SU1685513A1 - Method of preparing catalyst for oxidation of sulfur containing compounds - Google Patents

Abstract

The invention relates to catalytic chemistry, in particular the preparation of a catalyst for the oxidation of sulfur compounds, for example, when neutralizing sulfide and mercaptans containing aqueous or aqueous alkaline solutions used in chemistry and petrochemistry. The goal is to increase the activity of the catalyst. For this, the cobalt phthalocyanine and / or its derivative is mixed with the polymer, the mixture is heated to the melting point of the polymer, and molded. The molded catalyst is then heat treated in an aqueous solution of sodium thiosulfate or in a medium of sulphurous alkaline effluents, which are formed during the alkaline purification of petroleum fractions, at 95-100 ° C for 1–3 hours and stirred with air. In this case, the catalyst obtained has a higher activity than the known one. Thus, the degree of oxidation of Na2S is 2 times higher than when using a non-thermoformed catalyst. 1 tab. cl

Description

The invention relates to a process for the preparation of heterogeneous phthalocyanine catalysts for the oxidation of sulfur compounds, namely the disposal of sulfide and / or mercaptide-containing aqueous or water-alkaline solutions, and can be applied in the gas, oil refining, petrochemical, chemical, and pulp and paper industries.

The purpose of the invention is to increase the activity of the catalyst for the oxidation of sulfur compounds.

The catalyst is obtained by mixing the cobalt phthalocyanine and / or its derivative with a polymer, heating the mixture to the melting point of the polymer, followed by molding and processing the molded

catalyst at 95-100 ° C for 1-3 hours in an aqueous solution of sodium thiosulfate or in a medium of sulfur-alkaline effluents, formed during alkaline purification of petroleum fractions, with air mixing.

Example 1. The catalyst composition, wt.%; Cobalt phthalocyanine 10, high pressure polyethylene up to 100, prepared by mixing the components, heating to the melting point of polyethylene 110-130 ° C and formed into granules with an average equivalent diameter of 3 mm. Then, the granules are heat treated in a 0.6 wt.% Aqueous solution of sodium thiosulfate at 95 ° C for 1, 2, 3, 5 and 8 hours with continuous stirring with air.

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The resulting catalyst is then tested in a bubble process for the oxidation of sulfur compounds.

To do this, 75 ml of an aqueous alkaline solution of sodium sulfide containing 0.3 wt.% Sodium sulfide in terms of sulfur and 3 wt.% Sodium hydroxide are oxidized with atmospheric oxygen in the presence of the resulting catalyst. Oxidation is carried out in a batch glass reactor with a diameter of 30 mm and a height of 350 mm, equipped with a reflux condenser, a contact thermometer with an automatic temperature control system, taps for oxygen supply and sampling, a perfluorinated glass partition at the oxygen disper- sion. and retaining the granular heterogeneous catalyst at 40 ° C, atmospheric pressure, volumetric oxygen feed rate of 6000 hours for 30 minutes. The sodium sulfide is oxidized to thiosulfate and sodium sulfate in a ratio of about 4: 1. The residual content of sodium sulphide is determined by a potentiometric method.

Example 2. The catalyst is obtained as in example 1, but is subjected to heat treatment in the medium of example 1 at 90 ° C for 5 and 8h.

The heat treated catalyst samples are subjected to tests for its activity in the oxidation of 75 ml of an alkaline solution of sodium sulfide in the reactor and the conditions of example 1.

Example 3. The catalyst is obtained as in Example 1, but is subjected to heat treatment in an environment of real sulfur-alkaline effluents from gas fractionation plants and the alkalisation of straight-run gasolines of the following composition, May. %: NaaS 0.8; RSNa 0.25; NaOH 3; the rest is water - at 100 ° C for 1, 2, 3, 5, 8 hours with continuous stirring with air.

The heat-treated sample of the catalyst is subjected to tests for its activity in the oxidation of 75 ml of an alkaline solution of sodium sulfide in the reactor and the conditions of example 1.

Example 4. A non-thermoprocessed sample of the catalyst of the composition given in example 1 was subjected to tests for its activity in the oxidation of 75 ml of alkaline solution of Na2S in the reactor and the conditions of example 1.

The test results for examples 1-4 are shown in the table.

Comparison of oxidation number 28 in the presence of heat-treated and non-heat-treated catalysts for the same time (30 minutes) shows that the activity of heat-treated catalysts is significantly higher than that of the non-heat-treated catalyst. Thus, the degree of oxidation of Na2S in the presence of a catalyst that has been heat-treated for one hour in an environment of sulfur-alkaline wastewater or in an environment of 0.6% aqueous solution N328203 for 3 hours at 95-100 ° C is more than twice the oxidation state of Na2S in the presence of a non-heat-treated catalyst.

The table below shows that the activity of the heat-treated catalyst depends on the alkalinity of the medium. During heat treatment of the catalyst in a medium of sulfur-alkaline effluent, its activity is reached already after 1 hour of treatment (example 3), and approximately the same degree of activity of the catalyst when it is treated in 0.6% aqueous sodium thiosulfate solution is reached in 3 hours (example one).

Claims (1)

The invention The method of preparing a catalyst for the oxidation of sulfur compounds by mixing phthalocyanine cobalt and / or its derivative with a polymer, heating the mixture to the melting temperature of the polymer followed by molding, characterized in that the molded catalyst is heat treated in an aqueous solution of sodium thiosulfate or in a medium of sulfur-alkali effluent formed by alkaline refining of petroleum fractions, at 95-100 ° C for 1-3 hours with air mixing.