Active, high specific surface area calcium hydroxide desulfurization (powder) technology carries out desulfurization absorption and product treatment in a dry state. This method offers advantages such as no wastewater or waste acid discharge, reduced equipment corrosion, no significant temperature drop during flue gas purification, higher flue gas temperature after purification, beneficial for chimney exhaust diffusion, and less 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, wide availability of desulfurizing agents, and low difficulty in project implementation.

As the number of equipment increases, the drawbacks of this technical route begin to surface, and how to deal with 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 power plants, hot air furnaces, and heating furnaces in steel enterprises, as well as glass and cement kilns. Some companies rent storage areas to store it, while others sell it to qualified institutions for disposal, with costs ranging from 300 to 500 yuan per ton, which adds to the companies' burden.

The revised "Solid Waste Pollution Prevention and Control Law of the People's Republic of China" came into effect on September 1, 2020, introducing new responsibilities for waste-producing enterprises 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 research and development efforts by our technical staff, we have successfully developed high-surface-area calcium hydroxide with a specific 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 has a 100,000-ton annual capacity, offering superior product performance!

Utilizing the HNPS desulfurization package developed by our company, over 30 sets have been industrialized in use, with excellent operational data, low costs, and satisfied customers. Currently, the ultra-low emission desulfurization technology has been successfully applied in coke oven pusher ground stations, dry-cooling coke dust removal, coke oven flue gas, steelmaking furnace, hot blast stove, power plant boilers, and waste incineration industrial furnaces.

High-activity, high-surface-area calcium hydroxide - microcrystalline structure under electron microscopy

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

Section 4: High-activity, high-specific-surface-area calcium hydroxide - recommended usage conditions

V. High Activity, High Specific Surface Area Calcium Hydroxide Properties

Highly active and high surface area calcium hydroxide features porosity, high activity, good dispersion, and high utilization rate. Its specific surface area is 3-4 times that of ordinary calcium hydroxide and is widely recognized as an excellent dry desulfurization product internationally. Dry desulfurization agents used in practice are primarily high surface area calcium hydroxide and baking soda. Baking soda reacts quickly but is relatively expensive and difficult to dispose of solid waste. By the 1980s, high 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 surface area calcium hydroxide possesses well-developed pores, allowing for quick adsorption and absorption reactions of HCl and SO2 in flue gas, achieving a utilization rate of over 85%.

Section 6: Introduction to HNPS Dry Desulfurization Process

Highly active and high-surface-area calcium hydroxide dry powder desulfurizer is directly喷射 into the flue gas channel via 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 mediums such as F-, Cl-, SO2, and SO3, and enters the bag dust collector with the flue gas. A small portion of the acidic mediums continues to react within the bag dust collector. The flue gas after desulfurization is then directly discharged by the induced draft fan.

This process is unaffected by the temperature of the smoke, and can effectively react at room temperature and above.

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 assist flow air disks, and other accessories.

2. Feeding System: Utilizes a high-precision rotating feeder, measuring by frequency conversion via sensors.

3. Power System: Positive pressure conveying with Roots blower 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 and feeder operation frequency. The system includes high and low 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 requirements with high desulfurization efficiency; the SO2 concentration in the outlet can reach near-zero emission levels; flue gas SO2 concentration is 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, directly injecting the ultra-fine powder into the flue gas channel via an efficient jet, where absorption reaction is completed during the flow of the flue gas.

4. Ensure low dust emissions in the system by either utilizing existing bag dust collectors or adding new ones.

5. Byproduct is general solid waste, consisting of saturated waste desulfurizer, primarily composed of CaSO4, Ca(OH)2, and CaCO3.

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

7. Replacing the baking soda process with an alternative, investment-saving, low-energy consumption solution, addressing solid waste issues.

Section 9: Typical Performance across Industries

   Coking Industry - Push Coke 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-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 Furnace, Heating Furnace - High-activity, High Surface Area Calcium Hydroxide Desulfurization

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