RU2669936C1 - Method for obtaining plasticisers - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: invention relates to a process for obtaining a plasticizer. This method comprises mixing the raw material with a solvent, selective purification and subsequent distillation of the solvent from the raffinate and extract solutions. Said method is characterized in that a distillate extract of the fraction 450–550 °C, obtained as a result of selective purification of petroleum oil fraction with a boiling point of 450–550 °C, or an extract of a mixture of the distillate fraction 450–550 °C, obtained by distilling oil with a boiling point of 450–550 °C, and deasphalted product obtained in the process of deasphalting tar with propane. As a solvent, a solution containing, by weight, %: water 2.0, N-methylpyrrolidone is the rest, the mass ratio of raw materials: solvent is set equal to 1:0.8–1.2, the resulting mixture is stirred for 25–30 minutes, and selective purification of raw materials is carried out by purification steps at temperatures 35 °C, 40 °C, 45 °C or 40 °C, 45 °C, 50 °C, setting the settling time at each purification stage of 25–30 minutes.EFFECT: increased efficiency and selectivity of the selective purification process by reducing the total raw material: solvent ratio to produce a plasticizer that meets the requirements of Directive 2005/69/EC.1 cl, 6 ex, 1 tbl

Description

The present invention relates to the refining industry and can be used to obtain plasticizers for tires and rubbers.

Selective purification extracts produced by refineries are used as aromatic plasticizers for tires and rubbers. Plasticizers reduce the viscosity and glass transition temperature, increase the elasticity and adhesiveness of rubbers, improve adhesion properties, facilitate technological processing. Plasticizing oils consist mainly of aromatic hydrocarbons of varying degrees of cyclicity, with most of this occurring in condensed structures. With the increase in cyclic structures in aromatic hydrocarbons, the strength of the rubber compound increases.

In accordance with environmental requirements, Directive 2005/69 / EC was introduced on January 1, 2010, according to which petroleum plasticizer oils cannot be sold and used in the production of tires and their components in the EU if they contain: more than 3 mass. % PAH extract according to the IP-346: 1998 method, more than 1 ppm benzo (a) pyrene and more than 10 ppm the sum of 8 carcinogenic PAHs: benzo (a) pyrene, benzo (e) pyrene, benzo (a) anthracene, chrysene, benzo (b) fluorantene, benzo (j) fluorantene, benzo (k) fluorantene, dibenz (a, h) anthracene. On September 23, 2016, Commission Regulation (EU) 2015/326 of March 2, 2015 entered into force, which states that the IP 346: 1998 method is not specific for carcinogenic PAHs and has several limitations: it cannot be used for base oils without additives , oils not containing asphaltenes and having in their composition at least 5% of components with a boiling point below 300 ° C. For samples that do not meet these requirements, this method may not be suitable. Thus, the Commission considers it advisable to replace the IP 346 method with the standard EN 16143: 2013 “Petroleum products - Determination of benzo (a) pyrene and some polycyclic aromatic hydrocarbons (PAHs) in filler oils - Method using double purification by liquid chromatography and subsequent analysis using chromatography-mass spectrometry - GC / MS ”as the recommended method for determining the conformity of plasticizer oils to restrictive requirements.

Thus, from plasticizers satisfying the requirements of Directive 2005/69 / EC, it is necessary to remove only carcinogenic polycyclic aromatic hydrocarbons and preserve aromatic hydrocarbons with a number of rings from 1 to 3, which are valuable components of rubber compounds.

To reduce the content of PAHs in plasticizer oils, liquid extraction is used using selective solvents such as phenol, furfural, N-methylpyrrolidone (N-MP), dimethyl sulfoxide (DMSO).

A known method of producing a plasticizer for rubber compounds, according to which a plasticizer is obtained by purification of distillate and residual extracts with furfural or N-MP with a mass ratio of solvent to oil fractions of 1.5-2.2: 1. RU 2072384 C1, 01/27/1997.

The disadvantage of this invention is the high content of PAHs, which is environmentally unsafe.

In a known method for producing a plasticizer, an oil fraction with boiling ranges of 330-420 ° C is subjected to selective purification with N-methylpyrrolidone at a solvent multiplicity of 1.2: 1 by weight in an industrial extractor for the production of oils and paraffins. The temperature of the top of the extraction column is 50-55 ° C, bottom 35-40 ° C. The raffinate and extract solutions are removed from the column, which enter the solvent regeneration. The oil fraction with boiling limits of 420-490 ° C is subjected to selective purification with N-methylpyrrolidone at a ratio of solvent to feedstock of 1.5: 1 by weight in a second industrial extractor for the production of oils and paraffins. The temperature of the top of the extraction column 64-68 ° C, bottom 44-48 ° C. The raffinate and extract solutions are removed from the column, which enter the solvent regeneration. The deasphalting agent after the propane deasphalting process, boiling off at a temperature above 490 ° С, is subjected to selective purification with N-methylpyrrolidone at a ratio of solvent to feedstock 2.0: 1 by weight in the third industrial extractor for the production of oils and paraffins, the top temperature of the extraction column is 75-80 ° С , bottom 60-65 ° C. The raffinate and extract solutions are removed from the column, which enter the solvent regeneration.

The extract solutions after purification of the above three oil fractions, two distillate and residual, are combined and regenerated together, isolating the mixed extract. Asphalt from propane deasphalting is added to the obtained extract in a mass ratio of asphalt: extract equal to 0.05: 1, and the resulting mixture is used as the target product — a plasticizer for rubber compounds. RU 2133260 C1, publ. 07/20/1999.

The disadvantages of the method include separate multi-stage cleaning of the feedstock with a high total solvent consumption, as well as the fact that the preparation of a plasticizer requires mixing of asphalt and extract solution, which complicates the process of preparation, and the disadvantage of plasticizer is a high PAH content, which is environmentally unsafe.

Closest to the proposed invention is a method for producing a plasticizer, including purification of oil fractions of oil with selective solvents, separation of the residual extract or a mixture of residual and distillate extracts, purification by extraction with a selective solvent - dimethyl sulfoxide in a mass ratio of solvent: extract of 2.0-4.0: 1 at a temperature of 30-120 ° C. Moreover, the extract is pre-diluted with paraffin-naphthenic solvent in a mass ratio of solvent: extract of 0.1-0.5: 1. After extraction is complete, the solvents are distilled off from the raffinate and extract. The resulting raffinate is used as a plasticizer for tires and rubbers with a given viscosity. RU 2313562 C2, publ. 12/27/2007.

The disadvantage of this method is the high consumption of a corrosive solvent, a high upper temperature limit of the extraction process, the need to dilute the feed with a hydrocarbon solvent, and the fact that the hydrocarbon solvent forms an azeotropic mixture with DMSO, which creates difficulties in the further stage of distillation of the solvent from the raffinate.

An object of the present invention is to develop a method for producing a plasticizer with a high content of aromatic hydrocarbons, a benzo (a) pyrene content of less than 1 ppm and a total of 8 carcinogenic PAHs specified in Directive 2005/69 / EC, less than 10 ppm, as well as increasing selectivity and reduction of material and energy costs of the selective cleaning process.

The technical result consists in increasing the efficiency and selectivity of the selective cleaning process by reducing the overall ratio of raw materials: solvent, with the receipt of a plasticizer that meets the requirements of Directive 2005/69 / EC.

The technical result is achieved in that the distillate extract of the 450-550 ° C fraction obtained as a result of the selective purification of the oil fraction of oil with a boiling point of 450-550 ° C or the extract of the mixture of the distillate fraction 450-550 ° C obtained by distillation of oil is used as raw material with a boiling point of 450-550 ° C and deasphalting agent obtained in the process of tar deasphalting with propane. As a selective solvent, a solution is used containing, wt%: 2.0 water, N-methylpyrrolidone - the rest. The introduction of water reduces the selectivity of N-methylpyrrolidone to a level that allows you to get a plasticizer with a low content of carcinogenic PAHs from extracts of selective purification. Raw materials are mixed with a selective solvent in a mass ratio of 1: 0.8-1.2. Mixing time is 25-30 minutes. Selective purification of the extracts is carried out according to the scheme of a three-stage countercurrent-periodic extraction in 3 cycles in a reactor equipped with a stirrer. The temperature at the stages of selective cleaning is 35 ° C, 40 ° C, 45 ° C or 40 ° C, 45 ° C, 50 ° C, the settling time at each stage of cleaning is set for 25-30 minutes at the same temperature.

This method allows you to create conditions close to the conditions of the counterflow process occurring in an industrial extraction column. The extraction temperature of the first, second, and third stages corresponded to the temperatures of the bottom, middle, and top of the extraction column. As a result of selective purification, a raffinate and extract solution are obtained. After the process is completed, the solvent is distilled off from the raffinate in the usual known manner. After distilling off the solvent from the raffinate and extract solutions, a raffinate is obtained as the target product, which meets the requirements of Directive 2005/69 / EC and a secondary extract as a by-product.

The invention is illustrated by the following examples.

Example 1

Raw materials - distillate extract of the 450-550 ° C fraction, obtained by selective purification of the oil fraction of 450-550 ° C, containing 11.0 wt% PAH according to IP-346, has a kinematic viscosity at a temperature of 100 ° C - 30.74 mm ² / s, the refractive index at a temperature of 50 ° C is 1.5460, mixed with a selective solvent in a mass ratio of 1: 1. The resulting mixture was stirred for 30 minutes and subjected to selective cleaning in stages at temperatures of 35 ° C, 40 ° C, 45 ° C. The settling time at each cleaning step is set for 30 minutes at the same temperature. As a result of selective purification, a raffinate and extract solution are obtained. After distillation of the solvent from the raffinate and extract solutions, a raffinate is obtained, which can be used as an environmentally friendly plasticizer and an extract, which can be used as a component of raw materials in the production of road and building bitumen.

The resulting plasticizer determines the content of PAH extract according to IP 346: 1998, kinematic viscosity at 100 ° C according to ASTM D445, refractive index at 50 ° C according to ASTM D 1218, carbon atom content in aromatic structures according to ASTM D 2140, aromatic content hydrocarbons according to IP 469, the content of benzo (a) pyrene and the sum of benzo (a) pyrene, benzo (e) pyrene, benzo (a) anthracene, chrysene, benzo (b) fluorantene, benzo (j) fluorantene, benzo (k) fluorantene dibenz (a, h) anthracene according to EN 16143.

The properties of the obtained plasticizer are given in the table.

Example 2

The raw materials of example 1 are mixed with a solvent in a mass ratio of raw materials: solvent = 1: 1, stirred for 25 minutes and subjected to selective cleaning in steps at temperatures of 40 ° C, 45 ° C, 50 ° C, setting the settling time at each cleaning step for 25 minutes at the same temperature. The properties of the obtained plasticizer are given in the table.

Example 3

Raw materials - extract of a mixture of a distillate fraction of 450-550 ° C, obtained by distillation of oil with a boiling point of 450-550 ° C and deasphalting agent obtained in the process of tar deasphalting with propane. Raw materials containing 8.3 wt% PAHs according to the IP-346 method have a kinematic viscosity at a temperature of 100 ° C of 37.86 mm / s, a refractive index at a temperature of 50 ° C of 1.5437, mixed with a solvent in a mass ratio of raw materials : solvent = 1: 0.8. Stirred for 28 minutes and subjected to selective cleaning in stages at temperatures of 35 ° C, 40 ° C, 45 ° C, setting the settling time at each stage of cleaning for 28 min at the same temperature. The properties of the obtained plasticizer are given in the table.

Example 4

The raw materials of example 3 are mixed with a solvent in a mass ratio of raw materials: solvent = 1: 0.9, stirred for 25 minutes and selectively cleaned in steps at temperatures of 40 ° C, 45 ° C, 50 ° C, setting the settling time on each cleaning steps for 30 minutes at the same temperature. The properties of the obtained plasticizer are given in the table.

Example 5

Raw materials - extract of a mixture of a distillate fraction of 450-550 ° C, obtained by distillation of oil with a boiling point of 450-550 ° C and deasphalting agent obtained in the process of tar deasphalting with propane. Raw materials containing 8.2 mass% PAHs according to IP-346 method have a kinematic viscosity at a temperature of 100 ° C - 29.70 mm / s, a refractive index at a temperature of 50 ° C - 1.5330, mixed with a solvent in a mass ratio of raw materials : solvent = 1: 0.8, stirred for 28 minutes and subjected to selective cleaning in steps at temperatures of 40 ° C, 45 ° C, 50 ° C, setting the settling time at each step of cleaning for 28 min at the same temperature. The properties of the obtained plasticizer are given in the table.

Example 6

The raw materials of example 5 are mixed with a solvent in a mass ratio of raw materials: solvent = 1: 1.2, stirred for 25 minutes and subjected to selective cleaning at temperatures in steps of 35 ° C, 40 ° C, 45 ° C, setting the settling time on each cleaning steps for 25 minutes at the same temperature. The properties of the obtained plasticizer are given in the table.

In the examples, N-MP (analytical grade) TU 2633-036-44493179-99 with rev. 1,2. Obtained by the proposed method, oil plasticizers are environmentally friendly, meet the requirements of Directive 2005/69 / EC.

Claims (1)

A method of obtaining a plasticizer, including mixing the feedstock with a solvent, selective purification and subsequent distillation of the solvent from raffinate and extract solutions, characterized in that the distillate extract of the 450-550 ° C fraction obtained from the selective purification of the oil fraction of oil with a boiling point is used as a raw material 450-550 ° C, or an extract of a mixture of a distillate fraction 450-550 ° C obtained by distillation of oil with a boiling point of 450-550 ° C, and deasphalting obtained in the process of deasphalting tar Pan, as a solvent, use a solution containing, wt.%: water 2.0, N-methylpyrrolidone - the rest, the mass ratio of raw materials: solvent is set equal to 1: 0.8-1.2, the resulting mixture is stirred for 25-30 min, and selective cleaning of the raw materials is carried out according to the cleaning steps at temperatures of 35 ° C, 40 ° C, 45 ° C or 40 ° C, 45 ° C, 50 ° C, setting the settling time at each cleaning step 25-30 min.