Flue gas desulfurization equipment

The boiler is the furnace where fossil fuels as coal and wood moistures are burned. The design temperature to operate the furnace is ideally above the meting point of the ash, as the buildup of hard slag increases maintenance costs. Combustion of fossil fuel generates ash, 70-80% is available as fly ash. Small amount stays as bottom ash in the furnace. This bottom ash can be removed through a hopper from the base of the furnace.

The electrostatic precipitator (ESP) is a solid particle filter. This device is very efficient in removing fine particles from flowing gas and is often used for fly ash removal in flue gas desulfurization. In wet scrubber systems energy is applied to the flowing fluid medium. When applied prior to the absorber, ESP applies energy to collect the particles only. This leads to less energy consumption to remove fly ash.

The spray tower or SO₂ absorber captures the sulfur oxides from the flue gas to clean the emitting gas of power plants. An alkali sorbent is sprayed to make contact with the flue gas. The reaction between alkali sorbent and SO₂ in the flue gas forms sulfite and further oxidation leads to sulfate  forming. This step determines the efficiency of the flue gas desulfurization process.

The clarifier separates all solids from the liquid and collects the sludge.

The dewatering system treats the sludge further for disposal to the landfill or for commercial use of the by-product, to make gypsum of it.