At present, there are many ways of flue gas desulfurization, such as wet desulfurization, dry desulfurization and so on. Here is a brief introduction of several common flue gas desulfurization methods.
1、 At present, the common wet desulfurization methods are calcium desulfurization, ammonia desulfurization and alkali desulfurization.
First of all, the calcium desulfurization method is introduced. Calcium desulfurization occupies a large share in the field of flue gas desulfurization in China. The main reason is that calcium desulfurization was applied earlier in China, the technology is relatively mature, and the investment cost is low. The raw material of calcium method desulfurization is calcium oxide, which is cheap and easy to get. Its desulfurization efficiency is also high, generally about 95%. The sulfur content of the treated flue gas is generally less than 3000mg / nm. The principle is that the flue gas contacts with the desulfurization liquid through the spray layer in the desulfurization tower to remove the sulfur dioxide in the flue gas and generate the by-product calcium sulfate. In the process of desulfurization, calcium oxide needs to be matured, so it needs the preparation of desulfurization solution, which requires the construction of maturation tank and sedimentation tank, so it occupies a large area and has the generation of external drainage. Its by-product calcium sulfate, namely gypsum, is in the trend of saturation at present, and its sales price is relatively low, or it is treated as solid waste investment by enterprises. This is a major problem of calcium desulfurization.
Ammonia desulfurization is mainly used in the chemical industry, the main reason is that the chemical industry generally has the preparation of ammonia or the production of waste ammonia. Compared with other industries, the investment of desulfurization agent using ammonia desulfurization in the chemical industry is lower. The desulfurization efficiency of ammonia method is higher than that of calcium method, generally about 97%, and the sulfur content of flue gas treated by ammonia method is also higher than that of calcium method. The desulfurization tower of ammonia desulfurization is packed tower, which has obvious sectional structure compared with the empty tower of calcium desulfurization. The by-product of ammonia desulfurization is ammonium sulfate, which can be used as chemical fertilizer or compound fertilizer. No three wastes are produced in the process of ammonia desulfurization, which is a clean and economic way in wet desulfurization. With more and more strict control of carbon emission, ammonia desulfurization is expected to become a widely used desulfurization method.
The forms of alkali desulfurization and calcium desulfurization are the same, but the desulfurizer is different. Generally speaking, both alkali desulfurization and calcium desulfurization need to cooperate with wet electrostatic precipitator to meet the emission standard of export particles.
2、 At present, sodium based dry desulfurization and activated coke (carbon) desulfurization are widely used
Sodium based dry desulfurization, also known as SDS dry desulfurization, is suitable for flue gas desulfurization with low sulfur content because of its simple equipment, small footprint and low investment. It is widely used in iron and steel industry, coking furnace, gas-fired boiler, etc. This kind of desulfurization method can transport the material which meets the grinding standard to the flue through the grinder and the conveying fan, and react with the sulfur dioxide in the flue gas in the dry state, and its desulfurization efficiency is also high, generally more than 90%.
Activated coke (carbon) desulfurization is a kind of physical adsorption desulfurization. The sulfur dioxide in the flue gas is adsorbed in the active coke (carbon) by using the adsorptivity of the active coke (carbon), and then the gas of the active coke (carbon) is resolved under different temperature and pressure under the action of the analytical tower, so as to recover the pure gas and realize the recycling of raw materials. But its equipment covers a large area, and the investment cost is huge, so it is not widely used in small enterprises.
The above desulfurization methods are widely used in the market. If you want to know more about environmental protection desulfurization, please consult our official website of biological desulfurization .