Method for desulfurizing exhaust gas

Abstract

The invention discloses a method for desulfurizing exhaust gas. The method comprises the following steps: firstly, carrying out heat exchange on the exhaust gas, and reducing the temperature to 190 to 250DEG C; secondly, enabling the exhaust gas subjected to heat exchange to enter a quench zone, enabling the exhaust gas to be in contact with absorption liquid, and then carrying out adiabatic saturation absorption on the exhaust gas so as to reduce the temperature of the exhaust gas to 60 to 80DEG C; thirdly, enabling the exhaust gas exhausted from the quench zone to enter a first absorption zone, enabling the exhaust gas to be in contact with sprayed absorption liquid in a filler and absorbing sulfur dioxide in the exhaust gas by the absorption liquid; fourthly, enabling the exhaust gas exhausted from the first absorption zone to enter a second absorption zone, enabling the exhaust gas to be in countercurrent contact with the sprayed absorption liquid in the filler, and removing all remaining sulfur dioxide from the exhaust gas; fifthly, carrying out multistage washing on the exhaust gas exhausted from the second absorption zone, and removing a salt solution entrained in the exhaust gas; sixthly, removing droplets in the exhaust gas exhausted from a multistage washing zone and then discharging. The method disclosed by the invention has the advantages that the operation is simple, operation expenses are reduced, the occupied area is greatly reduced, and emission indexes can be far lower than the environmental protection standard level; the method is in the leading level of technology.

Description

technical field [0001] The invention relates to a treatment method for waste gas, in particular to a treatment method for waste gas containing sulfur dioxide. Background technique [0002] Since the improved Claus sulfur recovery technology realized industrial production in the 1930s, after nearly 90 years of development and improvement, it has become mature and perfect. 300-800mg / Nm 3 , cannot meet the current standard requirements. [0003] At this stage, the reduction-absorption method is commonly used in the tail gas treatment of sulfur recovery units, that is, all the sulfur-containing compounds in the tail gas are first reduced to H 2 S, and then remove it, and finally recover it in the form of acid gas or elemental sulfur, and the absorption liquid can be recycled and used. SCOT is a typical reduction-absorption method. The main disadvantage of this process is that the equipment investment, operation cost and energy consumption are quite high. The oxidation-absorp...

AI Technical Summary

Problems solved by technology

SCOT is a typical reduction-absorption method. The main disadvantage of this process is that the equipment investment, operation cost and energy consumption are quite high.

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