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. Flue Gas 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. 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, 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 protection 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 multiplied 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, thereby increasing 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" took 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. has successfully developed high surface area calcium hydroxide after four years of research and development efforts by our technical staff. The specific surface area (BET) reaches over 45 m2/g. By independently developing core equipment, we have created a new production process, achieving large-scale production. Our Tianjin production base boasts a 100,000-ton capacity with exceptional product performance!
With our company's developed HNPS desulfurization system, over 30 units have been industrially utilized with excellent operational data, low costs, and satisfied customers. Currently, the system has successfully applied ultra-low emission desulfurization in coking plant pusher ground stations, dry-cooling coke dust removal, coke oven flue gas, steelmaking heating furnaces, hot blast stoves, power plant boilers, and waste incineration industrial kilns.
High-activity, high-specific-surface-area calcium hydroxide - microscopic crystal 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 and high specific surface area calcium hydroxide characteristics
Highly active, high specific surface area calcium hydroxide features porous structure, high activity, good dispersibility, and high utilization. Its specific surface area is 3-4 times that of common calcium hydroxide and is widely recognized as an excellent dry desulfurization product internationally. In practical dry desulfurization applications, the main agents are high specific surface area calcium hydroxide and baking soda. While baking soda has a faster reaction rate, it is relatively expensive and difficult to dispose of solid waste. By the 1980s, high specific surface area calcium hydroxide had been extensively used in waste-to-energy and thermal power plants for desulfurization in Europe, America, and Japan, successfully replacing baking soda. The high specific surface area calcium hydroxide has well-developed pores, enabling it to quickly adsorb and absorb HCl and SO2 in flue gas, with a utilization rate exceeding 85%.
Section 6: Introduction to HNPS Dry Desulfurization Process
Highly active, high specific surface area calcium hydroxide dry powder desulfurizer is directly jetted into the flue gas duct via air conveying. Under the action of the high-efficiency jetting unit, the calcium hydroxide powder quickly disperses into the flue gas, adsorbs and absorbs most of the acidic media such as F-, Cl-, SO2, and SO3 in the flue gas. It then enters the bag filter along with the flue gas. A small portion of the acidic media continues to react in the bag filter, and the烟气, after desulfurization, is directly discharged by the induced draft fan.
This process is unaffected by the temperature of the smoke, and it can effectively react at room temperature and above.
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 auxiliary flow air disks, and other accessories.
2. Feeding System: Utilizes a high-precision rotating feeder, measured by frequency conversion through sensors.
3. Power System: Positive pressure conveying with Roots blower or compressed air, one in operation and one in reserve.
4. Control System: Centralized control in the control room, with computer screens displaying key operating states or parameters such as material level, feeder operation frequency, etc. The system includes high and low material level alarms, material level display, status of the Roots blower, and fault alarms.
Section 8: High-activity, High-Surface-Area Calcium Hydroxide Dry Desulfurization Features
1. Meets ultra-low emission requirements, with high desulfurization efficiency; SO2 outlet concentration can reach near-zero emission standards; Flue gas sulfur dioxide concentration between 40-300 mg/Nm³, particularly cost-effective.
2. Wide temperature range, utilizing flue gas treatment from 30-350°C, with high desulfurization efficiency.
3. The process is simple, with ultra-fine powder directly sprayed into the flue by an efficient jet, completing the absorption reaction during the flow of flue gas.
4. Ensure low dust emissions for the system with either the reuse or addition of bag dust collectors.
5. By-products are general solid waste, specifically saturated waste desulfurizing agent, mainly consisting of CaSO4, Ca(OH)2, and CaCO3.
6. Centralized control room operation without increasing staff, with minimal equipment footprint, especially suitable for low-temperature, low-sulfur environments.
7. Replacing the baking soda process with an alternative, it offers cost savings, low energy consumption, and addresses solid waste issues.
Section 9: Typical Performance across Various Industries
1. Coke-making Industry - Coke Pushing Ground StationShougang Qian'an Sinochem Coal Chemical Co., Ltd.'s No.1, No.2, and No.3 coke ovens - Push coke ground dedusting with high-activity, high-specific 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-specific Surface Area Calcium Hydroxide Desulfurization
3. Steel Industry - Hot Blast Furnaces, Heating Furnaces - High Activity, High 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
