Coal mills are not designed for agro-waste
Electricity production through combining biomass and coal, in coal-based thermal power plants is an efficient way of utilizing the agro-residue and avoiding environmental pollution. At the same time, this generates extra revenue for farmers by sale of agro-residue as raw material input to the pallet manufacturer.
NTPC Ltd and its successful model
NTPC Ltd. (formerly known as National Thermal Power Corporation Limited) is an Indian company in the business of generation of electricity and related activities. Our latest project involves the production of burning agro-waste pallets to generate energy. This is in line with the new policy of the Indian Ministry of Power. NTPC has started the first phase of its project by successfully co-firing 200MW at its coal-based plant located in Dadri (near Delhi). This model can be applied to its other coal-fired plants across India. NTPC will procure the pallets at approximately INR 5,500/tonne increasing farmers’ income with INR 11,000/acre.
The Indian Ministry of Power has brought out a policy for “Biomass utilization for power generation through co-firing in coal-based power plants”. According to the policy, coal-based thermal power plants shall endeavor to use 5-10% blend of biomass pallets made, primarily, of agro-residue along with coal after assessing the technical feasibility, safety and quality.
The raw agro-residue cannot be directly used in thermal power plants, because coal mills are not designed to pulverize the fibrous biomass. To be able to transform the biomass into burnable pallets, they need to be grinded into smaller particles. Burning of agricultural residues not only reduces the fertile strength of the soil, but also releases huge amounts of ash in air which suddenly increases the level of PM 2.5 and PM 10 micro-particles in the air.
For the agro-residue to be usable for burning, the loose biomass needs to be turned into pallets and then roasted. The roasting is also called ‘torrefaction’, which means slow- and mild-pyrolysis, cooking and high-temperature drying of the biomass in a temperature regime between 200 and 3000 0C in an inert atmosphere. The biomass pallets are brittle and hydrophobic with improved physical and chemical properties such as grindability, storage stability, energy density and they have the potential to significantly reduce the cost of transportation, storage, and downstream processing.
Potential future impact
The 20 plants have a total consumption of 19,440 tonnes per day, thereby creating a market of around INR 500 million. Thus, about 145 million tonnes of farm residue being burnt in the fields every year across country if fully utilized by biomass co-firing in power plants and it can produce about 30,000 MW of electricity year-round. This is as much electricity as solar panels of 1,50,000 MW produce in a year. Along with this, there could be a market of about INR 1000 billions.
Parties invited to join the fuel revolution
At its plant in Dadri, NTPC has demonstrated that this model is successful and can be deployed across the country for not only environmental benefits (through reduction in air pollution), but also through generating additional income and benefiting the livelihood of Indian farmers by providing economic value to the stubble waste. NTPC is now reaching out to interested parties for sourcing pallets for its power plants across the country and will hold a workshop to train them on the new entrepreneurs before the bids.
Please note that for this item the contact person is not the owner of the item, but the person below.
Mr Ashvini Kumar Verma
Manager (Project Engg.-Mechanical), NTPC limited
Mr. Aditya Raghwa