SU1678422A1 - Method for sulphur dioxide and hydrogen sulphide separation - Google Patents

Abstract

The invention relates to methods for separating the S02 and H2S present in gas mixtures used in analytical chemistry to determine the HaS and S02 in air and to completely separate the analyzed gases. Gas separation is carried out in a column-type apparatus, passing a gas-air mixture containing 10 mg / m3 50g and 20 mg / m3 Hg5, at a speed of 8.5 cm / s and at a temperature of 20 ° C through a layer of polymeric sorbent. The polymer sorbent is a copolymer of styrene with divinylbenzene, containing a di- ethylamine residue in the functional unit, pretreated with a solution of either hydrochloric, or phosphoric, or citric acid to a sorbent acid content of 1 to 4 mEq / g. The method provides a complete separation of sulfur dioxide and hydrogen sulfide. 1 tabl, with with

Description

The invention relates to methods for separating sulfur dioxide and hydrogen sulfide present in gas mixtures, and can be used in the chemical and metallurgical industry and analytical chemistry.

The purpose of the invention is the complete separation of gases.

Example 1. Take 10 g of a polymer sorbent, which is a styrene-divinylbenzene copolymer containing a dielectric amine residue in the functional unit (technical name Anion-AH-AN-511), placed in a glass beaker c. with a mixer and pour 200 ml of a solution containing 0.365 g of hydrochloric acid. The mixture is stirred until neutral with methyl orange, then air dried for 36 hours.

The resulting sorbent containing 0.1 mg-SQ / r hydrochloric acid (the dissociation constant is 1) is placed in a conventional dynamic column 10 mm in diameter, through which a gas-air mixture containing 10 mg / ml SO and 20 mg / m 3 of hydrogen sulfide is passed. The speed of pulling is 8.5 cm / s, relative humidity 50%, temperature 20 ° С.

When passing the gas-air mixture through the layer of sorbent 50 is almost completely retained. H2S concentration at the outlet of the column injured its concentration at the inlet (20 mg / m)

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The separation selectivity of Kc is 100%.

Example 2. 8 g of an AN-511 anion exchange resin were taken, placed in a glass beaker with a stirrer, and 250 ml of a solution containing 0.680 g of phosphoric acid was poured. The mixture is stirred until neutral with methyl orange, and then dried in air for 36 hours.

The resulting sorbent containing 2.6 mEq / g of phosphoric acid (dissociation constant 7,) was tested under the same conditions as in Example 1.

When the gas-air mixture is passed through the sorbent layer, the SOz is almost completely retained. The concentration of HaS at the outlet from the column is equal to its concentration at the inlet (20 mg / m3).

The separation selectivity of Kc is 100%.

Example 3: Take 12 g of the AN-511 anion exchange resin, place it in a glass beaker with a stirrer, and pour 300 ml of a solution containing 3.075 g of citric acid. The mixture is stirred until neutral with methyl orange, then air dried for 36 hours.

The resulting sorbent containing 0.4 mEq / g of citric acid (dissociation constant 7,) is tested under the same conditions as in Example 1,

When passing the gas-air mixture through the SO sorbent layer, it is almost completely retained. The concentration of HaS at the outlet of the column is equal to its concentration at the inlet (20 mg / m3),

The separation selectivity of Kc is 100%.

Example 4. 10 g of an AN-511 anion exchange resin are taken, placed in a glass beaker with a stirrer, and 250 ml of a solution containing 2.640 g of butyric acid is poured. The mixture is stirred until neutral with methyl orange, then air dried for 36 hours.

The resulting sorbent containing 6.0 mg-eq / g of butyric acid (dissociation constant 1, was tested under the same conditions as in Example 1.

When passing the gas-air mixture through the layer of sorbent, the SO2 is almost completely retained. The H2S concentration at the outlet of the column is 15 mEq / g.

The separation selectivity of Kc is 75% .i

Under similar conditions, samples of anion exchanger AH-511 containing 0.5; 1.0; 1.5; 2.0; 2.5 mg eq / g of hydrochloric acid, which corresponds to neutralization of 10, 20, 30, 40 and 50% of the active resin groups, respectively.

The test results are summarized in table.

As can be seen from the table, when neutralizing less than 20% of the active groups, a 100% separation of the mixture of HaS and S02 is not achieved.

Neutralization of more than 30% of the active groups is impractical because it leads to a significant decrease in the capacitance at S02.

Use as a sorbent of a copolymer of styrene with divinylbenzene, containing diethylenetriamine residue in the functional unit, pre-treated with either hydrochloric or phosphoric or citric acid, allows you to completely separate sulfur dioxide and hydrogen sulfide, while in the known method of complete separation of HaS and SOa not happening ,

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION Method for separating sulfur dioxide and hydrogen sulfide present in gas mixtures by passing through a polymer sorbent, characterized in that, for the purpose of complete separation, a styrene-divinylbenzene copolymer containing a residue of dytilenetriamine in the functional unit, previously processed is used as the polymer sorbent with a solution of either hydrochloric or phosphoric or citric acid until the acid content in the sorbent is from 1 to 4 mg-eq / g.