Active, high-specific-surface-area calcium hydroxide desulfurization (powder) technology performs desulfurization absorption and product treatment under dry conditions. 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 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.

I. 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, characterized by its 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 quantity 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 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 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 "Solid Waste Pollution Control Law of the People's Republic of China" 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 dedicated research and development, with the efforts of our scientific and technical personnel, we have successfully developed high surface area calcium hydroxide with a surface area (BET) exceeding 45 m2/g. By independently developing core equipment, we have created a new production process, achieving mass production. Our Tianjin production base boasts a 100,000-ton annual capacity, delivering superior product performance!

Utilizing the HNPS desulfurization package developed by our company, it has been industrially applied in over 30 units with excellent operational data, low costs, and satisfied customers. Currently, it has successfully been implemented in coke oven 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 for ultra-low emissions desulfurization.

High-activity, high-surface-area calcium hydroxide - Microcrystalline structure under electron microscope

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

Section 5: High-activity, high-surface-area calcium hydroxide characteristics

Highly active and high specific surface area calcium hydroxide boasts characteristics such as porosity, high activity, good dispersibility, and high utilization rate. Its specific surface area is 3-4 times that of common calcium hydroxide, and it is widely recognized as an excellent dry desulfurization product internationally. Dry desulfurization agents used in practice mainly include highly 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 for desulfurization in waste-to-energy and thermal power plants in Europe, America, and Japan, successfully replacing baking soda. The highly specific surface area calcium hydroxide has well-developed pores, which 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 and high specific surface area calcium hydroxide dry powder desulfurizer, directly jetted into the flue gas duct through air conveying. Under the action of the high-efficiency jetting device, the calcium hydroxide powder rapidly 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: Characteristics of High-activity, High-specific-surface-area Calcium Hydroxide Desulfurization System

1. Storage System: Large capacity powder storage silos, radar and anti-rotation level control, safety valve, vibration motor, arch breaking auxiliary flow air discs, and other accessories.

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

3. Power System: Positive pressure conveying by Roots blower or compressed air, one in use and one in reserve.

4. Control System: Centralized control in the control room, with computer screens displaying material level, feeder operation frequency, and other key operating states or parameters. The system is equipped with high and low material level alarms, material level display, status of the Roots blower operation, and fault alarms.

Section 8: Characteristics of High-activity, High-Surface-Area Calcium Hydroxide Dry Desulfurization

1. Meets ultra-low emissions requirements with high desulfurization efficiency; export SO2 concentration can reach 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. Utilize existing or newly installed bag dust collectors to ensure the system meets ultra-low dust emission requirements.

5. By-products are general solid waste, consisting of saturated waste desulfurizing agent, primarily containing CaSO4, Ca(OH)2, and CaCO3.

6. Centralized control room operation without increasing staff, small equipment footprint, particularly suitable for low-temperature, low-sulfur environments.

7. Substitute the baking soda process with the SDS method, offering cost savings, lower energy consumption, and waste management solutions.

Section 9: Typical Performance Across 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-cooled coke 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 Plants and Power Station Boilers - High Activity, High Specific Surface Area Calcium Hydroxide Desulfurization