Active, high specific 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 cooling of flue gas during purification, high flue gas temperature after 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.
I. Desulfurization Technology Introduction
In recent years, 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. The SDS desulfurization process route using sodium bicarbonate as the alkali source has rapidly expanded its market share due to its high desulfurization efficiency, wide availability of desulfurizing agents, and low difficulty in engineering implementation.
As the number of equipment increases, the drawbacks of this technological 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 falls under the category of general solid waste that is difficult to dispose of in compliance with regulations. Authoritative statistics indicate 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 enterprises, as well as glass and cement kilns. Some companies rent land to build storage warehouses for storage, while others sell it to qualified institutions for disposal, with costs ranging from 300 to 500 yuan per ton, adding to the burden on businesses.
The revised "Law of the People's Republic of China on the Prevention and Control of Environmental Pollution by Solid Wastes" came into effect on September 1, 2020, introducing new responsibilities for enterprises generating solid wastes and imposing severe penalties on illegal activities. The pressure on businesses has surged!
Tianjin Huaneng Langtian Environmental Protection Equipment Co., Ltd. After four years of research and development efforts by our scientific and technical personnel, we have successfully developed high surface area calcium hydroxide with a specific surface area (BET) exceeding 45 m2/g. Through independently developed core equipment, we have created a new production process, achieving mass production. Our Tianjin production base boasts a 100,000-ton capacity, with excellent product performance!
With our company's developed HNPS desulfurization system, over 30 units have been industrially applied with favorable operational data, low costs, and satisfied customers. Currently, the system has been successfully applied for ultra-low emission desulfurization in coke oven pusher ground stations, dry quenching coke dust removal, coke oven flue gas, steel heating furnaces, hot blast stoves, power plant boilers, and waste incineration industrial kilns.
High-activity, high-specific-surface-area calcium hydroxide - microcrystalline structure under electron microscopy
Section 3: High-activity, high-specific-surface-area calcium hydroxide desulfurizing agent specifications
Section 4: High-activity, high-specific-surface-area calcium hydroxide - recommended usage conditions
Five. High-activity, high-surface-area calcium hydroxide characteristics
Highly active and high specific surface area calcium hydroxide boasts features such as porosity, high activity, good dispersibility, and high utilization rates. Its specific surface area is 3-4 times that of regular calcium hydroxide, making it a recognized excellent dry desulfurization product internationally. Dry desulfurization agents used in practice primarily include highly specific surface area calcium hydroxide and baking soda. While baking soda reacts quickly, it is relatively expensive and difficult to dispose of solid waste. By the 1980s, Europe, the United States, and Japan had widely adopted highly specific surface area calcium hydroxide for desulfurization in waste-to-energy and thermal power plants, successfully replacing baking soda. Highly specific surface area calcium hydroxide features well-developed pores, enabling the rapid adsorption and absorption of HCl and SO2 in flue gas, with an efficiency exceeding 85%.
Section 6: Introduction to HNPS Dry Desulfurization Technology
Highly active, high surface area calcium hydroxide dry powder desulfurizer, directly喷射 into the flue gas duct through air conveying, where the calcium hydroxide powder rapidly disperses in the flue gas under the action of an efficient jet. It adsorbs and absorbs most of the acidic media such as F-, Cl-, SO2, and SO3 in the flue gas, and then enters the bag dust collector with the flue gas. A small portion of the acidic media continues to react in the bag dust collector. The flue gas after desulfurization is directly discharged through an induced draft fan.
This process is unaffected by smoke temperature fluctuations; it can effectively react above room temperature.
Section 7: Characteristics of High-activity, High-Surface-Area Calcium Hydroxide Desulfurization System
1. Storage System: Equipped with large-capacity powder storage silos, radar and anti-rotation level sensors, safety valves, vibration motors, arch-breaking aid flow air disks, and other accessories.
2. Feeding System: Utilizes a high-precision rotary feeder, measuring through frequency conversion with sensors.
3. Power System: Positive pressure conveying by Roots blower or compressed air, with one in operation and one in reserve.
4. Control System: Centralized control in the control room, with computer screens displaying main operating states or parameters such as material level and feeder operating frequency. The system is equipped with high and low level alarms, material level display, and status and fault alarms for the Roots blower.
Section 8: Characteristics of High-activity, High-Surface-Area Calcium Hydroxide Dry Desulfurization
1. Meets ultra-low emission requirements with high desulfurization efficiency; SO2 emissions can reach near-zero levels with export concentrations; flue gas SO2 concentration ranges between 40~300 mg/Nm3, particularly cost-effective.
2. Wide temperature window, with smoke treatment using 30-350℃ for high desulfurization efficiency.
3. The process is simple, utilizing an efficient jet to directly spray ultra-fine powder into the flue, where absorption reactions are completed during the flow of flue gas.
4. Ensure low dust emissions for the system, either by upgrading existing bag dust collectors or adding new ones.
5. By-products are general solid waste, specifically saturated waste desulfurizing agent, mainly composed of CaSO4, Ca(OH)2, and CaCO3.
6. Centralized control room operation without increasing staff, with minimal equipment footprint, particularly suitable for low-temperature, low-sulfur environments.
7. Substitute baking soda process with investment savings, low energy consumption, and waste management solutions.
Section 9: Typical Performance in Various Industries
1. Coke Making Industry - Push Coke Ground StationShougang Qian'an Sinochem Coal Chemical Co., Ltd.'s No.1, No.2, and No.3 coke ovens - Push coke surface dust removal with high-activity, high-surface-area calcium hydroxide desulfurization. The industrial unit was put into operation on June 8, 2021, with stable data below 10 mg/m3.
2. Coking Industry - Dry Quenching Gas and Coke Oven Flue Gas - High-activity, High-Surface Area Calcium Hydroxide Desulfurization
3. Iron and Steel Industry - Hot Blast Furnace, Heating Furnace - High Activity, High Specific Surface Area Calcium Hydroxide Desulfurization
4. Other Industries - Waste-to-Energy Plants & Power Station Boilers - High-activity, High-specific-surface Area Calcium Hydroxide Desulfurization
