Briefly introduce the technical methods of flue gas desulfurization阅读：4637 更新时间：2019-10-16 15:22 Source: Environmental Protection Machinery Co., Ltd. Longxin reading: 4637 Updated: 2019-10-16 15:22
【Wet Desulfurization Technology】
The wet desulfurization technology is relatively mature, and the production and operation are safe and reliable. It always occupies a leading position among many desulfurization technologies.
The wet flue gas desulfurization technology is a gas-liquid reaction with fast reaction speed and high desulfurization efficiency, which are generally higher than 90%. The technology is mature and widely applicable. However, the product is liquid or sludge, which is difficult to handle, and the equipment is severely corrosive. After washing, the flue gas needs to be reheated, the energy consumption is high, the floor area is large, and the investment and operating costs are high. The system is complex, the equipment is huge, the water consumption is large, and the one-time investment is high. It is generally suitable for large power plants.
Common wet flue gas desulfurization technologies include the limestone-gypsum method, the indirect limestone-gypsum method, and the lemon absorption method.
【Dry Flue Gas Desulfurization】
A typical dry desulfurization system is to spray a desulfurizing agent (such as limestone, dolomite or slaked lime) directly into the furnace. When calcined at high temperature, the desulfurizing agent forms porous calcium oxide particles, which reacts with SO2 in the flue gas to form calcium sulfate to achieve the purpose of desulfurization.
The dry desulfurization technology has a simple process, no sewage and acid treatment issues, low energy consumption, especially the higher temperature of the flue gas after purification, which is conducive to the diffusion of chimney exhaust gas, and does not produce a "white smoke" phenomenon. The flue gas does not require secondary heating and is less corrosive. However, the desulfurization efficiency is low, the equipment is huge, the investment is large, the floor area is large, and the operation technology is required.
Dry flue gas desulfurization technology has been applied to large converters and blast furnaces in the iron and steel industry, but this method is not very suitable for small and medium blast furnaces.
Commonly used dry flue gas desulfurization technologies include activated carbon adsorption, electron beam radiation, charged dry absorbent injection, and metal oxide desulfurization.
【Semi-dry Desulfurization Technology】
The semi-dry desulfurization technology is to spray the lime slurry directly into the flue gas, or humidify and mix the lime powder and soot into the flue to form a mixture of calcium sulfite, dry calcium sulfate powder and soot.
The semi-dry desulfurization technology is a desulfurization method between the wet method and the dry method. Its desulfurization efficiency and desulfurization agent utilization rate are also in between. The method is mainly applicable to the flue gas treatment of small and medium boilers. .
This technology has low investment and low operating cost. Although the desulfurization rate is lower than that of wet desulfurization technology, it can still reach 70%, and has a small corrosiveness, a small footprint, a reliable process, and a good development prospect. Semi-dry desulfurization includes spray-drying desulfurization, semi-dry and semi-wet desulfurization, and powder-particle spray bed desulfurization.