Vietnam Biogas Project : Leading USR Process and GFS Tanks for Palm Oil Mill Waste

Vietnam’s palm oil industry, while smaller than neighboring Indonesia and Malaysia, has been expanding steadily, particularly in the southern provinces such as Binh Phuoc and Dong Nai. As domestic demand for vegetable oils rises, more mills are processing fresh fruit bunches (FFBs) to meet market needs. However, this growth brings an environmental challenge: Palm Oil Mill Effluent (POME).

For every ton of FFBs processed, a typical mill discharges 0.7 to 1 cubic meter of POME. Fresh POME is hot (60–80°C), acidic (pH 3.3–4.6), and contains high levels of solids, oil, grease, and organic matter. Without proper treatment, POME can pollute rivers, harm aquatic life, and release methane-a potent greenhouse gas-into the atmosphere. For Vietnamese mill operators seeking sustainable growth, managing POME is not just a regulatory requirement but also an economic opportunity.

Advantages of Converting POME into Biogas

Converting POME into biogas offers clear environmental and financial benefits. Instead of leaving wastewater in open lagoons, a well-designed biogas project captures methane and turns it into a valuable energy resource. The key advantages include:

Energy Independence: Biogas can replace diesel or grid electricity for mill operations, including boilers and generators, reducing energy costs significantly.

Greenhouse Gas Reduction: Capturing methane prevents its release into the atmosphere, helping mills lower their carbon footprint.

Pollution Control: Anaerobic digestion reduces the biological oxygen demand (BOD) and chemical oxygen demand (COD) of POME, producing cleaner effluent that is safer for discharge or reuse.

Fertilizer Value: The nutrient-rich digestate (nitrogen, phosphorus, potassium, magnesium, and calcium) can be applied safely to palm oil plantations as an organic fertilizer.

Regulatory Readiness: Vietnamese environmental regulations are tightening. A proper biogas project ensures compliance and avoids penalties.

Center Enamel: Professional Design for Biogas Projects

For over 36 years, Center Enamel has been a global leader in water, wastewater, and biogas projects. As Asia’s largest manufacturer of Glass-Fused-to-Steel (GFS) tanks, the company combines extensive R&D capability with practical engineering experience. Center Enamel provides custom-engineered designs for every biogas project, tailored specifically to the characteristics of POME and the client’s operational goals.

Their team handles everything from process calculations to detailed mechanical design. Whether a client needs a complete turnkey system or specific process packages, Center Enamel ensures optimal performance, durability, and cost-efficiency. With certifications including ISO9001, NSF61, CE/EN1090, and EN28765, their designs meet international standards while remaining fully adaptable to local conditions in Vietnam.

Wastewater Pretreatment Process

Before POME enters the anaerobic reactor, proper pretreatment is essential. This stage removes large solids, sand, and grease, protecting downstream equipment and ensuring stable biological performance. Center Enamel’s pretreatment system includes three main components:

Screen Machine: Mechanical bar screens remove large suspended solids and floating debris. This prevents clogging of pumps, pipes, and valves, reducing maintenance and downtime.

Horizontal Flow Oil Separator: This unit is designed specifically to remove grease and oil from POME. The horizontal flow design, combined with adequate residence time, allows oil to float and be skimmed off effectively, reducing the organic load on the anaerobic reactor.

Regulating Tanks: POME flow and composition vary greatly depending on production cycles. Regulating tanks balance these fluctuations by temporarily storing influent, mixing different batches, adjusting pH, and providing physical cooling. They also facilitate hydrolysis and acidification-an initial breakdown of complex organic molecules into simpler compounds-preparing the wastewater for efficient anaerobic digestion.

Introduction to the USR Process

The Upflow Solids Reactor (USR) is one of the most effective anaerobic digestion technologies for treating organic wastewater with solid content (TS) between 3% and 6%-making it an ideal match for raw POME. In the USR Process, wastewater is distributed evenly at the bottom of a vertical, cylindrical, air-tight reactor tank. As the liquid flows upward, it passes through a dense bed of anaerobic solids, where microorganisms digest the organic material and produce biogas.

The treated effluent overflows through an outlet at the top, while excess sludge is discharged from the bottom. Center Enamel determines reactor volume based on volumetric load, typically 3–5 kg COD/(m³·d) for POME under mesophilic digestion conditions. The USR Process offers high solids retention, stable biogas production, and low energy consumption, making it the preferred core technology for any modern biogas project targeting palm oil mill waste.

Core Products: GFS Tanks + Double Membrane Roof

Center Enamel manufactures two primary products that work together seamlessly in biogas projects:

Glass-Fused-to-Steel (GFS) Tanks: These tanks combine the mechanical strength of steel with the corrosion resistance of glass. The enamel is fused to the steel at over 800°C, creating a hard, inert, and durable surface. This surface withstands the acidic, abrasive nature of POME and biogas without degrading. GFS tanks are engineered to meet rigorous design standards, including AWWA D103 and EuroCode, ensuring long service life even in Vietnam’s tropical climate.

Double Membrane Roof: For most biogas project conditions, Center Enamel recommends the double membrane roof. Its advantages include lower roof cost, reduced footprint compared to traditional gas holders, and simplified construction. The double membrane roof also eliminates the need for a separate ground-mounted gas holder, saving valuable land. However, for sites with extreme weather (high wind speeds or heavy snow loads) or when a ground-mounted gas holder is preferred, a Glass-Fused-to-Steel roof is available-especially for tank diameters under 23 meters.

Together, GFS Tanks and the double membrane roof form a complete, sealed, and highly efficient biogas capture and storage system.

Supporting Equipment for a Complete Biogas Project

Beyond the main reactor and roof, a fully functional biogas plant requires several other critical components. Center Enamel supplies all necessary auxiliary equipment to ensure seamless, trouble-free operation:

Gas Holder: For storing biogas prior to combustion or electricity generation.

Lagoon / Black Membrane: For post-treatment polishing or long-term effluent storage.

Hot Water Boiler: To maintain optimal mesophilic temperatures (around 35–37°C) inside the USR reactor, especially during cooler months or nighttime.

Emergency Torch System: Safely combusts excess biogas when production exceeds demand, preventing pressure buildup and ensuring safety.

Lifting Pumps: To transfer POME between different treatment stages reliably.

Dehydration and Desulfurization Tank: Removes moisture and corrosive hydrogen sulfide (H₂S) from raw biogas, protecting engines, boilers, and piping.

Screw Sludge Dewatering Machine: Reduces the volume of digested sludge, making it easier to handle, transport, or apply as fertilizer.

Center Enamel’s Efficient Installation Capability

One of Center Enamel’s strongest advantages is rapid, efficient on-site installation. With an annual production capacity of over 250,000 GFS tank sheets, their logistics and assembly processes are highly streamlined. The bolted tank design requires no heavy welding or specialized construction equipment, which significantly cuts installation time and labor costs-a critical benefit for Vietnamese mills located in remote areas.

The modular nature of GFS Tanks allows easy transportation by truck to sites with limited road access. A professional technical team supervises the entire assembly process, ensuring that every bolted joint and seal meets strict quality standards. This efficiency translates into less downtime for the mill, faster project completion, and a quicker return on investment. For mill owners in Vietnam, this means their biogas project can start generating energy and revenue months earlier than traditional concrete or welded steel alternatives.

One-Stop Biogas Project Solutions for Vietnamese Palm Oil Mills

Center Enamel is not just a tank supplier; they are a complete one-stop solution provider for palm oil mills in Vietnam and worldwide. Their business scope covers everything from initial concept to operational handover: EPC service, Process Package, and Equipment Supply. For a Vietnamese palm oil mill owner, this single-source responsibility means less complexity, better coordination, and guaranteed performance.

They handle site assessment, civil design, mechanical installation, electrical and control systems, and commissioning. By offering integrated biogas project solutions built around the efficient USR Process and durable GFS Tanks, Center Enamel enables mill operators to turn a costly waste problem into a profitable energy asset. Their team understands local conditions in Vietnam, including climate, regulatory frameworks, and operational practices. This holistic approach is why hundreds of clients across more than 100 countries trust Center Enamel for their environmental and energy projects.

Frequently Asked Questions (FAQ)

Q1: What is the typical biogas yield from a USR Process treating POME in a Vietnam biogas project?
Under mesophilic conditions (35–37°C), the USR Process can typically produce 25–35 cubic meters of biogas per cubic meter of raw POME, depending on influent COD concentration. This translates into significant energy savings for a typical Vietnamese palm oil mill, often covering 50–80% of the mill’s thermal or electrical energy needs.

Q2: How do GFS Tanks perform in Vietnam’s tropical climate with high humidity and rainfall?
GFS Tanks are engineered for harsh environments. The glass-fused-to-steel coating is highly resistant to UV radiation, humidity, and acid rain. Unlike field-coated tanks, the factory-fused enamel does not crack, peel, or corrode over time. With proper foundation design, GFS Tanks perform reliably for 30+ years in Vietnam’s hot, humid conditions.

Q3: What is the typical lead time for a complete biogas project from Center Enamel to Vietnam?
From contract signing, Center Enamel typically delivers a complete biogas project (including design, manufacturing, shipping, installation, and commissioning) within 6–9 months, depending on project scale. Their bolted GFS tank design and pre-fabricated components significantly reduce on-site construction time compared to cast-in-place concrete alternatives.