Flue Gas Desulfurization (FGD) Plants

Air Quality Control Systems (AQCS)
  • Max. Capacity

    1,050 MW

  • Max. Inlet SO2 Concentration

    80,000 mg/Nm3 (Coal fired)

  • Max. SO2 Removal Efficiency


  • High Reliability

The flue gas desulfurization (FGD) plant removes sulfur dioxides (SO2) from flue gas produced by boilers, furnaces, and other sources. Mitsubishi Power effectively contributes to the prevention of air pollution through its wet limestone-gypsum FGD process and seawater FGD process, and both processes can treat a large range of SO2 concentrations for greater plant reliability and economics.



We have supplied more than 300 FGD plants worldwide and have acquired a larger market share by offering the following features:

  • High SO2 removed efficiency meeting required emission standards for all kinds of fossil fuels
  • Multiple pollutant control with associated environmental control equipment
  • High reliability
  • Energy and utility savings

Wet Limestone-Gypsum FGD Process

This process is suitable for large-scale flue gas treatment, and can uses a low cost absorbent (limestone), and produces stable and valuable by-products (gypsum).
Typical system flow is shown below.

Flue Gas Desulfurization (FGD) Plants-01.jpg
System Flow

Scrubber Types

Mitsubishi Power offers two types of scrubbers: one is a double contact flow scrubber and the other is a spray tower scrubber. The optimal scrubber type is selected based on flue gas conditions, site layout, etc.

Flue Gas Desulfurization (FGD) Plants-02.jpg
Double Contact Flow Scrubber (DCFS)
Flue Gas Desulfurization (FGD) Plants-03.jpg
Spray Tower Scrubber


We have delivered over 300 FGD plants under the following conditions.

Desulfurization Efficiency 70 thru 99%
Dedusting Efficiency 70 thru 90%
Inlet SO2 Concentration
Coal, Lignite 750 thru 22,000 mg/Nm3 (260 thru 7,700 ppm)
Oil, VR, etc. 700 thru 16,000 mg/Nm3 (240 thru 5,600 ppm)
Sintering 700 thru 84,000 mg/Nm3 (240 thru 29,400 ppm)

Seawater FGD Process

This process can be applied in regions with soft regulations on SO2 emissions and initial cost is lower than the wet limestone-gypsum FGD process due to the simple equipment configuration.
Typical system flow is shown below.

Flue Gas Desulfurization (FGD) Plants-04.jpg
System Flow

Major Components of Seawater FGD

The seawater FGD consists of two major components : grid tower scrubber and the aeration basin. In the grid tower scrubber, seawater absorbs SO2 from the flue gas. In the aeration basin, the SO2 rich seawater is treated to make it suitable for discharge to back to the sea.

Flue Gas Desulfurization (FGD) Plants-05.jpg
Grid Tower Scrubber
Flue Gas Desulfurization (FGD) Plants-06.jpg
Aeration Basin


We have delivered seawater FGD plants under the following wide conditions.

Desulfurization Efficiency 70 thru 98%
Typical Inlet SO2 concentration 650 thru 5,300 mg/Nm3(230 thru 1,900 ppm)
Typical Capacity 370,000 thru 630,000 Nm3/h
Fuel Coal, Oil, etc.