Feasibility Study of Biogas Upgrading Facility Development from Anaerobic Digestion of Palm Oil Mill Effluent in Indonesia

Palm Oil Mill Effluent (POME) can be processed using anaerobic digestion technologies to produce biogas. Biogas, that was produced from the anaerobic digestion process from POME, contained a high impurity CO2 30% - 45% and H2S around 1500 - 3000 ppm. In this research, a feasibility study was conducted to develop an anaerobic digestion facility from POME and biogas upgrading facility using absorption-based technologies: water scrubbing and amine scrubbing. The technical study was carried out using Aspen Plus software with a biogas flow rate of 0.8 MMCFD and methane content in biogas of 65% mole fraction. The target biomethane product contains CH4> 95%, CO2< 5%, H2S < 10 ppm and water content<10 lb/MMscf. The investment and operating costs for an aerobic digestion facilities use data from previous biogas projects that have been registered in the UNFCCC CDM (Clean Development Mechanism) project in Indonesia. Meanwhile, the biogas upgrading facility's investment cost is obtained from the simulation results using Aspen Plus software. An economic study was conducted to calculate the gas price of biomethane with an expected internal rate of return of 12%. The purity level of biomethane from water scrubbing facilities reached 97.38% and from amine scrubbing facilities reached 99.93%. From the simulation and calculation result, the lowest gas price of biomethane was $ 13.06/MMB tu using amine scrubbing technology.