A step forward, two steps back

HERE IS AN old English idiom, almost a cliché, that goes "one step forward, and two steps back". This is how one can aptly describe our approach on the subject of flue gas desulphurisers (FGDs).

- SOMIT DASGUPTA

FGDs are used to remove sulphur dioxide (SO2) from the flue gases emitted by coal/gas-based power stations. This should not be confused with decarbonisation since it has nothing to do with carbon dioxide and in fact, sulphur dioxide is not even one of the greenhouse gases (GHGs).

Yes, the presence of SO2 does add to particulate matter (PM2.5) which can have an adverse effect on our health, especially the respiratory system, through environmental pollution.

In 2015, the ministry of environment, forest and climate change (MoEFCC) introduced new environmental norms for coal-based generation in India. These norms were comparable to world standards; for example, sulphur oxides (SOx) and nitrogen oxides (NOx) were limited to 100 milligrams per normal cubic meter (mg/nm3), particulate matter shouldn't be higher than 30 mg/nm3, mercury was limited to 0.03 mg/nm3, and water was to be less than 3 cubic meters per megawatt-hour (m3/Mwh).

All power stations were to install the FGDs by 2017. However, there was no progress in the matter for various reasons.

The two-year time frame which was given for implementation was not practical, as there was hardly any domestic capacity available for the manufacture of FGDs.

Besides, the entire installation process actually takes three years and hence a two-year time frame was inexplicable.

Then there was the issue of the cost of FGDs, which could vary from ₹0.5 crore per Mw to ₹1.2 crore per Mw.

The cost of retrofitting an FGD was higher when compared to planning for one at the drawing stage itself.