Anaerobic digestion and biogas production

In this study, biogas production efficiency was investigated by using hydrolysis and methane reactors under mesophilic conditions. At the beginning of the study, cattle excrement was provided from Çukurova University Farm. Characterization study was carried out with this cattle excrement with TKN, Ammonia, Solids, Organic Matter, pH and Alkalinity tests. Hydrolysis and methane reactors were used in the experimental study. In the non-recycled reactors, the solid and hydraulic retention times (KAS / HAS) are equal. The hydrolysis reactor with a volume of 8 liters was operated at pH 5.80 and room temperature. The methane reactor with a volume of 2.5 L was operated at a temperature of 38 oC and a pH of 7.5. The methane reactor was operated with 5%, 10% and 15% organic solids loading. On the 8th day of the commissioning of the hydrolysis reactor, no change was observed in the amount of total solids while 11% removal of volatile solids and 45% increase in volatile fatty acid concentrations were observed. While no significant change was observed in terms of Total Solids (TS) removal, 16% Total Volatile Solids (TVS) removal was determined at the end of the 20th day. The volatile solid removal at day 20 increased to only 16%, indicating that the 8 day solid retention time was sufficient for the hydrolysis reactor. Each organic loading time in the methane reactor is 8 days. Total solid, volatile solid, total and bicarbonate alkalinity and volatile fatty acids were monitored daily with biogas production for 7 days. The gas production potential of the feces was investigated by carrying 5%, 10% and 15% organic loading from hydrolysis reactor to methane reactor. The composition of the gas deposited in the methane reactor was determined by Gas chromatography (GC). Biogas methane percentage and VS removal percentages were observed as 38%, 61% and 80% and 11%, 14,67% and 16% respectively. Cumulative biogas amounts for 5% 10%, 15% organic loading were determined as 5321 ml / day, 16655 ml / day and 29128 ml / day, respectively. As a result, this study shows that cattle feces are an efficient source for biogas production and shed light on the literature that the use of biogas through energy production and heat can provide enormous energy savings.