Low temperature removal method for COS with relatively high concentration in gas

Abstract

The invention provides a low temperature removal method for COS with a relatively high concentration in gas. The low temperature removal method mainly comprises the following steps: process gas is maintained or heated to 30-80 DEG C and is introduced into hydrolysis desulfuration towers to be treated; the hydrolysis desulfuration towers are filled with a COS hydrolysis agent and an H2S oxidation desulfuration agent in a stacking or laminating manner; the H2S oxidation desulfuration agent can be subjected to sulfur-blowing thermal regeneration at 200-300 DEG C, and the performance of the COS hydrolysis agent is less or barely reduced after a thermal regeneration process; two or more hydrolysis desulfuration towers are arranged, can be connected in series or parallel for use and comprise vertical heating sleeves, and hydrolysis agent-desulfuration agent bed layers are arranged among the sleeves; and captured elemental sulfur is melted, gasified and blown out by the hydrolysis desulfuration towers during the thermal regeneration at 200-300 DEG C and is collected as sulfur by virtue of a regeneration condenser. The low temperature removal method has the beneficial effects that the desulfuration process is simple and reliable, the COS removal rate is easily maintained above 90% or even above 95%, the control is easy, the elasticity of processing quantity is high, and the method has strong adaptability to the degrees and fluctuation of contents of H2S and COS, and is safe and environment-friendly and low in operation cost.

Description

technical field [0001] The invention relates to a gas desulfurization method, in particular to a low-temperature removal method of high-concentration COS in gas. Background technique [0002] In the process of chemical production, there are many gases containing H 2 S, COS and other sulfides, when the amount of sulfides is large, most of the sulfides are generally separated by MDEA method, low-temperature methanol washing and other methods, and then processed through a suitable sulfur recovery process; but when the gas volume is small, this The process of separation and enrichment first, followed by sulfur recovery, is difficult to apply due to the complexity of the process, large investment, and cumbersome operation and control. [0003] When the air volume is not very large, H 2 When the concentration of S and COS is low, low-temperature organic sulfur hydrolysis agent is generally used to hydrolyze COS into H 2 S, and then converted to elemental sulfur by oxidative des...

AI Technical Summary

Problems solved by technology

[0005] When COS or H 2 High S concentration, such as COS concentration higher than 500ug / L or H 2 When the S concentration is higher than 1000ug / L, the hydrolysis of COS in the low-temperature organic sulfur hydrolysis agent will be inhibited, and the hydrolysis rate is difficult to maintain above 90%, let alone above 95%.

The conversion absorption type fine desulfurizer can also treat this gas in a short time, but the sulfur capacity is low or the breakthrough time is short, and often the regenerability is not good

[0006] Some process gases, such as CO gas produced from coke, carbon dioxide and oxygen in a gas-making furnace, calcium carbide furnace gas prepared from coke and calcium oxide at high temperature, yellow phosphorus electric furnace tail gas, have high CO content, and most of the sulfur exists in the form of COS , and the concentration is more than 1000ug / L, even more than 2000ug / L, the hydrolysis rate of COS is not high enough when low-temperature organosulfur hydrolysis agent is used, and the removal rate of COS is difficult to maintain above 90%, let alone above 95%. The concentration is still high; however, if a medium-temperature or high-temperature hydrolysis agent and conditions are used, the cost is relatively high; because the gas volume is small and the amount of sulfide is small, the method of separation and enrichment first and then sulfur recovery is not applicable

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