Waste could produce biofuel in Indian city

The 5,000 tonnes of waste generated in the city of Chennai, India, per day has the potential to be converted to 120 million litres of aviation fuel and 40.5 million litres of diesel per year.

An expert told newspaper The New Indian Express that through plasma gasification and vitrification process - a technology developed by NASA - the waste could be generated into wealth.

Vinod Bose, coordinator in South India for the Indian arm of US-based Solena Fuels, says his company is vying for a tie up with the state government under the public-private partnership.

He says under the technology, segregation of garbage at source was not necessary: 'It is a complete recycling process without producing any harmful products.'

The technology used a mixture of feedstock to power its systems including agricultural wastes, urban wastes, or any other matter that was carbon based.

The feedstock is prepared and fed into a plasma reactor, which holds one or more plasma torches, which heat the reactor to roughly 5,000°C. The high temperature plasma field is used to transform all organic components into a clean and useful synthetic gas (biosyngas).

Since the chemistry of the reactor is controlled, the major gases formed are carbon monoxide and hydrogen. Once formed, biosyngas is sent to a gas-conditioning island where it is quenched very quickly and rapidly cooled. This cooling causes precipitation of volatile metals into the slag and removes any residual sulphur, chlorides and mercury. Almost 99% of the particulate matter could be removed.

Once this phase is completed, the syngas would be compressed and sent to a gas turbine to produce renewable power and steam in a combined cycle or the biosyngas would be delivered to a Fischer Tropsch process to produce biofuels, including biojet fuel, bionaptha and biodiesel.