Bongaigaon, Dec. 1: A septuagenarian here is showing a novel way of producing cooking gas and manure from cow dung and urine, thereby reducing dependence on the "at-times-elusive" LPG refills.

Arun Karmakar, 70, learnt the art of producing marsh gas during a series of awareness programmes that he attended in Gujarat four years back.

Marsh gas is biogas, that forms in wetlands, whose principal component is methane and is produced naturally in marshes and swamps.

"My cow excretes around 4kg dung and four litres of urine every day and a mix of them helps produce cooking gas for two hours," Karmakar, a resident of Bagan Road, told The Telegraph.

His method is quite simple. "I collect the excretory waste of my locally bred cow and dump it in a dry well that already has a healthy deposition of the waste. Thereafter, an inverted plastic drum is placed over the dump while a few bricks are heaped over it to apply pressure. A few minutes later, the marsh gas that emanates from the fresh waste is channelled through a rubber tube connected to a burner," Karmakar, who runs an optical store, said.

"Now, I need just one LPG refill a month instead of two, thanks to this method," he added.

When the gas stops generating, a black paste-like substance is formed inside the drum. "This substance is a substitute for manure that can be used in flower gardens and for growing vegetables," Karmakar said.

Since Karmakar's small house does not have enough space for a flower garden, he distributes the manure free of cost among those who grow vegetables and flower plants in his locality. "I distribute the manure to promote the practice of generating gas through this method," he said.

"This pure, organic manure is very potent. I experienced it when I used it for my kitchen garden and flower garden," said Sanjay Sarma, a resident of New Colony, Bongaigaon.

One needs at least five cows to become totally dependent on marsh gas for their daily cooking. "But, unfortunately, I do not have the space to keep five cows," Karmakar said.

"The waste of only locally bred cows that feed on grass can effectively generate marsh gas. Crossbred cows generally thrive on chemical-fortified fodder and the gas formation from their waste is not up to the mark," he said.