Integrated method for simultaneously realizing denitrification, desulfurization and heavy metal removal from flue gas, and special equipment suitable for the method

Abstract

The invention relates to an integrated method for simultaneously realizing denitrification, desulfurization and heavy metal removal from flue gas, and special equipment suitable for the method. The integrated method is characterized in that an acidic gas capture agent adopted by the invention captures SO2 and / or highly charged nitrogen oxides NOx in raw flue gas and thus ammonium sulfate as a by-product and / or ammonium nitrate as a by-product is obtained finally, and the acidic gas capture agent adsorbs heavy metals in the raw flue gas simultaneously, wherein the above processes are carried out in a same absorbing device. The special equipment suitable for the method of the invention comprises an absorbing tower, a raw flue gas input pipeline having an external connection with the absorbing tower body, a purified flue gas output pipeline having an external connection with the absorbing tower body, a system for supplying the acidic gas capture agent and absorbents, a demisting water input pipeline, an absorption liquid cycling system, a slurry discharge system, and a separation and treatment system, wherein the raw flue gas input pipeline is provided with a supercharging system anda forced oxidation system. Through the method of the invention, the integrated purification processes of denitrification, desulfurization and heavy metal removal from flue gas can be completed in a same device and by-products from the integrated purification processes are ammonium sulfate and ammonium nitrate, wherein ammonium sulfate and ammonium nitrate can be utilized as components of fertilizers. Through the method, waste water and waste residue are not produced in the integrated purification processes and the integrated purification processes have the advantages of simple system, low cost, high recovery rate, etc.

Description

technical field [0001] The invention belongs to the technical field of flue gas purification, and in particular relates to an integrated method and special equipment for flue gas desulfurization, denitrification and heavy metal removal. Background technique [0002] Sulfur dioxide (SO 2 ), nitrogen oxides (mainly including NO and NO 2 ) and heavy metals (Hg, Ag) and other pollutants have become the main sources of air and soil pollution. At present, there are many flue gas or industrial tail gas pollution control technologies, among which the relatively mature and representative flue gas SO 2 The current desulfurization technologies include limestone-gypsum method, ammonia method, double alkali method, etc. The denitrification technologies for controlling flue gas NOx pollutants include SCR (selective catalytic reduction, selective catalytic reduction method), SNCR (Selective Non-Catalytic Reduction, non-selective catalytic reduction method), low-nitrogen combustion metho...

AI Technical Summary

Problems solved by technology

Its disadvantages are: large one-time investment, large floor area, large system resistance, high power consumption, and no mercury removal function

In short, as far as the current actual situation is concerned, no matter what technology is used, the SO 2 The removal of NOx and NOx is realized in two devices with different functions. It does not have the function of integrating high-efficiency removal in the same device, and there is no simultaneous removal of sulfur dioxide, nitrogen oxides and heavy metals in the same device. technology

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