NTPC has a fix to curb Delhi smog: Floats tender to buy machinery to convert farm waste into power

Even as hapless citizens watch state governments shift blame for the national capital’s poor air quality, NTPC is moving ahead with its plans to play its role of a good corporate citizen in salvaging the situation. The company Tuesday floated a tender to buy plant and machinery to convert farm waste into pellets that will ultimately be blended with coal to produce power.

The floating of the tender by the start-owned power generator hasn’t come a day soon, coming as it does when the air quality in Delhi has worsened over the years, with the level of cancer-causing pollutants reaching alarming levels last month. Burning of stubble in Punjab and Haryana is mostly blamed for the air pollution in Delhi in winters.

Doctors and environmental experts have repeatedly warned that breathing the Delhi air on such days is extremely harmful to health and could result in lung cancer and other diseases. While the states have taken half-hearted steps to prevent farmers from burning the stubble, the farmers have mostly ignored those diktats, seeking financial incentives to stop the activity.

NTPC is working on a solution to this problem by utilising the farm residue for power generation in its coal-fired power plants which would add value to farm residue and create a market for it. Farmers may then start to sell the waste against the current practice of burning it right in the field.

The company seeks to identify vendors for supply and installation of plant and machinery for torrifaction of farm residue and manufacturing of pellets. Torrifaction is a process in which biomass is subjected to high temperature in absence of oxygen to convert it into a coal-like material.

Torrifaction increases calorific value, reduces moisture content and makes biomass brittle and grindable in normal coal mills. It also leads to reduction in transport component of torrified biomass due to increase in calorific value of biomass after torrifaction.

While the state-owned power generator has already demonstrated the co-firing of raw biomass pellets blended with coal for up to 7 per cent quantity, it is further looking at possibility of cost effective utilization of farm residue to make torrified pellets for use as a fuel in its power plants.

NTPC aims to replace coal with secondary fuel such as paddy straw and other farm waste-based briquettes and pellets to the extent of 5 per cent to 10 per cent of daily consumption at plants wherever this machinery can be installed.

The raw farm residue cannot be directly utilized in power plants and needs to be processed first in form of pellets or torrified biomass. Another advantage of torrifaction is reduction in transport component of torrified biomass due to increase in calorific value of biomass after torrifaction.

Through another tender floated by India’s largest power generation utility, it intends to procure 850-1000 tons per day of paddy straw and other farm waste.