Extraction method for removing impurities from stock solution in synthesis of carboxylic acids

FIELD: chemistry.

SUBSTANCE: invention relates to the removal of the metallic catalyst from stock solution, obtained during the synthesis of carboxylic acids, normally terephthalic acid. Method of removing the metallic catalyst from the stream of stock solution containing carboxyl acid includes the following stages: (a) graduating the stock solution, which contains the carboxyl acid, metallic catalyst, impurities, water and solvent, in the zone of the first evaporator obtaining a stream of water vapour and a stream of concentrated stock solution; (b) evaporating of the specified stream of concentrated stock solution to the zone of the second evaporator forming a stream rich in the solvent and a stream of super-concentrated stock solution; (c) removing organic impurities from super-concentrated stock solution with the help of water-solvent solution in the zone of the separating phase of solid substance/liquid forming a stream of water and a second stream of water; (d) mixing in the zone of mixing water and not necessarily the extraction solvent with the specified water stream and the specified second water stream forming and aqueous solution; (e) adding the extraction solvent to the specified water solution in the extraction zone forming a stream of extract and a stream of raffinate containing the specified metallic catalyst; and (f) separating the specified stream of extract in the separating zone forming a stream of organic impurities with a high boiling point and a stream of the removed extraction solvent. In a different version of the realisation of the method of removing the metallic catalyst from the stream of stock solution containing the carboxylic acid includes the following stages: (a) evaporating of the stock solution containing the carboxylic acid, metallic catalyst, impurities, water and solvent, in the zone of the first evaporator obtaining a stream of water and a stream of concentrated stock solution; (b) evaporating the specified stream of concentrated stock solution in the second evaporating zone obtaining a stream rich in the solvent and stream of super-concentrated stock solution, where about 85 to about 99% mass, of the solvent and water is removed from the specified stock solution at the stage (a) and stage (b) in combination; (c) removing of organic impurities from the specified super-concentrated stock solution with help of the water-solvent solution in the zone of the separating phase of solid substance/liquid forming a stream of water and a second stream of water; where the specified water-solvent solution is introduced to the specified zone of the separating phase of solid substance/liquid at a temperature interval from about 20°C to 70°C; (d) mixing in the zone for mixing water and not necessarily the extraction solvent with the specified stream of water and the specified second water stream forming a water mixture; (e) introducing the extraction solvent to the specified water solution to the extraction zone forming a stream of extract and a stream of raffinate; and (f) separating of the specified flow of extract in the zone of separation forming a flow of organic impurities with a high boiling point and a flow of the extraction solvent removed.

EFFECT: increase in the efficiency of the method of removing impurities and working capacity of the method in comparison to the existing methods.

17 cl, 1 tbl, 1 dwg

 

The technical field to which the invention relates.

This invention relates to the recovery of a metal catalyst from a mother liquor obtained in the synthesis of carboxylic acid, typically terephthalic acid. In particular, the method comprises adding water to flow supercentenarians mother liquor to extract the metal catalyst and then one-step extraction educated so water mixture to remove the organic impurities to produce the extract stream and the flow of raffinate containing the metal catalyst.

Background of invention

Terephthalic acid is produced in industry by oxidation of paraxylene in the presence of a catalyst, such as, for example, Co, Mn, Br, and solvent. Terephthalic acid is used in obtaining the polyester fibers, films and resins must be further processed to remove impurities that are present due to the oxidation of paraxylene.

Terephthalic acid (TPA) is an intermediate product in obtaining polyesters for use as plastics and fibers. Industrial methods of producing TPA based on catalyzed by heavy metals the oxidation of paraxylene, usually with bromidum promoter in acetic acid as solvent. Due to the limited solubility of T Is To acetic acid in the practical conditions of oxidation in the oxidation reactor formed suspension TPA crystals. Usually TPA crystals is withdrawn from the reactor and separated from the reaction mother liquor using traditional methods of phase separation solid/liquid. The mother liquor, which contains most of the catalyst and the promoter used in the way that recycle to the oxidation reactor. In addition to the catalyst and promoter of the mother solution also contains dissolved TPA and many by-products and impurities. These by-products and impurities appear partially from minor impurities present in the feed stream paraxylene. Some impurities caused by incomplete oxidation of paraxylene, giving the partially oxidized products. Other by-products are the result of competing side reactions in the oxidation of paraxylene to terephthalic acid.

Solid TPA crystals obtained by separation of the phases, the solid/liquid, usually washed with fresh solvent, replacing the main part of the mother liquor and then dried to remove the greater part of the solvent is acetic acid. The dried crude TPA crystals contaminated with impurities that were present in the mother solution, since these impurities seacadets with TFA-crystals. Impurities are also present due to occlusion in the structure of the TPA crystals and due to incomplete UDA is possible from the mother liquor when washing with fresh solvent.

Many of the impurities in the mother solution, which are recirculated, are relatively inert to further oxidation. Such impurities include, for example, isophthalic acid, phthalic acid and trimellitic acid. Also contains impurities, which are more prone to oxidation, such as, for example, 4-carboxybenzene, paratoluidine acid and paratoluidine aldehyde. The concentration of inert to the oxidation of the impurities tend to accumulate in the mother solution. The concentration of these inert impurities will increase in the mother solution, to achieve equilibrium, therefore, the amount of each impurity contained in a dry TPA product is determined by the equilibrium with the speed of its formation or administration in the oxidation process. The usual level of impurities in the crude TFA makes it unsuitable for direct use in most polymer applications.

Traditionally the crude TPA can be cleaned either by transformation into the corresponding complex of dimethyl ether by dissolving in water with subsequent hydrogenation with standard hydrogenation catalysts. Recently, to obtain TPA polymer purity used secondary oxidation processing. Regardless of the method used for the purification of TPA with converting it into a suitable DL is used in obtaining the polyester, it is desirable to minimize the concentration of impurities in the mother solution, and thereby to facilitate subsequent purification of TPA. In many cases it is impossible to obtain purified TPA polymer purity, if you are not using any means of removing impurities from the mother liquor.

One of the technologies for the removal of impurities from the recycled stream, typically used in the chemical processing industry, is abstraction, or clean by blowing/leaching" some portion of the recirculated flow. Usually the exhaust stream just replace or if it is economically justified, is subjected to various treatments to remove unwanted impurities in the extraction of valuable components. One example is the US 4939297, shown here as a reference. The amount of lead required for regulation of impurities, does not depend on the way; however the amount of lead equal to 10-40% of the mother liquor, is usually sufficient to receive TPA. When receiving TPA degree of assignment of stock solution required to maintain acceptable concentrations of impurities, in combination with the high value of the metal catalyst and components of the solvent mother liquor makes easy replacement of the exhaust stream is economically unviable. Thus, there is a need for fashion, which removes essentially all of the expensive metal catalysts and acetic acid contained in the mother solution, removing most of the impurities present in the waste stream. The metal catalyst must be removed in the active form suitable for reuse in the cycle on phase oxidation of paraxylene.

This invention is a substantial improvement of the typical way of abstraction. Some of the advantages are:

1) improved performance and reliability by reducing the possibility of clogging;

2) reduction in total energy consumption.

The present invention improves the efficiency of the method of removing impurities and the efficiency of the method compared to existing methods.

Brief description of the invention

This invention relates to the removal of impurities and removing the metal catalyst from a mother liquor obtained in the synthesis of carboxylic acid, typically terephthalic acid. More specifically, the method comprises adding water to a concentrated stock solution with extraction of metal catalyst and then one-step extraction of the thus obtained aqueous mixture to remove the organic impurities to produce the extract stream and the flow of raffinate.

The purpose of this image is etenia is a method of obtaining flow superconcentrators the mother liquor.

Another purpose of this invention is to provide a method for extracting a flow of the metal catalyst from the flow of the mother liquor.

Another purpose of this invention is to provide a method of removing impurities and extract flow metal catalyst from a mother liquor obtained in the synthesis of carboxylic acids.

In the first embodiment of the present invention provides a method of extracting a metal catalyst from a mother liquor. The method includes the following stages:

(a) evaporating the mother liquor containing carboxylic acid, a metal catalyst, impurities, water and a solvent, in the area of the first evaporator to obtain a stream of water vapor and the flow of the concentrated mother liquor;

(b) evaporation of flow of the concentrated mother liquor in the zone of the second evaporator with the formation of the enriched solvent stream and stream supercentenarians mother liquor;

(C) selection of organic impurities solution water-based solvent from superconcentrators the mother liquor in the area of phase separation solid/liquid with the formation of a water stream and a second stream;

(d) mixing in the mixing zone water and, optionally, the extraction solvent with the water flow and the second water thread is with the formation of the aqueous mixture;

(e) adding an extraction solvent to the aqueous mixture in the zone of extraction with the formation of the extract stream and the flow of raffinate (fine thread); and

(f) optionally, separating the extract stream in the separation zone with the formation of the flow of organic impurities with high boiling point and flow extracted extraction solvent.

In another embodiment, the present invention provides a method of obtaining flow superconcentrators the mother liquor. The method includes the following stages:

(a) evaporating the mother liquor containing carboxylic acid, a metal catalyst, impurities, water and a solvent, in the area of the first evaporator to obtain a stream of water vapor and the flow of the concentrated mother liquor; and

(b) evaporation of flow of the concentrated mother liquor in the zone of the second evaporator with obtaining enriched solvent stream and stream supercentenarians mother liquor,

where evaporation stages (a) and (b) in combination removes about 95-98% of the mass. solvent from the mother liquor;

where the area of the second evaporator includes an evaporator (evaporator unit), operating at a temperature of about 20-70°C.

In another embodiment, the invention provides a method of extracting a metal catalyst from a mother liquor, including the store the following stages:

(a) evaporating the mother liquor containing carboxylic acid, a metal catalyst, impurities, water and a solvent, in the area of the first evaporator to obtain a stream of water vapor and the flow of the concentrated mother liquor;

(b) evaporation of flow of the concentrated mother liquor in the zone of the second evaporator with obtaining enriched solvent stream and stream supercentenarians mother liquor, where about 85-99% of the mass. solvent and water is removed from the mother liquor at the stage of (a) and phase (b) combined;

(C) selection of organic impurities with an aqueous solution of superconcentration the mother liquor in the area of phase separation solid/liquid with the formation of a water stream and a second stream; where the solution of water-solvent is injected into the area of phase separation solid/liquid in the temperature range from about 20°C to 70°C;

(d) mixing in the mixing zone water and, optionally, the extraction solvent with the water flow and the second water flow with formation water mixtures;

(e) adding an extraction solvent in the aqueous mixture in the zone of extraction with the formation of the extract stream and the flow of raffinate; and

(f) an optional separating the extract stream in the separation zone with the formation of the flow of organic impurities with high is accoi boiling and flow extracted extraction solvent.

These objectives and other objectives will be more obvious to a person skilled in the art after reading this description.

Brief description of drawings

The drawing illustrates different variants of the present invention, which provides a method of extracting a metal catalyst from a mother liquor and a method of obtaining flow superconcentrators the mother liquor.

Detailed description of the invention

In one embodiment, the invention provides a method of extracting a metal catalyst from a mother liquor 101, as shown in the drawing. The method includes the following steps.

Stage (a) comprises evaporating the mother liquor 101 containing carboxylic acid, a metal catalyst, impurities, water and a solvent, in the area of the first evaporator 121 obtaining water vapor 104 and flow of the concentrated mother liquor 105.

The mother liquor 101 away from the process of oxidative synthesis of carboxylic acids. The mother liquor 101 serves as a flow of power in this way. The mother liquor contains a carboxylic acid, water, a solvent, a metal catalyst and impurities. Impurities contain organic bromides and corrosion metals. Organic bromides are used as promoters in oxidation reactions. Examples of corrosive metals are the Xia iron and chromium compounds, which inhibit, reduce or completely destroy the activity of the metal catalyst.

Suitable carboxylic acid selected from the group consisting of terephthalic acid, isophthalic acid, naphthaleneboronic acid and mixtures thereof.

Suitable solvents include aliphatic monocarboxylic acids, preferably containing 2 to 6 carbon atoms, or benzoic acid and mixtures thereof and mixtures with water. Preferably the solvent is acetic acid, mixed with water in a ratio of about 5:1 to about 25:1, preferably in the range of from about 10:1 to about 15:1. Everywhere in the description of the solvent will be called acetic acid. However, it should be noted that they may also use other suitable solvents, such as discussed here.

In the first stage of this method, the mother liquor concentrated in the traditional way in the area of the first evaporator 121 containing the evaporator (evaporator unit), with flow of water vapor 104 and flow of the concentrated mother liquor 105. The evaporator operates under conditions of atmospheric or slightly above atmospheric pressure, typically from about 1 ATM to about 10 ATM. The flux of water vapor 104 contains the main amount of water and solvent, and the flow of the concentrated mother liquor 105 will gain the balance of water and solvent, not removed from the mother liquor 101. Evaporation removes approximately 50-80% of the mass. solvent and water, usually acetic acid and water, which are present in the mother solution.

Stage (b) comprises evaporation of flow of the concentrated mother liquor 105 in the area of the second evaporator 150 with obtaining enriched solvent stream 144 and flow supercentenarians mother liquor 145.

The flow of the concentrated mother liquor 105 then injected into the area of the second evaporator 150, which contains at least one evaporating device. The evaporator operates under vacuum conditions. Evaporation is carried out at a temperature of from about 20°C to about 70°C; other interval is from about 30°C to about 50°C. a Combination of evaporators 121 and 150 acts to concentrate the mother liquor, as represented by flow 101, to the state, which removes about 75-99% of the mass. solvent and water, usually acetic acid and water. In another embodiment, the combination of evaporators 121 and 150 acts to concentrate the mother liquor, represented by stream 101 to the state, which removes about 85-99% of the mass. solvent and water, usually acetic acid and water. In addition, the intervals as defined in the present description and the subsequent claims, should be understood as concr the IDT describing the whole interval, and not only the end point (point). For example, the description of the interval 0-10 should be taken as a description of the specific values 2, 2,5, 3,17 and all other included numbers, and not only 0 and 10.

Stage (C) includes a selection of organic impurities 146 solution of the water-solvent 149 from the stream supercentenarians mother liquor 145 in the area of phase separation solid/liquid 151 with the formation of water flow 147 and the second water stream 148.

Stage phase separation solid/liquid includes flow supercentenarians mother liquor 145 in the area of phase separation solid/liquid 151 obtaining organic impurities 146, the water flow 147 and the second water stream 148. Area phase separation solid/liquid 151 contains at least one device is a phase separation solid/liquid. There are no restrictions on the type of device phase separation solid/liquid. Examples of such devices include (but are not limited to filters, and centrifuges. The water stream 147 is obtained by filtering flow supercentenarians mother liquor 145.

The second water stream 148 is obtained by filtering flow supercentenarians mother liquor 145 and washing with a solution of water-solvent 149. Organic impurities 146, isolated from superconcentrates the spent mother liquor 145 in the area of phase separation solid/liquid 151, subjected to extraction of metal oxidation catalyst by adding a solution of water-solvent 149 with the formation of the second water stream 148, where at least 80% of metal oxidation catalyst is extracted into the aqueous phase of the water flow 147 and the second water stream 148. Usually at least 90% of metal oxidation catalyst is extracted into the aqueous phase of the water flow 147 and the second water stream 148. Water flow 147 and the second water stream 148 can be optionally combined before exiting the zone phase separation solid/liquid 151.

The solution of water-solvent 149 contains water and optionally additional solvent. The solvent may be any substance capable of dissolving the metal catalyst with the formation of uniformly dispersed solution at the molecular or ionic level. Typically, the solvent includes acetic acid, but may also be used solvents, which were previously stated at the stage (a). Preferably the extraction is carried out in the same device, and that phase separation solid/liquid. Perhaps the most unexpected is that when using water as the extracting agent at temperatures in the range of from about 20°With up to about 70°C, preferably from about 30°With up to about 50°S, eno is the number of corrosion of the metal remains in the organic impurities 146, where the need for removing the corrosion of metal by heating and filtering, as in the other existing methods, is eliminated. Organic impurities 146, which are solids separated from the metal catalyst may be removed from the system.

Stage (d) comprises mixing in the mixing zone 122 water 106 and, optionally, the extraction solvent 108 water flow 147 and the second water flow 148 with the formation water mixture 107.

Water flow 147 and the second water stream 148 can be combined in the mixing zone 122. In one embodiment of the invention the mixing zone 122 contains a traditional mixer. If necessary, the mixing zone 122 may be a solution of water-solvent 106 in a quantity sufficient to dissolve the metal catalyst in the stream water mixture 107.

Usually about 0.5-1.0 hours water 1 tsp United water flow 147 and the second water stream 148 is sufficient to dissolve the catalyst, preferably about 1:1 o'clock mass. The introduction of water not only removes metal catalyst, but also contributes to pumping the resulting suspension in the extraction apparatus. It is desirable to maintain the circulation water mixture 107 via an external circulation loop. A small amount of extraction solvent 108, typically about 1-10 wt. -%, PR is doctitle 5 wt. -%, can be introduced into the mixing zone 122 for better handling suspension by reducing the adhesion of solids to the vessel wall. This is shown by the dashed arrow from the stream 108 in the drawing. Preferably, but not necessarily, subjected to an aqueous mixture of 107 before extraction to heat treatment at a temperature of about 60-95°With the other interval is approximately 80-90°With, for about 0.5 to 4 hours, preferably about 1-2 hours At the above-mentioned processing of organic bromides interact with obtaining inorganic bromides, which preferably remain in the water fraction, out of the extraction apparatus. This minimizes the number bromodomain compounds discharged from the system together with undesirable impurities. Heat treatment saves bromides and simplifies the removal of organic impurities.

Stage (e) contains an introduction extraction solvent 108 in an aqueous mixture of 107 in the area of extraction 123 with the formation of the extract stream 109 and the flow of raffinate 110.

The aqueous mixture 107 serves in the area of extraction 123, where water mixture 107 and extraction solvent 108 are in contact in the zone of extraction 123. The aqueous mixture 107 and extraction solvent 108 is mixed with a stream of the extract 109 solvent containing water and organic impurities and organic solvent, which obrazu the lighter phase, and the flow of raffinate 110 containing a metal catalyst, corrosion metals and water. The extract stream 109 output as the upper stream, and the stream of the raffinate 110 is removed from the bottom of the extraction device in the zone of extraction 123. In this invention one extraction zone 123 is a single-stage countercurrent extraction apparatus. In another embodiment, the implementation area extraction 123 contains a countercurrent extraction apparatus.

Extraction solvent 108 used in the extraction apparatus, must be essentially insoluble in water and to minimize the amount of organic solvent dissolved in the aqueous fraction. In addition, the extraction solvent 108 is preferably azeotropic agent, which serves to facilitate the extraction of the solvent from the organic extract. Solvents which are proven, are particularly applicable, are C1-C6-allylacetate, in particular n-propyl (n-RA)(n-PA)), isopropylacetate, isobutyl acetate, sec-butyl acetate, ethyl acetate and n-butyl acetate, but may also be used other water-insoluble organic solvent having a suitable density and sufficiently low boiling point, such as para-xylene. N-propyl and isopropylacetate are especially preferred due to their relative is of low solubility in water, excellent azeotropic behavior and their ability to remove residual acetic acid, and high-boiling organic impurities from the aqueous mixture.

The extraction may be carried out using ratios of solvent is from about 1 to 4 mass solvent 1 mass power extraction device depending on the composition of the power extraction device. Flow rate combined feed in the extraction apparatus usually vary in the interval from 1 to about 3 h-1. Although the extraction can be performed at a temperature and ambient pressure may be used for heating of the solvent and extraction device at about 30-70°With, there can be used other interval from about 40°With up to about 60°C. While a stream of extract 109 contains a small amount of metal catalyst and corrosion of metals, in essence, the entire metal catalyst and the main part of the corrosion of metals contained in the heavier phase - stream of the raffinate 110.

Stage (f) includes the optional separation of the extract stream 109 in the separation zone 124 with the formation of the flow of organic impurities with high boiling point 115 and the flow of the extracted extraction solvent 117.

The extract stream 109 contains an organic solvent and the organization is organic impurities. The extract stream 109 may further comprise acetic acid and water, often in small quantities. The extract stream 109 may be distilled in the separation zone containing conventional distillation equipment. Suitable distillation equipment includes, for example, the distillation column.

A large part of the organic impurities are extracted with an organic solvent in the zone of extraction 123. This is because organic matter has a high degree of solubility in an organic solvent, and to a lesser extent in acetic acid. By distillation of the lighter phase of the extraction device, an organic solvent is evaporated, allowing organic impurities concentrate in the bottom stream from the column.

Stream extracted extraction solvent 117 can be recycled to the extraction unit in the area of extraction 123 and the oxidizing reactor, respectively. The flow of the high-boiling organic impurities 115 is removed as sludge from the bottom of the distillation column for recycling.

Although the composition of the various streams in the method varies depending on the process conditions, a typical composition of the stream are shown in table 1. Table 1 components are shown in the left column, and the number of these components in each stream figure 1 shows the column number, the corresponding number of the flow in figure 1. Quantitative values for the components shown in table 1, can apply to any units of mass, unless they comply with all components and all threads. For example, the mother liquor 101 contains acetic acid in the amount of 915 lb, 915, etc.

-
Table 1

The material balance
The material balance method

The flow in Fig. 1
101104105144145146147148149106107108109110
Acetic acid915,0534,1380,9289,591,50,89,181,5--90.6-88.62.0
Water55,039,315,713,12,60,70,37,86,280,088.1-57.230.9
n-propyl----------400.0399.20.8
Terephthalic acid0,71-0,71-0,710,620,070,02--0,09-0,09-
Isophthalic acidof 5.83-of 5.83-of 5.83to 4.980,580,26--0,85-0,84-
Phthalic acid3,81-3,81-3,810,030,383,39--3,78-3,600,18
Benzoic acid8,120,06of 8.060,028,040,070,807,17--7,97-of 7.96-
4-carboxybenzene1,56-1,56 -1,561,230,160,17--0,33-0,33-
Trimellitate acid1,17-1,17-1,170,210,120,84--0,96-0,900,07
Pair-tolarova acid2,960,012,95-2,941,600,291,05--1,35-of 1.340,01
Pair-Truelove aldehyde0,510,050,460,030,44-0,040,39--0,43-0,43-
Miscellaneous2,50-2,50-2,500,452,05---2,05-2,030,02
Organic bromide1,30-1,30- 1,300,071,24---0,37-0,37-
Ion bromide0,34-0,34-0,340,020,32---1,23-0,011,22
Cobaltthe 1.44-the 1.44-the 1.440,070,680,68--1,37-0,011,35
Manganese0,10-0,10-0,10-0,050,05--0,10--0,09
Corrosion metals0,08-0,08-0,080,020,06---0,06--0,06
Only10005734273031241116103 68020040056337
The quantitative values of the components shown in table 1, can apply to any units of mass, unless they comply with all components and all threads.

1. The allocation method of the metal catalyst from the stream of mother liquor containing carboxylic acid, which comprises the following stages:

(a) evaporating the mother liquor containing carboxylic acid, a metal catalyst, impurities, water and a solvent, in the area of the first evaporator to obtain a stream of water vapor and the flow of the concentrated mother liquor;

(b) evaporating the specified stream concentrated mother liquor in the zone of the second evaporator with the formation of the enriched solvent stream and stream supercentenarians mother liquor;

(c) extraction of organic impurities from superconcentrators the mother liquor using a solution of water-solvent in the area of phase separation solid/liquid with the formation of a water stream and a second stream;

(d) mixing in the mixing zone of the water and optional solvent extraction solvent with the specified water flow and the specified second water stream with the formation of water with the art;

(e) adding an extraction solvent to the said aqueous mixture in the zone of extraction with the formation of the extract stream and the flow of raffinate containing the specified metal catalyst; and

(f) the Department specified the extract stream in the separation zone with the formation of the flow of organic impurities with high boiling point and flow extracted extraction solvent.

2. The method according to claim 1, in which about 50-80 wt.% these solvent and water are removed from the specified stock solution in stage (a).

3. The method according to claim 2, in which the specified stock solution in stage (a) and phase (b) in combination are removed from about 75 to about 99 wt.% these solvent and water.

4. The method according to claim 1, in which the specified stock solution in stage (a) and phase (b) in combination are removed from about 85 to about 99 wt.% these solvent and water.

5. The method according to claim 1, in which the specified stock solution in stage (a) and phase (b) in combination are removed from about 90 to about 99 wt.% these solvent and water.

6. The method according to claim 1, wherein said solution of water-solvent type in the specified area of the phase separation solid/liquid in the temperature range from about 20 to about 70°C.

7. The method according to claim 1, wherein said solution of water-solvent type in the specified area of separation of the phases, the solid matter/liquid in the temperature range from about 30 to about 50° C.

8. The method according to claim 1, in which the specified area extraction contains countercurrent extraction apparatus.

9. The method according to claim 1, in which the specified area extraction contains single-stage extraction device.

10. The method according to claim 1, wherein said extract stream contains a solvent selected from the group consisting of n-propyl, isopropylacetate, isobutylacetate, sec-butyl acetate, ethyl acetate and n-butyl acetate.

11. The method according to claim 1, in which the specified area of the second evaporator includes an evaporator device operating at a temperature of from about 20 to about 70°C.

12. The method according to claim 9, wherein said second evaporator operates under vacuum conditions.

13. The allocation method of the metal catalyst from the stream of mother liquor containing carboxylic acid, comprising the following stages:

(a) evaporating the mother liquor containing carboxylic acid, a metal catalyst, impurities, water and a solvent, in the area of the first evaporator to obtain a stream of water vapor and the flow of the concentrated mother liquor;

(b) evaporating the specified stream concentrated mother liquor in the zone of the second evaporator with obtaining enriched solvent stream and stream superconcentrators the mother liquor, from about 85 to about 99 wt.% rest is rites and water are removed from the specified stock solution in stage (a) and phase (b) in combination;

(c) extraction of organic impurities from the specified superconcentrators the mother liquor using a solution of water-solvent in the area of phase separation solid/liquid with the formation of a water stream and a second aqueous stream, where the specified solution of water-solvent type in the specified area of the phase separation solid/liquid in the temperature range from about 20 to about 70°C;

(d) mixing in the mixing zone of the water and optional solvent extraction solvent with the specified water flow and the specified second water stream with the formation of the aqueous mixture;

(e) introduction the extraction solvent at a specified water mixture in the zone of extraction with the formation of the extract stream and the flow of raffinate containing the specified metal catalyst; and

(f) the Department specified the extract stream in the separation zone with the formation of the flow of organic impurities with high boiling point and flow extracted extraction solvent.

14. The method according to item 13, in which from about 50 to about 80 wt.% these solvent and water are removed from the specified stock solution in stage (a).

15. The method according to item 13, in which the specified area extraction contains countercurrent extraction apparatus.

16. The method according to item 13, in which the specified area extraction contains one of EXT the promotional device.

17. The method according to item 13, wherein said extract stream contains a solvent selected from the group consisting of n-propyl, isopropylacetate, isobutylacetate, sec-butyl acetate, ethyl acetate and n-butyl acetate.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: method of obtaining product - purified carboxylic acid, includes: (a) oxidation of aromatic initial materials in primary oxidation zone with formation of raw carboxylic acid suspension; where raw carboxylic acid suspension contains terephthalic acid; where said oxidation is carried out at temperature within the range from 120°C to 200°C; (b) withdrawal of admixtures from raw suspension of carboxylic acid, removed at temperature from 140°C to 170°C from stage of oxidation of paraxylol in primary oxidation zone and containing terephthalic acid, catalyst, acetic acid and admixtures, realised in zone of solid products and liquid separation with formation of mother liquid flow and product in form of suspension; where part of said catalyst in said suspension of raw carboxylic acid is removed in said mother liquid flow; and where into said zone of solid products and liquid separation optionally additional solvent is added; (c) oxidation of said product in form of suspension in zone of further oxidation with formation of product of further oxidation; where said oxidation is carried out at temperature within the range from 190°C to 280°C; and where said oxidation takes place in said zone of further oxidation at temperature higher than in said primary oxidation zone; (d) crystallisation of said product of further oxidation in crystallisation zone with formation of crystallised product in form of suspension; (e) cooling of said crystallised product in form of suspension in cooling zone with formation of cooled suspension of purified carboxylic acid; and (i) filtration and optionally drying of said cooled suspension of purified carboxylic acid in filtration and drying zone in order to remove part of solvent from said cooled suspension of carboxylic acid with obtaining of said product - purified carboxylic acid.

EFFECT: purified carboxylic acid with nice colour and low level of admixtures, without using stages of purification like hydration.

8 cl, 1 tbl, 1 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method, by which the carboxylic acid/diol mixture, that is suitable as the initial substance for the manufacture of polyester, obtained from the decolourised solution of carboxylic acid without actually isolating the solid dry carboxylic acid. More specifically, the invention relates to the method of manufacturing a mixture of carboxylic acid/diol, where the said method includes the addition of diol to the decolourised solution of carboxylic acid, which includes carboxylic acid and water, in the zone of the reactor etherification, where diol is located at a temperature sufficient for evaporating part of the water in order to become the basic suspending liquid with the formation of the specified carboxylic acid/diol mixture; where the said carboxylic acid and diol enter into a reaction in the zone of etherification with the formation of a flow of a complex hydroxyalkyl ether. The invention also relates to the following variants of the method: the method of manufacture of the carboxylic acid/diol mixture, where the said method includes the following stages: (a) mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of damp carboxylic acid; where the said carboxylic acid is selected from the group, which includes terephthalic acid, isophthatic acid, naphthalenedicarboxylic acid and their mixtures; (b) discolourisation of aforesaid solution of damp carboxylic acid in the zone for reaction obtaining the decolourised solution of carboxylic acid; (c) not necessarily, instantaneous evaporation of the said decolourised solution of carboxylic acid in the zone of instantaneous evaporation for the removal of part of the water from the decolourised solution of carboxylic acid; and (d) addition of diol to the decolourised solution of carboxylic acid in the zone of the reactor of the etherification, where the said diol is located at a temperature, sufficient for the evaporation of part of the water in order to become the basic suspending liquid with the formation of the carboxylic acid/diol mixture; where the aforesaid carboxylic acid and diol then enter the zone of etherification with the formation of the flow of complex hydroxyalkyl ether; and relates to the method of manufacture of carboxylic acid/diol, where the said method includes the following stages: (a) the mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of carboxylic acid; (b) discolourisation of the said solution of damp carboxylic acid in the reactor core with the formation of the decolourised solution of carboxylic acid; (c) crystallisation of the said decolourised solution of carboxylic acid in the zone of crystallisation with the formation of an aqueous suspension; and (d) removal of part of the contaminated water in the aforesaid aqueous solution and addition of diol into the zone of the removal of liquid with the obtaining of the said carboxylic acid/diol mixture, where diol is located at a temperature sufficient for evaporating part of the contaminated water from the said aqueous suspension in order to become the basic suspending liquid.

EFFECT: obtaining mixture of carboxylic acid/diol.

29 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method, by which the carboxylic acid/diol mixture, that is suitable as the initial substance for the manufacture of polyester, obtained from the decolourised solution of carboxylic acid without actually isolating the solid dry carboxylic acid. More specifically, the invention relates to the method of manufacturing a mixture of carboxylic acid/diol, where the said method includes the addition of diol to the decolourised solution of carboxylic acid, which includes carboxylic acid and water, in the zone of the reactor etherification, where diol is located at a temperature sufficient for evaporating part of the water in order to become the basic suspending liquid with the formation of the specified carboxylic acid/diol mixture; where the said carboxylic acid and diol enter into a reaction in the zone of etherification with the formation of a flow of a complex hydroxyalkyl ether. The invention also relates to the following variants of the method: the method of manufacture of the carboxylic acid/diol mixture, where the said method includes the following stages: (a) mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of damp carboxylic acid; where the said carboxylic acid is selected from the group, which includes terephthalic acid, isophthatic acid, naphthalenedicarboxylic acid and their mixtures; (b) discolourisation of aforesaid solution of damp carboxylic acid in the zone for reaction obtaining the decolourised solution of carboxylic acid; (c) not necessarily, instantaneous evaporation of the said decolourised solution of carboxylic acid in the zone of instantaneous evaporation for the removal of part of the water from the decolourised solution of carboxylic acid; and (d) addition of diol to the decolourised solution of carboxylic acid in the zone of the reactor of the etherification, where the said diol is located at a temperature, sufficient for the evaporation of part of the water in order to become the basic suspending liquid with the formation of the carboxylic acid/diol mixture; where the aforesaid carboxylic acid and diol then enter the zone of etherification with the formation of the flow of complex hydroxyalkyl ether; and relates to the method of manufacture of carboxylic acid/diol, where the said method includes the following stages: (a) the mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of carboxylic acid; (b) discolourisation of the said solution of damp carboxylic acid in the reactor core with the formation of the decolourised solution of carboxylic acid; (c) crystallisation of the said decolourised solution of carboxylic acid in the zone of crystallisation with the formation of an aqueous suspension; and (d) removal of part of the contaminated water in the aforesaid aqueous solution and addition of diol into the zone of the removal of liquid with the obtaining of the said carboxylic acid/diol mixture, where diol is located at a temperature sufficient for evaporating part of the contaminated water from the said aqueous suspension in order to become the basic suspending liquid.

EFFECT: obtaining mixture of carboxylic acid/diol.

29 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention pertains to the perfection of the method of regulating quantities of dissolved iron in liquid streams during the process of obtaining aromatic carboxylic acids or in the process of cleaning technical aromatic carboxylic acids, characterised by that, to at least, part of the liquid stream for regulating the quantity of dissolved iron in it, at least one peroxide with formula R1-O-O-R2 is added. Here R1 and R2 can be the same or different. They represent hydrogen or a hydrocarbon group, in quantities sufficient for precipitation of the dissolved iron from the liquid. The invention also relates to the perfection of the method of obtaining an aromatic carboxylic acid, through the following stages: A) contacting the crude aromatic material which can be oxidised, with molecular oxygen in the presence of an oxidising catalyst, containing at least, one metal with atomic number from 21 to 82, and a solvent in the form of C2-C5 aliphatic carboxylic acid in a liquid phase reaction mixture in a reactor under conditions of oxidation with formation of a solid product. The product contains technical aromatic carboxylic acid, liquid, containing a solvent and water, and an off-gas, containing water vapour and vapour of the solvent; B) separation of the solid product, containing technical aromatic carboxylic acid from the liquid; C) distillation of at least part of the off gas in a distillation column, equipped with reflux, for separating vapour of the solvent from water vapour. A liquid then forms, containing the solvent, and in the upper distillation cut, containing water vapour; D) returning of at least, part of the liquid from stage B into the reactor; E) dissolution of at least, part of the separated solid product, containing technical aromatic carboxylic acid, in a solvent from the cleaning stage with obtaining of a liquid solution of the cleaning stage; F) contacting the solution from the cleaning stage with hydrogen in the presence of a hydrogenation catalyst and under hydrogenation conditions, sufficient for formation of a solution, containing cleaned aromatic carboxylic acid, and liquid, containing a cleaning solvent; G) separation of the cleaned aromatic carboxylic acid from the solution, containing the cleaning solvent, which is obtained from stage E, with obtaining of solid cleaned aromatic carboxylic acid and a stock solution from the cleaning stage; H) retuning of at least, part of the stock solution from the cleaning stage, to at least, one of the stages B and E; I) addition of at least, one peroxide with formula R1-O-O-R2, where R1 and R2 can be the same or different, and represent hydrogen or a hydrocarbon group, in a liquid from at least one of the other stages, or obtained as a result from at least one of these stages, to which the peroxide is added, in a quantity sufficient for precipitation of iron from the liquid.

EFFECT: controlled reduction of the formation of suspension of iron oxide during production of technical aromatic acid.

19 cl, 1 dwg, 6 ex, 4 tbl

FIELD: carbon materials and hydrogenation-dehydrogenation catalysts.

SUBSTANCE: invention relates to improved crude terephthalic acid purification process via catalyzed hydrogenating additional treatment effected on catalyst material, which contains at least one hydrogenation metal deposited on carbonaceous support, namely plane-shaped carbonaceous fibers in the form of woven, knitted, tricot, and/or felt mixture or in the form of parallel fibers or ribbons, plane-shaped material having at least two opposite edges, by means of which catalyst material is secured in reactor so ensuring stability of its shape. Catalyst can also be monolithic and contain at least one catalyst material, from which at least one is hydrogenation metal deposited on carbonaceous fibers and at least one non-catalyst material and, bound to it, supporting or backbone member. Invention also relates to monolithic catalyst serving to purify crude terephthalic acid, comprising at least one catalyst material, which contains at least one hydrogenation metal deposited on carbonaceous fibers and at least one, bound to it, supporting or backbone member, which mechanically supports catalyst material and holds it in monolithic state.

EFFECT: increased mechanical strength and abrasion resistance.

8 cl, 4 ex

FIELD: industrial production of methacrylic acids at reduced amount of industrial wastes.

SUBSTANCE: proposed method is performed by catalytic oxidation of propane, propylene or isobutylene in vapor phase at separation of final product and forming of high-boiling mixture as by-product which contains (according to Michaels addition) water, alcohol or methacrylic acid added to methacrylic group. By-product is decomposed in thermal decomposition reactor at simultaneous distillation of decomposition products in distilling column from which methacrylic acid is taken in form of distillate. Flow of liquid decomposition residue is forced for peripheral direction by means of mixing blades before withdrawal from reactor. Peripheral direction is obtained with the aid of liquid fed from the outside of decomposition reactor; to this end use is made of initial high-boiling material or flow of liquid discharged from decomposition reactor. If necessary, etherification stage is performed through interaction with alcohol for obtaining methecrylic ester. Decomposition of by-product formed at obtaining methacrylic acid by oxidation of propylene or isobutylene or at obtaining methacrylic acid by interaction of acid with alcohol by alcohol through introduction of by-product into thermal decomposition reactor provided with distilling column which has plates made in form of disks and toroids for simultaneous decomposition and distillation. Plant proposed for realization of this method includes thermal decomposition reactor and distilling column, level meters and lines for discharge of liquid containing easily polymerized compounds. Level indicator mounted at area of accumulation of liquid shows pressure differential. Line for detecting the side of high pressure of this level meter is connected with accumulated liquid discharge line.

EFFECT: updated technology; increased yield of target products.

38 cl, 14 dwg, 2 tbl, ex

FIELD: chemical technology.

SUBSTANCE: invention relates to technology for synthesis of acetic acid by the cabonylation reaction of methanol with carbon monoxide. Method involves preparing the productive flow in the reaction section containing acetic acid, acetaldehyde, water and other impurities. In the cleansing treatment the reaction products are subjected for treatment wherein acetaldehyde impurities are oxidized to either acetic acid after its isolation and recovered to the reaction zone or to carbon dioxide and water that removed from the system. As result, method provides excluding the negative effect of acetaldehyde at step for separation of the reaction products. Oxygen, air or their mixtures, ozone, carbon peroxide or peracetic acid are used as oxidant. As possible variants of the method, the productive flow is fed to distillation column wherein flow of light products or heavy products are isolated under condition that each of these flow involves acetic acid, acetaldehyde and water. Then "light" or "heavy" flow is subjected for oxidation as said above to reduce the concentration of acetaldehyde. As a variant of the method the flow of heavy products can be treated by extraction with water followed by oxidation of acetaldehyde-containing aqueous phase. Invention provides improvement of method due to exclusion of the necessity of purification of the end product from acetaldehyde impurity.

EFFECT: improved treatment method.

20 cl, 3 tbl, 35 ex

FIELD: industrial organic synthesis.

SUBSTANCE: method comprises contacting vapor-phase mixture at 150-205°C with alkali and/or alkali-earth metal carboxylate dispersed on activated carbon resulting in conversion of alkyl iodides into corresponding carboxylic acid esters, while iodine becomes bound in the form of inorganic iodide.

EFFECT: facilitated freeing of carboxylic acid product from organic iodine compounds.

4 cl, 2 tbl, 32 ex

FIELD: chemical technology.

SUBSTANCE: invention relates to the improved method for extraction of carbonyl and (or) acid compounds from the complex multicomponent organic liquid mixtures. Method involves treatment of organic liquid mixtures with sodium sulfite an aqueous solution at intensity of mechanical stirring providing formation of uniform emulsion. The content of carbonyl compounds and acids in the parent mixture to be treated is determined and treatment is carried out with 4.16-26% aqueous solution of sodium sulfite as measured 1.05-1.1 mole of sodium sulfite per 1 g-equiv. of carbonyl compound, and in exceeding of the content of acids (g-equiv.) in the parent mixture over the content of carbonyl compounds - with 1 mole sodium sulfite per 1 g-equiv. of acids and in the mass ratio of sodium sulfite aqueous solution to organic mixture = (1-2.5):(2-1) at temperature 15-30°C; if the content of acids in the parent mixture (g-equiv.) is less the content of carbonyl compounds (g-equiv.) then under control of pH value change in an aqueous phase method involves additional addition of mineral or organic acid in the amount as a difference in the content of carbonyl compounds (g-equiv.) and the content of acids (g-equiv.) in the parent charge of organic mixture per treatment at such rate that pH value of aqueous would decrease constantly but not less 6.5. This simple method provides removing both carbonyl compounds and acids being without significant limitations for the content of carbonyl compounds and acids in the parent mixture. Invention can be used in different branches of industry for treatment of compositions or for utilization of carbonyl compounds and (or) acids.

EFFECT: improved method for extraction.

5 cl, 3 tbl, 26 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for purifying naphthalene carboxylic acid. Method involves contacting crude naphthalene acid with solvent used for purifying in the presence of hydrogen and catalyst that comprises a precious metal of VIII group taken among palladium, platinum and ruthenium and metal of group IVB taken among silicon, germanium, tin and lead at temperature about from 520 to 575°F. Proposed method provides preparing reduced amount of organic pollution in purified acid as compared with other methods of purification.

EFFECT: improved purifying method.

19 cl, 1 dwg, 5 tbl, 5 ex

FIELD: chemical industry; environmental protection technologies and methods of utilization of the waste mercury-containing catalyzer.

SUBSTANCE: the invention is pertaining to the field of environmental protection technologies, in particular, to the processes of utilization of the waste mercury-containing catalyzer for the process of hydrochlorination of the ethine. The invention presents the method of utilization of the mercury-containing catalyzer by its heating in the medium of the reducing gas, in the capacity of which use the residual gas of the high-temperature homogeneous pyrolysis of hydrocarbons. The heating is conducted at the temperature of 400-700°C within 4-7 hours. The technical result of the invention is the complete extraction (99.99 %) of mercury from the waste catalyzer, that transforms the mercury into the non-toxic substance.

EFFECT: the invention ensures the complete extraction of mercury from the waste catalyzer, that transforms the mercury into the non-toxic substance.

5 tbl, 6 ex, 1 dwg

FIELD: structural chemistry and novel catalysts.

SUBSTANCE: invention provides composition including solid phase of aluminum trihydroxide, which has measurable bands in x-ray pattern between 2Θ=18.15° and 2Θ=18.50°, between 2Θ=36.1° and 2Θ=36.85°, between 2Θ=39.45° and 2Θ=40.30°, and between 2Θ=51.48° and 2Θ=52.59°, and has no measurable bands between 2Θ=20.15° and 2Θ=20.65°. Process of preparing catalyst precursor composition comprises moistening starting material containing silicon dioxide-aluminum oxide and amorphous aluminum oxide by bringing it into contact with chelating agent in liquid carrier and a metal compound; ageing moistened starting material; drying aged starting material; and calcining dried material. Catalyst includes carrier prepared from catalyst composition or catalyst precursor and catalytically active amount of one or several metals, metal compounds, or combinations thereof. Catalyst preparation process comprises preparing catalyst carrier from starting material containing silicon dioxide-aluminum oxide and amorphous aluminum oxide by bringing it into contact with chelating agent and catalytically active amount of one or several metals, metal compounds, or combinations thereof in liquid carrier, ageing starting material; drying and calcinations. Method of regenerating used material involves additional stage of removing material deposited on catalyst during preceding use, while other stages are carried out the same way as in catalyst preparation process. Catalyst is suitable for treating hydrocarbon feedstock.

EFFECT: improved activity and regeneration of catalyst.

41 cl, 3 dwg, 8 tbl, 10 ex

The invention relates to the chemical and metallurgical industries, producing sulfuric acid and using vanadium catalysts, as well as to the processing of vanadium-containing industrial wastes.

The invention relates to hydrochemical methods of disposal of waste vanadium catalysts obtained in the production of sulfuric acid by the contact method of the gases from the combustion of sulfur from waste gases ferrous and nonferrous metallurgy

The invention relates to a method for regenerating catalyst for the dimerization and codimerization of lower olefins and can be used in the petrochemical industry

The invention relates to a method of regeneration of catalysts for the conversion of SO2in SO3in particular to methods of regeneration of vanadium catalysts

There is a method of regeneration of vanadium catalyst for oxidation processes (AVT

FIELD: structural chemistry and novel catalysts.

SUBSTANCE: invention provides composition including solid phase of aluminum trihydroxide, which has measurable bands in x-ray pattern between 2Θ=18.15° and 2Θ=18.50°, between 2Θ=36.1° and 2Θ=36.85°, between 2Θ=39.45° and 2Θ=40.30°, and between 2Θ=51.48° and 2Θ=52.59°, and has no measurable bands between 2Θ=20.15° and 2Θ=20.65°. Process of preparing catalyst precursor composition comprises moistening starting material containing silicon dioxide-aluminum oxide and amorphous aluminum oxide by bringing it into contact with chelating agent in liquid carrier and a metal compound; ageing moistened starting material; drying aged starting material; and calcining dried material. Catalyst includes carrier prepared from catalyst composition or catalyst precursor and catalytically active amount of one or several metals, metal compounds, or combinations thereof. Catalyst preparation process comprises preparing catalyst carrier from starting material containing silicon dioxide-aluminum oxide and amorphous aluminum oxide by bringing it into contact with chelating agent and catalytically active amount of one or several metals, metal compounds, or combinations thereof in liquid carrier, ageing starting material; drying and calcinations. Method of regenerating used material involves additional stage of removing material deposited on catalyst during preceding use, while other stages are carried out the same way as in catalyst preparation process. Catalyst is suitable for treating hydrocarbon feedstock.

EFFECT: improved activity and regeneration of catalyst.

41 cl, 3 dwg, 8 tbl, 10 ex

FIELD: chemical industry; environmental protection technologies and methods of utilization of the waste mercury-containing catalyzer.

SUBSTANCE: the invention is pertaining to the field of environmental protection technologies, in particular, to the processes of utilization of the waste mercury-containing catalyzer for the process of hydrochlorination of the ethine. The invention presents the method of utilization of the mercury-containing catalyzer by its heating in the medium of the reducing gas, in the capacity of which use the residual gas of the high-temperature homogeneous pyrolysis of hydrocarbons. The heating is conducted at the temperature of 400-700°C within 4-7 hours. The technical result of the invention is the complete extraction (99.99 %) of mercury from the waste catalyzer, that transforms the mercury into the non-toxic substance.

EFFECT: the invention ensures the complete extraction of mercury from the waste catalyzer, that transforms the mercury into the non-toxic substance.

5 tbl, 6 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to the removal of the metallic catalyst from stock solution, obtained during the synthesis of carboxylic acids, normally terephthalic acid. Method of removing the metallic catalyst from the stream of stock solution containing carboxyl acid includes the following stages: (a) graduating the stock solution, which contains the carboxyl acid, metallic catalyst, impurities, water and solvent, in the zone of the first evaporator obtaining a stream of water vapour and a stream of concentrated stock solution; (b) evaporating of the specified stream of concentrated stock solution to the zone of the second evaporator forming a stream rich in the solvent and a stream of super-concentrated stock solution; (c) removing organic impurities from super-concentrated stock solution with the help of water-solvent solution in the zone of the separating phase of solid substance/liquid forming a stream of water and a second stream of water; (d) mixing in the zone of mixing water and not necessarily the extraction solvent with the specified water stream and the specified second water stream forming and aqueous solution; (e) adding the extraction solvent to the specified water solution in the extraction zone forming a stream of extract and a stream of raffinate containing the specified metallic catalyst; and (f) separating the specified stream of extract in the separating zone forming a stream of organic impurities with a high boiling point and a stream of the removed extraction solvent. In a different version of the realisation of the method of removing the metallic catalyst from the stream of stock solution containing the carboxylic acid includes the following stages: (a) evaporating of the stock solution containing the carboxylic acid, metallic catalyst, impurities, water and solvent, in the zone of the first evaporator obtaining a stream of water and a stream of concentrated stock solution; (b) evaporating the specified stream of concentrated stock solution in the second evaporating zone obtaining a stream rich in the solvent and stream of super-concentrated stock solution, where about 85 to about 99% mass, of the solvent and water is removed from the specified stock solution at the stage (a) and stage (b) in combination; (c) removing of organic impurities from the specified super-concentrated stock solution with help of the water-solvent solution in the zone of the separating phase of solid substance/liquid forming a stream of water and a second stream of water; where the specified water-solvent solution is introduced to the specified zone of the separating phase of solid substance/liquid at a temperature interval from about 20°C to 70°C; (d) mixing in the zone for mixing water and not necessarily the extraction solvent with the specified stream of water and the specified second water stream forming a water mixture; (e) introducing the extraction solvent to the specified water solution to the extraction zone forming a stream of extract and a stream of raffinate; and (f) separating of the specified flow of extract in the zone of separation forming a flow of organic impurities with a high boiling point and a flow of the extraction solvent removed.

EFFECT: increase in the efficiency of the method of removing impurities and working capacity of the method in comparison to the existing methods.

17 cl, 1 tbl, 1 dwg

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