Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/03—Preparation of carboxylic acid esters by reacting an ester group with a hydroxy group
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C213/00—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton
  • C07C213/06—Preparation of compounds containing amino and hydroxy, amino and etherified hydroxy or amino and esterified hydroxy groups bound to the same carbon skeleton from hydroxy amines by reactions involving the etherification or esterification of hydroxy groups
• • 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
  • C07C67/52—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
  • C07C67/54—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation by distillation
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/50—Improvements relating to the production of bulk chemicals
  • Y02P20/582—Recycling of unreacted starting or intermediate materials

Definitions

• the present invention relates to the production of alkyl acrylate by a continuous process by transesterification.
• the transesterification reaction involves a "short" chain alkyl acrylate said to be light in the presence of a "long” carbon chain alcohol said to be heavy in the generally presence of catalyst and polymerization inhibitor, according to formula (1). ) following general:
• the recovered products present in the reaction mixture in particular unreacted reagents and the catalyst, are recycled as far as possible within the process.
• US 6,977,310 discloses the treatment of the reaction crude by a first distillation column which separates the light products and sends the heavy products in a second column to separate the desired product from the catalyst and polymerization inhibitors.
• Document US Pat. No. 7,268,251 discloses various treatment methods for the crude reaction product comprising at least four distillation or rectification columns for purifying the desired product, including an evaporator for separating the catalyst.
• JP 2005-239564 it is proposed to use a distillation column according to the "divided wall column” technology, for purifying a reaction mixture of (meth) acrylic esters.
• This technology based on the implementation of a single column, however, has disadvantages such as its cost compared to a conventional column (must be installed a partition wall), and inflexibility vis-à-vis the changes in the nature of the flows to be treated.
• EP 0968995 describing a process for producing alkyl acrylates which discloses the use of a distillation column, where the reagents and the desired product are recovered at the top in gaseous form and in the foot under liquid form respectively.
• the transesterification reaction in this process occurs directly in the distillation column.
• the major drawbacks of using a homogeneous catalyst in a distillation column are to drastically increase its consumption due to the reflux of the different effluents, and also in case of precipitation of the catalyst to foul the distillation column.
• the catalyst is directly located in the distillation column and can not be recycled continuously.
• the efficiency of the reaction is directly impacted by the effectiveness of the catalyst which decreases over time. The catalyst change is very expensive since the process must be stopped and the column thoroughly cleaned between each catalyst feed.
• JP 2005-239564 it is necessary to use a column according to the "divided wall column” technique to obtain a short chain alkyl (meth) acrylate of sufficient purity, such as than butyl methacrylate.
• the Applicant has found many drawbacks to this use, since it is a column of size generally much greater than that of a conventional column, therefore of higher cost, and whose implementation is difficult in terms optimization of operation, distribution of introduced polymerization inhibitors, or cleaning in case of deposits on the walls.
• This process allows both a simplification and an improvement of the effluent treatment compared to those of the prior art to achieve a product of high purity and high productivity.
• the method according to the invention allows a significant reduction in purification costs compared to those generated in current processes.
• the present invention relates to a process for the continuous production of alkyl acrylate by transesterification reaction between a light alkyl acrylate and a heavy alcohol in the presence of at least one catalyst and at least one polymerization inhibitor. represented by the following reaction:
• R 2 OH H 2 C CHCOOR 2 + R 1 OH
• R represents a methyl or ethyl group
• R 2 represents a linear or branched alkyl group of 4 to 9 carbon atoms, which may have a nitrogen atom
• said reaction being carried out in a reactor coupled to a distillation column in which the azeotropic mixture composed of light alkyl acrylate and light alcohol generated by the transesterification reaction is withdrawn continuously, characterized in that the reaction crude comprising the unreacted reactants, the reaction products formed, the catalyst (s) and the polymerization inhibitor (s) is sent to a single distillation column under reduced pressure in which distillation makes it possible to obtain:
• the process according to the invention is characterized in that the transesterification catalyst is an alkyl titanate, preferably ethyl titanium and / or 2-octyl titanate dissolved in 2-octanol. .
• the process is characterized in that R 2 represents a linear or branched alkyl group containing 8 carbon atoms, preferably 2-octyl.
• the process according to the invention is characterized in that R 1 represents an ethyl group.
• the method according to the invention is characterized in that the catalyst is present in an amount of 5.10 "4 to 5.10” 2 moles per mole of R 2 OH, preferably at 10 "3-10 "2 moles per mole of R 2 OH.
• the process according to the invention is characterized in that it is suitable for the manufacture of 2-octyl acrylate for which ethyl titanium and or 2-octyl titanate in 2-octanol.
• the process according to the invention is characterized in that the molar ratio of the compound and the compound R 2 OH is between 1 and 3, preferably between 1.3 and 1.8.
• the process according to the present invention is characterized in that the transesterification reaction is carried out at a pressure of between 350 mmHg (ie 0.47 ⁇ 10 5 Pa) and the pressure atmospheric (760 mmHg, ie 10 5 Pa), and at a temperature between 90 ° C and 150 ° C, preferably 100 ° C and 130 ° C.
• the light alkyl acrylate reagent is chosen from methyl acrylate or ethyl acrylate, more preferably ethyl acrylate.
• the raw materials are of natural and renewable origin, that is to say, biosourced.
• 2-octanol can be obtained by alkaline treatment of ricinoleic acid derived from castor oil.
• the light alkyl acrylate may be derived from acrylic acid of renewable origin, which can be obtained in particular from glycerol, according to a process comprising a first step of dehydration of glycerol to acrolein followed by a gas phase oxidation step of the acrolein thus obtained; or obtained by dehydration of 2-hydroxypropionic acid (lactic acid) or 3-hydroxypropionic acid and its esters.
• the heavy alcohol reagent R 2 OH is a primary or secondary alcohol, having a linear or branched alkyl chain comprising from 4 to 9 carbon atoms, preferably from 5 to 9 carbon atoms, and which may comprise a nitrogen atom.
• the R 2 OH reagent can be chosen, without this list being limiting, among butan-1-ol, butan-2-ol, iso-butanol, pentan-1-ol (amyl alcohol ), 2,2-methylpropan-1-ol (isoamyl alcohol), hexan-1-ol, benzyl alcohol, 1-octanol, 2-octanol, 2-ethylhexanol, nonanol, ⁇ , ⁇ -dimethylaminoethanol, N, N-diethylaminoethanol.
• the alcohol is selected from 2-octanol, 2-ethylhexanol, and
• the R 2 OH reagent is 2-octanol.
• the catalyst is selected from any catalyst having the ability to catalyze the transesterification reaction between a light alkyl acrylate and a light alcohol, for example acids such as sulfuric acid and p-toluenesulfonic acid; basic compounds such as alcoholates, hydroxides, carbonates, phosphates, oxides or complexes of alkali or alkaline earth metals; metal alkoxide complexes such as aluminum or magnesium alcoholate; titanium-based compounds such as titanium alkoxides, phenoxides of titanium or alkyl titanates; compounds based on lead, zinc or tin; complexes of copper, iron or zirconium.
• acids such as sulfuric acid and p-toluenesulfonic acid
• basic compounds such as alcoholates, hydroxides, carbonates, phosphates, oxides or complexes of alkali or alkaline earth metals
• metal alkoxide complexes such as aluminum or magnesium alcoholate
• titanium-based compounds such as titanium alkoxid
• the catalyst according to the process of the invention is chosen from an alkyl titanate of formula Ti (ORi) 4 or Ti (OR 2 ) 4 in solution in alcohol RiOH and / or R 2 OH, for example a solution of 80 to 90% of ethyl titanium in the alcohol R 2 OH or ethanol, and / or the titanate of R 2 OH in the alcohol R 2 OH. It is understood that the alcohol used to dissolve the catalyst is the same as that used or generated in the transesterification reaction.
• 2-octyl titanate dissolved in 2-octanol obtained beforehand by reaction at 100 ° C. of ethyl titanate or isopropyl titanate with 2-octanol is used.
• the reaction is carried out in the presence of one or more polymerization inhibitors which are introduced into the reactor at a rate of 1000 to 5000 ppm relative to the crude reaction mixture.
• polymerization inhibitors that may be used, mention may be made, for example, of phenothiazine, hydroquinone, hydroquinone monomethyl ether, diterbutyl para-cresol (BHT), TEMPO (2,2,6,6-tetramethyl) piperidinyloxy), di-tert-butylcatechol, or TEMPO derivatives, such as 4-hydroxy (OH) -TEMPO, alone or mixtures thereof in all proportions.
• a further addition of polymerization inhibitor is generally performed at the subsequent purification treatment, particularly at the distillation column.
• the single distillation column treating the crude reaction product according to the process of the invention is a simple distillation column, for example an ordered packing column or a tray column generally comprising between 15 and 20 theoretical trays, for example 18 theoretical trays. whose pressure can be adjusted to the desired level, possibly protected by thermal insulation, and possibly equipped with access devices for maintenance operations.
• the term "simple distillation column” means a column containing distillation trays with or without spillways, or containing loose or ordered packing with possibly refilling trays for dispensing liquid, capable of operating at pressures below atmospheric pressure.
• This column is equipped with a system for removing the product in vapor form, in the lateral position of said column, and does not include a vertical partition wall.
• the azeotropic mixture can be used in a light ester synthesis unit (6).
• the crude reaction mixture (5) contains the desired alkyl acrylate with, as light products, the heavy alcohol (R 2 OH) and the light alkyl acrylate unreacted, and as heavy compounds, the catalyst, the polymerization inhibitor (s) as well as heavy reaction by-products.
• the crude reaction mixture (5) is subjected to a purification treatment in a single distillation column (CX2) in order to obtain, on the one hand, the pure desired alkyl acrylate (9) which is withdrawn laterally, on the other hand at the top of the column are the residual alcohols (R-iOH and R 2 OH) and the unreacted light alkyl acrylate (7) intended to be recycled (1 1), and at the bottom of the column the catalyst, polymerization inhibitor , heavy reaction byproducts and heavy ester (8) to be recycled in part (12) to the reactor (A), the other part being sent (10):
• Column (CX2) is a simple distillation column operating under reduced pressure, preferably corresponding to an ordered packing column or trays comprising between 15 and 20 theoretical trays, preferably 18 theoretical trays operating under reduced pressure.
• the distillation column treating the crude reaction product operates at a pressure of between 20 and 150 mmHg (ie between 0.027 ⁇ 10 5 Pa and 0.2 ⁇ 10 5 Pa), preferably between 20 and 75 mmHg (ie between 0.027 ⁇ 10 5 Pa). and 0.1 Pa ( 5 Pa).
• the desired alkyl acrylate is withdrawn laterally in the gas phase at the bottom of the distillation column, between the theoretical plates 12 and 14 for a column with 18 theoretical plates.
• the reactor is heated, bubbled with air and as soon as the temperature reaches 125 ° C. under 640 millibars, the stabilized AE (3) is introduced continuously with 2000 ppm of PTZ, 2-octanol (1) and ethyl titanate dissolved in 2-octanol (2), in mass proportions 50, 1 / 49.7 / 0.2.
• the AE / Ethanol azeotrope (4) is continuously withdrawn with a 40/60 mass composition. This mixture (4) is recycled to the light ester plant.
• the reaction crude (5) obtained by continuous reaction, contains A20CT, unreacted AE, unreacted 2-octanol and a mixture comprising the catalyst with the polymerization inhibitors and heavy derivatives.
• the stream (5) is sent continuously to a single distillation column (CX2) of 18 theoretical plates operating under reduced pressure and heated by an external exchanger at a temperature of 140 ° C.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Crystallography & Structural Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
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• 2012
  • 2012-12-17 FR FR1262123A patent/FR2999572B1/fr not_active Expired - Fee Related
• 2013
  • 2013-12-16 JP JP2015547127A patent/JP6373276B2/ja active Active
  • 2013-12-16 WO PCT/FR2013/053083 patent/WO2014096648A1/fr not_active Ceased
  • 2013-12-16 US US14/650,906 patent/US10000439B2/en active Active
  • 2013-12-16 CN CN201380065961.4A patent/CN104918911B/zh active Active
  • 2013-12-16 EP EP13824608.7A patent/EP2931695B1/fr active Active
  • 2013-12-16 KR KR1020157019055A patent/KR102079840B1/ko active Active
  • 2013-12-16 BR BR112015013542-0A patent/BR112015013542B1/pt active IP Right Grant
• 2018
  • 2018-02-09 JP JP2018021660A patent/JP2018109019A/ja not_active Withdrawn

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