Active, high specific 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 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.

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 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 technological route begin to show, and how to deal with 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 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 blast stoves, and heating furnaces in 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 varying from 300 to 500 yuan per ton, thereby increasing the burden on businesses.

On September 1, 2020, the revised "Law of the People's Republic of China on the Prevention and Control of Environmental Pollution by Solid Wastes" came into effect, introducing new responsibilities for waste-producing enterprises and imposing severe penalties on illegal activities. Corporate pressure has surged!

Tianjin Huaneng Langtian Environmental Protection Equipment Co., Ltd. After four years of research and development efforts by our scientific staff, 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, offering products with excellent performance!

Utilizing the HNPS desulfurization package developed by our company, over 30 units have been industrially applied with excellent operating 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 in coke oven flue gas, steelmaking furnace heating, hot blast furnace, power plant boilers, and waste incineration industrial furnaces.

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

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

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

Five. High activity and high specific surface 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 ordinary calcium hydroxide and is widely recognized as an excellent dry desulfurization product internationally. Dry desulfurization agents used in practice are primarily 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 for desulfurization in Europe, America, and Japan, successfully replacing baking soda. High specific surface area calcium hydroxide has well-developed pores, allowing for rapid adsorption and absorption reactions with 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, 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 jetting device. 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 within the bag dust collector. 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: Equipped with large-capacity powder storage silos, radar and anti-rotation level control, safety valves, vibration motors, arch-breaking aid flow air discs, and other accessories.

2. Feeding System: Utilizes a high-precision rotating feeder, which measures through 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 screens displaying key operating states or parameters such as material level and feeder operation frequency. The system includes high and low 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 standards, with high desulfurization efficiency; SO2 emissions can reach near-zero levels; flue gas SO2 concentration ranges between 40~300mg/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. Ensure the existing or new bag dust collector meets the ultra-low dust emission requirements of the system.

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

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

7. Replacing the baking soda process with an alternative, cost-effective investment, low energy consumption, and waste disposal solution.

Section 9: Typical Performance in Various Industries

   Coking Industry - Coke Pushing Ground StationShougang Qian'an Sinochem Coal Chemical Co., Ltd.'s No.1, No.2, and No.3 coke ovens - Push coke surface dust removal - High-activity, high-specific surface area calcium hydroxide desulfurization, industrial unit put into operation on June 8, 2021, with stable data below 10mg/m³.

2. Coking Industry - Dry Coke Dust Emission and Coke Oven Flue Gas - High-activity, High-specific surface area calcium hydroxide desulfurization

3. Iron and Steel Industry - Hot Blast Furnaces, Heating Furnaces - High Activity, High Specific Surface Area Calcium Hydroxide Desulfurization

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