Co-firing of biomass pellets in thermal power plants
Recently the Air Quality Management Commission (CAOM) has reviewed the progress of Biomass Co-firing/Tendering in Thermal Power Plants (TPPs).
- In September 2021, CAOM directed 11 thermal power plants (TPPs) to try to use a 5-10% blend of biomass pellets made primarily from agricultural residues. In other words, the commission had directed the use of biomass for power generation through co-firing in 11 TPPs. This will help in addressing the problem of air pollution caused by stubble burning in the fields and reduce the carbon footprint of thermal power plants. Also, this will ensure proper site combustion or ex-situ use of the stubble.
- However, as per CAOM review, only 7 out of 11 TPPs have started co-firing.
Biomass Co-firing:
Biomass co-firing is the combustion of coal as well as biomass in coal based power plants.
The following three different models or concepts exist for co-firing:
- Direct Co-firing: Under this, the combustion of biomass and coal is done in the same furnace.
- Indirect Co-firing: In this, solid biomass is converted into a clean fuel gas using a biomass gasifier. The gas can then be combusted in the same furnace with coal.
- Parallel Co-firing: In addition to the conventional boiler, a completely separate biomass boiler is installed.
Biomass co-firing has the following advantages:
- Lower capital cost, higher efficiency, increased economy of scale or less expensive process.
- Reduction in cost of electricity due to better performance of large sized and conventional coal based power plants, etc.
Initiatives to reduce air pollution with coal based TPPs:
- National Mission on Use of Biomass in Thermal Power Plants, 2021
- Thrust on setting up of Flue Gas Desulfurization (FGD) units
- Advanced Ultra-Super Critical Technology Research and Development Project
- Revised and stringent emission norms for coal based TPPs
Source – The Hindu
