High-activity calcium-based desulfurizer

Active, high surface area calcium hydroxide desulfurization (powder) technology carries out desulfurization absorption and product treatment in a dry state. This method boasts advantages such as no wastewater or waste acid discharge, low equipment corrosion, no significant temperature drop in flue gas 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.

Section 1: 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, broad source of desulfurizing agents, and low difficulty in engineering implementation.

As the number of equipment increases, the disadvantages 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 substance has excellent solubility in water and falls under the category of general solid waste that is difficult to dispose of in compliance with regulations. According to authoritative statistics, 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 air furnaces, and heating furnaces of steel enterprises, as well as glass and cement kilns. Some companies rent land to build storage warehouses for disposal, while others sell it to qualified institutions for processing, with costs ranging from 300 to 500 yuan per ton, adding to the burden on businesses.

The revised "Environmental Protection Law of the People's Republic of China on Solid Waste Pollution" came into effect on September 1, 2020, introducing new responsibilities for enterprises generating solid waste and imposing severe penalties on illegal acts. The pressure on businesses has surged!

Tianjin Huaneng Langtian Environmental Protection Equipment Co., Ltd. After four years of攻关, with the efforts of our technical staff, we have successfully developed high surface area calcium hydroxide with a surface area (BET) of over 45 m2/g. By independently developing core equipment, we have created a new production process and achieved large-scale production. Our Tianjin production base has a 100,000-ton capacity, and our products offer superior performance!

With the HNPS desulfurization system developed by our company, more than 30 units have been industrially applied with good operating data, low cost, and satisfied customers. Currently, the system has successfully been applied 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, achieving ultra-low emission desulfurization.

High-activity, high-specific-surface-area calcium hydroxide - microscopic crystal structure under electron microscopy

Section 3: High-activity, high-specific-surface-area calcium hydroxide desulfurization agent specifications

Section 4: Reference Usage Conditions for High-activity, High-Surface Area Calcium Hydroxide

Section 5: High Activity and High Specific Surface Area Calcium Hydroxide Characteristics

Highly active and high specific surface area calcium hydroxide features porous structure, high activity, good dispersion, and high utilization rate. Its specific surface area is 3-4 times that of ordinary calcium hydroxide and is recognized internationally as an excellent dry desulfurization product. The practical dry desulfurization agents mainly include high specific surface area calcium hydroxide and baking soda. Baking soda has a fast reaction rate but is relatively expensive and difficult to dispose of as 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 for desulfurization, successfully replacing baking soda. The highly active calcium hydroxide with well-developed pores can quickly adsorb and absorb HCl and SO2 from flue gas, achieving a utilization rate of over 85%.

Section 6: Introduction to HNPS Dry Desulfurization Process

Highly active, high surface area calcium hydroxide dry powder desulfurizer, directly sprayed into the flue gas duct through air flow conveyance. Under the action of the high-efficiency jetting device, 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, and enters the bag filter with the flue gas. A small portion of the acidic media continues to react in the bag filter, 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: Features 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 discs, and other accessories.

2. Feeding System: Utilizes a high-precision rotary feeder, measured by frequency conversion through sensors.

3. Power System: Positive pressure conveying with Roots blowers or compressed air, one in use 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 operation frequency, etc. The system is equipped with high and low material level alarms, material level display, and status and fault alarms for the Roots blower.

Section 8: High-activity, high-specific surface area calcium hydroxide dry desulfurization features

1. Meets ultra-low emission standards with high desulfurization efficiency; SO2 emissions can reach near-zero levels; 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 by an efficient jet, completing the absorption reaction during the flow of flue gas.

4. Replace or add new dust bag collectors to ensure the system meets ultra-low dust emission requirements.

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, small footprint for equipment, especially suitable for low-temperature, low-sulfur environments.

7. Substitute the baking soda process with a more cost-effective and energy-efficient alternative, addressing solid waste issues.

Section 9: Typical Performance across Various Industries

   1. Coking Industry - Push Coke 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, and the data has stabilized below 10 mg/m3.

2. Coking 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 Specific Surface Area Calcium Hydroxide Desulfurization

4. Other Industries - Waste-to-Energy Power Plants & Power Station Boilers - High-Activity, High-Surface Area Calcium Hydroxide Desulfurization