Biogas

Digester from Palm Oil Mill Effluent (POME)

PT EVANS

PT Bumi Mas Agro

East Kalimantan

March 2020 – 2021

The project was for the design, installation, and commissioning of a Closed Lagoon Bio-Reactor (CLBR) for the treatment of palm oil mill effluent (POME).

The objective of the project was to meet the environmental and operational objectives of the managing company. High levels of COD can be converted into biogas using a process of Anaerobic Digestion (AD). This involves maintaining the effluent produced by the palm oil fabrication process being retained in a covered lagoon for a period of up to 30 days. The process results in the conversion of COD into biogas, with a methane content of around 60%. Rather than being emitted into the atmosphere, the methane is collected and used in spark-ignition engines to provide energy to the mill.

This not only reduces the environmental impact of the process, but also results in an improvement in the operational efficiency of the plant.

• The project was designed to treat the palm oil effluent produced from the production of palm oil.
• The mill handles 60 tonnes per hour of fresh fruit bunch generating 600m3 of wastewater a day.
• The lagoon was designed to accommodate 23,300m3 of wastewater from a factory that processes 60 tonnes per hour of Fresh Fruit Bunch.
• It was designed to handle up to 34,370Nm3/day (1,432Nm3/hour)  of biogas, the equivalent of 2.9 MWe electrical power.
• Total project budget, including permissions, land preparation and power generation equipment of USD $4 million.

• Captures 20,622 Nm³ of methane/day, preventing direct atmospheric release.
• This methane capture is equivalent to ~151,060 tCO₂e avoided /year.
• Generates renewable electricity that replaces coal-powered grid supply.
• By displacing grid electricity, the project avoids an additional ~22,895 tCO₂e / year.

  Total climate benefit: ~173,955 tCO₂e avoided annually — combining methane capture and fossil-fuel displacement.

*Note (assumptions):

• Methane density: 0.7168 kg/Nm³; Methane GWP100 = 28 tCO₂e/tCH₄.

• Annual methane captured ≈ 5,395 tonnes CH₄/year.

• Electricity generated ≈ 26,935 MWh/year (based on ~3.07 MWe).

• Grid emission factor: 0.85 tCO₂e/MWh (Indonesia coal-dominant grid).

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