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.

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 protection challenge. Sodium-based desulfurization ash is a mixture of sodium sulfate, sodium sulfite, and sodium carbonate..Materials have excellent water solubility and are classified as general solid waste that is difficult to dispose of in compliance with regulations. Authoritative statistics show that 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 storage, while others sell it to qualified institutions for disposal, with costs ranging from 300 to 500 yuan per ton, which adds to the burden on businesses.

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 team, 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 boasts a 100,000-ton capacity, with products exhibiting excellent performance!

With the HNPS desulfurization package developed by our company, over 30 sets have been industrially applied, demonstrating good operational data, low costs, and satisfied customers. Currently, it has been successfully applied in coking furnace push-ash ground stations, dry-cooling coke dust removal, coke oven flue gas, steel heating furnaces, hot blast furnaces, power plant boilers, and waste incineration industrial kilns, achieving ultra-low emissions desulfurization.

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

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

V. High-activity, high-specific-surface-area calcium hydroxide characteristics

Highly active, high surface area calcium hydroxide features porosity, high activity, good dispersion, and high utilization. Its specific surface area is 3-4 times that of ordinary calcium hydroxide and is widely recognized internationally as an excellent dry desulfurization product. The main dry desulfurization agents in practice are high 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. In the 1980s, high surface area calcium hydroxide was extensively used in waste-to-energy and thermal power plants in Europe, America, and Japan, successfully replacing baking soda. High 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 Technology

Highly active, high surface area calcium hydroxide dry powder desulfurizer is directly喷射 into the flue gas duct through air flow conveyance. 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, 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 by 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-specific-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 auxiliary air discs, and other accessories.

2. Feeding System: Utilizes a high-precision rotating feeder with frequency conversion 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 screens displaying main operating states or parameters such as material level, feeder operating frequency, etc. The system is equipped with high and low level alarms for material level, material level display, status of the Roots blower, and fault alarms.

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

1. Meets ultra-low emission requirements with high desulfurization efficiency; export SO2 concentration can reach near-zero emission standards. Flue gas sulfur dioxide 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, with ultra-fine powder directly sprayed into the flue gas channel through an efficient jet, completing the absorption reaction during the flow of the flue gas.

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

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

6. Centralized control room operation without increasing personnel, with minimal footprint for equipment, particularly suitable for low-temperature, low-sulfur environments.

7. Replacing the baking soda process with an alternative, it offers cost savings, low energy consumption, and addresses solid waste issues.

Section 9: Typical Performance in Various Industries

   1. 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 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. Coking Industry - Dry Quenching Gas and Coke Oven Flue Gas - High-activity, High-Surface Area Calcium Hydroxide Desulfurization

3. Iron and Steel Industry - Hot Blast Furnace, Heating Furnace - High Activity, High 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