SU1719031A1 - Method of cleaning gas from hydrogen sulfide and mercaptanes - Google Patents

Abstract

The invention relates to the field of gas purification from sulfur compounds and can be used in the gas, petroleum and chemical industries. The aim of the invention is to eliminate effluent. To do this, in the proposed method, as an absorbent of hydrogen sulfide, alkali metal mercitalide obtained at the second stage of contact is used in a stoichiometric amount, the spent solution is treated with iron hydroxide in a stoichiometric amount, ferrous sulfide is separated, and the alkaline solution is recycled into the second level of contact. 1 il.

Description

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The invention relates to the field of gas purification from sulfur compounds and can be used in the gas, petroleum and chemical industries.

The aim of the invention is to eliminate effluent.

The drawing shows a process flow diagram of the method.

The gas containing hydrogen sulfide and mercaptans enters the absorber 1 where the pump 2 serves the absorption solution containing the alkali metal mercaptides. The treated absorber from the adsorber enters the reactor 3, where it is treated with iron hydroxide. The reaction products from the reactor 3 are directed to a filter 4 for separating the solid phase. The filtrate, which is an alkali metal hydroxide, is sent to the second adsorber 5, where the gas absorbed from hydrogen sulfide and containing mercaptans simultaneously enters the absorber 1. The alkali metal mercaptide formed is returned to the stage of gas purification from hydrogen sulphide in the absorber 1, and the purified gas is removed from the adsorber 5. The gas with hydrogen sulphide concentration of 1 g / m 3 and mercaptans 0.5 g / m 3 are cleaned. The gas flow rate is 100,000 m3 / day. In the absorber for cleaning serves an aqueous solution of mercaptide

sodium in the amount of 63 l / h, with a concentration of 2 mol / l, the spent solution is treated in the reactor with iron hydroxide in the amount of 11 kg / h. As a result of processing

NaOH in the amount of 4.6 kg / h and FeS - 10.5 kg / h is formed in the reactor. The alkali is separated and sent to a second absorber, where the gas is purified from hydrogen sulfide. The gas contains 7.98 kg / h of mercaptans. For

extracting such a quantity of mercaptans to the absorber must be returned after the filter alkali in the amount of 4.6 kg / h and pump fresh alkali at the rate of 2 kg / h. As a result of processing, sodium mercaptide is obtained in the absorber, which is returned to the gas purification stage from hydrogen sulfide. The degree of gas purification from hydrogen sulfide is 99.69%, from mercaptans - 99.9%.

Reactive substances (alkali metal mercaptide, iron hydroxide) are taken in stoichiometric amounts. When stoichiometric ratios are exceeded, purification deteriorates or a mixture of recoverable components — hydrogen sulfide — is formed.

and mercaptans.

In the proposed method, in contrast to the prototype method, the effluent is eliminated and in this way contamination of the environment with sulfur compounds is eliminated.

Claims (1)

Invention Formula The method of gas purification from hydrogen sulphide, comprising two successive stages of contacting with countercurrent, at the first stage - with an aqueous solution of hydrogen sulphide absorbent, at the second stage - with an alkaline solution, which, in order to eliminate drains, / 1 L / NJ ngs W PefOHh % R An alkali metal mercaptide obtained in the second contacting stage is used in stoichiometric amounts as a hydrogen sulfide absorbent, the spent solution is treated with iron hydroxide in a stoichiometric amount, ferrous sulfide is separated, and the alkaline solution is recycled to the second contacting level. yu.g faOtf N S / f