SU40496A1 - The method of purification of coking, generator and similar gases from hydrogen sulfide - Google Patents

Description

The proposed method of purifying coking and similar gases from hydrogen sulphide relates to wet scrubbing techniques to produce elemental sulfur and ammonium sulphate and is based on the ability of sulphurous acid to oxidize hydrogen sulphide according to the reaction

2H2S4-SO2:; 2H2O-i-3s. . . (i)

However, as is known, this reaction proceeds under special conditions and, moreover, not completely. The difficulty of its implementation lies in the fact that it only under special conditions goes fast enough, giving a full flush, as well as in the fact that it proceeds not literally according to equation (1), but is accompanied by side reactions that lead to the formation of complex thioacids. (see Gluud. “Production of coke t. II, p. 148, and Mullert.“ Sulfur in coal, p. 107, ed. 1932).

As discovered in the course of experimentation, the oxidation of hydrogen sulfide with sulfuric acid occurs instantaneously and completely in the presence of ammonia with its ratio to hydrogen sulfide as 1: 1, only in the presence of sulfuric acid, according to the following equation:

2NH8 + 2H2S + H2SO4 + SO2 - - (NHJ2 S2O4 + H2O + 3S,... (2)

moreover, its flow in the desired direction requires known after (2) ,,

This process arises, on the one hand, from the nature of the reaction salts, and, on the other hand, from the nature of the coke-gas production, without which it cannot meet the goal.

The use of this reaction for the purification of coking and similar gases from hydrogen sulphide can be carried out by a number of the methods described below, to a certain extent due to the nature of the reaction itself and the technological conditions of coking benzene and similar industries.

The gas obtained in the heat treatment process of solid combustible minerals, containing hydrogen sulphide and ammonia, is first subjected to scrubbing with water to produce weak ammonia water, after which the resulting ammonia scrubber water is used as a washing liquid to trap the hydrogen sulphide. As a result of these gas purification measures, a dilute ammonium hydrosulfite solution is obtained, which is subjected to additional processing, for which it is pumped into a special apparatus, to which a dilute solution of sulfuric acid saturated with a temperature of 60-100 ° C or sulfuric acid and a stream of gas is also supplied. containing sulfur dioxide. The ammonium sulphate solution obtained according to reaction (2) is filtered off from the liberated elemental sulfur, subjected to evaporation, and the elemental sulfur is dried.

In view of the fact that the proposed method is not without a drawback, consisting mainly in the need to evaporate relatively large volumes of a dilute solution of ammonium sulfate, due to the concentration of scrubber ammonia water, in a modified method the desulfurization containing hydrogen sulfide and ammonia gas are in the gas phase. For this, the gas containing hydrogen sulfide and ammonia is directly transferred to a special apparatus, called a saturator, filled with a solution of sulfuric acid, saturated sulfuric acid or sequentially saturated with it, resulting in the continuous formation of elemental sulfur and ammonium sulfate in the process. while maintaining the process water balance (in order to avoid additional evaporation of the sulphate solution after filtering off the sulfur) by maintaining an appropriate temperature of the direct gas and bath turatora. Since the simultaneous release of ammonium sulfate and elemental sulfur in the solid form is undesirable due to the complexity of their separation, the process is carried out with an excess amount of sulfuric acid so that the saturator mother solution is ammonium bisulfite. Upon further treatment with ammonia, sulfate is formed, which precipitates as a crystal from the mother liquor, on the basis of which the crawling / not in the saturator is not, according to process management, sulfur and ammonium bisulfate are released from the saturator with an injector into the dentrofuge, where the sulfur is released, and the bisulfate solution flows into another downstream apparatus, where it is neutralized by ammonia, obtained by processing the condensation ammonia water on a lime column. The precipitated ammonium sulfate, in turn, is ejected by the injector into the centrifuge, where it takes off, and the mother liquor is pumped into the pressure tank for dilute sulfuric acid feeding the first saturator.

For a more intimate representation of the method, the drawing shows an installation diagram.

In the coking ovens direct gas scheme /, which has undergone a condensation unit 2, an exhauster 3 and a tar separator 4 containing ammonia and hydrogen sulfide, enters the reshapher 5, and then into a sulfate saturator 6. The gas containing hydrogen sulfide and ammonia in the reaction of neutralizing the sulfuric acid solution the saturator ammonia contained in the gas goes further to the desulfurizer 7, also filled with a sulfuric acid solution, where an aqueous solution of ammonium bisulfite from the pressure tank 13 is continuously introduced into the gas stream. As a result, a scrubber is the indirect reaction of the oxidation of hydrogen sulfide with sulfur dioxide. Next, a scrubber 8 passes to trap SOj and a saturator 9 purified from hydrogen sulphide, the gas enters the final refrigerators W and then into the benzene scrubber, etc.

Resulting in the saturator 7 by the reaction of hydrogen sulfide and ammonium bisulfite in the sulfuric acid medium sulfur as storage discharged from carbonator injector through the trough in tsentrofugu 20, where after otfugovani and washing water is provided on the serving of its conveyor belt, and the mother sulfuric acid solution also containing solution ammonium sulfate, supplied by pump 18 to sulfuric acid tank 72 serving saturator 6. The ammonium bisulfite solution required for desulfurization is obtained by cutting It is easier to saturate with sulfur dioxide in the absorber 28 of concentrated ammonia water obtained during processing on the limestone column of condensation water, and sulfur dioxide is from a part of the sulfur of the cleaning process burned in a special furnace 27. The water balance of the process is very easy to regulate by preheating the gas in the decanters, t . e. is similar to the method that occurs when

production of ammonium sulphate or coke oven gas.

In addition, the diagram shows: nano tank / 7 for water, resin collector 14, collector 15 for mockup, collection 16 for nodal water, pressure tank 17 for groundwater, centrifugal 19 for ammonium sulfate, dissociator 21, reflux condenser 22, condenser 23 , ammonia column 24, absorber 25, collection 25 for concentrated ammonia water and cooling towers 29.

The subject matter of the invention

1. A method for purifying coking, generator and the like gases from hydrogen sulfide, characterized in that the hydrogen containing hydrogen sulfide, after liberation from ammonia, is treated with an ammonium bisulfite solution in a sulfuric acid bath heated to a temperature of 60-100 °.

2. Alteration of the method indicated in paragraph 1, characterized in that the direct gas containing ammonia or after

the release from it is processed in the process of sparging with a solution of sulfuric acid heated to a temperature of 60-100, saturated or continuously saturated with sulfur dioxide.

3. Acceptance of the method indicated in paragraph 2, characterized in that, in order to protect from simultaneous precipitation in a solid form of elemental sulfur to ammonium sulfate in a sulfuric acid bath, the acidity of the bath is maintained so that the formation of ammonia from the gas takes place A concentrated solution of ammonium bisulfate.

4. Acceptance of the method indicated in paragraphs. 1-3, characterized in that the concentrated ammonium bisulfate solution obtained after separation of elemental sulfur to obtain sulfate is neutralized with ammonia or ammonia obtained in the processing process on lime columns of condensed ammonia water contained in a direct gas.