The Delhi Jal Board (DJB) plans to engage private companies to purchase raw biogas generated at sewage treatment plants (STPs), aiming to commercially utilise the gas produced during sludge digestion instead of flaring it or leaving it underutilised, Hindustan Times reported.
The initiative will initially cover two of Delhi’s 37 STPs: Keshopur Phase-I and Yamuna Vihar Phase-II. The DJB has invited expressions of interest to assess market demand, technical capabilities and commercial proposals, with agencies likely to be selected by November, a senior official said.
The Keshopur Phase-I STP is being upgraded from 12 million gallons per day (MGD) to 18 MGD, while the Yamuna Vihar Phase-II plant has a capacity of 15 MGD, equivalent to around 68 million litres per day.
Under the proposed arrangement, private companies will purchase untreated biogas directly from the plants and establish facilities to process it for applications such as power generation and vehicle fuel. Potential uses include gas purification, compression, bottling and conversion into bio-compressed natural gas (bio-CNG).
The DJB will supply raw biogas at designated delivery points and provide land within the STP premises on a lease or licence basis. Selected companies will be responsible for designing, installing, operating and maintaining their facilities, as well as securing the necessary statutory approvals and clearances.
Delhi generates nearly 1,000 MGD of sewage daily, while its current sewage treatment capacity stands at 814 MGD. The DJB already uses some biogas generated at its treatment plants for captive power generation and internal requirements.
However, biogas produced at the Keshopur Phase-I and Yamuna Vihar Phase-II plants is currently being flared. The Yamuna Vihar facility generates 18,173 cubic metres of biogas per month, while the Keshopur plant has a designed biogas generation capacity of 257.26 cubic metres per hour.
The project report estimates that the upgraded 18-MGD Keshopur plant could generate between 10,436 and 13,045 cubic metres of biogas daily, depending on the assumptions used for volatile suspended solids.
A DJB official said eligible companies would be shortlisted based on their responses, following which the utility would issue a detailed request for proposals (RFP). The model could subsequently be extended to other sewage treatment plants across Delhi.
