Active, high surface area calcium hydroxide desulfurization (powder) technology performs desulfurization absorption and product treatment in a dry state. This method boasts advantages such as no wastewater or waste acid discharge, reduced equipment corrosion, no significant temperature drop during flue gas purification, higher flue gas temperature post-purification, favorable for chimney exhaust diffusion, and minimal secondary pollution. It is suitable for flue gas desulfurization technology in industries such as steel, coking, cement, glass, and ceramics.
Section 1: Desulfurization Technology Introduction
In recent years, the dry desulfurization technology for flue gas has seen increasing application in small and medium-sized flue gas desulfurization systems, with mature technology and stable operation. Among them, the SDS desulfurization process route using sodium bicarbonate as the alkali source has rapidly expanded its market share due to its high desulfurization efficiency, broad source of desulfurizing agents, and low difficulty in engineering implementation.
As the number of equipment increases, the drawbacks of this technical route begin to show, and how to handle desulfurization ash has become a new environmental challenge. Sodium-based desulfurization ash is a mixture of sodium sulfate, sodium sulfite, and sodium carbonate..The material has excellent water solubility and is classified as general solid waste that is difficult to dispose of in compliance with regulations. Authoritative statistics show that the coking industry alone produces up to 300,000 tons of sodium-based desulfurization ash annually. This figure is further increased by the power plants, hot blast stoves, and heating furnaces of steel companies, as well as glass and cement kilns. Some companies rent land to build warehouses for storage, while others sell it to qualified institutions for disposal, with costs varying from 300 to 500 yuan per ton, thereby increasing the burden on businesses.
As of September 1, 2020, the revised "Environmental Protection Law of the People's Republic of China on Solid Waste Pollution" came into effect, introducing new responsibilities for enterprises generating solid waste and imposing severe penalties on violations. The pressure on businesses has surged!
Tianjin Huining Langtian Environmental Protection Equipment Co., Ltd. has successfully developed highly porous calcium hydroxide after four years of research and development, with the efforts of our technical staff. The specific surface area (BET) exceeds 45 m2/g. Through independently developed core equipment, we have created a new production process, achieving large-scale production. Our Tianjin production base has a 100,000-ton capacity, offering excellent product performance!
With our company's developed HNPS desulfurization system, over 30 units have been industrially applied with excellent operational data, low costs, and satisfied customers. Currently, the system has been successfully applied for ultra-low emission desulfurization in coking plant push-out ground stations, dry-cooling coke environment dust removal, coke oven flue gas, steelmaking heating furnaces, hot blast stoves, power plant boilers, and waste incineration industrial furnaces.
High-activity, high-specific surface area calcium hydroxide - microscopic crystalline structure under electron microscopy
Section 3: High Activity, High Specific Surface Area Calcium Hydroxide Desulfurization Agent Specifications
Section 4: High-activity, high-specific surface area calcium hydroxide - recommended usage conditions
V. High Activity, High Specific Surface Area Calcium Hydroxide Characteristics
Highly active, high specific surface area calcium hydroxide boasts characteristics such as porosity, high activity, good dispersion, and high utilization. Its specific surface area is 3-4 times that of ordinary calcium hydroxide and is recognized internationally as an excellent dry desulfurization product. Dry desulfurization agents used in practice mainly include high specific surface area calcium hydroxide and baking soda. While baking soda has a fast reaction rate, it is relatively expensive and difficult to dispose of solid waste. By the 1980s, high specific surface area calcium hydroxide had been widely used in waste-to-energy and thermal power plants in Europe, America, and Japan, successfully replacing baking soda. High specific surface area calcium hydroxide has well-developed pores, enabling rapid adsorption and absorption reactions of HCl and SO2 in flue gas, with a utilization rate exceeding 85%.
Section 6: Introduction to HNPS Dry Desulfurization Process
Highly active and high surface area calcium hydroxide dry powder desulfurizer, directly sprayed into the flue gas duct through air conveying, rapidly disperses in the flue gas under the action of an efficient jet, adsorbs and absorbs most of the acidic media such as F-, Cl-, SO2, and SO3 in the flue gas, and enters the bag dust collector with the flue gas. A small portion of the acidic media continues to react in the bag dust collector, and the flue gas after desulfurization is directly discharged through the induced draft fan.
This process is unaffected by the temperature of the smoke, and can effectively react above room temperature.
Section 7: Characteristics of High-activity, High-Surface-Area Calcium Hydroxide Desulfurization System
1. Storage System: Large-capacity powder storage silos, radar and anti-rotation level sensors, safety valves, vibration motors, arch-breaking assist flow air discs, and other accessories.
2. Feeding System: Utilizes a high-precision rotating feeder for material delivery, with frequency conversion and measurement via sensors.
3. Power System: Positive pressure conveying by Roots blower or compressed air, one in operation and one in reserve.
4. Control System: Centralized control in the control room, with computer screen displaying main operating states or parameters such as material level, feeder running frequency, etc. The system is equipped with high and low level alarms for material level, material level display, status of the Roots blower, and fault alarms.
Section 8: Characteristics of Dry Desulfurization with High-activity, High-Surface-Area Calcium Hydroxide
1. Meets ultra-low emission requirements with high desulfurization efficiency; SO2 outlet concentration can reach near-zero emission standards; flue gas SO2 concentration ranges between 40~300 mg/Nm3, particularly cost-effective.
2. Wide temperature range, utilizing flue gas treatment at 30-350°C, with high desulfurization efficiency.
3. The process is simple, with ultra-fine powder directly sprayed into the flue gas duct through an efficient jet, completing the absorption reaction during the flow of flue gas.
4. Ensure the existing or newly added bag dust collector meets the ultra-low dust emission requirements of the system.
5. By-products are general solid waste, with the main components being saturated waste desulfurizing agent, mainly consisting of CaSO4, Ca(OH)2, and CaCO3.
6. Central control room centralized operation; no increase in staff, small footprint, especially suitable for low-temperature, low-sulfur environments.
7. Substitute for the baking soda process in SDS, with lower investment and energy consumption, and resolves solid waste issues.
Section 9: Typical Performance across Various Industries
Coking Industry - Coke Pushing Ground StationShougang Qian'an Sinopec Coal Chemical Co., Ltd.'s No.1, No.2, and No.3 coke ovens - Push coke surface dedusting with high-activity, high-surface-area calcium hydroxide desulfurization, the industrial unit was put into operation on June 8, 2021, with stable data below 10mg/m3.
2. Coke Industry - Dry Quenching Gas and Coke Oven Flue Gas - High Activity, High Surface Area Calcium Hydroxide Desulfurization
3. Steel Industry - Hot Blast Furnace, Heating Furnace - High Activity, High Specific Surface Area Calcium Hydroxide Desulfurization
4. Other Industries - Waste-to-Energy Power Plants and Power Station Boilers - High-activity, High-specific-surface-area Calcium Hydroxide Desulfurization
