System for removing SO3 from flue gas by ammonia-spraying and working method thereof

Abstract

The invention relates to a system for removing SO3 from flue gas by ammonia-spraying and a working method thereof, and belongs to the field of industrial waste gas purification and environmental protection and energy sources. Ammonia gas is injected before the flue gas is introduced into a dust collector, the ammonia gas reacts with SO3 in the flue gas to form solid ammonium sulfate particles, andthen the solid ammonium sulfate particles are removed in the dust collector, thus the purpose that SO3 in the flue gas is removed is realized. SO3 is solidified by ammonia-containing fly ash after wet mixing of desulfurization wastewater, and then ammonia gas regeneration is realized by using waste heat of the flue gas in an ammonia gas regenerator, thus the recycling of ammonia gas is realized.According to the system, an absorbent can be recycled and efficiently used, the efficient removal of SO3 in the flue gas is realized, the performance of the dust collector is improved, desulfurizationwastewater is synergistically treated, no secondary wastes are produced, and no adverse effects occur on the utilization of fly ash, so that the system has the advantages of waste treatment by waste,energy saving and consumption reduction and the like, and has wide application prospects.

Description

technical field [0001] The invention belongs to the field of industrial waste gas purification, environmental protection and energy, and specifically relates to a method for removing SO from flue gas by spraying ammonia 3 system and how it works. Background technique [0002] my country's coal-based energy structure will not change for a long time. Therefore, controlling the emission of coal-fired flue gas pollutants is an important task for my country's air pollution control. In the current situation where coal-fired power plants are fully promoting ultra-low emissions, SO 3 The problem of pollution is also getting more and more attention. Flue gas SO currently entering industrial applications 3 Removal technologies include alkaline absorbent injection, low-temperature electrostatic precipitator, wet electrostatic precipitator, etc. Among them, alkaline absorbent injection technology is widely regarded as a flue gas removal technology due to its advantages of low initial...

AI Technical Summary

Problems solved by technology

But this method has high SO 3 Under the requirements of removal efficiency, the consumption of absorbent is relatively large, and the corresponding operating cost is relatively high. Excessive absorbent can easily cause alkali poisoning of SCR catalyst and affect the specific resistance of dust, etc.

[0014] Another example is CN 103055684 B——"Using trona to effectively remove flue gas sulfur trioxide device and process", a nozzle system is installed at the flue between the tail of the SCR reactor and the air preheater, and sprayed into the flue Trona slurry, using the strong alkali properties of trona to treat SO 3 Carry out absorption and removal, but there is still the problem that the cost of absorbent is difficult to control

Images