EP3551603A1 - Method for preventing polymer deposition in a method for purifying (meth)acrylic acid - Google Patents
Method for preventing polymer deposition in a method for purifying (meth)acrylic acidInfo
- Publication number
- EP3551603A1 EP3551603A1 EP17816997.5A EP17816997A EP3551603A1 EP 3551603 A1 EP3551603 A1 EP 3551603A1 EP 17816997 A EP17816997 A EP 17816997A EP 3551603 A1 EP3551603 A1 EP 3551603A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- acrylic acid
- meth
- glyoxal
- derivative
- process according
- Prior art date
- Legal status (The legal status 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 status listed.)
- Pending
Links
Classifications
-
- 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
- C07C51/50—Use of additives, e.g. for stabilisation
-
- 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
- C07C57/00—Unsaturated compounds having carboxyl groups bound to acyclic carbon atoms
- C07C57/02—Unsaturated compounds having carboxyl groups bound to acyclic carbon atoms with only carbon-to-carbon double bonds as unsaturation
- C07C57/03—Monocarboxylic acids
- C07C57/04—Acrylic acid; Methacrylic acid
Definitions
- the present invention relates to the manufacture of (meth) acrylic acid, and its object is the reduction of fouling phenomena during the purification of (meth) acrylic acid containing glyoxal.
- the invention is based on the use of a quinoline derivative to limit the formation of polymers in a liquid phase containing (meth) acrylic acid and glyoxal.
- Some of these operations use one or more organic or aqueous solvents as absorption agents (gas-liquid exchanges) and / or as extraction agents in liquid medium (liquid-liquid exchanges), and / or as agents for separation by azeotropic distillation.
- These methods also include solvent recovery and purification steps, and necessarily involve a large number of distillation columns, operating at elevated temperatures, to yield a technical acrylic acid, in which the impurity content has been greatly reduced. .
- aldehydes such as furfuraldehyde, benzaldehyde, acrolein, or glyoxal
- aldehydes such as furfuraldehyde, benzaldehyde, acrolein, or glyoxal
- This additional purification generally carried out with the aid of chemical agents or by fractional crystallization, leads to a high purity grade of acrylic acid generally known as glacial acrylic acid or usable polymer grade acrylic acid. for the production of flocculants.
- All of these methods for purifying acrylic acid have in common the addition of polymerization inhibitors at different stages of purification in order to prevent the formation of polymers resulting from the polymerization of acrylic acid, and or by-products, and avoid fouling of the purification units, in particular distillation units.
- the addition of polymerization inhibitor is also necessary to stabilize the acrylic acid during its transportation and storage.
- nitroxide polymerization inhibitors have been proposed in patent FR 1,520,290, these compounds having a stabilizing property clearly superior to that of conventional inhibitors such as hydroquinone or benzoquinone.
- polymerization inhibitors are conventionally added to the streams, generally at the head equipment of distillation columns, condensers, etc. which may be the seat of a liquid-vapor equilibrium leading to the condensation of flows rich in (meth) acrylic monomer.
- EP 1 298 120 it is proposed to treat the flow of acrylic acid by reverse osmosis, to reduce the concentration of glyoxal contained in the permeation liquid to a content of less than 0.03% by weight. .
- This type of treatment Permeation is expensive in investment and maintenance (changing membranes) and can be difficult to implement on a charged flow.
- patent EP 1 396 484 only applies to the dehydration step in a recovery / purification process comprising the absorption of acrylic acid in the form of an aqueous solution, and consists in removing all from the dehydration column more than 50% of the glyoxal present in the aqueous solution of acrylic acid; a compound inhibiting the polymerization of acrylic acid may be added to the dehydration column.
- a compound inhibiting the polymerization of acrylic acid may be added to the dehydration column.
- These include, for example, hydroquinone, hydroquinone methyl ether, phenothiazine, or a 2,2,6,6-tetramethylpiperidinoxyl derivative, or mixtures thereof.
- benzoquinone or a quinoline derivative makes it possible to meet this need. It has thus been found that the presence of benzoquinone in a flux of acrylic acid containing a low glyoxal content makes it possible to effectively inhibit the polymerization of acrylic acid, and to reduce the fouling phenomena on the purification plants of acrylic acid. It also appeared the same effect for methacrylic acid which also has an increased risk of polymerization in the presence of glyoxal.
- Quinol derivatives in particular 1,4-benzoquinone, are generally known as polymerization inhibitors, but their particular effect on the inhibition of the polymerization of (meth) acrylic acid in the presence of glyoxal has never been described. . Accordingly, the invention proposes to provide a simple solution, easy to implement to maintain a high productivity of (meth) acrylic acid manufacturing processes. Summary of the invention
- the subject of the present invention is a process for preventing the deposition of compounds of a polymeric nature during purification operations of (meth) acrylic acid, characterized in that at least one flow of (meth) acid is added.
- R 1, R 2 , R 3, and R 4 independently denote a hydrogen atom or a C 1 -C 6 alkyl group, or R 1 and R 2 together with the atoms to which they are attached form a ring or heterocyclic saturated or unsaturated, preferably a phenyl and / or R 3 and R 4 form together and with the atoms to which they are attached a ring or heterocyclic saturated or unsaturated, preferably a phenyl group.
- said quinoline derivative in order to obtain the desired effect, must be added at a content expressed by the molar quinoline / glyoxal derivative ratio of between 0.1 and 5.
- the quinoline derivative is a compound selected from cyclic conjugated ethylenic diketones.
- the quinoline derivative may be chosen for example from 1,2-benzoquinone, 1,4-benzoquinone, naphthaquinone and anthraquinone.
- the quinoline derivative is introduced directly in liquid form, in solution in an aqueous solvent, or in solution in (meth) acrylic acid.
- the quinoline derivative is generated in situ in said (meth) acrylic acid stream.
- the (meth) acrylic acid may be of petrochemical origin or at least partly of renewable origin.
- purification operation is meant any step intended to modify the composition of the flow of (meth) acrylic acid of origin, for example during a separation operation of light by-products or heavy by-products, or during a dehydration operation.
- the purification operations may generally comprise distillations, liquid / liquid extractions, liquid / gas exchanges, separations using a film evaporator, or crystallizations.
- the flow of (meth) acrylic acid contains at least glyoxal, it being understood that the term "glyoxal” includes the glyoxal of formula C2O2H2 (ethanedial), as well as its derivatives which can be formed in situ in the process synthesis / purification of (meth) acrylic acid, in particular in the form of substituted glyoxal (for example methyl glyoxal), or in the form of monomeric or polymeric hydrates.
- glyoxal includes the glyoxal of formula C2O2H2 (ethanedial), as well as its derivatives which can be formed in situ in the process synthesis / purification of (meth) acrylic acid, in particular in the form of substituted glyoxal (for example methyl glyoxal), or in the form of monomeric or polymeric hydrates.
- the invention also relates to the use of at least one quinoline derivative to limit fouling problems during the purification of a flow of (meth) acrylic acid comprising at least glyoxal as impurity.
- Another subject of the invention relates to a process for purifying (meth) acrylic acid, characterized in that it comprises the addition of at least one quinolic derivative in a stream comprising at least (meth) acid acrylic and at least glyoxal.
- Another subject of the invention relates to a process for producing (meth) acrylic acid, characterized in that it comprises the said purification process.
- the aim of the invention is to produce technical (meth) acrylic acid without being confronted with the problem of fouling of the installations used to purify the crude reaction mixture of (meth) acrylic acid synthesis, in particular because of the presence of glyoxal formed during the synthesis process.
- the invention is based on the addition of a quinoline derivative corresponding to one of the formulas (I) or (II) in a (meth) acrylic acid stream containing glyoxal during purification steps, the quinoline / glyoxal derivative molar ratio being between 0.1 and 5.
- (meth) acrylic acid includes acrylic acid and methacrylic acid.
- the (meth) acrylic acid is acrylic acid.
- the (meth) acrylic acid may be of petrochemical origin or at least partly of renewable origin.
- acrylic acid is derived from a production process using propylene or propane as a raw material.
- the acrylic acid is obtained from a process using ethylene and CO 2 as raw materials.
- the acrylic acid is derived from a process using acetic acid as raw material.
- the methacrylic acid is obtained from isobutylene and / or tert-butanol, butane and / or isobutane.
- acrylic acid is derived from a production process using glycerol or glycerine as raw material.
- the acrylic acid is derived from a process for the dehydration of lactic acid or ammonium lactate, or of a process for the dehydration of 3-hydroxypropionic acid or of its ammonium salt.
- These compounds can be derived from the fermentation of biomass and / or sugars.
- incondensable light compounds under the conditions of temperature and pressure usually used: nitrogen, unconverted oxygen, carbon monoxide and carbon dioxide formed in small quantities by ultimate oxidation or rotating in a circle, by recycling, in the process,
- condensable light compounds in particular water, generated by the synthesis reaction or as a diluent, unconverted acrolein, light aldehydes, such as formaldehyde, acetaldehyde and glyoxal, formic acid and acid; acetic, heavy compounds: furfuraldehyde, benzaldehyde, maleic acid and anhydride, benzoic acid, 2-butenoic acid, phenol, protoanemonin.
- water generated by the synthesis reaction or as a diluent, unconverted acrolein, light aldehydes, such as formaldehyde, acetaldehyde and glyoxal, formic acid and acid
- acetic, heavy compounds furfuraldehyde, benzaldehyde, maleic acid and anhydride, benzoic acid, 2-butenoic acid, phenol, protoanemonin.
- a light compound is a compound whose boiling point is lower than that of (meth) acrylic acid under the pressure conditions used.
- a heavy compound is a compound whose boiling point is higher than that of (meth) acrylic acid under the pressure conditions used.
- the second stage of manufacture involves recovering the acrylic acid contained in the crude reaction mixture to turn it into technical acrylic acid.
- the process for the recovery / purification of acrylic acid comprises the extraction of acrylic acid by counter-current absorption in the form of an aqueous solution of acrylic acid, followed by generally by a dehydration step which is carried out in the presence of a solvent of acrylic acid immiscible with water, but may form with water an azeotrope.
- a dehydration step by azeotropic distillation with the solvent makes it possible to achieve a separation of water that is efficient and less expensive in energy. It can also be coupled to a separation by liquid-liquid extraction.
- the process for the recovery / purification of acrylic acid comprises the extraction of acrylic acid by counter-current absorption by means of a hydrophobic heavy solvent, generally followed by the separation by distillation of a mixture containing the acrylic acid in solution in the hydrophobic heavy solvent.
- acrylic acid recovery / purification processes which furthermore carry out several distillation steps to eliminate the light compounds and / or the heavy compounds, are known in the prior art, and are for example described in the WO documents. 10/031949 and WO 11/114051 relating to the synthesis of acrylic acid from glycerol, to which reference may be made in the context of the present invention.
- the process for recovering / purifying acrylic acid does not use an external organic solvent.
- the process as described in patent EP 2066613 B1 can be used, using only two distillation columns - a dewatering column and a finishing column - without introducing a solvent.
- the partial condensation method described in US2016 / 090347 can be used.
- the glyoxal present as impurity in the medium to be treated is found in different streams during the various process operations. Indeed, it is a rather light compound, most of which is eliminated at the same time as acetic acid, but a sufficiently large part also distils with acrylic acid.
- the flow of acrylic acid into which a quinoline derivative is introduced to prevent the formation of insoluble polymers is preferably a liquid stream.
- This liquid stream may be a feed stream of a distillation column, or a condensate of a distillation column, or reflux of a distillation column, in the purification process.
- Said flow of acrylic acid generally comprises at least 10% by weight of acrylic acid, preferably at least 30% by weight, in particular at least 50% by weight of acrylic acid, and can comprise up to 99, 5% by weight of acrylic acid.
- Said flow of acrylic acid further comprises at least 10 ppm of glyoxal, and may comprise a glyoxal content ranging from 10 to 5000 ppm.
- the acrylic acid content in the streams can be determined by gas phase or liquid phase chromatography and the glyoxal content can be determined by liquid chromatography.
- Said flow of acrylic acid may also comprise at least one polymerization inhibitor, for example in particular from 50 ppm to 5% by weight, in particular from 0.01% to 3% by weight, relative to the medium containing acrylic acid.
- the polymerization inhibitor (s) can be chosen from phenolic derivatives such as hydroquinone and its derivatives such as methyl ether of hydroquinone; 2,6-di-tert-butyl-4-methyl phenol (BHT); and 2,4-dimethyl-6-tert-butylphenol (Topanol A); phenothiazine and its derivatives; manganese salts, such as manganese acetate; the salts of thiocarbamic or dithiocarbamic acid, such as thiocarbamates and metal dithiocarbamates, such as copper di-n-butyldithiocarbamate; N-oxyl compounds, such as 4-hydroxy-2,2,6,6-tetramethylpiperidinoxyl (4-OH-TEMPO); compounds with
- the flow of acrylic acid comprises phenothiazine as a polymerization inhibitor, at a content ranging from 50 ppm to 5% by weight, in particular from 100 ppm to 1% by weight. .
- the quinoline derivative corresponding to one of the formulas (I) or (II) above is generally introduced in liquid form, in solution in an aqueous solvent, or in solution in acrylic acid.
- 1,4-Benzoquinone is preferably used as the quinoline compound.
- the quinoline derivative can be generated in situ in the acrylic acid stream, in particular from a hydroquinone derivative or a catechol derivative, and an oxidizing compound, according to the following reaction schemes:
- the groups R 1, R 2 , R 3 and R 4 meet the definitions defined above.
- the groups R 1 to R 4 are the hydrogen atom, the in situ generation of the quinoline derivative being carried out from hydroquinone or catechol.
- This embodiment may be advantageous in order to avoid the delicate handling of certain quinol derivatives.
- the oxidation can be carried out using an oxidizing compound chosen, for example, from metal salts, in particular manganese or copper salts, or N-oxyl derivatives, in particular 4-OH-Tempo,
- the 1,4-benzoquinone is generated in situ by oxidation of the hydroquinone with the aid of an oxidizing compound such as 4-OH-Tempo, according to the following reaction:
- hydroquinone is a polymerization inhibitor widely used in acrylic acid manufacturing processes, and may already be present in the various acrylic acid streams comprising glyoxal. Polymeric deposition of formation during the acrylic acid purification operations can then be avoided by simply adding 4-OH-Tempo, in the form of a low-toxicity aqueous solution available commercially, the benzoquinone then being generated in situ.
- the content of quinoline derivative introduced into the flow of acrylic acid to prevent fouling of the plant, expressed by the molar ratio quinoline / glyoxal derivative is between 0, 1 and 5.
- the quinoline derivative is introduced. so that the molar ratio quinoline / glyoxal derivative is between 0.2 and 5, preferably between 0.2 and 3, in particular between 0.5 and 2.
- a quinoline derivative, preferably 1,4-benzoquinone is introduced or generated in situ.
- a quinoline derivative preferably 1,4-benzoquinone
- a distillation column in which (which) concentrate acetic acid and glyoxal in a process for producing acrylic acid from propylene.
- a quinoline derivative preferably benzoquinone
- an acrylic acid stream comprising from 90 to 99.5% by weight of acrylic acid, from 10 to 1000 ppm of glyoxal and 100 to 10,000 ppm phenothiazine.
- the method of purifying acrylic acid according to the invention comprising the addition of at least one quinoline derivative in a stream comprising at least acrylic acid and at least glyoxal, can be easily part of any synthesis process of acrylic acid.
- PTZ phenothiazine (CAS 92-84-2)
- the medium was placed in an oil bath at 110 ° C under 230 mbar for 2 h. An air bubble of 5 ml / min was applied for the duration of the experiment. At the end of the experiment, the The liquid phase was drained and any solids present were recovered, dried under vacuum and weighed.
- Benzoquinone and naphthaquinone have sufficiently inhibited the polymerization of acrylic acid to prevent the formation of insoluble solids that can lead to fouling of the plant (tests 23 to 30).
- Example 3 Use of Benzoquinone Generated in situ, Continuous Testing
- An industrial flow of acrylic acid containing about 50 ppm of glyoxal (0.91 mmol / l), 200 ppm HQ (1.91 mmol / l) and adding 1000 ppm of PTZ was injected at a rate of 100 g / h. in a glass thermosiphon reboiler of approximately 200 ml, surmounted by a total reflux condenser and equipped with an overflow (ie a residence time of 2 h).
- the reboiler operates at 110 ° C in the liquid under a pressure of 380 mbar.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR1662118A FR3060000B1 (en) | 2016-12-08 | 2016-12-08 | PROCESS FOR AVOIDING DEPOSITION OF POLYMERS IN A PROCESS FOR THE PURIFICATION OF (METH) ACRYLIC ACID. |
PCT/FR2017/053414 WO2018104661A1 (en) | 2016-12-08 | 2017-12-06 | Method for preventing polymer deposition in a method for purifying (meth)acrylic acid |
Publications (1)
Publication Number | Publication Date |
---|---|
EP3551603A1 true EP3551603A1 (en) | 2019-10-16 |
Family
ID=58314437
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP17816997.5A Pending EP3551603A1 (en) | 2016-12-08 | 2017-12-06 | Method for preventing polymer deposition in a method for purifying (meth)acrylic acid |
Country Status (8)
Country | Link |
---|---|
US (1) | US10781157B2 (en) |
EP (1) | EP3551603A1 (en) |
JP (1) | JP7016366B2 (en) |
KR (1) | KR102455976B1 (en) |
CN (1) | CN110049962B (en) |
BR (1) | BR112019010354B1 (en) |
FR (1) | FR3060000B1 (en) |
WO (1) | WO2018104661A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11447439B2 (en) * | 2018-07-26 | 2022-09-20 | Basf Se | Method for inhibiting unwanted radical polymerisation of acrylic acid present in a liquid phase P |
Family Cites Families (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1520290A (en) * | 1966-04-26 | 1968-04-05 | Bp Chem Int Ltd | Acrylic acid stabilization process |
GB1127127A (en) | 1966-04-26 | 1968-09-11 | Bp Chem Int Ltd | Stabilization of acrylic acid |
US4599144A (en) * | 1984-06-25 | 1986-07-08 | Standard Oil Company (Indiana) | Process for recovery of methacrylic acid |
JP2725593B2 (en) * | 1993-04-15 | 1998-03-11 | 株式会社日本触媒 | Method for preventing polymerization of (meth) acrylic acid and its ester |
US5728872A (en) | 1994-06-27 | 1998-03-17 | Lutz Riemenschneider | Stabilized acrylic acid compositions |
US5789613A (en) | 1996-05-07 | 1998-08-04 | Rohm And Haas Company | Reduction of carbonyl impurities in α, β-unsaturated acids and esters |
JP4110610B2 (en) * | 1998-03-23 | 2008-07-02 | 住友化学株式会社 | Method for preventing polymerization of acrylic acid |
CN1240205A (en) * | 1998-06-11 | 2000-01-05 | 住友化学工业株式会社 | Preparation of prepenoic acid and its polymerization inhibition |
DE10036958A1 (en) * | 2000-07-28 | 2002-02-07 | Basf Ag | Process for the preparation of tert-C4-C8-alkyl esters of (meth) acrylic acid |
JP4455790B2 (en) | 2001-09-28 | 2010-04-21 | 株式会社日本触媒 | Method for producing (meth) acrylic acid |
JP3905810B2 (en) * | 2002-09-03 | 2007-04-18 | 株式会社日本触媒 | Method for preventing polymerization in acrylic acid production process |
JP4056429B2 (en) * | 2003-06-05 | 2008-03-05 | 株式会社日本触媒 | Method for producing (meth) acrylic acid |
FR2861725B1 (en) | 2003-11-04 | 2005-12-30 | Arkema | PROCESS FOR THE PURIFICATION OF THE (METH) ACRYLIC ACID OBTAINED BY OXIDATION OF A GASEOUS SUBSTRATE |
CN102887820B (en) | 2006-09-15 | 2015-01-07 | 阿克马公司 | Process for producing acrylic acid |
FR2935971B1 (en) | 2008-09-16 | 2010-11-19 | Arkema France | BIO-ACRYLIC ACID OF POLYMERIC GRADE AND PROCESS FOR MAKING SAME FROM GLYCEROL |
FR2957594B1 (en) | 2010-03-18 | 2013-04-26 | Arkema France | PROCESS FOR PRODUCING POLYMER GRADE BIO-RESOURCE ACRYLIC ACID FROM GLYCEROL |
DE102010042216A1 (en) | 2010-10-08 | 2011-06-09 | Basf Se | Inhibiting the unwanted radical polymerization of acrylic acid present in a liquid phase, comprises adding a chemical compound of copper to the liquid phase, and the liquid phase additionally contains propionic acid and glyoxal |
US9944582B2 (en) | 2013-05-20 | 2018-04-17 | Saudi Basic Industries Corporation | Method for the purification of acetic acid and acrylic acid |
FR3017617B1 (en) * | 2014-02-19 | 2016-02-12 | Arkema France | PROCESS FOR PRODUCING BIO-SOURCE ACRYLIC ACID |
DE102014114193A1 (en) | 2014-09-30 | 2015-08-13 | Basf Se | Process and plant for the recovery of acrylic acid |
-
2016
- 2016-12-08 FR FR1662118A patent/FR3060000B1/en active Active
-
2017
- 2017-12-06 EP EP17816997.5A patent/EP3551603A1/en active Pending
- 2017-12-06 JP JP2019530722A patent/JP7016366B2/en active Active
- 2017-12-06 US US16/465,171 patent/US10781157B2/en active Active
- 2017-12-06 WO PCT/FR2017/053414 patent/WO2018104661A1/en unknown
- 2017-12-06 CN CN201780075340.2A patent/CN110049962B/en active Active
- 2017-12-06 BR BR112019010354-6A patent/BR112019010354B1/en active IP Right Grant
- 2017-12-06 KR KR1020197019660A patent/KR102455976B1/en active IP Right Grant
Also Published As
Publication number | Publication date |
---|---|
JP2019536809A (en) | 2019-12-19 |
KR102455976B1 (en) | 2022-10-17 |
WO2018104661A1 (en) | 2018-06-14 |
FR3060000A1 (en) | 2018-06-15 |
BR112019010354B1 (en) | 2022-10-04 |
CN110049962B (en) | 2021-12-14 |
JP7016366B2 (en) | 2022-02-21 |
FR3060000B1 (en) | 2020-05-01 |
CN110049962A (en) | 2019-07-23 |
US10781157B2 (en) | 2020-09-22 |
US20200002262A1 (en) | 2020-01-02 |
BR112019010354A2 (en) | 2019-08-27 |
KR20190091523A (en) | 2019-08-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
FR2501673A1 (en) | CONTINUOUS PROCESS FOR PRODUCING TEREPHTHALIC ACID | |
EP3606903B1 (en) | Process for purifying (meth)acrylic acid including a dividing-wall distillation column | |
FR3041958B1 (en) | IMPROVED PROCESS FOR THE PRODUCTION OF POLYMERIC (METH) ACRYLIC ACID | |
EP0946486B1 (en) | Purification of acrylic acid obtained by catalytic oxidation of propylene | |
FR2798382A1 (en) | PROCESS FOR THE PURIFICATION OF ACRYLIC ACID OBTAINED BY OXIDATION OF PROPYLENE AND / OR ACROLEIN | |
EP1680389A2 (en) | Method for purifying (meth)acrylic acid obtained by oxidizing a caseous substrate | |
EP3551603A1 (en) | Method for preventing polymer deposition in a method for purifying (meth)acrylic acid | |
WO2023073303A1 (en) | Improved method for producing high-purity butyl acrylate | |
EP4291547A1 (en) | Improved process for manufacturing high-purity alkyl acrylates | |
WO2017187067A1 (en) | N,n-dimethylaminoethyl acrylate composition stabilized in respect of discoloring effects | |
JP4601120B2 (en) | Acrylic acid production method | |
FR3094716A1 (en) | POLYMER GRADE ACRYLIC ACID PRODUCTION | |
WO2021205090A1 (en) | Method for purifying (meth)acrylic acid | |
WO2023025999A1 (en) | Improved method for producing high-purity butyl acrylate | |
WO2024052284A1 (en) | Improved method for producing alpha-beta-unsaturated carboxylic acids from poly(3-hydroxyalkanoate) | |
JP2002155021A (en) | Polymerization inhibitor composition for vinyl monomer and method for producing high-purity (meth)acrylic acid | |
EP1288185A2 (en) | Stabilisation of acrolein |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: UNKNOWN |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE |
|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE |
|
17P | Request for examination filed |
Effective date: 20190510 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
DAV | Request for validation of the european patent (deleted) | ||
DAX | Request for extension of the european patent (deleted) | ||
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: EXAMINATION IS IN PROGRESS |
|
17Q | First examination report despatched |
Effective date: 20200728 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: EXAMINATION IS IN PROGRESS |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: EXAMINATION IS IN PROGRESS |
|
TPAC | Observations filed by third parties |
Free format text: ORIGINAL CODE: EPIDOSNTIPA |