WO2013037133A1 - Procédé de préparation d'acide méthacrylique et/ou de méthacrylates d'alkyle - Google Patents

Procédé de préparation d'acide méthacrylique et/ou de méthacrylates d'alkyle Download PDF

Info

Publication number
WO2013037133A1
WO2013037133A1 PCT/CN2011/079770 CN2011079770W WO2013037133A1 WO 2013037133 A1 WO2013037133 A1 WO 2013037133A1 CN 2011079770 W CN2011079770 W CN 2011079770W WO 2013037133 A1 WO2013037133 A1 WO 2013037133A1
Authority
WO
WIPO (PCT)
Prior art keywords
process according
carbon atoms
carboxylic acids
isolated
alcohol
Prior art date
Application number
PCT/CN2011/079770
Other languages
English (en)
Inventor
Hermann Siegert
Original Assignee
Evonik Roehm Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Evonik Roehm Gmbh filed Critical Evonik Roehm Gmbh
Priority to PCT/CN2011/079770 priority Critical patent/WO2013037133A1/fr
Publication of WO2013037133A1 publication Critical patent/WO2013037133A1/fr

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C67/00—Preparation of carboxylic acid esters
    • C07C67/08—Preparation of carboxylic acid esters by reacting carboxylic acids or symmetrical anhydrides with the hydroxy or O-metal group of organic compounds
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/42—Separation; Purification; Stabilisation; Use of additives
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/42—Separation; Purification; Stabilisation; Use of additives
    • C07C51/43—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation
    • C07C51/44—Separation; Purification; Stabilisation; Use of additives by change of the physical state, e.g. crystallisation by distillation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
    • C07C51/42—Separation; Purification; Stabilisation; Use of additives
    • C07C51/48—Separation; Purification; Stabilisation; Use of additives by liquid-liquid treatment
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C67/00—Preparation of carboxylic acid esters
    • C07C67/48—Separation; Purification; Stabilisation; Use of additives
    • C07C67/58—Separation; Purification; Stabilisation; Use of additives by liquid-liquid treatment

Definitions

  • the present invention relates to processes for preparing methacrylic acid and/or alkyl methacrylates by heterogeneous-catalytic partial oxidation of organic compounds.
  • methacrylic acid and/or alkyl methacrylates having 1 to 8 C atoms in the alkyl radical, more particularly methyl methacrylate (MMA), by heterogeneous-catalytic partial oxidation of isobutene and/or tert-butanol (TBA) in the gas phase has spread rapidly since 1982 especially in the Asiatic sphere.
  • methyl methacrylate (MMA) by heterogeneous-catalytic partial oxidation of isobutene and/or tert-butanol (TBA) in the gas phase has spread rapidly since 1982 especially in the Asiatic sphere.
  • methyl tert-butyl ether (MTBE) which is available in large quantities, and which is cleaved beforehand into isobutene and methanol by a separate, upstream process.
  • the methanol released in this procedure can be used again at least predominantly in the later esterification stage for the preparation of MMA.
  • the process is characterized generally by continuous operation.
  • the process has numerous advantages. As compared with the acetone cyanohydrin process, which is the otherwise most commonly operated conventional process, there is no need to use large and superstoichiometric amounts of concentrated sulphuric acid or to recycle it, a costly and inconvenient operation, for purification. Moreover, there is also no need for prussic acid, which has to be prepared separately and with special precautions on account of its toxicity.
  • a disadvantage is found to be the relatively low operational yield of only around 62% to 68% on a molar basis, depending on process configuration and oxidation catalysts used, which typically are based on specific knowledge on the part of the manufacturers concerned.
  • the process despite its above- identified advantages, is fairly marginal in competition, depending on raw-materials prices and product prices; in other words, when all of the production costs are added up, there is no particular advantage over the acetone cyanohydrin process, with its apparent cost and inconvenience, which has a 91 % to 93% molar operational yield.
  • By-products of the heterogeneously catalyzed partial oxidation in the gas phase are particularly oxidation products, beginning with CO/C0 2 and formaldehyde, and continuing through to higher-boiling compounds, such as phthalic acid, terephthalic acid and isophthalic acid. Unless they are gases, these by-products are found initially, in the course of operation, in the quench condensate of the off-stream from the heterogeneous-catalytic partial oxidation, this off-stream comprising predominantly water, and being recovered for the purpose of collecting the methacrylic acid produced. Some of this water is a product of the oxidation reactions. In addition, water is added to the reactant in order to stabilize the reaction mixture, or is added as fresh water as part of the quenching operation.
  • the crude methacrylic acid which is the initial target product, is typically extracted as selectively as possible from this quench condensate by means of liquid-liquid extraction.
  • the extractant used is typically heptane or a similarly boiling hydrocarbon, for example toluene, MMA or a mixture of these compounds.
  • the extractant is distilled off continually from this extract, for repeated use, and is passed back to the extraction.
  • the oxidation by-products described above are present, as is a residual fraction, not recovered in the preliminary stage, of the target or intermediate-target product, methacrylic acid.
  • This process wastewater on account of its very high organic components content of up to 20% by weight, is typically burnt in special combustion units.
  • One particular object was to reduce the high energy requirements for work-up and for the elimination of the by-products.
  • a further objective of the present invention may be seen as being that of specifying a process for preparing methacrylic acid and/or alkyl methacrylates which can be realized with particular simplicity and cost-effectiveness.
  • the process of the invention for preparing methacrylic acid and/or alkyi methacrylates can be realized in a particularly simple and cost-effective way.
  • the process of the present invention can be carried out in known units and on an industrial basis.
  • the process of the invention serves for the preparation of methacrylic acid and/or alkyi methacrylates having 1 to 8 C atoms in the alkyi radical by heterogeneous-catalytic partial oxidation of organic compounds in the gas phase.
  • Organic compounds which can be used for preparing methacrylic acid and/or alkyi methacrylates having 1 to 8 C atoms in the alkyi radical are known in the art. Among others, for example, it is possible to use isobutene and/or tert-butanol. Furthermore, methyl tert-butyl ether (MTBE), which is available in large quantities, can be used as well, being cleaved beforehand into isobutene and methanol in a separate, upstream process. The methanol released in this operation can be used again at least predominantly in the later esterification stage for the preparation of MMA.
  • the process is characterized generally by continuous operation.
  • methacrylic acid is obtained first of all, and can be esterified in further process steps, in which case, preferably, alcohols having 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms, can be used, such as, for example, methanol, ethanol, n-propanol, isopropanol, butanol, pentanol, hexanol, cyclohexanol, heptanol and octanol.
  • alcohols having 1 to 8 carbon atoms more preferably 1 to 4 carbon atoms
  • At least one carboxylic acid having 2 to 5 carbon atoms is isolated from the wastewater stream produced in this process.
  • the methacrylic acid produced is recovered generally from what is called a quench condensate, comprising predominantly water.
  • the crude methacrylic acid which is the initial target product is extracted as selectively as possible by means, for example, of liquid-liquid extraction.
  • the extractant used is typically heptane or a similarly boiling hydrocarbon, such as toluene, MMA or a mixture of these compounds.
  • the wastewater stream for the purposes of the invention is the water phase from which a large part of the crude methacrylic acid has been removed (extraction raffinate).
  • At least one carboxylic acid having 2 to 5 carbon atoms is isolated from this wastewater stream.
  • These carboxylic acids include acetic acid, propanoic acid, butanoic acid and/or pentanoic acid.
  • the process of the invention permits in this case the isolation of the individual carboxylic acids or mixtures of these carboxylic acids.
  • the carboxylic acids can be isolated directly, particularly as a mixture.
  • the carboxylic acids can also be isolated as esters.
  • the carboxylic acids may first be separated from the water phase and concentrated, in order to shift the equilibrium of the reaction in the direction of the ester.
  • Particularly suitable esters derive more particularly from alcohols having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms. Linear, branched or cyclic alcohols may be used in this reaction.
  • These alcohols include more particularly methanol, ethanol, n-propanol, isopropanol, butanol, pentanol, hexanol, cyclohexanol, heptanol and octanol.
  • the esterification is widely known per se and is set out in Ullmanns's Encyclopaedia of Industrial Chemistry, Fifth Edition, for example.
  • an extraction can be carried out.
  • a liquid-liquid extraction can be carried out, the selected extractant being isolated from the carboxylic acids and higher-boiling accompanying compounds by means of a distillation procedure, and returned to the liquid- liquid extractor.
  • hydrophobic organic solvents such as, for example, alcohols, ketones, aldehydes, esters, ethers, hydrocarbons and mixtures of these solvents with one another and also with further solvents.
  • hydrophobic solvent implies that the miscibility of this solvent with water ought to be extremely low.
  • the extractant ought to be able to accommodate an extremely high fraction of by-products from the wastewater from the preparation of methacrylic acid. These by-products in some cases have a high fraction of polar groups.
  • the alcohols which can be employed as extractants include, among others, alcohols having 4 or more carbon atoms, preferably 4 to 12 and more preferably 4 to 9 carbon atoms.
  • the alcohols may have a linear, branched or cyclic structure.
  • the alcohols may comprise aromatic groups or substituents, such as halogen atoms.
  • These alcohols comprise, for example, 1 -butanol, 2-butanol, isobutyl alcohol and other C 4 alcohols; 1 -pentanol, isoamyl alcohol, tert-amyl alcohol, 2-pentanol and other C 5 alcohols; 1 -hexanol, 2-methyl-1 -pentanol, 3-methyl-1 -pentanol, 2,2-dimethyl-1 -butanol, 2-ethyl-1 -butanol, 4-ethyl-1 -pentanol, 2-hexanol, 3-hexanol, 3-methyl-2-pentanol, 2,3-dimethyl-2-butanol, 2-methyl-3-pentanol, 3-methyl-3- pentanol, 4-methyl-2-pentanol, 2-methyl-2-pentanol and other C 6 alcohols; n-heptyl alcohol, 2-methyl-1 -hexyl alcohol, 3-methyl-1 -hex
  • the ketones which can be used as extractants include, for example, methyl ethyl ketone, diethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl butyl ketone, methyl 1 - methylpropyl ketone, methyl-2-methylpropyl ketone, ethyl propyl ketone and other ketones having 4 or more carbon atoms, preferably 4 to 12 and more preferably 4 to 9 carbon atoms.
  • aldehydes which can be used as extractants include, for example, butyraldehyde, valeraldehyde, benzaldehyde and other aldehydes having 4 or more carbon atoms, preferably 4 to 12 and more preferably 4 to 9 carbon atoms.
  • the ethers which can be used as extractants include, among others, diethyl ether, di-n- propyl ether, diisopropyl ether, di-n-butyl ether, diisobutyl ether and other ethers having 4 or more carbon atoms, preferably 4 to 12 and more preferably 4 to 9 carbon atoms.
  • Extractants which can be used include, for example, aliphatic, alicyclic and aromatic hydrocarbons. These hydrocarbons include, among others, pentane, hexane, more particularly n-hexane and 3-methylpentane, heptane, more particularly n-heptane and 3- methylhexane, octane, cyclopentane, cyclohexane, benzene, toluene, xylene and ethylbenzene.
  • hydrocarbons include, among others, pentane, hexane, more particularly n-hexane and 3-methylpentane, heptane, more particularly n-heptane and 3- methylhexane, octane, cyclopentane, cyclohexane, benzene, toluene, xylene and ethylbenzene.
  • esters have 2 to 5 carbon atoms in the acid residue and 1 to 8 carbon atoms in the alcohol residue. They include more particularly esters of ethanoic acid, propanoic acid, butanoic acid and pentanoic acid, such as, for example, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, pentyl acetate, hexyl acetate, octyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, pentyl propionate, hexyl propionate, octyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, pentyl butyrate, hexyl butyrate and octyl butyrate, with ethy
  • the extractant preferably has a boiling point in the range from 10 to 200 °C, more preferably in the range from 20 to 120°C and very preferably in the range from 40 to 90 °C under atmospheric pressure (1024 mbar).
  • the pressure at which the extraction for removing the carboxylic acids or carboxylic esters from the wastewater stream can be carried out is not critical. Hence the extraction may take place under subatmospheric, superatmospheric or atmospheric pressure. This extraction is preferably carried out under a pressure in the range from 0.02 to 10 bar, more preferably under a pressure in the range from 0.5 to 2 bar.
  • the extraction can be carried out in a wide temperature range.
  • the extraction takes place preferably at a temperature in the range from 0 °C to ⁇ ⁇ ' ⁇ , more preferably in the range from 10 to 90 °C and very preferably in the range from 20 °C to 50 °C.
  • This apparatus may feature, for example, bubble columns, packed columns, pulsed columns, columns with rotating internals and/or mixer-settler batteries.
  • distillation procedures For the purpose of removing the carboxylic acids and the higher-boiling organic compounds from the extractant it is possible to employ distillation procedures, which may take the form of a simple distillation or special variants.
  • the special variants include, in particular, rectification, also called countercurrent distillation.
  • the carboxylic acids having 2 to 5 carbon atoms can be separated from higher-boiling accompanying components by means of at least one distillation procedure, more particularly by rectification.
  • the higher-boiling accompanying components separated from the carboxylic acids and/or carboxylic acid derivatives may be passed on preferably for thermal utilization by combustion.
  • carboxylic acids having 2 to 5 carbon atoms may be separated by means of rectification procedures. This may take place directly or after partial or complete esterification of these carboxylic acids with an alcohol having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms. It is possible here to use linear, branched or cyclic alcohols.
  • These alcohols include more particularly methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, pentanol, hexanol, cyclohexanol, heptanol and octanol, with methanol, ethanol, n-butanol or isobutanol being preferred.
  • the esters obtained in this way can be separated by rectification procedures.
  • the distillation conditions are guided by factors including the carboxylic acids present in the wastewater stream, the intended separation efficiency, the apparatus used, and the alcohols used optionally for the esterification. Correspondingly, these conditions may lie within a wide range, and optimization is a very simple matter to the skilled person.
  • the distillation may be carried out at subatmospheric, superatmospheric or atmospheric pressure.
  • the distillation procedures as for example the rectification procedures, are carried out advantageously under a pressure in the range of 0.002-5 bar, more particularly 0.02 to 3 bar and more preferably 0.1 to 0.5 bar.
  • the distillation plants used preferably in the present process comprise, in particular, customary stills and special embodiments, examples being rectifiers. These distillation plants are general knowledge, and these plants may generally comprise columns having one or more separating stages.
  • the number of separating stages for the purposes of the present invention means the number of trays in the case of a tray column, or the number of theoretical plates in the case of a column containing ordered packing or a column with random packing elements.
  • Examples of a multi-stage distillation column with trays include those such as bubblecap trays, sieve trays, tunnel-cap trays, valve trays, slotted trays, sieve-slotted trays, sieve- bubblecap trays, nozzle trays, centrifugal trays;
  • examples of a multi-stage distillation column with random packing elements include those such as Raschig rings, Lessing rings, Pall rings, Berl saddles and Intalox saddles;
  • examples of a multi-stage distillation column with ordered packing include those of the Mellapak (Sulzer), Rombopak (Kuhni) and Montz-Pak (Montz) types and also packings with catalyst pockets, an example being Kata-Pak.
  • a distillation column with combinations of regions of trays, of regions of random packing elements or of regions with ordered packings may also be used.
  • the column may be fitted with internals.
  • the column may preferably have a condenser for condensing the vapour, and a liquid-phase evaporator.
  • the organic compounds present in the wastewater produced after the extraction may preferably be isolated in an optional step by distillation procedures, including rectification procedures, for example, and/or by stripping, and returned to the process.
  • the organic compounds include, in particular, extractants and also compounds having a low boiling point.
  • gases such as air, nitrogen or water vapour, are passed through the wastewater, with organic compounds being transferred into the gas phase and separated off.
  • the wastewater produced in the present process can be purified by means of biological treatment.
  • the aqueous phase obtained after the extraction step includes a substantially lower proportion of organic compounds than before the extraction step, with the compounds present in the wastewater generally having good biodegradability.
  • the biological treatment preferably comprises at least one aerobic stage, more preferably at least one anaerobic stage and at least one aerobic stage.
  • Figure 1 shows a preferred plant for implementing the process of the invention.
  • Line 1 guides a wastewater stream, from a process for preparing methacrylic acid and/or alkyl methacrylates having 1 to 8 C atoms in the alkyl radical by heterogeneous-catalytic partial oxidation of isobutene and/or tert-butanol in the gas phase, into an extractor 2.
  • the organic phase can be introduced via line 3 into a distillation plant 4.
  • Line 5 allows the aqueous phase to be transferred into a unit for stripping, 6.
  • the organic compounds recovered by stripping, including especially the extractant, can be passed back via line 7 into the extractor 2.
  • the processed aqueous phase can then be transferred via line 8 into a biological treatment plant.
  • the organic phase transferred into the distillation plant 4 is separated, with the extractant in particular being separated from the other organic compounds.
  • the extractant may preferably be selected such that its boiling point is lower than the boiling point of the majority of organic compounds present in the wastewater.
  • the by-products obtained by the process for preparing methacrylic acid and/or alkyl methacrylates can be accumulated preferably in the liquid phase, while the extractant can be removed from the distillation unit 4 overhead.
  • the extractant recovered can be passed back via line 9 into the extractor 2.
  • the by-products obtained in the liquid phase of the distillation plant 4 can be transferred via line 10 into a further distillation plant 1 1 .
  • the by-products are separated, and more particularly the compounds having a high boiling point, which are often obtained in a low concentration as a by-product in the preparation of methacrylic acid, can be separated off.
  • the higher-boiling compounds may be taken from the liquid phase of the second still 1 1 , and methacrylic acid, for example, may be isolated by a distillation plant 13 from this liquid phase, depending on the choice of distillation parameters. The remainder of the liquid phase may be taken from the plant via line 14.
  • the distillation plant 1 1 From the overhead stream in the distillation plant 1 1 it is possible to separate off organic compounds, more particularly carboxylic acids with a low boiling point. These carboxylic acids may be separated in a further distillation plant (not shown) or converted into the esters. In the plant depicted in Figure 1 , the concentrated carboxylic acids are transferred via line 12 into a reactor 15, in which the carboxylic acids are reacted with at least one alcohol, for example methanol, ethanol, n-butanol or isobutanol, to give the corresponding esters.
  • at least one alcohol for example methanol, ethanol, n-butanol or isobutanol
  • the products obtained are transferred from the reactor 15 via line 16 into a further distillation plant 17, for example a still or a rectifier, and separated.
  • the higher-boiling carboxylic acids may be transferred via line 18 from the liquid phase of the distillation plant 17 into the reactor 15, while the low-boiling esters, the water obtained, and unreacted alcohol can be transferred via line 19 into a phase separator 20.
  • the alcohol used for the esterification may be separated from the product ester, by adding water via line 21 , for example, with a large proportion of the alcohol transferring to the aqueous phase.
  • the aqueous phase can be transferred via line 22 into a further distillation plant 23, the alcohol being separated from the water.
  • the alcohol recovered may be introduced via line 24 into the reactor 15.
  • the aqueous phase can be purified biologically or introduced into the phase separator 20.
  • the alcohol, or azeotrope of alcohol and water, that is used in the present example has a lower boiling point than water, and so water is recovered from the liquid phase, and the alcohol is recovered overhead. With a different set-up, the water may also be removed overhead and the alcohol from the liquid phase.
  • the organic phase obtained in the phase separator 20 may be transferred via line 25 into a further distillation plant 26, in which the esters obtained are separated.
  • the alcohol present in the organic phase can often be taken off overhead from the distillation plant and introduced into the phase separator 20 via line 27, for example. This separation may also take place, for example, in the form of an azeotrope.
  • esters having the highest boiling point In the liquid phase, the ester having the highest boiling point is isolated, and can be removed from the plant via line 28. Further desired esters of the carboxylic acid may be taken from the distillation plant 26 at various points, with resultant products being able to be transferred to additional plants 30, via lines, as for example line 29, and purified. These esters may be taken from the plant via line 31 , for example.
  • the distillation plants 4, 1 1 , 13, 17, 23 and 26 may be designed as conventional stills having one or more separating stages, or as rectifiers.
  • ethyl acetate as extractant and ethanol as alcohol may be used for preparing the esters.
  • the plant may be operated such that carboxylic acids with a boiling point higher than that of acrylic acid can be taken from the liquid phase of the distillation plant 1 1 .
  • Methacrylic acid may be isolated from the liquid phase via the distillation plant 13, for example.
  • the further organic compounds from the liquid phase may be passed on for energy recycling.
  • the carboxylic acids recovered overhead in the distillation plant 10 more particularly acetic acid and acrylic acid, can be converted with ethanol into the corresponding esters, for example ethyl acetate and ethyl acrylate.
  • esters are subsequently separated in distillation plant 26, with ethyl acrylate being recovered in the liquid phase and ethyl acetate at a middle point in the distillation plant; the ethyl acetate can be purified further in plant 30.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

La présente invention concerne un procédé de préparation continue d'acide méthacrylique et/ou de méthacrylates d'alkyle présentant 1 à 8 atomes de carbone dans le radical alkyle par oxydation partielle sous catalyse hétérogène de composés organiques en phase gazeuse, au moins un acide carboxylique présentant 2 à 5 atomes de carbone étant isolé du courant d'eau usée produit lors de ce procédé.
PCT/CN2011/079770 2011-09-16 2011-09-16 Procédé de préparation d'acide méthacrylique et/ou de méthacrylates d'alkyle WO2013037133A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2011/079770 WO2013037133A1 (fr) 2011-09-16 2011-09-16 Procédé de préparation d'acide méthacrylique et/ou de méthacrylates d'alkyle

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2011/079770 WO2013037133A1 (fr) 2011-09-16 2011-09-16 Procédé de préparation d'acide méthacrylique et/ou de méthacrylates d'alkyle

Publications (1)

Publication Number Publication Date
WO2013037133A1 true WO2013037133A1 (fr) 2013-03-21

Family

ID=47882552

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2011/079770 WO2013037133A1 (fr) 2011-09-16 2011-09-16 Procédé de préparation d'acide méthacrylique et/ou de méthacrylates d'alkyle

Country Status (1)

Country Link
WO (1) WO2013037133A1 (fr)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998040342A1 (fr) * 1997-03-07 1998-09-17 Basf Aktiengesellschaft Procede d'extraction d'acide (meth)acrylique
WO2009095111A1 (fr) * 2008-01-30 2009-08-06 Evonik Röhm Gmbh Procédé de préparation d’acide méthacrylique de pureté élevée

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998040342A1 (fr) * 1997-03-07 1998-09-17 Basf Aktiengesellschaft Procede d'extraction d'acide (meth)acrylique
WO2009095111A1 (fr) * 2008-01-30 2009-08-06 Evonik Röhm Gmbh Procédé de préparation d’acide méthacrylique de pureté élevée

Similar Documents

Publication Publication Date Title
KR100760100B1 (ko) 에틸 아세테이트 및 이소프로필 아세테이트의 동시적인 공동생성방법 및 정제방법
JP2009528323A (ja) カルボン酸の反応性蒸留方法
CA2556998A1 (fr) Elimination des composes reducteurs de permanganate dans les circuits de carbonylation de methanol
JP3934163B2 (ja) アクリル酸ブチルの精製方法
US9403750B2 (en) Method for producing 2-octyl acrylate by direct esterification
KR102647454B1 (ko) (메트)아크릴 에스테르의 정제 방법
US4554054A (en) Methacrylic acid separation
CZ214196A3 (en) Purification process of acrylic acid obtained by catalytic oxidation of propylene
JP2019163294A (ja) 軽質（メタ）アクリル酸エステルの製造方法
KR920005693B1 (ko) 메타크릴산 에스테르의 제조방법
JP2005502695A (ja) （メタ）アクリル酸エステルの製造方法
WO2009013623A2 (fr) Distillation azéotropique avec régénération du solvant
CN110997619B (zh) 连续制备丙烯酸正丁酯或丙烯酸异丁酯的方法
CN105050997A (zh) 通过酯交换制造丙烯酸2-丙基庚酯的方法
US20130131376A1 (en) Method for producing a carboxylic acid ester
EP2272818A1 (fr) Processus d'obtention d'un mélange de mono, di et triesters carboxyliques à partir de glycérol brut
CN104053642B (zh) 通过酯交换制备丙烯酸2-辛基酯的方法
US10661196B2 (en) Process for producing acetic acid
US20060205973A1 (en) Process for preparing alkyl esters of (meth)acrylic acid
US20050059837A1 (en) Method for producing butyl acrylate
CN112262119B (zh) 纯化轻质丙烯酸酯的方法
WO2013037133A1 (fr) Procédé de préparation d'acide méthacrylique et/ou de méthacrylates d'alkyle
CN104053643B (zh) 通过酯交换制备丙烯酸2-辛基酯的方法
US6494996B2 (en) Process for removing water from aqueous methanol
KR960006664B1 (ko) 카르복실산의 수용액으로부터 카르복실산을 추출 분리하는 방법

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11872408

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11872408

Country of ref document: EP

Kind code of ref document: A1