Biogas units, solution for garbage menace?

Consumers complaining of poor of LPG cylinder supply is a common sight. Here, a family comprising five members, needs only two LPG cylinders a year.

Sheetal N Singh, research and development officer at Karnataka State Biofuel Development Board, says she uses two LPG cylinders per year. The biofuel plant at her house generates biogas needed for the entire family’s chores.

“One cubic meter of biogas can be generated from one-and-a-half-kilo wet waste,” she says. The plant which costs about Rs 30,000, needs a sintex tank of 1,000 litres, in-let and outlet for the flow of gas, a burner, and around 15 litres of water.

Sheetal says, to begin with, leave the cow dung in the tank for 15 to 20 days, during which methane is produced.

“Ignite the burner after 14 to 18 days and once it starts burning, stop using the cow dung and replace the same with kitchen waste,” she explains. The gas can be used for two to four hours at a time. The entire process requires 10 to 12 hours.

“If the kitchen waste is stored the previous night, biogas will be ready to use the next day,” she says. Listing out some drawbacks, Sheetal says the process is time consuming. For instance, if the time taken to boil water is eight minutes, using LPG cylinders, it takes around 10 minutes on biogas.

Similarly, if rice is boiled in 15 minutes, it will take an additional four minutes on biogas,” she notes.