Study on flue gas desulphurization (FGD) systems refutes thermal power industry’s contention that the country does not have enough limestone
New Delhi, March 31, 2020: India has enough reserves of limestone to enable thermal power plants to install flue gas desulphurization (FGD) systems by 2022 in order to meet the new emission norms for the sector, says a new report released online here by Centre for Science and Environment (CSE). This refutes the contention of power plants, which have been trying to delay implementation of the norms by -- among other things -- raising concerns about availability of limestone and use of its byproduct, FGD gypsum.
To meet India’s new emission norms by 2022, a large number of coal-based thermal power plants have to install FGD systems. Limestone is a key raw material in most FGD systems for controlling sulphur dioxide (SO2) emissions. Flue gas desulphurization – limestone availability and gypsum use, as the CSE report is titled, attempts to examine the issue of availability of limestone for FGD.
Said Sunita Narain, director general, CSE: “Many thermal power companies have been raising various concerns regarding FGD installation; one of these is about the availability of limestone, and the use or disposal of FGD gypsum, a by-product of the FGD operation. This report attempts to address both these key issues.”
Say CSE researchers behind the report: “The coal-based power sector would require only seven to 10 million tonnes of limestone annually for operating FGD systems. This is less than 3 per cent of India’s present limestone consumption. For use in FGD, high-quality limestone (CaCO3 > 90 per cent) with minimal impurities is desirable. Industry experts believe that producing additional high-quality limestone would not be a challenge given our large reserves. Moreover, regional distribution of limestone reserves shows that access will not be a problem as a majority of power plants are located within 200 km of a limestone mine.”
Gypsum is a scarce resource in India. The quality of FGD gypsum is at par or even better than mineral gypsum and it has become a substitute for mineral gypsum across the world. China is able to utilise more than 70 per cent of its FGD gypsum, largely in cement and construction. In India as well, gypsum is an integral component of cement production and the sector has to rely on costly imports or poor-quality synthetic gypsum. CSE estimates that by adopting FGD, India’s power plants would produce around 12-17 million tonnes of gypsum which can easily meet the domestic shortfall and reduce the import burden. The cost of limestone, says CSE, will not be significant as it can be offset by selling FGD gypsum.
Said Narain: “India is the largest emitter of SO2 in the world, contributing more than 15 per cent of global anthropogenic emissions. FGD systems in thermal power plants can reduce SO2 emissions from them by 80 per cent, points out this CSE report.”
For more on this or for interviews etc, please contact Sukanya Nair of The CSE Media Resource Centre, firstname.lastname@example.org, 88168 18864.
To access the CSE report: https://www.cseindia.org/flue-gas-desulphurization-limestone-availability-and-gypsum-use-10043