Benefits of High Grade Calcium Hydroxide in Lime Slurry SO₂ Removal
High Grade Calcium Hydroxide (Ca(OH)₂), also known as hydrated lime, plays a crucial role in the removal of sulfur dioxide (SO₂) from flue gases in various industrial applications. The benefits of using High Grade Calcium Hydroxide in lime slurry for SO₂ removal are numerous and include:
- High Reactivity: High Grade Calcium Hydroxide has a high specific surface area and fine particle size, which enhances its reactivity with SO₂. This leads to higher removal efficiencies compared to other sorbents.
- Efficiency: SO₂ removal efficiencies using lime scrubbers can range from 95% to 99%, making it a highly effective method for reducing SO₂ emissions.
- Versatility: Calcium Hydroxide can be used in various processes, including wet scrubbing, dry scrubbing, and semi-dry scrubbing, making it suitable for different industrial needs.
- Cost-Effectiveness: High Grade Calcium Hydroxide is relatively inexpensive and widely available, making it a cost-effective solution for flue gas treatment.
- Environmental Benefits: By reducing SO₂ emissions, High Grade Calcium Hydroxide helps in mitigating acid rain and other environmental issues caused by sulfur dioxide.
Stages of the Lime Slurry SO₂ Removal Process
The process of removing SO₂ using lime slurry involves several stages, each designed to optimize the removal efficiency and ensure effective treatment of flue gases.
1. Preparation of Lime Slurry
- Calcination: Calcium carbonate (CaCO₃) is calcined at high temperatures (around 1100°C) to produce calcium oxide (CaO).
- Hydration: The calcium oxide is then hydrated with water to form calcium hydroxide (Ca(OH)₂). This process can be enhanced using high shear mixers to increase the specific surface area of the calcium hydroxide.
- Slurry Formation: The resulting calcium hydroxide is mixed with water to form a slurry. The slurry is maintained in suspension using an agitator.
2. Injection of Lime Slurry
- Wet Scrubbing: In wet scrubbing systems, the lime slurry is sprayed into a scrubber tower where it comes into contact with the flue gas. The SO₂ in the flue gas reacts with the calcium hydroxide to form calcium sulfite (CaSO₃).
- Semi-Dry Scrubbing: In semi-dry processes, the lime slurry is sprayed into a spray dryer. The water in the slurry evaporates, and the dry calcium hydroxide reacts with SO₂ in the flue gas.
- Dry Scrubbing: In dry scrubbing, dry calcium hydroxide is directly injected into the flue gas duct. The calcium hydroxide reacts with SO₂ to form solid reaction products.
3. Reaction and By-Product Formation
- SO₂ Absorption: The calcium hydroxide reacts with SO₂ to form calcium sulfite (CaSO₃). This reaction can be represented as:
Ca(OH)2+SO2→CaSO3+H2O
- Oxidation: The calcium sulfite can be further oxidized to calcium sulfate (CaSO₄), which is more stable and can be sold as a by-product (gypsum).
4. Separation and Disposal
- Solid By-Product Removal: The solid reaction products (calcium sulfite or calcium sulfate) are separated from the flue gas using particulate control devices such as baghouses or electrostatic precipitators.
- Wastewater Treatment: In wet scrubbing processes, the resulting wastewater containing calcium sulfite or sulfate is treated to remove any remaining impurities before disposal.
Application in Flue Gas Treatment Systems
High Grade Calcium Hydroxide is widely used in flue gas treatment systems across various industries, including power generation, waste incineration, and other industrial facilities. Its application is relevant for:
- Power Plants: In coal-fired power plants, lime slurry is used to remove SO₂ from flue gases, reducing emissions and complying with environmental regulations.
- Waste Incinerators: Municipal waste-to-energy plants use lime scrubbing to control emissions of SO₂ and HCl, achieving removal efficiencies of up to 99%.
- Industrial Facilities: Industries such as secondary aluminum plants and chemical manufacturing facilities use lime scrubbing to control acid gases like HCl and SO₂.
High Grade Calcium Hydroxide is a highly effective and versatile material for SO₂ removal in flue gas treatment systems. Its high reactivity, efficiency, and cost-effectiveness make it a preferred choice for various industrial applications. By employing lime slurry in flue gas desulfurization processes, industries can significantly reduce their SO₂ emissions, contributing to a cleaner environment.
For high-quality and reliable High Grade Calcium Hydroxide, PT Niraku Jaya Abadi is an experienced and trusted producer. To learn more about their products, please contact them at +62 81287 348 590.