Methane Potential (BMP) test was carried out according to certain ratio of sample mixtures: dairy cattle manure, pig slurry, and mixture of dairy cattle manure and pig slurry. The amount of methane accumulated during BMP test period was high in the experimental groups containing dairy cattle manure. As a second experiment, semi-dry anaerobic digestion experiment was carried out using only the dairy cattle manure collected from floor of the dairy cattle house. Judging from the experimental results, the optimum hydraulic retention time (HRT) of semi-dry anaerobic digestion for dairy cattle manure containing 13% of TS was 25 days. The amount biogas generated from the semi-dry anaerobic digestor with the TS of 13% of the dairy cattle manure ranged from 1.36~1.50v/v-d and the average was 1.44v/v-d. The optimum HRT of the semi-dry anaerobic digestor for dairy cattle manure containing TS of 15% and the semi-dry anaerobic digestor for dairy cattle manure containing TS of 17% was the same as 30 days. The amount biogas generated from the semi-dry anaerobic digestor with the TS of 15% of the dairy cattle manure ranged from 1.42~1.52v/v-d and the average was 1.47v/v-d. The amount biogas generated from the semi-dry anaerobic digestor with the TS of 17% of the dairy cattle manure ranged from 1.50~1.61v/v-d and the average was 1.55v/v-d.