Converting POME into Biogas in Thailand: Your Biogas Solution Provider

Thailand’s palm oil sector is concentrated in the southern provinces of Surat Thani, Krabi, and Chumphon, where hundreds of mills generate a highly polluting byproduct known as palm oil mill effluent (POME). With COD levels ranging from 40,000 to 80,000 mg/L and a temperature of 40–60°C, raw POME poses a severe risk to rivers and wetlands if discharged untreated . As a dedicated biogas solution provider, Center Enamel helps Thai mills convert this waste stream into valuable renewable energy using proven anaerobic digestion technology. This article outlines the complete POME-to-biogas pathway, from pretreatment and USR digestion to gas utilization and tank infrastructure, explaining why an integrated EPC approach delivers both environmental compliance and operational savings.

Thailand’s POME Challenge and the Case for Biogas

Thailand’s tropical climate and extensive palm plantations make it the world’s third-largest palm oil producer. Each tonne of fresh fruit bunches processed yields roughly 0.7–1 m³ of POME, a thick, brownish liquid with high oil and grease content, acidic pH, and extreme organic loading . For decades, many mills relied on open ponding, a low-cost method that releases methane—a greenhouse gas over 20 times more potent than CO₂—directly into the atmosphere while consuming vast land areas . Stricter enforcement of industrial discharge standards and rising demand for sustainable palm oil have made conventional lagoon treatment increasingly untenable. Capturing methane through anaerobic digestion not only prevents environmental damage but also provides a dispatchable energy source for mill operations, reducing diesel and grid electricity costs.

The POME-to-Biogas Treatment Process

Converting POME into biogas begins with pretreatment, a critical step that protects downstream equipment and stabilizes biological performance. Raw effluent first passes through a mechanical bar screen that intercepts fibers, shells, and large suspended solids capable of clogging pipes and damaging pumps. A horizontal flow oil separator then removes residual grease and floating oil, reducing the organic load on the anaerobic reactor and preventing fatty acid accumulation that can inhibit methanogens. The pretreated POME flows into a regulating tank, where flow rate, temperature, and pH are equalized to create consistent conditions for digestion. This buffering capacity is essential because POME arrives hot and acidic, and sudden fluctuations can destabilize the microbial community. Only after these conditioning steps does the wastewater enter the anaerobic digestion stage, where bacteria break down organic matter in the absence of oxygen and produce methane-rich biogas.

USR Process: The Heart of POME Digestion

The Upflow Solids Reactor (USR) is specifically engineered for organic wastewater with total solids content between 3% and 6%, making it an ideal match for raw POME . Inside the vertical, cylindrical tank, wastewater is distributed evenly across the bottom and flows upward through a dense bed of anaerobic sludge. Microorganisms attach to and digest the suspended organic particles, converting COD into biogas while the treated liquid exits through an outlet at the top. The reactor’s gas holder collects methane as it rises, and a recycle line maintains optimal upflow velocity to prevent sludge washout. For mesophilic digestion of POME, the volumetric loading rate should be designed at 3–5 kg COD/(m³·d) to balance treatment efficiency with process stability . The USR’s airtight roof and robust mixing design ensure reliable biogas production even when feed characteristics vary.

Biogas Treatment and Utilization

Raw biogas leaving the USR is saturated with water vapor and contains hydrogen sulfide, which is corrosive to engines and boilers. The gas first passes through a dehydration unit to remove moisture, followed by a desulfurization vessel filled with media that adsorbs H₂S. A booster fan then pressurizes the clean gas and a flowmeter measures production for process control. The treated biogas can be routed to several end uses: a biogas generator produces electricity and heat for the mill, a boiler supplies hot water or steam for sterilization and clarification, or a flare provides safe destruction of surplus gas during maintenance. Capturing and utilizing this methane transforms an environmental liability into a reliable energy asset.

GFS Tanks and Double Membrane Roofs

Two core products anchor every biogas project: Glass-Fused-to-Steel (GFS) tanks and double membrane roofs. GFS tanks are manufactured by fusing molten glass to steel at approximately 820–930°C, creating an inert, inorganic bond that combines steel’s structural strength with glass’s exceptional corrosion resistance . This dual-layer coating withstands the aggressive hydrogen sulfide, volatile fatty acids, and pH swings found inside anaerobic digesters, delivering a service life exceeding 30 years. The double membrane roof is the preferred cover for USR tanks under normal operating conditions. Its outer membrane protects against weather while the inner membrane stores biogas directly above the digester, eliminating the need for a separate ground-mounted gas holder. This design reduces material costs, saves valuable land, and lowers foundation construction expenses—advantages that matter greatly for mills with limited space .

Diverse Storage Tank Solutions

Center Enamel offers a range of tank configurations to match specific project requirements and site conditions. Galvanized steel tanks provide a tough, wear-resistant coating for cost-sensitive applications where moderate corrosion resistance is sufficient. Fusion Bonded Epoxy (FBE) tanks, developed with AkzoNobel, deliver advanced coating technology for enhanced chemical resistance and long-term durability. Stainless steel tanks in AISI 304/316 are available for high-purity water storage or extremely harsh environments where glass and epoxy coatings may not be appropriate. This diversified portfolio allows every biogas project to specify the optimal tank material for its process stream, budget, and lifespan expectations.

Supporting Equipment for Complete Biogas Systems

Beyond digestion and storage, a fully functional biogas plant requires auxiliary equipment that ensures safety, efficiency, and byproduct management. A gas holder provides buffer storage to balance gas production against fluctuating demand. A black membrane lagoon handles excess liquid digestate, containing it safely while preventing groundwater contamination. A hot water boiler recovers heat from the biogas generator or burns biogas directly to supply process hot water. An emergency torch system safely burns off excess gas during upset conditions or maintenance, protecting the double membrane roof from overpressure. Lifting pumps transfer POME and sludge between process stages with reliability, while dehydration and desulfurization tanks house the media that clean the gas. Finally, a screw sludge dewatering machine separates digested sludge into a solid fraction suitable for composting or land application and a liquid fraction returned to the lagoon or used as fertilizer.

Why Choose Center Enamel as Your Biogas Solution Provider

Center Enamel delivers complete, single-source biogas solutions rather than isolated equipment. As an EPC contractor, the company handles process design, equipment manufacturing, civil works coordination, installation, and commissioning under one contract, eliminating the interface risks and delays that plague multi-vendor projects. The USR and GFS tank technologies are developed and manufactured in-house, ensuring seamless compatibility between reactor design, roof selection, and gas handling equipment. With certifications including CE/EN1090, ISO9001, NSF61, WARS, and EN28765, and designs conforming to AWWA D103, OSHA, and EuroCode, every project meets rigorous international standards. Local support and spare parts availability in Southeast Asia further reduce downtime and lifecycle costs. For Thai mills seeking a reliable partner to convert POME into biogas, this integrated capability translates directly into faster project delivery, lower total cost of ownership, and predictable operational performance.

Conclusion

Thailand’s palm oil industry faces mounting pressure to manage POME responsibly while controlling energy costs. Anaerobic digestion through the USR process offers a proven pathway to convert this high-strength wastewater into biogas, and the right infrastructure—GFS tanks, double membrane roofs, and complete auxiliary equipment—determines how reliably and economically that conversion performs. By choosing a biogas solution provider with in-house engineering, manufacturing, and EPC capabilities, Thai mills can transform an environmental burden into a long-term energy asset.

FAQ

What is POME and why is it harmful to the environment?
Palm oil mill effluent is the wastewater generated during palm oil extraction. It contains extremely high organic matter, oil, and suspended solids. If released untreated, it depletes oxygen in water bodies, harms aquatic life, and releases methane, a potent greenhouse gas.

How much biogas can be produced from POME?
Biogas yield depends on POME characteristics and digestion conditions, but anaerobic digestion typically produces 20–28 m³ of biogas per m³ of POME, with methane content around 50–60%. This gas can generate electricity or heat for mill operations.

Can treated POME be used as fertilizer?
Yes. Digested POME contains nitrogen, phosphorus, potassium, magnesium, and calcium. After solid-liquid separation and appropriate stabilization, the liquid and solid fractions can be applied to palm plantations as organic fertilizer, closing the nutrient loop.