How hydroxycarbonylmethyl one or more pentenoic acid to adipic acid
(57) Abstract:The subject of the invention is a method of hydroxycarbonate pentenoic acid to adipic acid using carbon monoxide and water in the presence of a catalyst based on iridium and/or rhodium and at least one IDataReader promoter, the reaction mixture is subjected to the refining process, if necessary after concentration, allowing to separate at least a portion of the expensive catalyst thus separated catalyst recycle in the process hydroxycarbonylmethyl pentenoic acids, butadiene or butadiene derivatives. 11 C.p. f-crystals. The invention relates to a method of catalytic hydroxycarbonylmethyl pentenoic acid to adipic acid.There is a method of producing adipic acid by hydroxycarbonylmethyl one or more pentenoic acids, in particular 3-pentenol acid and 4-pentenol acid, with carbon monoxide and water, in the presence of a catalyst based on iridium, rhodium or mixtures thereof and IDataReader promoter. Usually the reaction is carried out in the liquid phase at a temperature of 50-300oC and at a partial pressure of m is t by crystallization, then part of her return to the stage of hydroxycarbonate, and the crystallized product release (WO A2 92/16476).However, the separation method of crystallization requires the establishment of appropriate heat transfer to obtain crystals of appropriate size, capable of drainage. In addition, the maximum yield of solid product of crystallization of not higher than 30-40%. All this requires instruments with significant and leads to the blocking of a large number of expensive catalyst.The present invention is to remedy these disadvantages by separation of the finished product, as well as in the implementation of the recycling catalyst hydroxycarbonate.This problem is solved by the proposed method of hydroxycarbonate one or more pentenoic acid to adipic acid using carbon monoxide and water in the presence of a catalyst based on iridium and/or rhodium and at least one IDataReader promoter with subsequent separation of the resulting reaction medium, which consists in the fact that the separation is carried out by refinement, if necessary, carried out after the concentration, which includes three stud is inovas acid and deposition of crystals on the walls of the apparatus at the stage of crystallization, Department of the remaining flowing fraction containing at least a portion of the catalyst in the second stage runoff and progressive heating of the precipitated on the walls of the apparatus crystals and their leaching in the third stage - the stage of drying to obtain the fraction of the drainage containing another portion of the catalyst and other components of the reaction mixture, thus separating at least a portion of the catalyst and recycle it to the stage of hydroxycarbonate.Under partenopei acid in the framework of the present invention understand 2-pontenova, 3-pontenova, 4-pontenova acid and mixtures thereof.It is particularly convenient to use 3-pontenova acid, individually or in a mixture of its isomers, as it is affordable and gives good results in the process of hydroxycarbonate.Used for the reaction of hydroxycarbonate the catalyst may be based on rhodium, iridium or the two metals.Suitable is any source of rhodium or iridium.As examples of sources of rhodium, which can be used, you can refer to the compounds mentioned in the European patent EP-A-O477112.As sources of iridium can be called, the>; IrBr3, 3H2O;
[Ir(Cl(cod)]2.(cod = cycloocta-1,5-diene, acac = acetylacetonate).The preferred iridium catalysts are: [Ir(Cl(cod)]2Ir4(CO)12and Ir(acac)(CO)2.According to the invention particularly preferred catalysts based on iridium or iridium and rhodium.The amount of catalyst can vary within wide limits.Typically, the amount, expressed in moles of the metal of iridium and/or metal rhodium per liter of the reaction mixture of 10-4- 10-1leads to satisfactory results. Can be used and smaller amounts, however, the reaction rate is negligible. Large number of feasible economically.Preferably the concentration of iridium and/or rhodium is 510-4- 10
In an autoclave equipped with stirring using autosizemode turbine, introducing of 2.45 g (7.3 mmol) of iridium in the form of [IrCl(cod)]2(3.3 mmol/l of the reaction mixture); 4,17 g (18,6 mol) HI in the form of aqueous 57%-aqueous solution (8.4 mmol/l); of 177.8 g (9.9 mol) of water (4.5 mmol/l) and 2084 g (20,84 mol) 3-pentenol acid (RA).The autoclave is connected to a gas supply under pressure, hermetically closed. Enter the CO cooling and under a pressure of 2 bar (0.2 MPa) and within 20 min, heated to 185oC through elektronagrevatel ring. When reaching this temperature, the set pressure of 20 bar (2 MPa).Follow the kinetics of the reaction by the absorption of CO associated with the reactor auxiliary reservoir, and the pressure in the autoclave remains constant.After the duration of the reaction, 30 min, which corresponds to the complete consumption of the introduced water, the reaction is stopped by cooling the reaction mixture. The autoclave Tegaserod and the reaction mixture is extracted in a liquid state at 120oC.The reaction mixture was analyzed by vapor chromatography and high performance liquid chromatography (HPLC).Get the following global acid (A-1) - 65
the output of methylglutaric acid (A2) - 11
output ethyl-succinic acid (A3) - 3
the output gamma valerolactone (VAL) - 11
output valerianic acid (Pa) - 2
the yield of 2-pentenol acid (P2) - 8
The linear coefficient, expressed as a ratio in percentage of the resulting A1 to the total aggregate formed digisat A1, A2 and A3, is 82%.The reaction rate (calculated for 20 min absorption CO) is 5.4 absorbed moles of CO per hour and per liter of reaction mixture.The reaction mixture is concentrated by distillation of the volatile products in the 90oC, at a pressure of 1 kPa; thus receive the mixture, which is subjected to the refining process.Example 2. Refining the concentrated reaction mixture obtained in example 1.Used machine is a metal cylinder with an inner diameter of 45 mm and a height of 65 cm, closed at its base pneumatic valve a small amount and is provided in its upper part screw cap, through which two temperature probe and the input of nitrogen.The entire apparatus is surrounded by a double jacket in which coolant is circulated at a controlled temperature.
adipic acid is of 66.00
2-methyl-glutaric acid - 11,20
2-methyl-succinic acid - 2,00
gamma valerolactone - 1,80
2-pontenova acid - 3,00
3-pontenova acid - 14,50
4-pontenova acid - 1,30
iridium (metal) - 0,0887
iodine - 0,1565
This reaction mixture in the liquid state at a temperature of 131oC is loaded into the apparatus at the same temperature.
adipic acid - 10,0
2-methyl-glutaric acid - 32,0
2-ethyl-succinic acid - 5,4
gamma valerolactone - 8,4
2-pontenova acid - 7,9
3-pontenova acid and 33.5
4-pontenova acid - 2,5
iridium (metal) - 0,210
iodine - 0,370
adipic acid - 48,0
2-methyl-glutaric acid - 19,5
2-ethyl-succinic acid - 3,3
gamma valerolactone - 4,8
2-pontenova acid - 5,5
3-pontenova acid - 18,5
4-pontenova acid - 0
iridium (metal) - of 0.133
iodine - 0,228
adipic acid is 95.8
2-methyl-glutaric acid - 2,2
2-ethyl-succinic acid - 0
gamma valerolactone - 0
2-pontenova acid - 0
3-pontenova acid - 2,0
4-pontenova acid - 0
iridium (metal) - 0,0149
iodine - 0,0264
The raffinate, therefore, contains 76% of adipic acid and only 9% of iridium and iodine present in the reaction mixture originating from the reaction of hydroxycarbonate.Flowing fraction contains 45% of iridium and iodine and 3% adipic kissela, plums, consisting in the aggregate from flowing faction and faction drainage contains 91% of iridium and iodine with 24% of adipic acid from the reaction mixture. Various separating and raffinate allow either to minimize the amount of adipic acid that is present in the discharge, or to increase the degree of recovery of iridium and iodine according with the advantage of the criterion of separation.Example 3. Recirculation in response hydroxycarbonylmethyl flowing fraction obtained in example 2,
Recycle 100 g flowing fraction obtained in example 2. To it was added 3-pontenova acid and water in order to have an initial reaction mixture with the same concentration of iridium and HI, the original mixture used in example 1, i.e., 3,3 mmol/l iridium and 8.5 mmol/l HI.The concentrations of other components in the initial mixture the following: 7 mmol/l P3; 0.2 mmol/l P2; 0.04 mmol/l P4; 0.24 mmol/l VAL; 0.18 mmol/l A1; 0.6 mmol/l A2; 0.1 mmol/l A3; 4,2 mmol/l of water.Hydroxycarbonylmethyl carried out as described in example 1. After reaction for 40 min, which corresponds to the expenditure entered the water, the autoclave is cooled and analyze various components of the final reaction mixture.Recip is Teal-glutaric acid (A2) - 13
output ethyl-succinic acid (A3) - 3
the output gamma valerolactone - 9
output valerianic acid (Pa), 3
the yield of 2-pentenol acid (P2) - 7
The linear coefficient is expressed by the ratio of percentage content of the formed A1 to the total aggregate formed digisat A1, A2 and A3, is 80%.The reaction rate (calculated for 20 min absorption CO) is 4,4 absorbed moles of CO per hour and per liter of reaction mixture. Kinetics of order 1 with respect to P3 suggests, therefore, have the activity of the catalyst, identical to the one observed in example 1 (amount absorbed CO/number of loaded P3). 1. How hydroxycarbonylmethyl one or more pentenoic acid to adipic acid using carbon monoxide and water in the presence of a catalyst based on iridium and/or rhodium and at least one IDataReader promoter with subsequent separation of the resulting reaction medium, characterized in that the separation of the reaction medium is carried out, if necessary, after concentration, through refining, which includes three stages, namely adjustable and progressive cooling of the reaction mixture with postsale, Department of the remaining flowing fraction containing at least a portion of the catalyst in the second stage runoff and progressive heating of the precipitated on the walls of the apparatus crystals and their leaching in the third stage - the stage of drying to obtain the fraction of the drainage containing another portion of the catalyst and other components of the reaction mixture, thus separating at least a portion of the catalyst and recycle it at the stage of hydroxycarbonate.3. The method according to p. 1, characterized in that the refining process to separate at least 40 wt.% the catalyst contained in the reaction mixture, preferably at least 80 wt.%.3. The method according to p. 1 or 2, characterized in that the after hydroxycarbonylmethyl the reaction mixture before refining concentrate to remove at least part of the most volatile compounds that it contains.4. The method according to p. 3, characterized in that the concentrate of the reaction mixture, which is directed at the stage of refining, is 10 to 90 wt.% by weight of the reaction mixture originating from the process hydroxycarbonate.5. The method according to PP.1 to 4, characterized in that hydroxycarbonylmethyl assistancee acid with the number of carbon atoms is less than 20, saturated aliphatic or cycloaliphatic hydrocarbons and their halogenated derivatives of aromatic hydrocarbons and their halogenated derivatives and simple aliphatic, aromatic or mixed ethers.6. The method according to PP.1 to 4, characterized in that hydroxycarbonylmethyl carried out in the environment pentenoic acids.7. The method according to PP.1 - 6, characterized in that the adjustable and progressive cooling of the reaction mixture is carried out in the interval from the initial temperature at least equal to the crystallization temperature of the mixture and preferably in the range from the crystallization temperature to a temperature at which conduct hydroxycarbonylmethyl, to a final temperature that is greater than or equal to the melting temperature of the eutectic components of the reaction mixture.8. The method according to p. 1, characterized in that the initial temperature of the refining is 100 - 200oC and the final temperature 0 - 70oC.9. The method according to p. 1, characterized in that the stage of drying is carried out by heating at a temperature in the range from finite temperature phase runoff to 150oC, preferably at a temperature in PR which is 1 - 30 PM11. The method according to p. 1, characterized in that the fraction obtained after stage runoff, recycle on stage hydroxycarbonate.12. The method according to p. 1, characterized in that the fraction obtained in the stages of runoff and drainage, recycled to the stage of hydroxycarbonate.
FIELD: industrial organic synthesis.
SUBSTANCE: subject of invention is continuous carbonylation of long-chain aliphatic hydrocarbons to produce alcohols, acids, and other oxygen-containing products such as esters. Process comprises paraffin dehydrogenation, carbonylation, and fraction distillation-mediated end product recovery. Advantageously, mixture of paraffins containing different number of carbon atoms isolated from kerosene fraction is processed. Non-converted paraffins are recycled into dehydrogenation zone. Prior to be fed into carbonylation zone, stream is processed by selectively hydrogenating diolefins. In the carbonylation stage, homogenous catalytic system is used containing palladium/imidazole or palladium/triphenylphosphine complex, aliphatic acid (preferably formic acid), and solvent. Catalytic system further includes promoter selected from group: lithium iodide, zirconium chloride, tin chloride, and lithium bromide.
EFFECT: simplified technology, increased conversion of raw materials and selectivity in formation of desired products.
14 cl, 2 dwg, 1 tbl, 11 ex
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for synthesis of saturated aliphatic carboxylic acids with stable carbon isotopes (1-13C). Method involves the hydrocarboxylation reaction of α-olefins with carbon monoxide (13CO) and water at temperature 100-170°C and under pressure not exceeding 5 MPa in the presence of a solvent and catalytic system containing palladium compound as complex PdCl2(PPh3)2 and triphenylphosphine PPh3 taken in the ratio from 1:2 to 1:100, respectively. Synthesized carboxylic acids can be used as diagnostic test-preparations in medicine practice and in criminology, scientific investigations and in other fields. Invention provides synthesis of enanthic acid and caprylic acid labeled by stable carbon isotope 13C at position 1 for a single step, to increase yield of acids as measured for isotope raw, to decrease cost price of acids and to obtain derivatives of (1-13C)-caprylic acid - (1-13C0-caprylate sodium and (carboxy-13C)-trioctanoine.
EFFECT: improved methods of synthesis.
9 cl, 6 ex
SUBSTANCE: present invention relates to a new catalyst system, a new carbonylation reaction medium and to a method of carbonylation of ethylene-unsaturated compounds using the new catalyst system. The catalyst system, which is capable of catalysing carbonylation of an ethylene-unsaturated compound, can be obtained by combining: a) group VIIIB metal, or its compound, b) bidentate phosphinic or arsinic ligand and c) acid, where the said ligand is present in molar excess of at least 2:1, compared to the said metal or said metal in its compound, and the said acid is present in molar excess ranging from 5:1 to 95:1, compared to the said ligand. In another version the catalyst system, which is capable of catalysing carbonylation of an ethylene-unsaturated compound, can be obtained by combining: a) group VIIIB metal, or its compound, b) bidentate phosphic or arsinic ligand and c) acid, where molar ratio of the said ligand to the said metal or said metal in its compound lies in the range greater than 5:1 to 750:1, and the said acid is present in molar excess of at least 2:1, compared to the said ligand.
EFFECT: invention also relates to a method of carbonylation of an ethylene-unsaturated compound, a reaction medium, use of catalyst a system and a complex, which is capable of catalysing carbonylation of an ethylene-unsaturated compound.
39 cl, 35 ex, 9 tbl, 3 dwg
SUBSTANCE: invention relates to a method for synthesis of 1-13C-caprylic acid which is used as a diagnostic preparation when diagnosing motor-evacuation functions of the stomach. The method involves hydrocarboxylation reaction of 1-heptene with carbon monoxide 13CO and water at temperature 100-170°C and pressure not above 5 MPa, in the presence of a solvent and a catalyst system which contains a complex compound of palladium and triphenylphosphine in ratio ranging from 1:2 to 1:100, where the solvent used is dioxane and/or aromatic hydrodrocarbon.
EFFECT: obtaining 1-13C caprylic acid with high isotope purity, increased cost-effectiveness of the process owing to increased degree of utilisation of isotope material.
5 cl, 9 ex
SUBSTANCE: invention relates to an improved method of producing oxalic acid, involving feeding carbon dioxide through 1.0-13.0 M aqueous trifluoroacetic acid solution which is saturated with oxygen at temperature of 15-25°C and atmospheric pressure. Oxalic acid is separated by evaporating the obtained product. The invention can be used in chemical industry.
EFFECT: method which enables to produce oxalic acid in a single step at room temperature and atmospheric pressure.
2 cl, 2 ex
SUBSTANCE: invention relates to production of palladium catalysts, which can be used for hydrogenating organic electrolytes with unsaturated C-C bonds in molecules, in particular, for selective hydrogenation of maleic acid into succinic acid in aqueous medium. Catalyst is palladium nanoparticles with size of 1.2-5 nm, applied amount of 0.1-2.5 wt% per powder supports of various chemical nature (Al2O3, SiO2, TiO2, ZrO2, Sibunit), having relatively low specific surface area of 2-455 m2/g, which minimises effect of diffusion of reagents, caused by existence of adsorbed solvate layers and double electric layer on surface of support, on rate of catalytic process. Required dispersed state of palladium nanoparticles is achieved by that hydrolytic precipitation of palladium on a support from solutions of H2PdCl4 is carried out at pH 9-9.5 directly in presence of support with further liquid-phase reduction of catalyst, which enables to achieve higher dispersion of applied metal due to complete hydrolysis of complexes of palladium chloride and reducing ageing time of formed hydro complexes in solution as a result of their fast adsorption on support.
EFFECT: technical result is high activity and selectivity of obtained catalysts for hydrogenation of maleic acid into succinic acid in aqueous medium in mild conditions.
5 cl, 2 dwg, 1 tbl, 15 ex
SUBSTANCE: two-stage continuous process of preparing propionic acid is provided; it comprises the step of hydrogenating the carbon dioxide in the synthesis gas in the presence of a catalyst comprising cobalt metal on the support as organometallic framework MIL-53 structure (Al), and a step of hydroxycarbonylation of ethylene with carbon monoxide and water in the presence of hydroxycarbonylation catalyst, which is a metallic rhodium on a carrier in the form of organometallic framework MIL-53 structure (Al), and the process is conducted in a flow 2- tray reactor at a pressure of 40-80 atm by contacting the fixed catalyst bed located on the top shelf and the reactor heated to a temperature of 500°C, with a raw material mixture of H2 and CO2 at a volumetric feed rate of gas feedstock 500-1000 h-1, followed by mixing of the produced gas containing CO-H2-CO-H2O mixture heated to 500-520°C with cold ethylene fed into the inter-bed space and the resulting gas mixture at a ratio of CO:H2O:C2H4 close to 1:1:1 is fed to the lower shelf of the reactor and is contacted at a temperature of 140-200°C with the hydroxycarbonylation catalyst therein. The process is carried out at a volume ratio of H2:CO2 in the gas feedstock of 0.8-1.2, and use catalysts having a size of 2-4 nm metallic particles with a cobalt content of 10 wt % rhodium and 5-15 wt %.
EFFECT: propionic acid increase in the yield and selectivity of its formation, while simplifying the process technology and reducing energy consumption, provides a recycling method of the greenhouse gas.
3 cl, 3 dwg, 1 ex
SUBSTANCE: synthesis method by 13C-linoleic, 13C-linolenic, 14C-linoleic and 14C-linolenic acids includes the carbon dioxide condensation, marked by 14C or 13C, with the Grignard reagent, produced from 1-bromo-8.11-heptadecandiene (in case of linoleic acid) or from 1-bromo-8.11.14-heptadecanthriene (in the case of linolenic acid), carried out in the following sequence of steps: a - production of the Grignard reagent by the reaction of metallic magnesium with 1-bromo-8.11-heptadecandiene (in case of linoleic acid) or with 1-bromo-8.11.14-heptadecantriene (in case of linolenic acid) in the presence of metallic iodine; b - carboxylation of the Grignard reagent, produced at point a, for 5-15 min at temperature -20°C at constant stirring, carbon dioxide, marked by 14C or 13C, produced by the sulfuric acid of barium carbonate decomposition, marked by 14C and 13C, at the CO2 pressure of not more than 500 mm Hg. (maintaining by the drop metering of sulfuric acid); after stopping the pressure change in the system, the reaction flask is cooled with the liquid nitrogen in order to provide the quantitative transfer of the remaining in the system 14CO2 or 13CO2 in it, close the tap connecting the device to the CO2 source, and the reaction mixture is stirred for 15 minutes at the temperature -20°C with the purpose to fully incorporate the isotopically marked carbon dioxide into the product of the synthesis: linoleic or linolenic acid.
EFFECT: target products manufacture process acceleration, reduction of carbon dioxide losses, increase of its total chemical and radiation yield in comparison with the prototype, and elimination of the isotope-marked atoms distribution along the entire length of the acyl chain, the simplification and cheapening of the target products the linoleic and linolenic acids manufacture process, is ensured by the decrease in the duration, the increase of the radiation and chemical yield of the product along the source of the isotope in comparison with the prototype, the radioactive wastes release into the external environment is almost completely excluded, as its inclusion into the target product is approaching to the quantitative.
10 tbl, 2 ex, 4 dwg
FIELD: crystal growing.
SUBSTANCE: invention relates to adipic acid crystals and treatment thereof to achieve minimum crystal caking. Crystals are prepared by crystallization of adipic acid from aqueous medium or between treating it with aqueous solution. Crystals are then subjected to ripening stage, that is crystals are held at temperature between 10 and 80°C until content of exchangeable water in crystals falls below 100 ppm, while using an appropriate means to maintain ambient absolute humidity at a level of 20 g/m3. Renewal of ambient medium is accomplished by flushing crystal mass with dry air flow having required absolute humidity. Means to maintain or to lower absolute humidity contains moisture-absorption device placed in a chamber. Content of exchangeable water in crystals is measured for 300 g of adipic acid crystals, which are enclosed in tightly sealed container preliminarily flushed with dry air and containing 2 g of moisture absorbing substance. In chamber, temperature between 5 and 25°C is maintained for 24 h. Content of water will be the same as amount of water absorbed by absorbing substance per 1 g crystals. Total content of water exceeds content of exchangeable water by at least 20 ppm.
EFFECT: minimized caking of crystals and improved flowability.
13 cl, 5 ex
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to the improved method for isolating crystalline terephthalic acid comprising less 150 mas. p. p. per million (ppm) of p-toluic acid with respect to weight of terephthalic acid. Method involves the following steps: (1) preparing a solution containing from 10 to 35 wt.-% of dissolved terephthalic acid wherein from 150 to 1100 ppm of p-toluic acid is dissolved with respect to mass of terephthalic acid at temperature from 260°C to 320°C and under pressure providing maintaining the solution in liquid phase; (2) charge of solution from step (1) to crystallization zone comprising multitude amount of associated crystallizers wherein the solution is subjected for cooling at evaporation at the controlled rate by the moderate pressure and temperature reducing resulting to crystallization of terephthalic acid and wherein the solution pressure at the end of crystallization zone is equal to atmosphere pressure or lower; (3) condensation of solvent evaporated from crystallizers and recovering the condensed solution to the crystallization zone to place of descending flow from crystallizer wherein solvent is removed by evaporation, and (4) isolation of solid crystalline terephthalic acid comprising less 150 ppm of p-toluic acid with respect to the terephthalic acid mass by separation of the phase liquid-solid substance under atmosphere pressure. The advantage of method is preparing the end product in improved crystalline form and carrying out the process under atmosphere pressure or pressure near to atmosphere pressure.
EFFECT: improved method of crystallization.
3 cl, 1 dwg, 1 tbl, 2 ex
FIELD: chemical industry; methods of production of the purified crystalline terephthalic acid.
SUBSTANCE: the invention is pertaining to the improved method of production and separation of the crystalline terephthalic acid containing less than 150 mass ppm of the p-toluene acid in terms of the mass of the terephthalic acid. The method provides for the following stages: (1) loading of (i) para- xylene, (ii) the water reactionary acetic-acidic medium containing the resolved in it components of the oxidation catalyst, and (iii) the gas containing oxygen fed under pressure in the first zone of oxidation, in which the liquid-phase exothermal oxidization of the para-xylene takes place, in which the temperature and the pressure inside the first being under pressure reactor of the oxidization are maintained at from 150°С up to 180°С and from 3.5 up to 13 absolute bars; (2) removal from the reactor upper part of the steam containing the evaporated reactionary acetic-acidic medium and the gas depleted by the oxygen including carbon dioxide, the inertial components and less than 9 volumetric percents of oxygen in terms of the non-condensable components of the steam; (3) removal from the lower part of the first reactor of the oxidized product including (i) the solid and dissolved terephthalic acid and (ii) the products of the non-complete oxidation and (ii) the water reactionary acetic-acidic medium containing the dissolved oxidation catalyst; (4) loading of (i) the oxidized product from the stage (3) and (ii) the gas containing oxygen, into the second being under pressure zone of the oxidation in which the liquid-phase exothermal oxidization of the products of the non-complete oxidization takes place; at that the temperature and the pressure in the second being under pressure reactor of the oxidization are maintained from 185°С up to 230°С and from 4.5 up to 18.3 absolute bar; (5) removal from the upper part of the second steam reactor containing the evaporated water reactionary acetic-acidic medium and gas depleted by the oxygen, including carbon dioxide, the inertial components and less, than 5 volumetric percents of oxygen in terms of the non-condensable components of the steam; (6) removal from the lower part of the second reactor of the second oxidized product including (i) the solid and dissolved terephthalic acid and the products of the non-complete oxidation and (ii) the water reactionary acetic-acidic medium containing the dissolved oxidation catalyst; (7) separation of the terephthalic acid from (ii) the water reactionary acetic-acidic medium of the stage (6) for production the terephthalic acid containing less than 900 mass ppm of 4- carboxybenzaldehyde and the p-toluene acid; (8) dissolution of the terephthalic acid gained at the stage (7) in the water for formation of the solution containing from 10 up to 35 mass % of the dissolved terephthalic acid containing less than 900 mass ppm of the 4- carboxybenzaldehyde and the p-toluene acid in respect to the mass of the present terephthalic acid at the temperature from 260°С up to 320°С and the pressure sufficient for maintaining the solution in the liquid phase and introduction of the solution in contact with hydrogen at presence of the catalytic agent of hydrogenation with production of the solution of the hydrogenated product; (9) loading of the solution of the stage (8) into the crystallization zone including the set of the connected in series crystallizers, in which the solution is subjected to the evaporating cooling with the controlled velocity using the significant drop of the temperature and the pressure for initiation of the crystallization process of the terephthalic acid, at the pressure of the solution in the end of the zone of the crystallization is atmospheric or below; (10) conduct condensation of the dissolvent evaporated from the crystallizers and guide the condensed dissolvent back into the zone of the crystallization by feeding the part of the condensed dissolvent in the line of removal of the product of the crystallizer, from which the dissolvent is removed in the form of the vapor; and (11) conduct separation of the solid crystalline terephthalic acid containing less than 150 mass ppm of the p-toluene acid in terms of the mass of the terephthalic acid by separation of the solid material from the liquid under the atmospheric pressure. The method allows to obtain the target product in the improved crystalline form.
EFFECT: the invention ensures production of the target product in the improved crystalline form.
8 cl, 3 tbl, 2 dwg, 3 ex
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
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
SUBSTANCE: method of separating multi-atom alcohols, for instance, neopentylglycol and sodium formiate, includes evaporation and cooling of reaction mixture, addition of organic solvent, crystallisation of sodium formiate, separation of sodium formiate from saturated solution of multi-atom alcohol, for instance, by filtration, and crystallisation of multi-atom alcohol. Reaction mixture is evaporated until two liquid layers are formed, which are separated into light phase - water-multi-atom alcohol and heavy phase -water-salt, separated water-salt fraction of solution is cooled until sodium formiate contained in it in form of cryslallohydrate is crystallised, sodium formiate crystals are separated, and remaining mother-solution is returned to process head, to evaporation stage, then separated light phase - water-multi-atom alcohol is additionally evaporated until 70% of contained in it sodium formiate is crystallised, then cooled to 25-30°C and subjected to processing with organic solvent from line of single-atom saturated alcohols, for instance, methane, for removal of remaining admixtures, with further crystallisation of multi-atom alcohol from remaining mother-solution.
EFFECT: reduction of amount of used organic solvent, elimination of high-temperature stage of extraction, preservation of yield of pure target products.
2 cl, 2 dwg, 1 ex