The desulfurization technology for active, high surface area calcium hydroxide (powder form) 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 post-purification, favorable for chimney exhaust diffusion, and minimal secondary pollution. It is suitable for flue gas desulfurization in industries like 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..Material has excellent water solubility and falls under general solid waste that is difficult to dispose of in compliance with regulations. Official statistics show that the coking industry alone produces up to 300,000 tons of sodium-based desulfurization ash annually. This figure is further multiplied by the power plants, hot air furnaces, and heating furnaces of steel enterprises, as well as glass kilns, cement kilns, and others. Some companies rent land to build storage sheds for storage, while others sell the ash to qualified institutions for disposal, with costs ranging from 300 to 500 yuan per ton, adding to the companies' burdens.

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 enterprises generating solid wastes and strictly penalizing illegal activities. The pressure on businesses has surged!

Tianjin Huaneng Langtian Environmental Protection Equipment Co., Ltd. After four years of research and development, 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 large-scale production. Our Tianjin production base has a 100,000-ton capacity, and our products boast excellent performance!

With our company's developed HNPS desulfurization package, it has been industrially used in over 30 sets, with good operating data, low costs, and satisfied customers. Currently, it has successfully applied ultra-low emission desulfurization in coking plant push-aside ground stations, dry-cooling coke dust removal, coke oven flue gas, steel heating furnaces, hot blast stoves, power plant boilers, and waste incineration industrial kilns.

High-activity, high-specific-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 Properties

Highly active and high specific surface area calcium hydroxide features porous structure, high activity, good dispersion, and high utilization rate. Its specific surface area is 3-4 times that of ordinary calcium hydroxide, and it is recognized as an excellent dry desulfurization product internationally. The practical dry desulfurization agents mainly include high specific surface area calcium hydroxide and baking soda. While baking soda has a rapid 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 desulfurization in waste-to-energy and thermal power plants in Europe, America, and Japan, successfully replacing baking soda. High specific surface area calcium hydroxide has well-developed pores, which can quickly adsorb and absorb 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, rapidly dispersing into the flue gas under the action of an efficient jetting device. The calcium hydroxide powder adsorbs and absorbs most of the acidic media such as F-, Cl-, SO2, and SO3 in the flue gas, and enters the bag dust collector along with the flue gas. A small portion of the acidic media continues to react in the bag dust collector. The flue gas after desulfurization is directly discharged through an 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: Equipped with large-capacity powder storage silos, radar and anti-rotation type high and low level sensors, safety valves, vibration motors, arch-breaking assist airflow discs, and other accessories.

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

3. Power System: Positive pressure conveying with Roots blowers 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, feeder running 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: High-activity, high-specific-surface-area calcium hydroxide dry desulfurization features

1. Meets ultra-low emission standards with high desulfurization efficiency; export SO2 concentration can reach near-zero emission levels; flue gas sulfur dioxide concentration 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 or install new bag dust collectors to ensure ultra-low dust emissions meet system requirements.

5. By-products are general solid waste, specifically saturated waste desulfurizer, 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 alternative technology, offering cost savings, low energy consumption, and waste management solutions.

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 dedusting with high-activity, high-specific surface area calcium hydroxide desulfurization. The industrial unit was put into operation on June 8, 2021, and the data has remained stable 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 Plants and Power Station Boilers - High Activity, High Specific Surface Area Calcium Hydroxide Desulfurization