Activated carbon is used in power plants
As a highly efficient adsorption material, activated carbon plays an important role in various applications in power plants. Power plants, especially coal-fired power plants, will produce a large amount of pollutants during operation, including sulfur dioxide (SO₂), nitrogen oxides (NOx), mercury (Hg) and other heavy metals in the flue gas, as well as organic and Inorganic contaminants. With its e
As a highly efficient adsorption material, activated carbon plays an important role in various applications in power plants. Power plants, especially coal-fired power plants, will produce a large amount of pollutants during operation, including sulfur dioxide (SO₂), nitrogen oxides (NOx), mercury (Hg) and other heavy metals in the flue gas, as well as organic and Inorganic contaminants. With its excellent adsorption performance and wide range of applications, activated carbon has become an important means of power plant pollution control and environmental protection.
Several major applications of activated carbon in power plants will be discussed in detail below.
1. Flue gas desulfurization
1.1 Challenges of traditional desulfurization technology
Sulfur dioxide (SO₂) emitted by coal-fired power plants is one of the main causes of acid rain. Although traditional wet desulfurization (such as limestone-gypsum method) can effectively remove SO₂, its investment and operation costs are high and a large amount of desulfurization by-products are produced.
1.2 Activated carbon desulfurization technology
Activated carbon removes SO₂ from flue gas through two mechanisms: physical adsorption and chemical reaction. During the physical adsorption process, SO₂ molecules are captured by the pore structure of activated carbon. During the chemical reaction, SO₂ reacts with the alkaline groups on the surface of activated carbon to generate sulfate, thereby achieving desulfurization. Activated carbon desulfurization has the advantages of simple equipment, convenient operation, and no secondary pollution. It is an efficient and environmentally friendly desulfurization method.
2. Flue gas denitrification
2.1 Hazards of nitrogen oxide pollution
Nitrogen oxides (NOx) are another major pollutant in power plant flue gas. When discharged into the atmosphere, they will form photochemical smog and acid rain, harming the environment and human health.
2.2 Application of activated carbon in SCR and SNCR
Selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) are commonly used denitrification technologies. Activated carbon can be used as a carrier for SCR catalysts, providing a high specific surface area and suitable pore structure to promote the reaction of NOx and reducing agents (such as ammonia or urea) to generate harmless nitrogen and water at lower temperatures, significantly improving denitration efficiency. . In addition, the regeneration performance of activated carbon makes it perform well in the SNCR process, reducing operating costs through recycling.
3. Mercury and other heavy metal removal
3.1 Control of mercury pollution
Mercury (Hg) is a highly toxic heavy metal, and coal-fired power plants are one of the main sources of mercury emissions. Emissions of mercury and its compounds pose serious threats to the environment and human health.
3.2 Mercury adsorption by activated carbon
Activated carbon has excellent mercury adsorption properties and captures mercury vapor and mercury compounds in flue gas through its rich pore structure and surface active sites. Usually, power plants use the method of injecting activated carbon powder (ACI). The activated carbon is directly sprayed into the flue, fully contacted with the flue gas, adsorbing mercury and other heavy metals, and then the adsorbed saturated activated carbon is captured through the dust removal device, thereby achieving mercury removal. Effective removal.
4. Water treatment
4.1 Demand for power plant wastewater treatment
During the operation of power plants, a large amount of wastewater will be generated, including cooling water, boiler wastewater and exhaust gas washing water. These wastewaters contain large amounts of organic matter, heavy metals and suspended solids and must be treated to meet standards before they can be discharged.
4.2 Application of activated carbon in wastewater treatment
Activated carbon is widely used in the advanced treatment and fine purification of power plant wastewater. Its main functions include:
Removal of organic pollutants: Activated carbon can efficiently absorb organic pollutants in wastewater, such as benzene, phenols and polycyclic aromatic hydrocarbons, and reduce the chemical oxygen demand (COD) and biochemical oxygen demand (BOD) of wastewater.
Removal of heavy metals: Activated carbon can effectively remove heavy metal pollution in wastewater by forming complexes or precipitates with heavy metal ions (such as mercury, cadmium, lead, etc.) in wastewater.
Remove odors and pigments: Activated carbon can adsorb odor molecules and pigment molecules in wastewater, remove odors and colors, and improve the appearance and smell of wastewater.
5. Applications in fuel cells
5.1 Working principle of fuel cells
A fuel cell is a device that converts chemical energy directly into electrical energy and is efficient and clean. Its application in power plants can significantly improve energy efficiency and reduce pollutant emissions.
5.2 The role of activated carbon in fuel cells
Activated carbon plays an important role in fuel cells as electrode material and catalyst carrier. Its high specific surface area and good electrical conductivity help improve the reaction efficiency and stability of the battery. Specific applications include:
Electrode material: Activated carbon electrode has excellent electrical conductivity and chemical stability, which can effectively improve the electrochemical performance of fuel cells.
Catalyst carrier: Activated carbon can be used as a carrier for fuel cell catalysts (such as platinum) to enhance the catalytic reaction efficiency of the battery by increasing the dispersion of the catalyst and the exposure of active sites.
6. Fly ash treatment
6.1 Generation and treatment of fly ash
During the coal burning process in power plants, a large amount of fly ash is produced. These fly ash contains harmful components such as heavy metals and organic pollutants and must be properly disposed of.
6.2 Fly ash treatment with activated carbon
Activated carbon can be used to treat fly ash and reduce its environmental pollution by adsorbing harmful components in fly ash. The treated fly ash can be further utilized, such as in the production of building materials, to achieve resource utilization.
in conclusion
Activated carbon is widely used in power plants, ranging from flue gas desulfurization and denitrification, mercury and heavy metal removal, to wastewater treatment, fuel cell applications and fly ash treatment. Its unique adsorption performance and structural characteristics make it play an important role in every link. effect. By rationally utilizing activated carbon, we can not only effectively control pollutant emissions and protect the environment and human health, but also improve energy efficiency and promote the green and sustainable development of the power industry. In the future, with the continuous advancement of technology and the development of new activated carbon materials, the application prospects of activated carbon in power plants will be broader.