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 effluent waste acid, less equipment corrosion, no significant drop in flue gas temperature during purification, higher flue gas temperature after purification, conducive to 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. 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 challenge. Sodium-based desulfurization ash is a mixture of sodium sulfate, sodium sulfite, and sodium carbonate..The substance 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 to store the ash, 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.

As of September 1, 2020, the revised "Environmental Protection Law of the People's Republic of China on Solid Waste Pollution" came into effect, introducing new responsibilities for enterprises generating solid waste and imposing severe penalties on illegal activities. 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 calcium hydroxide with a high specific surface area, exceeding 45m2/g in specific surface area (BET). By independently developing core equipment, we have created a new production process and achieved mass production. Our Tianjin production base has a 100,000-ton capacity, and the product performance is outstanding!

With the HNPS desulfurization system developed by our company, over 30 units have been industrially applied with excellent operational data, low costs, and satisfied customers. Currently, the system has successfully been applied for ultra-low emission desulfurization in coke oven pusher ground stations, dry-cooling coke plants, dust removal in coke oven flue gases, steelmaking furnace heating, hot blast furnace, power plant boilers, and waste incineration industrial kilns.

High-activity, high-surface-area calcium hydroxide - Microcrystalline 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

V. High Activity and High Specific Surface Area Calcium Hydroxide Characteristics

Highly active, high specific surface area calcium hydroxide boasts characteristics such as porosity, high activity, good dispersion, and high utilization rates. 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. 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 in waste-to-energy and thermal power plants for desulfurization in Europe, America, and Japan, successfully replacing baking soda. With well-developed pores, high specific surface area calcium hydroxide 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 surface area calcium hydroxide dry powder desulfurizer, directly喷射 into the flue gas duct through air flow conveyance. Under the action of the high-efficiency jet, 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, 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-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 flow aid air discs, and other accessories.

2. Feeding System: Utilizes a high-precision rotating feeder for frequency conversion and measurement via sensors.

3. Power System: Positive pressure conveying with Roots blower or compressed air, one in operation and one in standby.

4. Control System: Centralized control in the control room with computer screen displaying material level, feeder operating frequency, and other main operating states or parameters. The system is equipped with 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 standards with high desulfurization efficiency; SO2 outlet concentration can achieve near-zero emission targets; flue gas SO2 concentration ranges 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, utilizing an efficient jet to directly spray ultra-fine powder into the flue, where absorption reaction is completed during the flow of flue gas.

4. Ensure the system meets ultra-low dust emission requirements with the reuse or addition of bag dust collectors.

5. Byproduct is general solid waste, specifically saturated waste desulfurizer, main components being 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. Substitute the baking soda process with an alternative that is cost-effective, energy-efficient, and addresses solid waste issues.

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 - coke pushing dust removal 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-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 & Power Station Boilers - High-activity, High-specific-surface-area Calcium Hydroxide Desulfurization