FGD System In Power Plant

Ruichang offers integrated solutions for FGD systems in power plants, we have a professional engineering team and strong production capacity, and our EPC project covers system design, equipment supply, civil construction, on-site installation, and etc.

With increasingly strict environmental protection requirements, FGD system(flue gas desulfurization technology) in thermal power plants has become an important means of controlling sulfur dioxide (SO ₂) emissions. Sulfur dioxide is one of the main pollutants produced by burning sulfur-containing fuels such as coal and petroleum, which can cause environmental problems such as acid rain and haze. Therefore, adopting advanced FGD technology is the key to reducing pollution and achieving green development in thermal power plants.

FGD process

1. Flue gas pretreatment: The flue gas discharged from the boiler or other combustion device enters the desulfurization system and first passes through the flue gas cooling device to adjust the flue gas temperature to a suitable range.
2. Slurry spray: The prepared calcium hydroxide slurry is sprayed into the spray drying tower through the nozzle to form small droplets.
3. Acid-base reaction: in the spray drying tower, the calcium hydroxide in the droplets reacts with SO ₂ in the flue gas to generate calcium sulfite and water. Water evaporates rapidly, leaving behind solid particles.
4. Solid particle capture: The solid particles generated by the reaction are separated from the flue gas by a bag filter or electrostatic precipitator.
5. Recycling: The captured solid particles are partially returned to the circulating fluidized bed reactor to continue participating in the reaction, and the unreacted calcium hydroxide is also reused.
6. Clean flue gas emissions: After dust removal, the clean flue gas is discharged through the chimney, with a smoke exhaust temperature of 80 ℃, no white smoke, and no corrosion.

FGD equipment

• Spray drying tower: one of the core equipment, which is responsible for injecting calcium hydroxide slurry into the hot flue gas to remove SO ₂ through rapid evaporation and chemical reaction.
• Circulating fluidized bed reactor: provides an environment where flue gas and calcium hydroxide powder come into full contact, promoting acid-base reactions.
• Bag filter (or electrostatic precipitator): captures the solid particles generated by the reaction and purifies the treated flue gas.
• Slurry preparation system: responsible for preparing and supplying calcium hydroxide slurry, usually including equipment such as lime digesters, slurry tanks, and mixers.
• Humidification device: Provides water humidification effect when necessary to assist in the reaction.

Advantages of FGD system in power plant

• High desulfurization efficiency: Using calcium hydroxide as a desulfurizer, the reaction efficiency is high, and the desulfurization efficiency is usually above 90%.
• No wastewater discharge: Water evaporates completely in high-temperature flue gas without generating wastewater, avoiding secondary pollution.
• Low temperature smoke exhaust: The smoke exhaust temperature is 80 ℃, which is lower than many traditional wet desulfurization processes and reduces heat loss.
• No white smoke, no corrosion: Due to the low exhaust temperature and low water content, white smoke and corrosion problems are avoided.
• Easy operation and maintenance: The equipment is simple, easy to operate and maintain, and the operating cost is relatively low.

FGD Technology

The semi-dry flue gas desulfurization process is an efficient technology for removing sulfur dioxide (SO ₂). It uses calcium hydroxide powder as a desulfurizer. It absorbs the acidic gas SO ₂ in the flue gas through acid-base reactions and gas-solid mass transfer in a circulating fluidized bed under the activation and humidification effect of water. This process has the characteristics of low exhaust temperature (80 ℃), no white smoke, no corrosion, no wastewater generation (no secondary pollution), and high desulfurization efficiency.

Process principle

• Acid-base reaction: SO ₂ in flue gas is an acidic gas, while calcium hydroxide (Ca (OH) ₂) is an alkaline substance. The two undergo an acid-base neutralization reaction, producing calcium sulfite (CaSO3) and water.
  SO2+Ca(OH)2→CaSO3+H2O\text {SO}_2 + \text{Ca(OH)}_2 \rightarrow \text {CaSO}_3 + \text {H}_2 \text {O}SO2 +Ca(OH)2→CaSO3+H2O
• Circulating fluidized bed gas-solid mass transfer: In the circulating fluidized bed, the flue gas and calcium hydroxide powder are in full contact, resulting in high mass transfer efficiency and fast reaction rate between the gas-solid phases.
• Water activation and humidification effect: in the spray drying tower, the water in the slurry evaporates rapidly under the action of high-temperature flue gas, increasing the reaction surface area and improving the reaction efficiency.

Ready to invest in an FGD system in power plant?

The global flue gas desulfurization system market is expected to experience volatile growth in 2024, mainly influenced by economic factors and supply chain issues. However, with the improvement of the economy and the alleviation of supply chain issues, market demand is expected to rebound in the second half of 2024.

The Asia Pacific region is the main market for flue gas desulfurization technology, especially in China and India, where there is a strong demand for sulfur dioxide emission control due to high coal consumption. Strict environmental regulations and increasing public awareness of the health impacts of air pollution have driven the demand for desulfurization systems in the region. Japan, South Korea, Australia and other countries are also investing in desulfurization technology to reduce SO ₂ and other pollutant emissions

In North America, especially in the United States and Canada, the flue gas desulfurization market is stable and environmental investments are gradually increasing to meet higher environmental standards.

The European market is expected to continue to grow due to strict implementation of environmental policies and regulations, with major countries including Germany, the United Kingdom, France, and Italy.

5 reasons you should invest in FGD plant

• Driven by environmental regulations: The increasingly stringent environmental regulations worldwide require companies to reduce emissions of pollutants such as SO ₂, which drives the demand for flue gas desulfurization technology. Investing in semi dry flue gas desulfurization technology can help companies comply with these regulations and avoid fines and penalties for environmental violations.
• Economic benefits: Although the initial investment is relatively high, the semi dry desulfurization technology can bring significant economic benefits in the long run due to its efficient desulfurization rate and low operating costs. The advantages of no wastewater discharge and no secondary pollution have reduced the cost of wastewater treatment and environmental governance.
• Market demand growth: With the continuous increase in demand for desulfurization technology in the Asia Pacific region, especially in China and India, the market prospects are broad. Investing in this technology can seize rapidly growing market opportunities and yield substantial returns.
• Sustainable development: In the context of the global transition towards sustainable development, adopting clean technologies such as semi dry desulfurization can significantly enhance the environmental image of enterprises and enhance market competitiveness. At the same time, this is also in line with the global trend of green economy development.
• Technological progress: With the continuous advancement of technology, the efficiency and reliability of semi dry flue gas desulfurization systems continue to improve. Investing in this field can gain the latest technological advantages and enhance the competitiveness of enterprises in the market.