Sulphuric acid tail-gas deep desulfurization method

Abstract

The invention discloses a deep desulfurization method of sulfate acid tail gas. The method additionally arranges a desulfurization tower behind a second adsorption tower of a sulphuric acid device; after the waste gas discharged from the second adsorption tower enters the desulfurization tower, an ammoniation absorbent is used for adsorbing SO2 in the waste gas to generate ammonium sulfite; the tail gas after the desulfurization passes through a demisting layer in the tower to eliminate acid fog; the purified tail gas is discharged through a chimney at high altitude; the ammonium sulfite in the absorbent is aerated and oxidized to be ammonium sulfate solution at the bottom of the tower; and after the concentration of circulation liquid ammonium sulfate meets the requirement, the circulation liquid ammonium sulfate is sent to a follow-up process to be processed and used. The deep desulfurization method of sulfate acid tail gas can cause the concentration of the SO2 in the tail gas to be lower than 100mg / m<3> in a standard state, greatly reduces the emission of the SO2 in the tail gas, is beneficial to the improvement of the atmospheric environment quality, meets the construction principles of energy conservation, emission reduction and sustainable development and has good social benefits; in addition, the deep desulfurization method can increase the recovery amount of the ammonium sulfate, and has certain economic benefits.

Description

technical field [0001] The invention relates to the production of sulfuric acid, specifically to the treatment of sulfuric acid tail gas, especially to the method for removing sulfur dioxide in the tail gas. Background technique [0002] Existing sulfuric acid production with two-turn-two-suction tail gas emission of SO 2 The concentration is relatively high, and the concentration under standard conditions reaches 700-960mg / m 3 , more serious environmental pollution, which is an urgent environmental problem for sulfuric acid manufacturers. [0003] Removal of SO from gas by using ammonia gas 2 The technology has been applied in the comprehensive treatment of flue gas desulfurization, such as Chinese patent application No. 200410098788.0 "Comprehensive Utilization Device and Method for By-products of Flue Gas Desulfurization", No. 200510017797.7 "A kind of ammonia-ammonium sulfate dry flue gas Desulfurization and denitrification equipment and process", etc. Although these...

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Problems solved by technology

However, at present, there is no sulfuric acid enterprise that adopts the two-transfer and two-absorption process to use ammonia gas desulfurization to remove SO in the tail gas. 2 reports, and there is no patent application for related technologies

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