Dry flue gas desulfurization is also called dry flue gas desulfurization. There are two types of dry flue gas desulfurization: One is desulfurization in the furnace, that is, CaCO3 injected into the furnace is calcined at high temperature and decomposed into Cao, which reacts with SO2 in the flue gas to generate calcium sulfate, which is fixed in the ash; the other is desulfurization at medium and low temperature, which has many kinds, such as SDS sodium based dry process technology, FGD circulating fluidized bed technology, SDA sodium based semi dry process, electron beam irradiation and activated carbon adsorption, etc., to achieve SO2 removal, collectively referred to as dry flue gas Desulfurization technology. It has the advantages of simple process, no waste water and acid treatment, low energy consumption, especially the high temperature of flue gas after purification, which is conducive to chimney exhaust diffusion and does not produce "white smoke" phenomenon. The purified flue gas does not need to be reheated and has little corrosiveness;
1) Its desulfurization mechanism is that sodium bicarbonate (NaHCO3) is activated under the action of high temperature flue gas, forming microporous structure on the surface, just like popcorn is exploded, the reaction is fast and sufficient, and can be completed in 2 seconds.
2) In the reactor, flue and bag filter, the ultra-fine powder of desulfurizer always reacts with SO2 in flue gas. The whole device is compact in structure, small in volume, reliable in operation, and the desulfurizing efficiency can reach more than 99%.
3) At the same time, the flue gas flows at high speed in the reactor, which overcomes the wall sticking problem in the traditional semi dry desulfurization reactor;
4) Na2SO4, a by-product of production, is recycled by bag filter and used as a chemical product. The by-product of desulfurization is dry state, and the system has no water. The end product logistics has good mobility and is suitable for pneumatic conveying.
5) SO3, HCl, HF and other acidic media in flue gas are absorbed and purified at the same time. After desulfurization, the flue gas can be discharged directly without reheating, so as to solve the problem of "white smoke".
6) The combined process of SDS desulfurization and SCR denitration is adopted to create excellent conditions for simultaneous desulfurization and denitration of flue gas. The Sox concentration in flue gas has a great influence on the service life of medium and low temperature SCR denitration catalyst, and even causes catalyst poisoning and blocking, which affects the stable operation of the system. Flue gas "desulfuration first, denitration later" solves the above problems.