Method of separating mixture of solvents methanol-tetrahydrofuran-acetonitrile-water-pyridine

FIELD: chemistry.

SUBSTANCE: invention relates to chemical industry. Method involves separation of a five-component mixture, which is carried out in circuits, including one or two three-column complexes of extractive distillation. Separating agents used are sulpholane and dimethylsulphoxide. In first version sulpholane is fed into first column of separation circuit and into first column of three-column complex, and dimethyl sulphoxide is fed into first column of two-column complex for processing mixture of methanol-tetrahydrofuran as obtained distillate. In second version sulpholane is fed into first column of first three-column complex, and dimethyl sulphoxide is fed into first column of second three-column complex for processing mixture of methanol-tetrahydrofuran-water as obtained distillate. Composition of initial mixture is equimolar, amount of separating agent to initial mixture ranges from 0.2:1 to 2.5:1, reflux varies within range of 0.1-3.5.

EFFECT: invention provides for extraction of all components of said five-component industrial mixture of solvents and reduced power consumption.

1 cl, 2 dwg, 2 tbl, 2 ex

 



 

Same patents:

FIELD: chemistry.

SUBSTANCE: method of separating a zeotropic mixture of butyl propionate and propionic acid, components of which have relative volatility close to one, includes separating said mixture by extraction rectification using sulpholane as the parting agent, taken in ratio of 1:6-7 to the starting mixture in an extraction rectification column with efficiency of 40-50 theoretical plates, wherein the reflux ratio in the column is equal to 2-3, followed by collection of butyl propionate in the distillate and the mixture of propionic acid and supholane in the bottom of the column (1); the mixture of propionic acid and sulpholane is then fed into a column for regenerating the parting agent (2) with efficiency of 8 theoretical plates and reflux ratio equal to 0.8-1; the parting agent is removed from the bottom of the column (2) and fed into column (1). Pressure in column (1) is equal to 760 mmHg and pressure in column (2) is equal to 100 mmHg.

EFFECT: simple technique, low capital costs and high quality of the obtained products.

1 dwg, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to versions of a method for the extraction of styrene and support of an extraction solvent efficiency in a system for styrene extraction from a styrene-enriched raw material. One of the versions includes the following stages: (a) supply of the styrene-enriched raw material into an extraction distillation column, (b) discharge of the styrene-enriched flow from the extraction distillation column, with the styrene-enriched flow containing styrene and an extraction solvent; (c) supply of the styrene-enriched raw material into the column for the solvent separation, d) discharge of the styrene-depleted flow from the column for the solvent separation, with the quantity of styrene in the styrene-depleted flow being lower than in the styrene-enriched flow; e) separation of a part of the styrene-depleted flow, f) bringing a part of the styrene-depleted flow in contact with an organic solvent in an equilibrium liquid-liquid system, which has several equilibrium stages, with the formation of a washed extraction solvent, containing the light organic phase and the heavy organic phase, with the light organic phase passing to the following equilibrium stage and the heavy organic phase returning to the first equilibrium stage; and g) recycling the washed extraction solvent back to the extraction distillation column.

EFFECT: method makes it possible to use solvents in a rational way.

17 cl, 4 dwg

FIELD: power engineering.

SUBSTANCE: invention is intended for extraction distillation. Device for extraction distillation of the extract from the flow of raw material comprises the extraction distillation column, raw material flow supply line, solvent supply line, reboiler with internal steam distributor, connected with the extraction distillation column, water steam supply line, connected with the steam distributor, and water steam supply line from the extraction distillation column, connected with the internal steam distributor. The extract is an aromatic hydrocarbon. Reboiler is selected from the group consisting of the kettle boiler, thermosyphon reboiler and reboiler with forced circulation.

EFFECT: improvement of efficiency of extraction distillation.

10 cl, 1 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention refers to the method of separating and purification of 1,3-butadiene from the mixture consisting mainly of C4-carbohydrates and containing 1,3-butadiene and C4-carbohydrates that differ from the former by the number of unsaturated bonds and/or α-acetylene protons including at least (an) area(s) of extractive rectification with the polar extractant, denudation and ordinary rectification that is characterized by the fact that at least a polar spirit with the boiling point over 120°C is used as the mentioned extractant; stripping of C4-carbohydrates from the areas of extractive rectification and denudation of the mentioned extractant is performed under the high pressure from 3.5 to 6.5 at, at least into the lower part and/or into the boiler(s) of the extractive rectification area(s) the carbohydrate intermediate desorbent with the boiling point from 27 to 85°C is introduced in the amount that provides its content in the cube(s) of the high pressure denudation area(s) from 3 to 30 % weight; then the intermediate desorbent is stripped from the greater part of the extractant in the low pressure denudation area with 1.0-2.0 at; the extractant is fed back to the upper part of the extractive rectification area(s) and the intermediate desorbent to at least the mentioned point(s) of extractive rectification, and 1,3-butadiene undergoes additional purification from chemical impurities by means of rectification, supposedly with the small amount of extractant.

EFFECT: reduction of losses of 1,3-butadiene and improvement of the processing and economical efficiency.

10 cl, 3 tbl, 3 ex, 3 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing pure 1-butene from C4 hydrocarbon fractions primarily containing 1-butene, 2-butene, and butane(s) with a 1,3-butadiene and isobutene impurity, involving preparation of a mixture primarily containing 2-butenes via rectification, catalytic isomerisation of 2-butenes into 1-butene and extraction of 1-butene via rectification, characterised by that at least catalysed isomerisation of 1-butene into 2-butene in said fraction is carried out at temperature lower than 120°C, as well as rectification with continuous removal of isobutane, isobutene and 1,3-butadiene in the distillate and obtaining a residual stream primarily containing 2-butene and n-butane, in which rectification conditions are maintained such that concentration of 1,3-butadiene and isobutene with respect to the sum of 2-butene is not higher than standard limits in the desired 1-butene. A large portion of n-butane is separated from the residual stream via extractive rectification with a polar agent and catalysed isomerisation of 2-butenes to 1-butene is carried out at temperature higher than 120°C, while continuously extracting the formed 1-butene via rectification.

EFFECT: high efficiency of the method.

14 cl, 5 ex, 4 tbl, 2 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of separating isopentane-isoamylene-isoprene-containing hydrocarbon fractions or butane-butylene-divinyl hydrocarbon fractions obtained at the first step of two-step dehydrogenation of corresponding paraffin hydrocarbons, involving separation of paraffin-olefin-diene fraction obtained at the first dehydrogenation step through extraction rectification, and is characterised by that a vapour stream is extracted from a desorber via lateral collection, where the said vapour stream contains large amount of diene, and after condensation, said stream is taken for extraction of the diene end product at the second extraction rectification step, and an olefin fraction which does not contain diene is collected from the top of the desorber and taken to the second dehydrogenation step.

EFFECT: use of said method increases output of the end product.

1 cl, 2 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to peptides which originate from an antigen recognised by autoantibodies used for diagnosing rheumatoid arthritis. The peptides are filaggrin molecule fragments which contain modified residues of arginine and having amino acid sequences given in the formula of invention. The invention discloses a method of diagnosing rheumatoid arthritis by detecting autoimmune antibodies using the said peptide(s) through reaction of the latter with the blood serum of patients suffering from rheumatoid arthritis. Presence of autoimmune antibodies in the analysed sample is indicated by presence of peptide complexes formed with the antibody.

EFFECT: disclosed peptide has high specificity and sensitivity.

4 cl, 1 dwg, 3 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to a method of extracting benzene from mixtures with non-aromatic hydrocarbons, simultaneously obtaining distillate through extractive rectification, characterised by that the selective solvent used is in form of mixtures containing 14.7-48.5 wt % sulfolane or N-formylmorpholine and 48.5-83.3 wt % methylpyrrolidone, containing 2-3 wt % water.

EFFECT: use of given method allows for obtaining benzene, toluene and distillate containing not more than 1-1,5 vol. % benzene, which can be used as a component of motor car fuel or as raw material for pyrolysis process.

1 cl, 1 ex, 4 tbl, 2 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of separating alkane and alkene fractions, possibly containing alkadiene impurities, using extraction rectification in the presence of polar extraction agent(s), wherein the basic amount of alkanes comes out in a distillate stream, and the basic amount of alkenes comes out in a strippant stream distilled from the extraction agent. The method is characterised by that before extraction rectification, the larger part of 1-alkene(s) in the alkane and alkene fractions is isomerised and/or hydroisomerised to 2-alkene(s) at temperature not above 100°C in the presence of heterogeneous catalyst(s) with activity during positional isomerisation of alkene, and possibly a small amount of polar substance which does not deactivate the catalyst(s).

EFFECT: more efficient separation of alkane and alkene mixtures through extraction rectification.

11 cl, 13 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: method includes supply of initial mixture and dimethylsulfoxide (DMSO) as separating agent, taken in ratio 7-7.5:1 to initial mixture, into extraction rectification column (1) efficiency 50 t.t., initial mixture being supplied on 30 t.t., separating agent on 10 t.t. of column (plate numeration from top of column), phlegm number in column constitutes 1.5-2, taking of benzol in distillate and mixture benzol-perfluorobenzol (PFB) - tertiary amyl alcohol (TAA)-DMSO from column (1) cube , supply of mixture PFB-TA-DMSO on 25 t.t. of column of separating agent regeneration (2) with efficiency 50 t.t., phlegm number in column being 1-3, removal separating agent from column cube and its supply to column (1), supply of column (2) distillate, representing aseotropic mixture PFB-TAA, for separation into complex of two columns (3) and (4) with efficiency 35 t.t., with removal from column cubes of TAA and PFB, respectively, aesotropic mixture being supplied on 18 t.t. of column (3), phlegm numbers of columns (3) and (4) being equal 0.5-1.5 and 1-2 respectively, re-cycle of aseotrope PFB-TAA, which is separated in distillate of column (4) into column(3) feeding, ratio of re-cycle of column (4) and feeding of column (3) being (1-1.1):0.66, pressure in columns (1)-(3) is 300 mm of mercury, pressure in column (4) - 760 mm of mercury.

EFFECT: simplification of technology, increase of ecological compatibility of process and quality of obtained products.

1 tbl, 1 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of stabilising organochlorine solvents selected from perchloroethylene, trichloroethylene, dichloroethylene and chloroform, in which the stabiliser is used in amount of 0.01-1.0% of the weight of the stabilised organochlorine solvent. The stabiliser used is epoxidated soya bean oil, or a stabilising system consisting of 95.55-98.90 wt % epoxidated soya bean oil, 0.10-0.40 wt % urotropin, 1.00-4.00 wt % ethanol and 0.00-0.10 wt % epichlorohydrin, or a stabilising system consisting of 50.0-96.0 wt % epoxidated soya bean oil and 4.0-50.0 wt % ethanol.

EFFECT: highly efficient stabilisation of organochlorine solvents, availability and low cost of stabiliser components and relatively low environmental hazard.

10 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to a method of inhibiting premature polymerisation of styrene monomers involving addition of the following combinations to the said monomers: (A) 0.001 to 10 wt % of a sulfonic acid compound having the following structure: , where R is a hydroxyl group, a straight or branched alkyl group having 1 to 32 carbon atoms or an alkylphenyl or alkylnaphthyl group, each having at least one straight or branched alkyl group having 1-32 carbon atoms; and (B) at least one amine selected from a group consisting of triethylamine, diethylamine, tributylamine, pyridine, N-(1,4-dimethylpentyl)aniline or N-methylpyrrolidinone in concentration of 0.1 to 2.0 molar equivalents per molar equivalent of the said sulfonic acid compound. The invention also relates to a composition for inhibiting premature polymerisation of styrene monomers.

EFFECT: design of a method through which uncontrolled exothermic reaction between the said sulfonic acid compound and the said styrene monomers can be prevented.

11 cl, 11 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a styrene inhibitor composition containing N,N-dimethyl-3,5-di-tert-butyl-4-hydroxybenzylamine, C7-C17 saturated carboxylic acid, characterised by that, it additionally contains an unsaturated carboxylic acid with the following ratio of components in wt %: N,N-dimethyl-3,5-di-tert-butyl-4-hydroxybenzylamine 66.7-33.3, C7-C17 saturated carboxylic acid 30-6.6, unsaturated carboxylic acid 3.3-60.

EFFECT: use of the polymerisation inhibitor enables to reduce polymerisation of styrene due to reduction of the amount of thermopolymer formed from 1,13 wt % to 0 wt % with less consumption of the inhibitor.

1 cl, 36 ex, 1 tbl

FIELD: natural substances, chemical technology.

SUBSTANCE: invention relates to a method for preparing chitosan and purification from components of the reaction mixture - low-molecular products of deacetylation and alkali excess. Invention relates to a method for purifying chitosan prepared by solid-state method involving treatment of reaction mass with extractant consisting of 3.3-20.0% of water, 32.2-57.1% of ethyl acetate and 24.6-64.5% of ethanol at the extractant boiling point. Also, invention relates to a method for purifying chitosan prepared by suspension method and involving treatment of the reaction mass with ethyl acetate and the following treatment with extractant consisting of 6.2-25.0% of water, 12.5-62.5% of ethyl acetate and 31.3-62.5% of ethanol at the extractant boiling point.

EFFECT: improved isolating and preparing method.

3 cl, 2 tbl, 1 dwg

The invention relates to a method of producing crystallization dicarboxylic acids from a solution containing not less than one organic dicarboxylic acid, by adding to the solution until crystallization or during crystallization, at least one anionic polyelectrolyte with a molecular weight of at least 2,000, preferably from 100000 to 500000, in the amount of from 0.01 to 200 h

FIELD: chemistry.

SUBSTANCE: method of separating a zeotropic mixture of butyl propionate and propionic acid, components of which have relative volatility close to one, includes separating said mixture by extraction rectification using sulpholane as the parting agent, taken in ratio of 1:6-7 to the starting mixture in an extraction rectification column with efficiency of 40-50 theoretical plates, wherein the reflux ratio in the column is equal to 2-3, followed by collection of butyl propionate in the distillate and the mixture of propionic acid and supholane in the bottom of the column (1); the mixture of propionic acid and sulpholane is then fed into a column for regenerating the parting agent (2) with efficiency of 8 theoretical plates and reflux ratio equal to 0.8-1; the parting agent is removed from the bottom of the column (2) and fed into column (1). Pressure in column (1) is equal to 760 mmHg and pressure in column (2) is equal to 100 mmHg.

EFFECT: simple technique, low capital costs and high quality of the obtained products.

1 dwg, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to versions of a method for the extraction of styrene and support of an extraction solvent efficiency in a system for styrene extraction from a styrene-enriched raw material. One of the versions includes the following stages: (a) supply of the styrene-enriched raw material into an extraction distillation column, (b) discharge of the styrene-enriched flow from the extraction distillation column, with the styrene-enriched flow containing styrene and an extraction solvent; (c) supply of the styrene-enriched raw material into the column for the solvent separation, d) discharge of the styrene-depleted flow from the column for the solvent separation, with the quantity of styrene in the styrene-depleted flow being lower than in the styrene-enriched flow; e) separation of a part of the styrene-depleted flow, f) bringing a part of the styrene-depleted flow in contact with an organic solvent in an equilibrium liquid-liquid system, which has several equilibrium stages, with the formation of a washed extraction solvent, containing the light organic phase and the heavy organic phase, with the light organic phase passing to the following equilibrium stage and the heavy organic phase returning to the first equilibrium stage; and g) recycling the washed extraction solvent back to the extraction distillation column.

EFFECT: method makes it possible to use solvents in a rational way.

17 cl, 4 dwg

FIELD: power engineering.

SUBSTANCE: invention is intended for extraction distillation. Device for extraction distillation of the extract from the flow of raw material comprises the extraction distillation column, raw material flow supply line, solvent supply line, reboiler with internal steam distributor, connected with the extraction distillation column, water steam supply line, connected with the steam distributor, and water steam supply line from the extraction distillation column, connected with the internal steam distributor. The extract is an aromatic hydrocarbon. Reboiler is selected from the group consisting of the kettle boiler, thermosyphon reboiler and reboiler with forced circulation.

EFFECT: improvement of efficiency of extraction distillation.

10 cl, 1 dwg, 1 ex

FIELD: chemistry.

SUBSTANCE: method of inhibiting polymerisation of vinyl aromatic compounds during extractive distillation includes the following steps: a) providing a mixture containing styrene; b) adding one 2-sec-butyl-4,6-dinitrophenol (DNBP) inhibitor to the mixture; and c) performing extractive distillation of the mixture after step b) to of separate styrene; d) forming less than 200 ppmw of a polymer from the styrene.

EFFECT: minimum polymer formation.

5 cl, 1 tbl, 1 ex

FIELD: chemistry.

SUBSTANCE: to separate a biazetropic mixture butylpropionate-propionic acid used is a method of extractive rectification with application as a separating agent of sulpholane (SF), taken in ratio 1:5-6 to an initial mixture in a column of extraction rectification with efficiency 35-50 t.t., with reflux ratio in the column being 1-3. Withdrawal of butylpropionate in distillate and the mixture propionic acid-sulpholane in the column bottom is carried out. After that, the mixture PC-SF is supplied to the column of the separating agent regeneration with efficiency 8 t.t., value of reflux ratio is 0.5-1.0. The separating agent is withdrawn from the column bottom and supplied into the column. Pressure in the columns constitutes 100 mm Hg. The method makes it possible to obtain the target products (BP, PA) of a specified quality - 99.5 mol%.

EFFECT: simplification of technology and reduction of capital expenditure, increased quality of obtained products.

1 dwg, 1 tbl

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