Active, high specific surface area calcium hydroxide desulfurization (powder) technology performs desulfurization absorption and product treatment in a dry state. This method boasts advantages such as no wastewater or waste acid discharge, reduced equipment corrosion, no significant cooling of flue gas during purification, high flue gas temperature after purification, favorable for 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.

I. 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 route using sodium bicarbonate as the alkali source has rapidly expanded its market share due to its high desulfurization efficiency, broad source 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 deal with 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 the category of general solid waste that is difficult to dispose of in compliance with regulations. Authoritative statistics indicate 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, thereby increasing the burden on businesses.

The revised "Environmental Protection Law of the People's Republic of China on Solid Waste Pollution" came into effect on September 1, 2020, 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 research and development efforts by our technical 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 has a 100,000-ton capacity, offering excellent product performance!

Utilizing the HNPS desulfurization package developed by our company, it has been industrially applied in over 30 units with excellent operational data, low costs, and satisfied customers. Currently, it has successfully achieved ultra-low emission desulfurization in industrial furnaces such as coke oven push ground stations, dry-coke dust removal, coke oven flue gas, steel heating furnaces, hot blast stoves, power plant boilers, and waste incineration.

High-activity, high-specific-surface-area calcium hydroxide - microscopic crystalline structure under electron microscopy

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

Section 4: High-activity, high-specific-surface calcium hydroxide - recommended usage conditions

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

Highly active, high surface area calcium hydroxide features porous structure, high activity, good dispersibility, and high utilization rate. Its specific surface area is 3-4 times that of common calcium hydroxide and is recognized as an excellent dry desulfurization product internationally. Dry desulfurization agents in practice are mainly 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. By the 1980s, high surface area calcium hydroxide had been widely used in desulfurization of waste-to-energy and thermal power plants in Europe, America, and Japan, successfully replacing baking soda. High surface area calcium hydroxide possesses well-developed pores, enabling rapid adsorption and absorption reactions of HCl and SO2 in flue gas, with a utilization rate exceeding 85%.

Section 6: Introduction to HNPS Dry Desulfurization Process

Highly active and high surface area calcium hydroxide dry powder desulfurizer, directly jetted into the flue gas duct through air conveying. Under the action of an efficient jetting device, the calcium hydroxide powder quickly disperses into the flue gas, adsorbs and absorbs most of the acidic media such as F-, Cl-, SO2, and SO3 in the flue gas, and enters the bag filter along 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 a blower.

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-rotational level sensors, safety valves, vibration motors, arch-breaking assist flow air disks, and other accessories.

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

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

4. Control System: Centralized control in the control room, with computer screens displaying material level, feeder operation frequency, and other key operating states or parameters. The system is equipped with high and low level alarms, material level display, status of the Roots blower, and fault alarms.

Section 8: Features of High-activity, High-specific-surface-area Dry Desulfurization Calcium Hydroxide

1. Meets ultra-low emission requirements with high desulfurization efficiency; SO2 outlet concentration can reach near-zero emission standards; flue gas SO2 concentration ranges between 40-300 mg/Nm3, particularly cost-effective.

2. Wide temperature window, 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 channel via an efficient jet, completing the absorption reaction during the flow of flue gas.

4. Ensure low dust emissions in the system with the reuse or addition of bag dust collectors.

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

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

7. Substitute the baking soda process with the SDS method, offering cost savings, low energy consumption, and waste disposal solutions.

Section 9: Typical Performance across 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 ground dedusting with high-activity, high-specific 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. Steel Industry - Hot Blast Furnaces, Heating Furnaces - High-activity, High Surface Area Calcium Hydroxide Desulfurization

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