RU2711550C1 - Method of producing a concentrate of sulphoxides and sulphons of oil origin - Google Patents

Abstract

FIELD: chemistry.SUBSTANCE: invention relates to a method of producing a concentrate of sulphoxides and sulphones, involving oxidation of sulfur-containing compounds in a hydrocarbon fraction with initial sulfur content of not less than 0.1 % hydrogen peroxide with concentration of 20–37 wt% in the presence of a catalyst mixture at temperature of 40 to 80 °C, separation of aqueous phase by separation and distillation of obtained hydrocarbon fraction at temperature of 30–550 °C Catalytic mixture contains formic acid, a compound containing molybdenum and a surfactant which is stable in the presence of hydrogen peroxide.EFFECT: two-step preparation of a concentrate of sulphoxides and sulphons without using an extraction step, as well as expensive and corrosive extractants.9 cl, 1 tbl, 33 ex

Description

Technical field

The invention relates to the field of oil refining and petrochemicals, in particular to the field of producing a concentrate of sulfoxides and sulfones. The proposed method for producing a concentrate of sulfoxides and sulfones can be used in the refining industry.

State of the art

The invention relates to a modified method for the extraction of oxidation products of organosulfur compounds, in particular sulfoxides and sulfones, from hydrocarbon fractions, which are effective extractants in hydrometallurgy and flotation agents in the metallurgical industry, and can also be used in agriculture as biological active components.

The prior art method for the separation of sulfoxides and sulfones from a mixture with hydrocarbons using solvents such as watered acetone or methanol (SU 577783 A1, published 16.10.1974). After the extraction, the extractant is regenerated by distillation, and the target concentrate of sulfoxides and sulfones remains in the bottom residue.

The prior art method for the extraction of sulfoxides and sulfones from a mixture with hydrocarbons and sulfur compounds using isopropyl alcohol as an extractant (RU 2446203, published 03/27/2012). In this method, after extraction of sulfoxides and sulfones, the extractant is also supposed to be regenerated by distillation, and in the bottom residue, the target concentrate of sulfoxides and sulfones is obtained.

The prior art method for producing petroleum sulfoxides using chlorine dioxide as an oxidizing agent, followed by extraction of oxidation products with chloroform (RU 2668810, published 07.08.2017). The use of extractant also makes it necessary to carry out the regeneration stage of the extractant. It should be noted that the use of corrosive chlorine-containing compounds will adversely affect process equipment, leading to increased wear.

The prior art method for producing sulfoxides by oxidizing sulfur compounds in a diesel fraction with hydrogen peroxide in the presence of a molybdenum-containing catalyst, followed by extraction of the products of oxidation with sulfuric acid (RU 2234498, published 08/20/2004). It should be noted that the method used in this method for the extraction of sulfoxides and sulfones involves the use of corrosive sulfuric acid of high concentration (more than 50%), which will lead to increased wear of process equipment.

Closest to the claimed method is a method for producing a mixture of sulfoxides and sulfones by oxidation of sulfur compounds in crude oil, followed by extraction of products by extraction with organic solvents (RU 2677462, published 01/17/19). The disadvantages of this method should also include the use of high-boiling extractants (DMF, acetonitrile, etc.), which requires significant energy costs during the regeneration and separation of the concentrate of sulfoxides and sulfones.

Known methods are aimed at obtaining a concentrate of sulfoxides and sulfones from light oil fractions (in particular gasoline and diesel). It is important to note that organic extractants are used to isolate oxidation products, which then need to be regenerated by distillation. Moreover, corrosive acids (sulfuric, acetic, etc.) or organic solvents in the form of alcohols or chloroform, which have insufficient affinity for oxidation products, are often used as extractants. The necessity of carrying out the stage of extraction and regeneration of the extractant by distillation leads to the appearance of additional stages that complicate the process, which should be attributed to the main disadvantage of these methods. Thus, the known methods for producing a sulfoxide and sulfone concentrate involve the use of a three-stage scheme: in the first stage, sulfur-containing compounds are oxidized, in the second stage, the oxidation products are extracted using an extractant, in the third stage, an extractant is regenerated and the target sulfoxide and sulfone concentrate is isolated.

A technical problem is the multi-stage methods for producing concentrates of sulfoxides and sulfones, as well as the use of corrosive acids.

The technical problem is solved by the claimed two-stage method for producing sulfoxides and sulfones, where, in the first stage, sulfur-containing compounds are oxidized in the oil fraction with hydrogen peroxide in the presence of a catalytic composition comprising formic acid, a compound containing molybdenum and a surfactant stable in the presence of hydrogen peroxide; in the second stage, the target concentrate of sulfoxides and sulfones is isolated by distillation of the oil fraction after oxidation

Disclosure of Invention

The technical result of this invention is a method that allows to obtain concentrates of sulfoxides and sulfones from oil fractions (gasoline, kerosene, diesel, vacuum gas oil) in two stages, which simplifies the technological scheme when using a wide range of hydrocarbon fractions (gasoline, diesel, vacuum gas oil), as well as without the use of corrosive compounds. This result is achieved due to the fact that after the stage of oxidation of organosulfur compounds in hydrocarbon fractions, the oxidation products sulfoxides and sulfones are extracted by distillation of the initial fraction. At the same time, sulfoxides and sulfones (which are solids with boiling points exceeding the boiling points of the indicated fractions) remain as bottoms, and the purified fraction with a reduced sulfur content is obtained in the process of distillation. Thus, there is no need to use an additional extraction step, as well as expensive organic solvents.

The technical result is achieved by a method of producing a concentrate of petroleum sulfoxides and sulfones, which includes the oxidation of sulfur-containing compounds with hydrogen peroxide with a concentration of 20-37% of the mass. in the presence of a catalytic mixture at a process temperature from 40 to 80 ° C, separation of the aqueous phase by separation and distillation of the obtained hydrocarbon fraction at temperatures of 30-550 ° C, depending on the fraction used. The composition of the catalytic mixture includes the following components

- formic acid

- a compound containing molybdenum

- surfactant stable in the presence of hydrogen peroxide. It is preferable to use the following substances as a compound containing molybdenum: ammonium molybdate - (NH ₄ ) ₂ MoO ₄ , sodium molybdate - Na ₂ MoO ₄ , ammonium paramolybdate - (NH ₄ ) ₆ Mo ₇ O ₂₄ , sodium paramolybdate - Na ₆ Mo ₇ O ₂₄ , ammonium phosphor molybdate - (NH ₄ ) ₃ PMo ₁₂ O ₄₀ , sodium phosphor molybdate - Na ₃ PMo ₁₂ C ₄₀ , molybdenum phosphorus - H ₃ PMo ₁₂ O ₄₀ , silicic molybdic acid-H ₃ SiMo ₁₂ O ₄₀ .

It is preferable to use the following substances as a surfactant stable in the presence of hydrogen peroxide: nonylphenols: Neonol AF 9-6, Neonol AF 9-8, Neonol AF 9-10, Neonol AF 9-12; alkyl sulfates: sodium lauryl sulfate, sodium laureth sulfate, sodium decyl sulfate; ethoxylated alcohols: Sintanol ALM-3, Sintanol ALM-7, Sintanol ALM-8, Sintanol ALM-10, Sintanol DS-10.

As the hydrocarbon fraction, it is preferable to use straight-run gasoline, diesel fractions, as well as non-hydrotreated vacuum gas oil with an initial sulfur content of at least 0.1%.

To carry out the oxidation reaction, components are taken in the following weight ratios:

hydrogen peroxide: sulfur = 6: 1 to 20: 1

catalytic mixture: sulfur = 1: 1 to 6: 1, while the components in the catalytic mixture vary in the following ranges (wt.%)

Formic acid 80-90 Molybdenum Compound 0.5-2 Surface-active substance, stable in the presence of hydrogen peroxide 0.5-2 Water 6-19,

at the same time, the components of the catalytic mixture are added to the hydrogen peroxide solution (20-37 wt.%), the order of adding the components can be arbitrary, the resulting solution is mixed at a speed of at least 600 rpm until a homogeneous mixture is formed, and then the resulting mixture is added to the hydrocarbon fraction for the oxidation of organosulfur compounds. To carry out oxidation, the mixture is stirred at a predetermined temperature of 40-80 ° C for 4-6 hours, after the reaction is complete, stirring is stopped, a two-phase system is formed in which the aqueous phase containing the catalytic mixture and the spent hydrogen peroxide solution is in the lower phase and is separated by any known methods, in particular, it can be removed on a separatory funnel. The upper phase containing the hydrocarbon fraction with oxidation products is subjected to distillation in the temperature range of 30-550 ° C (the temperature range of distillation and pressure are determined based on the fractional composition of the feedstock; for the gasoline fraction, distillation is carried out at atmospheric pressure in the temperature range 30-210 ° C, for a diesel fraction at atmospheric pressure in the temperature range of 250-340 ° C, for vacuum gas oil, distillation is carried out under reduced pressure of less than 0.3 atm in the range of 360-550 ° C, temperatures are indicated converted to atmospheric pressure). The distillation is carried out in any known manner, ensuring compliance with temperature and pressure. After distillation, a hydrocarbon fraction with a low sulfur content is obtained, and the target concentrate of sulfoxides and sulfones remains in the cube.

The implementation of the invention

Below is a more detailed description of the claimed invention. The present invention may be subjected to various changes and modifications understood by one skilled in the art upon reading this description. Such changes do not limit the scope of claims.

The method of obtaining a concentrate of petroleum sulfoxides and sulfones includes the following main steps:

1) Obtaining a solution of a catalytic oxidizing mixture in hydrogen peroxide;

2) Oxidation of organosulfur compounds present in the processed fraction using the obtained catalytic oxidizing mixture in hydrogen peroxide;

3) Separation of the aqueous phase containing the catalytic mixture and the spent hydrogen peroxide solution;

4) Distillation of the obtained fraction to obtain the target concentrate of sulfoxides and sulfones and a hydrocarbon fraction with a low sulfur content.

At the first stage, the components of the catalytic mixture are added to the hydrogen peroxide solution (mass fraction of 20-37%), the order of adding the components can be arbitrary, the resulting solution is mixed at a speed of at least 600 rpm until a homogeneous mixture is formed.

At the second stage, the solution of the catalytic mixture in hydrogen peroxide obtained at the first stage is added to the hydrocarbon fraction for the oxidation of organosulfur compounds. The hydrocarbon fraction can be straight-run gasoline and diesel fractions, as well as non-hydrotreated vacuum gas oil with an initial sulfur content of at least 0.1%. The mixture is stirred at a predetermined temperature of 40-80 ° C for 4-6 hours, after the reaction, stirring is stopped. The components for the reaction are taken in the following ratio:

hydrogen peroxide: sulfur = 6: 1 to 20: 1 by weight

catalytic mixture: sulfur = 1: 5 to 1:20 by weight, while the components in the catalytic mixture vary in the following ranges (wt.%)

Formic acid 80-90

Compound containing molybdenum 0.5-2

Surfactant stable in the presence of hydrogen peroxide 0.5-2

Water 6-19.

The sulfur content in the initial hydrocarbon fraction in mass fractions is predetermined by any method known from the prior art (a method based on the oxidation of sulfur and analysis of the obtained oxides; a method based on the reduction of sulfur to hydrogen sulfide; spectral method, etc.).

In the third stage, after the reaction is completed, a two-phase system is formed, the lower layer of the aqueous phase containing the catalytic mixture and the spent hydrogen peroxide solution is separated by any known method, in particular, it can be removed by a separatory funnel.

In the fourth stage, the upper phase containing the hydrocarbon fraction with the oxidation products is subjected to distillation in the temperature range of 30-550 ° C (the temperature range of distillation and the pressure are determined based on the fractional composition of the feedstock; for a gasoline fraction, distillation is carried out at atmospheric pressure in the temperature range 30 -210 ° C, for a diesel fraction at atmospheric pressure in the temperature range of 250-340 ° C, for vacuum gas oil, distillation is carried out at a reduced pressure of less than 0.3 atm in the range of 360-550 ° C, temperatures are calculated in terms of atmospheric pressure). The distillation is carried out in any known manner, ensuring compliance with temperature and pressure. After distillation, a hydrocarbon fraction with a low sulfur content is obtained, and the target sulfoxide and sulfone concentrate remains in the cube.

General methodology of the process

The total sulfur content in the initial hydrocarbon fraction was preliminarily analyzed by the X-ray fluorescence method on an ASE-2 device. As the hydrocarbon fraction for the process, we used a sample of straight-run gasoline fraction with a total sulfur content of 0.15% (PBP), a sample of straight-run diesel fraction with a total sulfur content of 0.75% (PDF), a sample of non-purified vacuum gas oil with a total sulfur content of 1, 44% (NGVG). The process was carried out using an aqueous solution of hydrogen peroxide (concentration of 20-37 wt.%) In the presence of a catalytic mixture (the composition of the mixture in each example, the amount of the mixture and hydrogen peroxide taken, oxidation conditions are shown in table 1). The rectification of the gasoline fraction was carried out at atmospheric pressure in the temperature range of 30-210 ° C, for the diesel fraction at atmospheric pressure in the temperature range of 250-340 ° C, for vacuum gas oil, distillation is carried out under reduced pressure of 0.1 atm in the range of 360-550 ° C (temperatures are given in terms of atmospheric pressure).

The oxidation was carried out in the temperature range 40-80 ° C for 4-6 hours, after the reaction, stirring was stopped. The components for the reaction were taken in the following ratio:

hydrogen peroxide: sulfur = 6: 1 to 20: 1 by weight

catalytic mixture: sulfur = 1: 5 to 1:20 by weight, while the components in the catalytic mixture vary in the following ranges (wt.%)

Formic acid 80-90

Compound containing molybdenum 0.5-2

Surfactant stable in the presence of hydrogen peroxide 0.5-2

Water 6-19.

At the end of the reaction, the aqueous phase was separated, the hydrocarbon phase was distilled under the conditions described above. As a result of distillation, we obtain a distilled fraction with a low sulfur content and a still bottom with a target concentrate of sulfoxides and sulfones. Next, the total sulfur content in the distilled fraction was analyzed, as well as the mass fraction of the bottom residue (from the mass of the initial fraction taken) containing the sulfoxides and sulfones concentrate (hereinafter the concentrate). The results are shown in table 1.

Claims (12)

1. A method of obtaining a concentrate of petroleum sulfoxides and sulfones, characterized in that it involves the oxidation of sulfur-containing compounds in the hydrocarbon fraction with an initial sulfur content of at least 0.1% hydrogen peroxide with a concentration of 20-37 wt.% In the presence of a catalytic mixture at a temperature of from 40 to 80 ° C, the separation of the aqueous phase by separation and distillation of the obtained hydrocarbon fraction at a temperature of 30-550 ° C, while the catalytic mixture includes formic acid, a compound containing molybdenum and a surfactant sustainable in the presence of hydrogen peroxide. 2. The method according to p. 1, characterized in that the straight-run gasoline or diesel fraction or non-hydrotreated vacuum gas oil is used as the hydrocarbon fraction. 3. The method according to p. 1, characterized in that as the compound containing molybdenum, use a compound selected from the group comprising ammonium molybdate - (NH ₄ ) ₂ MoO ₄ , sodium molybdate - Na ₂ MoO ₄ , ammonium paramolybdate - ( NH ₄ ) ₆ Mo ₇ O ₂₄ , sodium paramolybdate - Na ₆ Mo ₇ O ₂₄ , ammonium phosphor molybdate - (NH ₄ ) ₃ PMo ₁₂ O ₄₀ , sodium phosphor molybdate - Na ₃ PMo ₁₂ O ₄₀ , phosphor molybdic acid - H ₃ PMO ₁₂ O ₄₀ , silicomolybdic acid - H ₃ SiMo ₁₂ O ₄₀ . 4. The method according to p. 1, characterized in that nonylphenols are used as a surfactant stable in the presence of hydrogen peroxide; alkyl sulfates; ethoxylated alcohols. 5. The method according to p. 4, characterized in that Neonol AF 9-6, Neonol AF 9-8, Neonol AF 9-10, Neonol AF 9-12 are used as nonylphenol. 6. The method according to p. 4, characterized in that the sodium sulfate is sodium lauryl sulfate, sodium laureth sulfate, sodium decyl sulfate. 7. The method according to p. 4, characterized in that as ethoxylated alcohol use Sintanol ALM-3, Sintanol ALM-7, Sintanol ALM-8, Sintanol ALM-10, Sintanol DS-10. 8. The method according to p. 1, characterized in that for the oxidation reaction, the components are taken in the following weight ratios: hydrogen peroxide: sulfur = 6: 1 to 20: 1, catalytic mixture: sulfur = 1: 1 to 6: 1, while the components in the catalytic mixture vary in the following ranges (wt.%). Formic acid 80-90 Molybdenum Compound 0.5-2 Surface-active substance, stable in the presence of hydrogen peroxide 0.5-2 water 6-19. 9. The method according to claim 1, characterized in that the components of the catalytic mixture are added first to a 20-37 wt.% Aqueous solution of hydrogen peroxide, the resulting solution is mixed at a speed of at least 600 rpm until a homogeneous mixture is formed, and then the resulting mixture is added to hydrocarbon fraction, the resulting mixture is stirred at a temperature of 40-80 ° C for 4-6 hours, upon completion of the reaction, stirring is stopped, the aqueous phase is separated, and the organic phase is subjected to distillation in the temperature range of 30-550 ° C, after distillations receive a concentrate of sulfoxides and sulfones.