Active, high-specific-surface-area calcium hydroxide desulfurization (powder) technology performs 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 cooling of flue gas during purification, high flue gas temperature post-purification, facilitating chimney exhaust diffusion, and minimal secondary pollution. It is suitable for flue gas desulfurization 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 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 technical 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 material has excellent water solubility and falls under 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 kilns, cement kilns, and more. Some companies rent land to build storage warehouses for disposal, while others sell it to qualified institutions for processing, with costs ranging from 300 to 500 yuan per ton, which adds to 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 acts. 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 team, we have successfully developed high-specific surface area calcium hydroxide with a specific surface area (BET) of over 45m2/g. Through independently developed core equipment, we have created a new production process, achieving large-scale production. Our Tianjin production base has a 100,000-ton capacity, offering top-notch product performance!

With the HNPS desulfurization package developed by our company, over 30 units have been industrially used with good operational data, low cost, and satisfied customers. Currently, the ultra-low emission desulfurization has been successfully applied in coking furnace push-ash ground stations, dry quenching dust removal, coke oven flue gas, steelmaking heating furnaces, hot blast stoves, power plant boilers, and waste incineration industrial furnaces.

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: Reference Usage Conditions for High-Activity, High-Surface Area Calcium Hydroxide

Five. High-activity, high-surface-area calcium hydroxide characteristics

Highly active, high surface area calcium hydroxide features porosity, high activity, good dispersibility, and high utilization. Its specific surface area is 3-4 times that of regular calcium hydroxide, and it is widely recognized as an excellent dry desulfurization product internationally. In practice, the main dry desulfurization agents are highly surface area calcium hydroxide and baking soda. Baking soda has a fast reaction rate but is relatively expensive and difficult to dispose of solid waste. In the 1980s, high surface area calcium hydroxide was widely used in waste-to-energy and thermal power plants in Europe, America, and Japan, successfully replacing baking soda. Highly surface area calcium hydroxide has well-developed pores, and 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

High-activity, high-specific-surface-area calcium hydroxide dry powder desulfurizer, directly sprayed into the flue gas duct by air conveying, rapidly disperses into flue gas under the action of the high-efficiency sprayer, adsorbs and absorbs most of the acidic mediums such as F-, Cl-, SO2, and SO3 in the flue gas, 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烟气 post-desulfurization is then directly discharged through the induced draft fan.

This process is unaffected by the temperature of the smoke, and it 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 level sensors, safety valves, vibration motors, arch-breaking assist flow gas disks, and other accessories.

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

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

4. Control System: Centralized control in the control room, with computer screens displaying main operating states or parameters such as material level and feeder running frequency. The system is equipped with high and low material 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 emissions standards, high desulfurization efficiency, with export SO2 concentration reaching near-zero emission levels; flue gas sulfur dioxide concentration between 40~300 mg/Nm3, particularly cost-effective.

2. Wide temperature range with flue gas treatment from 30 to 350°C, achieving 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 flue gas.

4. Ensure the system meets ultra-low dust emission requirements for both existing and newly installed bag dust collectors.

5. By-products are general solid waste, with the by-products being saturated waste desulfurizing agents, primarily consisting of CaSO4, Ca(OH)2, and CaCO3.

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

7. Substitute for the baking soda process in SDS, with cost-effective investment, low energy consumption, and waste treatment solutions.

Section 9: Typical Performance in Various Industries

   1. Coking Industry - Coke Pushing 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. Coking Industry - Dry Quenching Gas 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 & Power Station Boilers - High-Activity, High-Surface-Area Calcium Hydroxide Desulfurization