From the ashes, emerges a green idea at Brahmapuram

On the evening of March 2, 2023, an inferno broke out in the mountains of plastic waste piling up high at the Kochi Corporation’s waste treatment plant in Brahmapuram, on the outskirts of the city.

For almost two weeks, flames have engulfed the sprawling garbage dump, mostly tonnes of plastic and non-biodegradable waste that has accumulated over a decade on the banks of the Kadamprayar, a critical source of fresh water, sending clouds of smoke across Kochi’s skyline. The fire, which lasted about two weeks and released large amounts of harmful gases and soot, reduced the city’s air quality to alarming levels. Hundreds of people sought medical attention for respiratory problems.

When the fire was finally doused, a large area of ​​the 110-acre plot at Brahmapuram in Vadavucode-Puthencruz panchayat on the outskirts of Kochi city looked like a war-torn wasteland; Behind him were smoldering embers, acrid smoke, and scorched earth so lifeless that it seemed as if even a blade of grass would never take root again.

Less than three years after the fire, a 10-acre plot at the epicenter of the shipyard has changed beyond recognition, hosting a Compressed Biogas plant funded by BPCL-Kochi Refinery. It will be officially inaugurated by Chief Minister Pinarayi Vijayan on Friday, February 26, 2026.

There are three green domes rising from what was once a charred wasteland. In fact, two of them are double-layered balloons mounted on top of the digesters, each capable of processing 75 tons of municipal solid waste per day. While the inner balloon inflates as raw biogas is produced, the outer shell maintains its form against bad weather conditions and ensures anaerobic operation of the digesters with the help of a water column controlled by the fan. The third structure consists of a ground-mounted balloon (a special, collapsible storage membrane designed specifically for biogas) with a capacity of 1,500 cubic meters.

Before the waste reaches the digesters, the heart of the gas production section, it goes through an elaborate cycle of pre-treatment and feed preparation. Biodegradable waste collected from 177 centers throughout the city is first transported to the facility and weighed there on a 60-ton electronic weighing machine. From there, the waste is discharged into a bunker in the pre-treatment area and transported forward on conveyors that pass through vibrators that separate non-biodegradable waste. The separated material is then directed to a grinder and a biogrinder which pulverizes the waste into a fine slurry 5 mm thick. The slurry moves on to the feed preparation stage where it is discharged into a drain pit and mixed with an equal amount of water. From there, it passes through intermediate tanks for further separation and the fibrous content is carefully removed. The slurry is then directed to a hydrolysis tank where accelerated breakdown of organic matter occurs. Finally, it is fed to two digesters operating on a Continuous Stirred Tank Reactor system. Together, the digesters produce 5.6 tonnes of biogas every day.

Fertilizer marketed by FACT

Every day, the digesters discharge 290 tonnes of Liquid Fermented Organic Manure (LFOM) and 28 tonnes of Solid Fermented Organic Manure (FOM), which are directed to a special compost shed for separation. Of this, 190 tonnes of LFOM is recycled within the plant itself, while the remaining 100 tonnes is marketed through Fertilizers and Chemicals Travancore (FACT), along with the 28 tonnes of FOM produced daily.

“We have signed an MoU to market FOM through our distribution network. Application of this type of fertilizer enriches the soil, facilitates better absorption of nitrogen and phosphorus, which benefits crop yields. That is why oil companies have started producing FOM products and fertilizer companies are also promoting them,” says Jeetendra Kumar, General Manager (Marketing), FACT.

Raw biogas produced by the digesters is stored in the ground-mounted balloon before being directed to the purification unit. In its raw form, gas contains 45-50% methane, 35-45% carbon dioxide (CO₂) and 0.1-0.4% hydrogen sulfide (H₂S). A water cleaning system is used to purify the biogas; It removes CO₂ and H₂S by feeding pressurized gas into a packed column while water is sprayed from above. This process increases methane purity to 97%. The refined gas is then compressed to a higher pressure and transferred to the refinery in Ambalamedu, where it is converted into green hydrogen, the engineer explained.

Carbon emissions decreased by 85,000 tons

A BPCL official said that when operated at full capacity, the plant will reduce carbon emissions by 85,000 tonnes per year, which is equivalent to planting 3.5 million trees and feeding them for a decade.

Similar biogas plants are under construction in various parts of Kerala. Projects developed under the public-private partnership (PPP) model in Palakkad and Thrissur are nearing completion. “In other districts, the government will transfer land and set up BPCL plant. An MoU has been signed for Kollam and the foundation stone will be laid in Kozhikode, while similar plants are being considered in Thiruvananthapuram and Changanassery. We are exploring a mix of centralized and decentralized waste treatment plants. There will not be a complete shift to this model, but it will be developed along with strengthening of decentralized systems.” MB Rajesh, Minister of Local Self Government.

The Kochi plant, which requires an annual operating expenditure of 7.5 billion rupees, is equipped with both internal and external safety systems, including a dedicated fire water network, to combat potential outbreaks. Company officials claim that this feature is unique.

Controlled combustion of gas

Engineers say the system is supported by a four-lakh-litre capacity tank, a borewell capable of supplying 5,000 liters of water per hour and a conventional well, with Kadamprayar also serving as an additional source of water. A deflagration mechanism ensures controlled combustion of the gas even if the pressure rises above the prescribed threshold, he explains.

However, the Company had initially proposed a heap composting facility under BPCL’s corporate social responsibility (CSR) initiative with an investment of ₹150 crore. “The proposal changed after the Brahmapuram fire. While hearing cases related to the incident, the Kerala High Court asked why the Corporation could not set up a facility similar to the one in Indore. Although the company behind the Indore project held consultations, it eventually withdrew citing feasibility concerns. It was at this point that BPCL entered talks with the State government and Ministers M B Rajesh and P. Rajeeve floated the possibility of a proposal for a CBG facility,” recalls former mayor M. Anilkumar.

Prime Minister Narendra Modi then held the groundbreaking ceremony of the proposed facility online in October 2023. The State Cabinet approved the CBG project the following month and the Corporation handed over the land in December. CEID Consultants and Engineering won the tender for the installation of the facility, while FACT Engineering and Design Organization (FEDO) was appointed as the Project Management Consultant.

Reasons for delay

The original deadline of March 2025 for completion of the project was not met. The plant’s trial run began in December 2025, starting with manure and then expanding to actual municipal solid waste. The main reason for this delay was the soil structure and the long monsoon. “We acquired the land in March 2024 and started filling it two months later. However, prolonged rains triggered soil subsidence, forcing us to drive piles for all but two structures. To ensure stability, we waited for two monsoon cycles before proceeding. Hence, the soil had time to settle,” explains R. Ugesh Raja, CEID Project Manager, who has been tasked with the operation and maintenance of the facility for the next decade.

Meanwhile, FEDO is preparing to finalize its partnership with the project, its first in Kerala. “We are in the process of conducting a Performance Assurance Test Run, the completion of which will mark the culmination of our role in the project,” says Sarath Santhosh, Senior Manager (Projects and Constructions), FEDO.

Treatment of the ‘rejected’

Kochi Corporation has allocated ₹15 crore for the operation of the CBG plant in the 2026-27 Budget. “It is our responsibility to process the waste at the time of segregation. Since the actual cost of processing the same is unclear, we have reserved a token allocation. The company engaged in bio-mining of old waste in Brahmapuram has expressed interest in processing the rejects and we have asked them to submit a project proposal. While the CBG plant is undoubtedly a boon for the city, we do not want the processing of the rejects to become an additional burden. We are also concerned about whether it will affect the quality of the waste supplied. Kochi Mayor VK Minimol said “Operations of the plant will continue in the long term as we have been told that the raw material must be ‘pure’, free from any acidic content,” he said.

From the ashes of Brahmapuram’s inferno has risen a facility that not only addresses the city’s growing waste crisis but also directly feeds into the country’s green energy goals. As Kochi takes this pioneering step, the challenge lies in ensuring consistent waste quality, managing rejects and sustaining operations through monsoon cycles and financial realities.