At the vegetable market in Mandavelli, traders are now sorting out the good vegetables from the bad. They are not throwing away the bad ones, though. They are keeping it. Wondering why? It is all for a good cause. The biodegradable waste is sent to a bio-methane plant next to the Amma Canteen on Kamaraja Salai in Mandaveli. Gas produced at the plant has been powering this canteen for a few months now.
The Thiruvanmiyur wholesale vegetable market is said to be contributing considerable amounts of bio-degradable waste to the plant.
Into a 15-metre cube digester, mashed waste is poured to be converted into methane. The gas is piped to the stoves at the canteen.
“The digester can take waste up to 750 kilos a day, but we are getting only 600 kilos. As we were unable to get much ‘feed’ from the Mandaveli market, vegetable waste from Thiruvanmiyur is being brought here,” says a corporation official in-charge of the project.
Up to two LPG cylinders could be saved every day if the canteen runs entirely on biogas, says the official.
The staff at the Amma canteen are however not entirely happy with green move. For them, using methane gas means longer cooking time.
“The pressure from the biogas plant is less compared to LPG. It takes 20 minutes to just boil the milk. We are still using LPG, to a large extent, for cooking. Only things like boiling water and milk and tempering are done on stoves connected to the methane gas plant,” says a woman working at the canteen.
This attitude needs to change, says the official.
“It is true that the pressure from the methane plant is lower, but the heat generated is the same. Therefore, major differences in cooking time will not be there. There is still a long way to go before we can persuade the staff to completely shift to using methane gas,” he adds.
To increase pressure, there are plans to place sand bags on top of the plant.
Waste matter from the bio-methanisation process is being put to good use.
“The slurry is left to dry and then used as manure for the gardens,” says the official.
There are also plans to approach residents of the neighbourhood asking them to segregate waste for the plant.
Similar plants are being constructed at sites attached to Amma Canteens in Pallikaranai, Alandur, Gosha Hospital and Pattalam. At Perambur Loco Works, such a plant is functioning.