Biogas production from cattle manure

In this study, optimum conditions for biogas production from cattle manure were determined by making two set of experiments. Independent variables were pH and amount of anaerobic sludge reactor inoculum for first set of experiments, pH and percent solid for second set of experiments.In both of the studies, 14 glass batch reactors each having 250 mL volume was used. Experiments were designed by using Box-Wilson experimental design method. Experimental results were analyzed by using ?Design Expert 7.0.0? program.In the first set of experiments, effect of pH and amount of anaerobic sludge reactor inoculum to acetic acid production rate, gas production rate and volatile solid percent reduction were investigated. Amount of anaerobic sludge reactor inoculum and pH were changed simultaneously (temperature and percent solid were constant) 50-150 g and 6,8-7,8 interval. After evaluation of the experimental results by using Design Expert 7.0.0 program, model equations and optimum conditions for dependent variables were determined. Optimum conditions for biogas production from cattle manure were pH 7,37 and amount of anaerobic sludge reactor inoculum 108,17 gram (1,67 g inoculum/g manure).In the second set of experiments, effect of pH and percent solid to acetic acid production rate, gas production rate and volatile solid percent reduction were investigated. Amount of percent solid and pH were changed simultaneously (temperature and amount of treatment solid were constant) %4-%12 and 6,9-7,5 interval. After evaluation of the experimental results by using Design Expert 7.0.0 program, model equations and optimum conditions for dependent variables were determined. Optimum conditions for biogas production from cattle manure were pH 7,22 and %8,07 percent solid.