High surface area calcium hydroxide

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 temperature drop during flue gas 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.

Part 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 route using sodium bicarbonate as the alkali source has rapidly expanded its market share due to its high desulfurization efficiency, wide source of desulfurizing agents, and low difficulty in engineering implementation.

As the number of equipment increases, the drawbacks of this technological route begin to surface, 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..Materials have excellent solubility in water 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, heating furnaces of steel companies, as well as glass kilns, cement kilns, and others. Some enterprises rent spaces to build warehouses for storage, while others sell the ash to qualified institutions for disposal, with costs varying from 300 to 500 yuan per ton, adding to the burden on the enterprises.

The revised "Solid Waste Pollution Control Law of the People's Republic of China" took 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. By independently developing core equipment and creating a new production process, we have achieved large-scale production. Our Tianjin production base has a 100,000-ton capacity, and our products boast excellent performance!

Utilizing the HNPS desulfurization package developed by our company, over 30 units have been industrially deployed with excellent operational data, low costs, and satisfied customers. Currently, the ultra-low emission desulfurization technology has been successfully applied in coking furnace pusher 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-surface-area calcium hydroxide - microcrystalline structure under electron microscopy

Section 3: High Activity, High Specific Surface Area Calcium Hydroxide Desulfurization Agent Specifications

Four. High-activity, high-surface-area calcium hydroxide, recommended usage conditions

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

Highly active and high specific surface area calcium hydroxide boasts characteristics such as porosity, high activity, good dispersibility, and high utilization rate. 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 highly 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. In the 1980s, highly specific surface area calcium hydroxide was widely used in waste-to-energy and thermal power plants for desulfurization in Europe, America, and Japan, successfully replacing baking soda. Highly specific 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 Process

Highly active, high surface area calcium hydroxide dry powder desulfurizer, directly jetted into the flue gas duct through air conveying, rapidly disperses into the flue gas under the action of an efficient jetting device, adsorbs and absorbs most of the acidic media such as F-, Cl-, SO2, and SO3 in the flue gas, and is then carried into the bag dust collector 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-specific-surface-area Calcium Hydroxide Desulfurization System

1. Storage System: Equipped with large capacity powder storage silos, radar and anti-rotation level gauges, safety valves, vibration motors, arch-breaking assist airflow discs, and other accessories.

2. Feeding System: Utilizes a high-precision rotating feeder, which measures by converting frequency via sensors.

3. Power System: Positive pressure conveying by 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 main operating states or parameters such as material level and feeder operating frequency. The system is equipped with high and low material level alarms, material level display, status and fault alarms for the Roots blower.

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

1. Meets ultra-low emission requirements with high desulfurization efficiency; the SO2 concentration in the outlet can reach zero-discharge levels; flue gas SO2 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 being directly喷射 into the flue gas channel by an efficient jet injector, completing the absorption reaction during the flow of flue gas.

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

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

6. Centralized control room operation, no additional staff required, minimal floor space needed, especially suitable for low-temperature, low-sulfur environments.

7. Replaces the baking soda process in SDS, offers cost savings and low energy consumption, and addresses solid waste issues.

Section 9: Typical Performance in Various Industries

   Coking Industry - Pushing Coking Ground StationShougang Qian'an Sinochem Coal Chemical Co., Ltd. 1#, 2#, and 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 10 mg/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 Furnaces, Heating Furnaces - High Activity, High Specific Surface Area Calcium Hydroxide Desulfurization

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