Dry Desulfurization

Active, high 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 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, dry flue gas desulfurization technology 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, broad source of desulfurizing agents, and low difficulty in project 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..The substance has excellent water solubility and falls under 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 multiplied by the power plants, hot blast stoves, and heating furnaces of steel enterprises, as well as glass and cement kilns. Some companies rent land to build 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.

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 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 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, and our products boast excellent performance!

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

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

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

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

Section 5: High Activity, High Specific Surface Area Calcium Hydroxide Characteristics

Highly active and high surface area calcium hydroxide boasts features such as porosity, high activity, good dispersibility, and high utilization rates. Its specific surface area is 3-4 times that of regular calcium hydroxide and is widely recognized as an excellent dry desulfurization product internationally. Dry desulfurization agents in practice are primarily high 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 surface area calcium hydroxide had been widely used in waste-to-energy and thermal power plants for desulfurization in Europe, America, and Japan, successfully replacing baking soda. High surface area calcium hydroxide has well-developed pores, allowing for rapid adsorption and absorption of 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喷射 into the flue gas channel through air flow transportation. Under the action of the high-efficiency jet, the calcium hydroxide powder rapidly disperses into the flue gas, 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 continue to react in the bag dust collector, and the flue gas after desulfurization is directly discharged through the 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 sensors, safety valves, vibration motors, arch-breaking assist flow air discs, and other accessories.

2. Feeding System: Utilizes a high-precision rotary feeder for material delivery, with frequency conversion measurement via sensors.

3. Power System: Roots blower or compressed air positive pressure conveying, 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, feeder running frequency, etc. The system is equipped with high and low level alarms, material level display, status of Roots blower operation, and fault alarms.

Section 8: Characteristics of Dry Desulfurization with High Active and High Specific Surface Area Calcium Hydroxide

1. Meets ultra-low emission requirements with high desulfurization efficiency; the SO2 concentration in the exhaust can reach near-zero emission 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 by an efficient jet, completing the absorption reaction during the flow of flue gas.

4. Ensure the system meets ultra-low dust emission requirements with the reuse or addition of bag dust collectors.

5. By-products are general solid waste, specifically saturated waste desulfurizer, with main components CaSO4, Ca(OH)2, and CaCO3.

6. Centralized control room operation without increasing personnel, minimal equipment footprint, 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 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 surface dust removal - 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. 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 Power Plants & Power Station Boilers - High-Activity, High-Surface Area Calcium Hydroxide Desulfurization