NTPC to scale up production of green coal

The last date to submit bids for the Greater Noida waste-to-coal plant is September 7, and for the Bhopal and Hubballi plants it is September 12.

In a first for the country, NTPC Ltd, one of India’s biggest coal consumers in the power sector, has successfully produced “green coal” (torrefied charcoal) in a trial, using garbage or municipal solid waste (MSW). After the trial in Varanasi (Uttar Pradesh), the central public sector undertaking (CPSU) has now decided to set up more such waste-to-coal plants across the country. The largest one is proposed to be set up in Greater Noida (Uttar Pradesh), with a capacity of 900 tons per day (TPD).

“We have demonstrated MSW-to-green charcoal at our plant in Varanasi and are now taking this to Greater Noida, Bhopal (Madhya Pradesh) and Hubballi (Karnataka),” said Gurdeep Singh, chairperson and managing director (CMD) of NTPC Ltd, while addressing the media and investors during a recent interaction. He also hinted at the company being open to build more such plants for those keen on environmental, social, and governance (ESG) investments.

NTPC Vidyut Vyapar Nigam Ltd (NVVNL), a subsidiary of NTPC, set up the green coal plant in Varanasi (Uttar Pradesh) — India’s first — with the capacity to produce 600 tons of green charcoal per day. The plant, comprising three reactors with a production capacity of 200 TPD each, is likely to be fully commissioned in December, senior officials of the company said, on condition of anonymity. Until now, the CPSU, along with its EPC (engineering procurement construction) contractor Macawber Beekay, has successfully trialled one reactor. While the second reactor has also been installed and trials are yet to begin, the third one will be set up this month.

For the upcoming projects, NVVNL has floated tenders to set up a 900 TPD waste-to-coal plant in Greater Noida’s Astauli village, a 400 TPD plant in Bhopal and 200 TPD in Hubballi. The last date to submit bids for the Greater Noida plant is September 7; for the Bhopal and Hubballi plants, it is September 12.

What is green coal?

Simply put, “green coal” is charcoal made using municipal solid waste (MSW) through torrefaction, a thermal treatment of the trash, technically called segregated combustible fraction (SCF). It is carried out in an oxygen deficient condition.

The process uses biomass pellets (produced using agro waste) to start the combustion process. It also results in production of some gases which, in turn, are used in the reactors to burn the MSW into charcoal, thereby keeping emissions to a minimum.

The charcoal that is discharged is further cleaned using a sieve. The pure char is then mixed with exacting proportions of a binder and water to give the green charcoal the shape of pellets.

How is green coal used?

The green charcoal can be fed into any thermal power plant and blended with naturally mined coal to generate electricity.

It can serve as a sustainable and fossil-free alternative for a host of other industries, such as metallurgy, chemicals, and so on.

Green coal is carbon neutral as it is derived from MSW without any mining of fossil fuels.

Currently, it is not possible to completely replace organic coal with green coal in the country’s thermal power plants. This is because green coal production is at a nascent stage. Secondly, no trials have been conducted to assess whether the existing coal-fired power plants can operate successfully with 100 percent green coal as a feedstock.

Can green coal make a difference?

Power plants are the biggest consumers of coal. Typically a 1,000 MW plant consumes about 5 million tonnes of coal annually. India’s total coal-based power generation capacity is about 200,000 MW, which theoretically means it can consume approximately 1 billion tonnes of coal annually.

“Even 10 percent of that, if replaced with green charcoal, will amount to 100 million tonnes of this fuel. It will require approximately 160 million tonnes of agro residue and municipal waste (considering 60 percent yield), sufficient to wipe out the entire unused agro residue in the country. It will also address the issue of farm fires and produce approximately 20,000 MW of renewable power while generating revenue worth Rs 50,000 crore per year,” Singh said.

According to Macawber Beekay, using 1 kg of green coal as solid fuel by replacing fossil coal reduces approximately 2 kgs of CO2 produced per kg of fossil coal.