Analysis of biogas production from palm oil mill effluent at different feed flow rates in biogas plant Sei Pagar Riau

Abstract

Abstract Indonesia’s palm oil industry is considered one of the biggest in the world. Palm Oil Mill Effluent (POME) has the potential for further processing, which can be used as a substitute for boiler fuel (co-firing). Research on converting POME to biogas for boiler fuel (co-firing) in the oil palm plantation Sei Pagar Riau has been carried out. This study aimed to investigate and analyze the biogas production from Palm Oil Mill Effluent at different feed flow rates in Biogas Plant Sei Pagar Riau. Experiments were carried out using the Continuous Stirred-Tank Reactor (CSTR). The reactor capacity was 2000 m3. The reactor was equipped with one unit of vertical agitator and three units of horizontal agitators. POME was distributed from the fat pit unit to the pretreatment unit using the fat pit transfer pump. From the pretreatment unit, then POME proceeds to the reactor using the reactor feed pump started from 2.4 m3/h then gradually increase to 6.3 m3/h as the highest feed flow rate. Biogas was produced in the anaerobic reactor at mesophilic temperature. This study showed that an increase in the POME feed flow rate into the reactor also increases the production of biogas generated in the reactor. The biogas production began to increase every day, with the highest average biogas production of 167 m3/h. The methane concentration was also measured and showed that the highest methane concentration was on day 6, with a value of 70%. And then, the methane concentration trend decreased. However, it was relatively stable in the range of 62.1%-66.7% on day 18 to day 53. Based on this research, it was found that the optimal biogas production of the Biogas Plant in Sei Pagar Riau was generated when the POME feed flow rate was gradually increased and reached the maximum capacity according to its design.