BATHINDA: 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 on Tuesday by Centre for Science and Environment (CSE).
The latest report refutes the contention of power plants, which have been delaying implementation of the norms by raising concerns about availability of limestone and use of its byproduct, FGD gypsum.
The coal-based thermal power plants have to install FGD systems to meet country’ new emission norms by 2022.
Limestone is a key raw material in most FGD systems for controlling sulphur dioxide (SO
) emissions. The report titled “Flue Gas Desulphurization- limestone availability and gypsum use”, is an attempt to examine the issue of availability of limestone for FGD.
CSE Director General Sunita Narain says “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.”
“India is the largest emitter of SO
in the world, contributing more than 15 per cent of global anthropogenic emissions. FGD systems in thermal power plants can reduce SO
emissions from these”, she says.
CSE researchers behind the report say “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 (CaCO
> 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 barring those in North India states.”
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. 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.
CSE report recommends, to ensure safety and minimize fugitive emissions, the Ministry of Environment, Forest and Climate Change (MoEF&CC) should release guidelines for ensuring appropriate safeguards in handling, storage and transport of limestone and gypsum.
The Bureau of Indian Standards (BIS) has specified broad guidelines for gypsum being used in the cement sector. The BIS may also need to specify the quality of limestone being used in FGDs to ensure good quality FGD gypsum.
In the long term, power plants should be directed to use all the FGD gypsum that is produced; however, the short-term disposal guidelines can be issued.