RU2752591C1 - Method for producing road bitumen - Google Patents

Abstract

FIELD: oil industry; construction industry; road construction.

SUBSTANCE: invention relates to a method for producing bitumen from propane deasphalting asphalt and can be used in the oil refining, road or construction industries. A method for producing road bitumen includes oxidizing a mixture of propane deasphalting asphalt with tar and residual extract. The initial mixture contains up to 60 wt. % of deasphalting asphalt as the main component, not less than 20 wt. % of tar and 20 wt. % of the residual extract as a liquefier. The initial mixture is divided into two streams, one of which enters the main reactor for the oxidation of raw materials with technical air, while the oxidation is carried out to a softening temperature of 70-75°C according to the ring-and-ball method. The other stream enters the separator-reactor for the oxidation of raw materials by off-gases from the main column reactor. In this case, the mixture obtained from the separator-reactor has a softening temperature up to 33°C according to the ring-and-ball method and contains up to 3 wt. % of slip stream - hydrocarbons condensed from gases in the above separator-reactor. Compounding of the obtained streams of oxidized raw materials from the main reactor and the separator-reactor in the mixer is carried out.

EFFECT: invention makes it possible to include up to 60% of propane deasphalting asphalt in bitumen raw materials, to reduce the concentration of air oxygen in exhaust gases, to utilize the slip stream using it as a plasticizing component of bitumen.

1 cl, 1 dwg, 1 tbl, 8 ex

Description

The invention relates to a method for producing bitumen from propane deasphalting asphalt and can be used in the oil refining, road or construction industries.

One of the urgent tasks of oil refineries of refineries with the progressive development of the production of oils in the process of propane tar deasphalting is the use of deasphalting asphalt for the preparation of road bitumen. Deasphalting asphalt is considered to be the worst raw material for the production of road bitumen. There is not a single deasphalting plant in Russia that works purposefully for the production of bitumen. The existing propane deasphalting units are designed for the production of residual oils. At the same time, the quality of asphalt is not regulated or monitored. Existing technologies and methods for the production of road bitumen make it possible to involve in favorable raw materials no more than 40 wt. % asphalt deasphalting.

Another important problem at many bitumen refineries is the utilization of hydrocarbon vapors.

Usually in the bitumen production, hydrocarbons condensed by water in the separator and vaporous oxidation products in thousands of tons of the valuable bitumen component are discharged into the sewage system and sludge collectors or burned in furnaces together with the gas part. Discharge of commercially valuable vapors of petroleum products into sewers and the atmosphere can be considered as direct energy losses. In addition, they contribute to the corrosion of the separator, pipelines and have a detrimental effect on the environment.

A known method of obtaining road bitumen by oxidation of asphalts by propane deasphalting of oil residues (Grudnikov IB Production of petroleum bitumen. M .: Chemistry, 1983, pp. 113-114), but the resulting bitumen have poor low-temperature properties.

When oxidizing propane deasphalted asphalt in a mixture with tar, it is possible to obtain road bitumen of improved quality, including BND grades in accordance with GOST 22245-90, however, the content of asphalt in the mixture should not exceed. 30 wt. %.

A known method of producing bitumen by oxidizing asphalt propane deasphalting of oil residues in a mixture with an additive, and as an additive, use the distillation residue of the rectification of synthetic fatty acids (KOSFA) in an amount of 5-20 wt. %. for raw materials oxidation (US Pat. RF No. 2083634, 1997).

The disadvantage is the low thermal stability of KOSZhK, as well as the high cost and resources of distillation residues of the rectification of synthetic fatty acids, which limit the possibilities of use.

A known method of producing construction bitumen, including the oxidation of asphalt deasphalting tar and extract of selective oil purification with oxygen, according to which asphalt deasphalting tar before oxidation is pre-mixed with an extract of selective oil purification, taken in an amount of 10-20 wt.% Of the mixture (pat. RF No. 2105786, 1998). This method does not allow to obtain viscous road bitumen of the BND grade.

A known method of producing bitumen by oxidizing a mixture of asphalts of deasphalting residues of direct distillation of oil (tar) and vacuum residue of waste lubricating oils. In this case, the amount of deasphalting asphalt involved in the production of bitumen is 50 wt. % for raw materials of oxidation, and the quality of bitumen increases due to a decrease in the brittleness temperature. (From. USSR 721456 1977).

However, the resources of waste oil residues are insignificant relative to the available resources of propane deasphalting asphalt and do not allow the use of this method in a large volume. In addition, the tensile values at 25 ° C for the resulting bitumen are close to the maximum permissible according to GOST standards.

The closest in terms of essential features is a method of obtaining bitumen by oxidation of weighted tar with a relative viscosity at 80 ° C for at least 60 seconds. without its preliminary dilution to obtain construction bitumen as the target product with a softening point of at least 90 ° C. To obtain road bitumen, the oxidized component - building bitumen with a softening temperature of at least 90 ° C - is compounded with a diluent and a plasticizer (in one mixer all components are simultaneously) to obtain road bitumen. As a diluent, propane deasphalting asphalt is used; as a plasticizer, various refinery products can be used, for example, an oil fraction boiling in the range of 450-520 ° C, and an extract of selective oil refining. Compounding is carried out with the following ratio of components, mass. %: propane deasphalting asphalt - 25-40, plasticizer - 10-20, construction bitumen with a softening temperature of at least 90 ° C - the rest (US Pat. RF No. 2349626, С10С 3/04, publ. 03/20/2009).

The known method solves the problem of obtaining high-quality road bitumen only from weighted raw materials with dilution of a plasticizing oil additive boiling in the range of 450-520 ° C, which limits the raw material base for obtaining high-quality road bitumen. In addition, the disadvantage of this method is the involvement of propane deasphalting asphalt not more than 40 wt. %, as well as the need to obtain overoxidized bitumen (at the stage of oxidation in an oxidizing column) with a high softening point, not lower than 90 ° C, which complicates the operation of the oxidation column due to possible increased coke formation.

The objective of the present invention is to improve the quality of bitumen, increase the amount of propane deasphalting asphalt involved in the raw material, reduce the concentration of air oxygen in the exhaust gases, utilize the blow off using it as a plasticizing component of bitumen, reduce harmful emissions into the atomosphere, increase productivity by 30% and obtain a commercial bitumen products meeting the requirements of GOST 33133-2014 grade BND.

This problem is solved by the fact that in the method of producing road bitumen, including the oxidation of a mixture of propane deasphalting asphalt with tar and residual extract, according to the invention, the initial mixture containing up to 60 wt. % asphalt deasphalting as the main component, not less than 20 wt. % tar and 20 wt. % of the residual extract as a liquefier, is divided into two streams, one of which enters the main reactor for the oxidation of raw materials with technical air, while the oxidation is carried out to a softening temperature of 70-75 ° C according to KiSh, the other stream enters the separator-reactor for the oxidation of raw materials by off-gases from the main reactor of the column type, while the mixture obtained from the separator-reactor has a softening temperature for KiSh up to 33 ° C and contains up to 3 wt. % blow off - hydrocarbons condensed from gases in the above-mentioned separator-reactor; compounding of the obtained streams of oxidized raw materials from the main reactor and the separator-reactor in the mixer is carried out.

The proposed method for the production of bitumen provides for the presence of a column-type separator-reactor, which simultaneously performs the functions of an oxidation gas separator and a feedstock oxidation reactor. Bitumen is obtained by the method of peroxidation of raw materials in the main reactor and diluted with under-oxidized bitumen (blown by oxidation gases) from the separator-reactor. Up to 60 wt. % asphalt deasphalting, as the main component, not less than 20 wt. % tar and 20 wt. % of the residual extract, as a diluent, and up to 3 wt. % blow off, condensed in the separator-reactor 5, as a plasticizing component. The gas-air mixture in the separator-reactor 5 is partially cleaned from harmful elements, while the oxygen content in the exhaust gases is reduced to 0.9 wt. %.

The technical result achieved by the invention is the production of road bitumen grade BND 50/70; BND 70/100 and BND 100/130 in accordance with GOST 33133-2014

The basic technological scheme for obtaining bitumen is shown in the figure, where, 1 - raw material mixer; 2 - technical air receiver; 3 - raw material heating furnace; 4 - reactor for oxidation of raw materials with technical air; 5 - separator-reactor for oxidation of raw materials with oxidation gases; 6 - scrubber; 7 - furnace for combustion of off-gases; 8 - commodity capacity; 9, 10, 11 - pumps; 12, 13 - air coolers.

The design of the separator-reactor 5 is identical to the main bitumen oxidation reactor 4.

The method is carried out as follows.

Raw materials: a mixture of tar, residual extract and deasphalting asphalt is heated in furnace 3 to 180-190 ° C and pumped by pump 9 into the main column-reactor 4 to the regulated level, after which air is supplied and at the same time pump 9 is filled with the initial mixture of separator-reactor 5 to regulated level. After filling both reactors, the main reactor 4 is transferred to circulation by pump 10 to obtain bitumen with a softening temperature set by calculation depending on the softening temperature of bitumen obtained in the separator-reactor 5 and the ratio when mixing them.

The oxidation temperature of the mixture with air in the reactor 4 should be 260-270 ° C. The temperature of the mixture bubbling with oxidation gases in the separator-reactor 5 should be 150-160 ° C, limited by the beginning of boiling of aromatic fractions.

The temperature of the oxidation off-gases from the separator-reactor 5 to the scrubber 6 should be 50-60 ° C, allowing condensation of up to 99 wt% paraffin-naphthenic and aromatic hydrocarbons in the separator-reactor 5. Continuous feed of raw materials into the separator-reactor 5 with a temperature of 150-160 ° C is produced through an air cooler 13. Continuous feed of raw materials into the reactor 4 with a temperature of 180-190 ° C is carried out through a heating furnace 3. Mixing of bitumen from the reactor 4 and the separator-reactor 5 is carried out in the commodity tank 8.

As initial components were used:

1. Deasphalting asphalts.

Deasphalting asphalt is produced in deasphalting units by treatment with liquid propane of oil tar in a volume ratio of 8-10: 1, followed by distillation of propane and isolation of the residue. Characteristics of deasphalting asphalt:

Density, g / cm ³ - 1.0071; softening temperature according to KiSh - 37 ° С; conditional viscosity VU ₅ ⁸⁰ - 614 sec. Sulfur content, wt% - 1.24. Group chemical composition (by HPLC method), paraffin-naphthenic hydrocarbons - 21.4%; aromatic hydrocarbons - 44.3%; resins -19.3% asphaltenes - 15.0%.

2. Tar from West Siberian oil.

Characteristics of tar:

Density, g / cm ³ - 0.9754; softening temperature according to KiSh - 25 ° С; conditional viscosity VU ₅ ⁸⁰ - 77 sec. sulfur content, wt% - 1.25. Group chemical composition (HPLC method), paraffin-naphthenic hydrocarbons - 24.9%, aromatic hydrocarbons - 47.7%; resins - 22.6%; asphaltenes - 4.8%.

Residual extract from selective oil refining

Residual extract characteristic:

Density, g / cm ³ - 0.9747; conditional viscosity VU ₅ ⁸⁰ - 22 sec. Sulfur content, wt% - 1.3. Group chemical composition (by HPLC method), paraffin-naphthenic hydrocarbons - 23.9%; aromatic hydrocarbons - 65.9%; resins - 10.2; asphaltenes - 0%.

3. Characteristics of a mixture of deasphalting asphalt, tar, residual extract in a ratio of 60:20:20 wt. %.

Softening temperature according to KiSh - 28 ° С; density, g / cm ³ - 0.9811; conditional viscosity VU ₅ ⁸⁰ - 194 sec. Sulfur content, wt% - 1.3. Group chemical composition (by HPLC method), paraffin-naphthenic hydrocarbons - 22.1%; aromatic hydrocarbons - 46.1%; resins - 19.4 asphaltenes - 12.4%.

4. Characteristics of a mixture of deasphalting asphalt, tar, residual extract in a ratio of 60:20:20 wt. % purged by oxidation gases in a column-type separator-reactor.

Softening temperature according to KiSh - 33 ° С; Density, g / cm ³ - 0.9818; Conditional viscosity VU ₅ ⁸⁰ - 209 sec. Sulfur content, wt% - 1.3. Group chemical composition (by HPLC method), paraffin-naphthenic hydrocarbons - 22.2%; Aromatic hydrocarbons - 45.4% Resins - 20.2 Asphaltenes - 12.4%

The chemistry of the claimed technological process.

The high quality of road bitumen materials is determined by their optimal group chemical composition, structure and dispersion. The dispersed structure of bitumen can be controlled by the introduction of low molecular weight hydrocarbons. Depending on their concentration in bitumen, they can plasticize or liquefy it. At low concentrations of low molecular weight hydrocarbons less than 4 wt. % there is a partial plasticization of the dispersed medium in the interframe layers, leading to an increase in the elasticity of the system and the preservation of a sufficiently strong coagulation framework in bitumen.

At a concentration of low molecular weight hydrocarbons of more than 4%, liquefaction of the system is observed, leading to the destruction of the coagulation framework and the transformation of bitumen into a dilute suspension of asphaltenes.

Paraffin-naphthenic low-molecular hydrocarbons, which are characterized by the maximum temperature range of serviceability and excellent fracture toughness, are considered to be a very significant component of bitumen. The very name of the group of paraffin-naphthenic hydrocarbons indicates the mixed nature of this fraction, which, along with paraffins of normal and isostructural structure, can include compounds with 5- and 6-membered cycloparaffin rings. In addition, compounds with aromatic rings can also be found. Paraffinonaphthenic hydrocarbons are plasticizers in bitumen, and replacing them with monocycloaromatic hydrocarbons cannot compensate for their plasticizing effect. For this reason, the deepening of oil refining leads to a significant deterioration in the quality of bitumen with a decrease in the content of paraffin-naphthenic hydrocarbons in the feed.

Deasphalting asphalt and bitumen from deasphalting asphalt contain less required amount of paraffin-naphthenic compounds and more resins and asphaltenes, which leads to their lower penetration, plasticity interval compared to bitumen of the same softening temperature obtained by oxidation of tar from the same oil.

It was found that the paraffin-naphthenic fraction in the process of oxidation of a mixture of tar, residual extract and deasphalting asphalt in the ratio 20:20:60 wt. % practically remains unchanged, while the amount of asphaltenes increases. When the mixture is oxidized to bitumen, together with the gaseous oxidation products, it is removed from the reactor and blown off. The amount of blowing depends on the depth of oxidation of the raw material. At a depth of oxidation up to the softening temperature for KiSh - 50 ° C, the amount of blowing is 2.2 wt. %, up to CuSh - 70 ° C - 3.5 wt. %.

The group chemical analysis of the blow-off showed the content of paraffin-naphthenic hydrocarbons in the blow-off to 42 wt%, table No. 1.

Fractional composition of blowing: content of kerosene fraction up to 50 wt. % with the beginning of boiling 160 ° C. Based on the analyzes carried out, it can be stated that blowing off is a valuable component for the plasticization of bitumen obtained from raw materials poor in paraffin-naphthenic hydrocarbons.

During the oxidation of the mixture, it was found that the oxygen content in the exhaust gases from the reactor 4 is from 6 wt. % up to 8 wt. %, and the oxygen content in the exhaust gases from the separator - reactor 5 is not more than 0.9 wt. %.

In the study of the gas part of the exhaust, it was found that it contains not only oxygen and steam, but also traces of a gaseous microcatalyst, namely: N, NO, NO ₂ , H ₂ S, SO ₂ , CO ₂ , low molecular weight organic acids and sulfur, which are both It is known to accelerate the oxidation process of petroleum feedstock and have a positive effect on the properties of the resulting bitumen.

It is known that dissolved gases in the case of chemisorption can be physically sorbed by a liquid surface, or enter into chemical reactions with a liquid sorbent, forming new chemical compounds that can have new useful properties and help to avoid or reduce the formation of hazardous waste, as well as provide resource conservation.

The essence of the proposed method is presented by the following examples.

Example 1. Raw materials: a mixture of deasphalting asphalt + tar + residual extract in a ratio of 60:20:20 wt. % is oxidized in reactor 4 to a softening temperature of 72 ° C. The resulting bitumen is sent to a mixer for compounding with a mixture oxidized by oxidation gases in a separator-reactor 5 to a softening temperature of 33 ° C by KiSh in a ratio of 60:40 wt. %. As a result, we get bitumen grade BND 70/100 (GOST 33133-2014) with the following quality indicators.

- softening temperature 48.0 ° С;

- penetration at 25 ° С from 77 dmm;

- extensibility at 0 ° C 4 cm;

- brittleness temperature minus 19.1 ° С

- change in softening temperature after heating - 4.0 ° С

Bitumen meets the requirements of the BND 70/100 brand (GOST 33133-2014).

Example 2. Raw materials: a mixture of deasphalting asphalt + tar + residual extract in a ratio of 60:20:20 wt. % is oxidized in reactor 4 to a softening temperature of 72 ° C. The resulting bitumen is sent to a mixer for compounding with a mixture oxidized by oxidation gases in a separator-reactor 5 to a softening temperature of 33 ° C by KiSh in a ratio of 70:30 wt. %. As a result, we get bitumen grade BND 50/70 (GOST 33133-2014) with the following quality indicators:

- softening temperature 52.1 ° С;

- penetration at 25 ° С 54 dmm;

- extensibility at 0 ° C 3.7 cm;

- brittleness temperature minus 16.0 ° С.

- change in softening temperature after heating -3.5 ° C.

Bitumen meets the requirements of the BND 50/70 brand (GOST 33133-2014)

Example 3. Raw materials: a mixture of deasphalting asphalt + tar + residual extract in a ratio of 60:20:20 wt. % is oxidized in reactor 4 to a softening temperature of 72 ° C. The resulting bitumen is sent to a mixer for compounding with a mixture oxidized by oxidation gases in a separator-reactor 5 to a softening temperature of 33 ° C in a ratio of 50:50 wt. %. As a result, we get bitumen grade BND 100/130 (GOST 33133-2014) with the following quality indicators

- softening point 46.3 ° С;

- penetration at 25 ° С 104 dmm;

- penetration at 0 ° С 33dmm;

- extensibility at 0 ° C 4.4 cm;

- brittleness temperature minus 21.0 ° С.

- change in softening temperature after heating -4.5 ° С.

Example 4. Raw materials: a mixture of deasphalting asphalt + tar + residual extract in a ratio of 60:20:20 wt. % is oxidized in reactor 4 to a softening temperature of 72 ° C. The resulting bitumen is sent to the mixer for compounding with the initial mixture in a ratio of 50:50 wt. %. As a result, we get bitumen grade BND 100/130 (GOST 33133-2014) with the following quality indicators

- softening temperature 45.1 ° С;

- penetration at 25 ° С 102 dmm;

- penetration at 0 ° С 31 dmm;

- extensibility at 0 ° C 4.0 cm;

- extensibility at 25 ° C 70 cm;

- brittleness temperature minus 20.0 ° С.

- change in softening temperature after heating -5.0 ° C.

Bitumen with maximum permissible quality indicators meets the requirements of GOST 33133-2014 grade BND 100/130.

Comparative indicators of the quality of bitumen according to the proposed method example No. 1, No. 2, No. 3 and according to the method of compounding with the initial mixture example No. 4 show that the quality indicators of bitumen obtained by the method of compounding with the initial mixture are inferior to those of the quality of bitumen produced according to the proposed method.

Example 5 (prototype). Tar of a commercial mixture of West Siberian oil with VU ⁸⁰ 127 sec is oxidized at a temperature of 280 ° C to building bitumen with a softening temperature of 98 ° C and penetration at 25 ° C - 10 dmm. Compounding such bitumen with propane deasphalting asphalt and an extract for selective oil refining in a ratio of 40:50:10 wt. % respectively received road bitumen BND 90/130 of the following quality:

- softening temperature 43.2 ° С;

- penetration at 25C 92 dmm;

- penetration at 0 ° С 28 dmm;

- extensibility at 25 ° C above 100 cm;

- brittleness temperature minus 17.8 ° С.

Comparative indicators of the quality of bitumen according to the proposed method example No. 1, No. 2, No. 3 and according to the prototype method example No. 5 show that the quality indicators of bitumen obtained according to the prototype are inferior to the quality indicators of bitumen manufactured according to the proposed method, despite the fact that the involvement of asphalt deasphalting in the proposed method is 10% more than in the prototype.

In the claimed method, in terms of bitumen quality, the concentration of propane deasphalting asphalt in commercial bitumen is limited to no more than 60 wt. % example No. 6, and also regulated by the softening temperature of over-oxidized bitumen 70-75 ° C, example No. 7 and No. 8.

Example 6. Raw materials: a mixture of deasphalting asphalt + tar + residual extract in a ratio of 61:20:19 wt. % is oxidized in reactor 4 to a softening temperature of 72 ° C. The resulting bitumen is sent to the mixer for compounding with a mixture of deasphalting asphalt + tar + residual extract in a ratio of 61:20:19 wt. % from the separator-reactor 5 oxidized with oxidation gases to a softening temperature of 33 ° C by KiSh in a ratio of 50:50 wt. %. As a result, we get bitumen grade BND 100/130 (GOST 33133-2014) with the following quality indicators

- softening point 44.7 ° С;

- penetration at 25 ° С 103 dmm;

- penetration at 0 ° C 27 dmm;

- extensibility at 0 ° C 4.0 cm;

- extensibility at 25 ° C 70 cm;

- brittleness temperature minus 19.0 ° С.

- change in softening temperature after heating -4.3 ° C.

Bitumen does not meet the requirements of GOST 33133-2014 grade BND 100/130 for penetration at 0 ° C and brittle temperature

Example 7. Raw materials: a mixture of deasphalting asphalt + tar + residual extract in a ratio of 60:20:20 wt. % is oxidized in reactor 4 to a softening temperature of 69 ° C. The resulting bitumen is sent to a mixer for compounding with a mixture of deasphalting asphalt + tar + residual extract in a ratio of 60:20:20 wt. % from the separator-reactor 5 oxidized with oxidation gases to a softening temperature of 33 ° C by KiSh in a ratio of 50:50 wt. % ;. As a result, we get bitumen grade BND 100/130 (GOST 33133-2014) with the following quality indicators

- softening temperature 45.6 ° С;

- penetration at 25 ° C 101 dmm;

- extensibility at 0 ° C 3.8 cm;

- extensibility at 25 ° C 70 cm;

- brittleness temperature minus 20.0 ° С.

- change in softening temperature after heating -4.6 ° С.

Bitumen does not meet the requirements of GOST 33133-2014 grade BND 100/130 in terms of elongation at 0 ° C.

The maximum permissible peroxidation of bitumen, not higher than the softening temperature for KiSh 75 ° C, is justified due to the high viscosity of the diluent.

Example 8. Raw materials: a mixture of deasphalting asphalt + tar + residual extract in a ratio of 60:20:20 wt. % is oxidized in reactor 4 to a softening temperature of 76 ° C. The resulting bitumen is sent to the mixer for compounding with a mixture of deasphalting asphalt + tar + residual extract in a ratio of 60:20:20 wt. % from the separator-reactor 5 oxidized with oxidation gases to a softening temperature of 33 ° C by KiSh in a ratio of 50:50 wt. %. As a result, we get bitumen grade BND 100/130 (GOST 33133-2014) with the following quality indicators

- softening temperature 45.0 ° С;

- penetration at 25 ° C 101 dmm;

- penetration at 0 ° С 3.7 dmm

- extensibility at 0 ° C 4.1 cm;

- extensibility at 25 ° C 70 cm;

- brittleness temperature minus 19.0 ° С.

- change in softening temperature after heating -4.2 ° C.

Bitumen does not meet the requirements of GOST 33133-2014 grade BND 100/130 for penetration at 0 and brittle temperature.

For compounded bitumen with a heavier diluent, with an increase in the softening temperature of overoxidized bitumen, the brittleness temperature increases, and penetration at 0 ° C decreases.

The proposed method allows you to increase the involvement of asphalt deasphalting up to 60 wt. % in raw materials for the production of road bitumen, significantly reduce the impact of harmful gases on the environment, increase the energy efficiency of production, due to the extraction and return of valuable hydrocarbon fractions to the technological process.

Claims (1)

A method of obtaining road bitumen, including the oxidation of a mixture of propane deasphalting asphalt with tar and residual extract, characterized in that the initial mixture containing up to 60 wt. % asphalt deasphalting as the main component, not less than 20 wt. % tar and 20 wt. % of the residual extract as a liquefier, is divided into two streams, one of which enters the main reactor for the oxidation of raw materials with technical air, while the oxidation is carried out to a softening temperature of 70-75 ° C according to KiSh, the other stream enters the separator-reactor for the oxidation of raw materials by off-gases from the main reactor of the column type, while the mixture obtained from the separator-reactor has a softening temperature of KiSh up to 33 ° C and contains up to 3 wt. % blow off - hydrocarbons condensed from gases in the above-mentioned separator-reactor; the compounding of the obtained streams of oxidized raw materials from the main reactor and the separator-reactor in the mixer is carried out.

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