Flue gas desulphurization (FGD) is the method of sulfur dioxide (SO2) removal from flue gas. However, it mainly produces at power plants, though there are other sources. It predominantly consists of Sulphur dioxides, Nitrogen dioxides. And particulate matters.
The Need For Sulphur Desulphurization –
Sulfur, present in fossil fuel gets oxidized by oxygen, also present in fossil fuel and form sulfur dioxide which on reaction with atmospheric water, forms acid rain. Moreover, Sulfur dioxide, through its annual emission, has become the primary gas pollutant. Over the last eighty years, it has been a concern for the environment and ecosystem. And the sad news is, people are less aware about this horrible concern, which is actually a threat to the human race. On top of that, environmentalists and industrialists were in dire need to remove sulfur dioxide from flue gas before releasing in the open air.
The Brief History Of Flue Gas Desulphurization –
Around 1850 new idea of flue gas desulphurization was established in England. In 1931 the first FGD unit was at Battersea Power Station. It is run by London Power Company. However, An article by Jamil et al. (2013) suggests, the Barthes and Bankside Power Plant (UK) first applied the desulfurization process in the year of 1927. During this period FGD installation took place majorly at the Swansea Station and the Fulham Station in England.
Methods Of Flue Gas Desulphurization –
However, methods of flue gas desulphurization include water scrubbing, metal ion solutions, catalytic oxidation, dry adsorption, wet lime scrubbing, double alkali process, processes based on SO2 reduction.
On top of that, an article by R.K. Srivastava and W. Jozewicz (2011) suggests that wet limestone FGD was widely selected over other FGD technologies. Majorly the plants that employ dry FGD technologies use Lime Spray Drying. Their article also suggests from data, that most wet limestone and installation are capable of removing ~90% of SO2. Whereas advanced, wet scrubbers can provide 95% removal of the same. Abrams et al. (2012) report that sea-site power plants have developed a new process using seawater and lime, that can remove almost 90% of SO2.
Current Scenario Of Flue Gas Desulphurization In India –
The government of India has taken the initiative for the reduction of emissions by the Intended Nationally Determined Contributions (INDCs). However, the United Nations Framework Convention on Climate Change (UNFCCC) has focused on reducing emission intensity by 2030. Environmental (Protection) Amendment Rules were issue by The Ministry of Environment. Forest and Climate Change (MoEFCC), has published, 2015 to reduce emissions of SO2. Meanwhile, NTPC has aimed to install FGD units in all plants in India.
Current Trends –
Leading international companies like Mitsubishi Heavy Industries, Doosan Lenjes, Siemens, Rafaco, Thermax, Clyde Bergemann Power Group, etc. vastly employ flue gas desulfurization techniques. Currently, flue gas desulphurization technology has benefited, including high desulphurization efficiency. It also adds high utilization process flow, lower investment, low land acquisition, a higher level of automation, etc. Recent studies and researches are focusing on desulfurization as efficiently as 99.9 %.