Sulfur recovery method for treating acid gas

Abstract

The invention provides a sulfur recovery method for treating acid gas, characterized by comprising a tail gas purification treatment stage, wherein Claus tail gas is cooled to 130 to 140 DEG C througha third-stage condenser; separated process gas enters a sulfur mist trap, and liquid sulfur is further collected; the process gas that comes out of the sulfur mist trap is heated by a third-stage reheater and then enters a hydrogenation reactor for hydrogenation hydrolysis reaction; the process gas which comes out of the hydrogenation reactor is condensed and cooled by a fourth-stage condenser, and then enters a selective oxidation reactor; the process gas which comes out of an outlet of the selective oxidation reactor enters a fifth-stage condenser and is cooled to 130 to 140 DEG C; the process gas which comes out of the fifth-stage condenser enters a complex iron ion solution. purified tail gas which comes out of the complex iron ion solution is introduced into an incinerator to be incinerated and emptied. The sulfur recovery method is efficient, energy-saving and economical, and not only improves the sulfur production rate, but also minimizes the SO2 emission concentration.

Description

technical field [0001] The invention belongs to the technical field of sulfur recovery, and in particular relates to a sulfur recovery process for treating acid gas. Background technique [0002] my country on SO 2 The emission standards are becoming increasingly stringent. Before 2012, the emission concentration of sulfur dioxide stipulated in the "Comprehensive Emission Standard of Air Pollutants" GB16297-1996 was not higher than 960mg / Nm 3 . The "Petrochemical Industry Pollutant Discharge Standard" GB31571-2015, which came into effect on July 1, 2015, requires that the tail gas SO 2 Emission concentration should be less than 100mg / m 3 , the tail gas emission concentration in special restricted areas is less than 30mg / m 3 . [0003] Now the Claus tail gas is generally absorbed by alcohol amine solution and treated again. Since the Claus reaction is an equilibrium reaction, and the temperature in the Claus reaction stage is generally high, the Claus conversion rate is ...

AI Technical Summary

Problems solved by technology

[0003] Now the Claus tail gas is generally absorbed by alcohol amine solution and treated again. Since the Claus reaction is an equilibrium reaction, and the temperature in the Claus reaction stage is generally high, the Claus conversion rate is not ideal, and the Claus tail gas H in 2 The S content is still very high. Passing such Claus tail gas into the alcohol amine liquid absorption and regeneration system requires particularly high alcohol amine liquid concentration, alcohol amine liquid desorption capacity, and amine liquid circulation flow rate, which is neither economical nor possible. Due to problems such as the quality of the amine liquid, the H in the exhaust gas was purified 2 S content is much greater than 10mg / m 3 , SO in the final flue gas 2 The emission concentration cannot meet the requirements of the national environmental protection law