Low sulfur emission sulfur recovery process for low concentration acid gas

Abstract

The invention provides a low-sulfur discharge sulfur recovery process for low-concentration acid gas. The low-concentration acid gas with H2S content less than 5% is treated by one selective oxidation reactor and two adsorption desulfurization towers that can be connected in parallel to achieve desulfurization. Purpose: The selective oxidation reactor is filled with H2S selective oxidation catalyst, and the adsorption desulfurization tower is filled with thermally regenerable catalytic oxidation adsorption desulfurizer; The total sulfur break of the exhaust gas is SO2 ≤ 10mg / m3. Through thermal regeneration, the service life and desulfurization capacity of catalytic oxidation adsorption desulfurizer are greatly increased. This process has the advantages of low sulfur emission, sulfur recovery rate close to 100%, long service life of desulfurizer, large desulfurization capacity, less replacement times, low cost, desulfurizer unloading, good scrap treatment conditions, safety and so on.

Description

technical field [0001] The invention relates to a sulfur recovery process, in particular to a low-sulfur discharge sulfur recovery process for low-concentration acid gas. Background technique [0002] During petrochemical, coal chemical, and coal gasification processes, part of the sulfur contained in raw materials is usually converted into H 2 S, separated to form H 2 The acid gas of S, the acid gas is generally processed through the sulfur recovery process, and the H 2 S is converted to elemental sulfur as much as possible. [0003] In the operation process of the sulfur recovery unit, there are also two problems of emptying tail gas and solid waste. The tail gas evacuated through the chimney, of which, SO 2 Concentration is a continuous monitoring item, although the upper limit of the current air pollutant comprehensive emission standard GB16297-1996 is 700mg / m 3 It is not difficult to achieve, but there may be more stringent emission standards in the industry or reg...

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Problems solved by technology

[0015] C. Multiple replacements of catalytic oxidation adsorption desulfurizers in the process bring more hidden dangers of safety and environmental pollution

[0016] After the catalytic oxidation adsorption desulfurizer loaded in the adsorption desulfurization tower is saturated or penetrated, it needs to be unloaded and replaced with a new catalytic oxidation adsorption desulfurizer, so there is a problem of regular replacement of the catalyst frequently; when unloading, the upper desulfurizer bed The layer often has agglomeration, which is difficult to unload, and the H physically adsorbed in the upper desulfurizer bed 2 S is released, there is an obvious peculiar smell, and the site environment of the unloading agent is poor. If proper treatment is not carried out, H will still be emitted during storage and transportation. 2 S, SO 2 odor, pollute the environment, and also affect the safety of operators; the unloaded waste desulfurizer contains more than 20% (mass) of sulfur, and there is a danger of flammability during storage and transportation, and SO 2 It will also cause environmental pollution; in the process of waste agent treatment, the processing factory is often small in scale and limited in facilities, which is likely to cause serious environmental pollution, and the sulfur contained in the waste agent cannot be effectively utilized.

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