Alternative scenarios to utilise excess biogas in Palm Oil Mill

Abstract

Palm Oil Mill is a factory which converts Fresh Fruit Bunch (FFB) to Crude Palm Oil (CPO) and Palm Kernel Oil (PKO). Within FFB converting processes, two types of waste are produced: 1)liquid waste and 2)solid waste. Liquid waste, named Palm Oil Mill Effluent (POME), contributes up to 60% of total FFB. Solid waste includes palm kernel shell and meal, fibre and empty fruit bunch gives in aggregate around 20% of total FFB. Initially, Palm kernel shell (PKS) is commonly utilised as fuel for boiler. Then in some mills, POME was additionally used as biomass for biofuel production (biogas) to support power supply in the mill. Biogas is utilised to generate electricity for Kernel Crushing Plant (KCP). Field observation data shows that electricity demand for KCP is 19.5 MWh/day or equivalent with 45% of total biogas production. The excess biogas, equivalent with 11,000 kWh/day, is flared. An alternative scenario instead of flaring is to use biogas as fuel for boiler. Thus, the previous fuel (PKS) could potentially be allocated for selling. Another scenario is to utilise excess biogas electricity generation to be distributed to staff houses near the mill. Therefore, this research study aims to calculate excess biogas that could be used for those scenarios: 1)Fuel substitution in the mill with different type of process, 2)Household electricity. Result shows that biogas demand in each scenario can supply 1) Minimum 2,900 kWh/day for non-processing hours and 6,436.65 kWh/day for processing hours, 2) Electricity for 557 houses/day.