BPCL’s new Brahmapuram plant to convert 150 tonnes of Kochi’s bio-waste into 5.6 tonnes of green fuel daily

Kochi: For years, the name Brahmapuram was synonymous with a mounting crisis. The 110-acre site in Kochi, burdened by 3.5 lakh metric tonnes of legacy waste, became a symbol of urban struggle, culminating in the catastrophic fire of March 2, 2023, that choked the city in smoke for days. However, Brahmapuram is preparing for a different headline tomorrow. On Friday, Chief Minister Pinarayi Vijayan will inaugurate Bharat Petroleum Corporation Limited’s (BPCL) state-of-the-art Compressed Biogas (CBG) plant, a first-of-its-kind in India, turning a site once feared for its toxic fumes into a powerhouse of clean energy. The plant, which is constructed in 10 acres of the corporation’s land at a cost of ₹88 crore, will convert around 150 tonnes of bio-degradable solid waste collected from Kochi into 5.6 tonnes of high-quality methane and products like fertilisers daily.

According to Raman Malik, BPCL’s Head of Brand and PR, the project, born from a Kerala High Court directive and a rapid proposal by the BPCL Kochi Refinery in November 2023, represents a “quiet green revolution”. “This facility isn't just a waste processing unit; it is a centrepiece of Bharat Petroleum’s mission to reach ‘Net Zero’ emissions by 2040”, Malik said, noting that the plant aligns with the National Biofuel Policy to reduce India's fossil fuel import dependence by 10%.

The plant is a feat of modern engineering. Despite the torrential Kerala monsoons, the team executed one lakh cubic meters of earth filling to stabilise the site. Most impressively, the massive 8,000 cubic metre concrete digesters, standing 12 m high and 30 m wide, were constructed in just 12 days using advanced slipform technology. This facility is the first of its kind in India to be directly linked to a refinery via a dedicated pipeline, ensuring that the green fuel produced is utilised immediately and efficiently for various purposes including hydrogen production.

How the magic happens: The process
According to Siby TP, BPCL Senior Manager in charge of the unit’s operations, the plant is designed to process 150 tonnes of source-segregated biodegradable Municipal Solid Waste (MSW) daily. The journey from urban refuse to high-grade fuel begins with sorting and pre-treatment, where compactor trucks deliver waste to specialised bunkers and a mechanical grabber feeds it into a hopper. A segregation belt equipped with vibrators shakes out non-organics, while a magnetic separator pulls out metal scraps to ensure only the purest biodegradable material moves forward.

“The segregated organic waste is first shredded and crushed into a thick slurry. This is mixed with recycled water in an unloading pit and filtered to remove any remaining impurities, ensuring the material is ideal for processing. The prepared slurry is then sent to a hydrolyser tank and from there into the ‘heart’ of the plant -two massive concrete digesters. Inside these sealed tanks, seven high-flow agitators keep the mixture constantly moving so that naturally occurring bacteria can break down the waste efficiently. Over a period of about 40 days, this biological process produces raw biogas containing roughly 45 to 60 per cent methane,” Siby explained.

The raw biogas is first collected in a double-layered balloon dome mounted above the digesters. From there, it is transferred to a ground-mounted storage balloon where the gas is stabilised before purification.

The next critical step is cleaning the gas. A water scrubber system removes impurities such as carbon dioxide and hydrogen sulphide. “We purify and enrich the gas until it contains at least 97% methane, making it a high-grade fuel. Once purified, the biogas is compressed to 60 kg/cm² and sent through a dedicated 3.2-km pipeline directly to the Kochi Refinery,” Siby said.

Circular economy: No waste left behind
The plant’s efficiency goes well beyond gas production, reflecting a true “zero-waste” circular economy model. The leftover slurry from the digesters is sent to a solid-liquid separation system. The solid portion becomes Fermented Organic Manure (FOM), which is dried, packed in a dedicated fertiliser shed and supplied to farmers. The liquid portion, known as Liquid Fermented Organic Manure (LFOM), is either recycled back into the process or treated at a 120 KLD-capacity Effluent Treatment Plant (ETP) before being safely discharged.

The entire facility is operated through an automated system from a centralised control room, enabling real-time monitoring and data tracking. Safety measures include a ground-mounted flare system, a fire water network and round-the-clock CCTV surveillance. The plant draws power from the KSEB Brahmapuram substation and is backed by an emergency diesel generator, ensuring the “green flame” keeps burning without interruption.

The ecological contribution of this plant is staggering. It is expected to reduce the carbon footprint by 85,000 tonnes of CO2 per year, an achievement Malik describes as “equivalent to planting 3.5 million trees and nurturing them for an entire decade”. Furthermore, the daily output provides a sustainable energy alternative equivalent to 1.8 tonnes of green hydrogen.

At the inaugural event, alongside CM Vijayan, Suresh Gopi, Minister of State for Petroleum and Natural Gas, will be in attendance. Other key dignitaries include state ministers MB Rajesh and P Rajeev, Chalakudy MP Benny Behanan, and Kochi Mayor VK Minimol. BPCL’s Director (Refineries) Sanjay Khanna, District Collector Priyanka G, and Shuchitwa Mission Executive Director Binu Francis will also be present.