Flue gas desulphurization (FGD) technology, commonly referred to as a Scrubber, a proved and effective method for removing sulphur dioxide emissions from the exhaust of coal fired power plants. About 95% of particulate pollutants are removed.
Flue gas (sometimes called exhaust gas or stack gas) is the gas which emanates from combustion of fossil fuel and contains the reaction products of fuel, combustion air and residual substances such as dust, sulphur dioxide, nitrogen oxides and carbon monoxide. Sulphur dioxide is one of the major pollutants, which leads to acid rain.
The basic principle of a sulphur dioxide scrubber system is the removal of SO2 by using its chemical characteristics to combine with water. The scrubbing liquid is bubbled through a slurry of lime, Ca(OH)2,which converts the sulphite ions from the flue gas to form gypsum, a highly stable compound.
The primary aim of arranging the laboratory learning for classes IX & X was to develop their practical competence by providing opportunity to relate and reinforce the theoretical concept of the scrubber method. They were made to perform an activity for the reaction of Sulphur dioxide with Calcium hydroxide slurry.
Objective: To study the reaction of Sulphur dioxide with Lime slurry, Calcium hydroxide.
Materials and Apparatus Required: Sulphur powder, Calcium hydroxide, Distilled water, Boiling tube, Beaker, Delivery tube, Cork, Iron stand, Bunsen burner.
Procedure: Sulphur powder on dry heating burns and combines with atmospheric oxygen to form Sulphur dioxide gas. This gas is passed through a concentrated solution of Calcium hydroxide.
Observation: On passing Sulphur dioxide gas through Calcium hydroxide solution, a white precipitate of Calcium sulphite is formed.
Inference: When Sulphur dioxide reacts with Calcium hydroxide, white precipitate of Calcium sulphite is formed.
This activity helped in enhancing the conceptual learning and developing scientific temperament among the students.
