Abstract: The invention relates to the manufacture of alkyl acrylates by direct esterification of acrylic acid with the corresponding alcohol. In particular, the invention relates to the use of a cracker in combination with a topping column equipped with a side draw-off allowing a stream rich in acidic impurities such as ?-hydroxypropionic acid and ?-acryloxypropionic acid to be drawn off during distillation of the crude reaction mixture, so as to produce an acrylic ester meeting purity standards compatible with its use for preparing acrylic polymers.

Abstract: The invention relates to the production of (meth)acrylic esters according to a process by direct esterification, and in particular to the purification of a crude reaction mixture comprising a C4-C12 (meth)acrylic ester using a dividing wall column employed in a particular configuration. The dividing wall column is equipped with a separating wall creating separation zones in the column, the wall not being joined to the upper dome of the column in the top part and being joined to the bottom of the column in the bottom part. The process according to the invention guarantees a product of very high purity, independently of the back-cracking reactions of the heavy by-products liable to arise during the purification of the product sought.

Abstract: The invention relates to a process for the continuous production of acrylic acid, in the absence of organic solvent and in the absence of chemical treatment of the aldehydes, and without employing a dividing-wall column, from a gaseous reaction mixture comprising acrylic acid obtained by gas-phase oxidation of a precursor of acrylic acid.

Abstract: The invention relates to the manufacture of alkyl acrylates by direct esterification of acrylic acid by the corresponding alcohol. In particular, the invention relates to the use of a topping column equipped with a side draw-off making it possible to draw off a stream rich in acid impurities, such as ?-hydroxypropionic acid and ?-acryloyloxypropionic acid, during the distillation of the crude reaction mixture, in order to produce an acrylic ester meeting purity standards which are compatible with its use to prepare acrylic polymers.

Abstract: The invention relates to the purification of an acrylic acid comprising aldehyde compounds in a low content, according to a distillation process in a distillation unit in the absence of chemical reagent for treating the aldehydes, producing a stream of polymer-grade acrylic acid which is withdrawn through a side outlet of the distillation unit. The invention makes it possible to eliminate the use of a product classified as CMR in the manufacture of polymer-grade acrylic acid from a technical-grade acrylic acid, and thus meets the HSE requirements for industrial plants.

Abstract: The invention relates to the production of (meth)acrylic esters according to a process by direct esterification, and in particular to the purification of a crude reaction mixture comprising a C4-C12 (meth)acrylic ester using a dividing wall column employed in a particular configuration. The dividing wall column is equipped with a separating wall creating separation zones in the column, the wall not being joined to the upper dome of the column in the top part and being joined to the bottom of the column in the bottom part. The process according to the invention guarantees a product of very high purity, independently of the back-cracking reactions of the heavy by-products liable to arise during the purification of the product sought.

Abstract: The invention relates to the production of (meth)acrylic esters according to a continuous process by transesterification, and in particular to the purification of a crude reaction mixture comprising a C4-C12 (meth)acrylic ester using a divided wall column employed in a particular configuration. This configuration results in a simplification of the purification process with a reduced energy consumption and a minimized content of impurities present in the purified (meth)acrylic ester. The invention also relates to a process for the production of C4-C12 (meth)acrylic ester comprising this recovery/purification process.

Abstract: The present invention relates to a process for treating aqueous effluents containing formaldehyde by distillation in the presence of acetic acid, in particular to a process for treating aqueous solutions resulting from the synthesis of acrylic acid. The invention also relates to the use of the purified aqueous solution in a process for producing acrylic acid by catalytic oxidation of propylene and/or propane in steam dilution.

Abstract: The invention relates to the production of (meth)acrylic esters according to a continuous process by transesterification, and in particular to the purification of a crude reaction mixture comprising a C4-C12 (meth)acrylic ester using a divided wall column employed in a particular configuration. This configuration results in a simplification of the purification process with a reduced energy consumption and a minimized content of impurities present in the purified (meth)acrylic ester. The invention also relates to a process for the production of C4-C12 (meth)acrylic ester comprising this recovery/purification process.

Abstract: The invention relates to the use of a column with a separating wall as a purification/finishing column in a (meth)acrylic acid recovery method based on the use of two distillation columns in the absence of external organic solvent. The method according to the invention improves the energy balance for the method while improving the technical quality of the (meth)acrylic acid recovered. The method according to the invention further produces polymer-grade (or glacial) (meth)acrylic acid compatible with the production of high-molecular weight acrylic acid polymers.

Abstract: The subject of the present invention is a process for the synthesis of C1-C10 alkyl (meth)acrylates, by direct esterification of the (meth)acrylic acid by the corresponding alcohol, the reaction being carried out in a fixed bed membrane reactor under conditions in which the water generated by the reaction is eliminated from the reaction mixture as it is formed. The process according to the invention may operate under conditions for which the reagents are not in excess, thereby minimizing the size and energy of the equipment for separation/recycling of the streams generated during the purification of the reaction medium.

Abstract: The invention relates to a method for producing alkyl (meth)acrylate comprising a linear or branched alkyl chain comprising 4 to 10 carbon atoms, by direct esterification of (meth)acrylic acid with a linear or branched alcohol comprising 4 to 10 carbon atoms in the presence of a catalyst, leading to formation of a reaction mixture comprising the desired ester, unreacted acid and alcohol, light by-products, and heavy by-products. The mixture undergoes purification treatment by separation means to obtain purified alkyl (meth)acrylate. The purification treatment comprises a step of membrane separation dehydration applied to at least one of the following: the stream subjected to the final distillation leading to the recovery of the purified (meth)acrylic ester, the aqueous stream originating from the settling out of the reaction mixture, or the stream resulting from the distillation of the light by-products present in the reaction mixture.

Abstract: The invention relates to the use of a column with a separating wall as a purification/finishing column in a (meth)acrylic acid recovery method based on the use of two distillation columns in the absence of external organic solvent. The method according to the invention improves the energy balance for the method while improving the technical quality of the (meth)acrylic acid recovered. The method according to the invention further produces polymer-grade (or glacial) (meth)acrylic acid compatible with the production of high-molecular weight acrylic acid polymers.

Abstract: The subject of the invention is a process for recovering/purifying a C1-C4 (meth)acrylic ester from a crude reaction mixture comprising said ester, the process being carried out using a purification system comprising a divided wall column and a decanter, resulting in a simplification of the process and in a high productivity of the ester produced corresponding to the standards in terms of purity. The invention also relates to a process for producing C1-C4 (meth)acrylic ester comprising this recovery/purification process.

Abstract: The subject of the present invention is a process for the synthesis of C1-C10 alkyl (meth)acrylates, by direct esterification of the (meth)acrylic acid by the corresponding alcohol, the reaction being carried out in a fixed bed membrane reactor under conditions in which the water generated by the reaction is eliminated from the reaction mixture as it is formed. The process according to the invention may operate under conditions for which the reagents are not in excess, thereby minimizing the size and energy of the equipment for separation/recycling of the streams generated during the purification of the reaction medium.

Abstract: A process for the synthesis of acrylic acid oligomer represented by formula (I): in which n is an integer ranging from 1 to 10, wherein the process comprises the step of heating acrylic acid at a temperature from 50° C. to 200° C. in the presence of a catalyst, water and at least one polymerization inhibitor. Formula (I) where n=0 is acrylic acid, the precursor for preparing the acrylic acid oligomer.

Abstract: The subject of the invention is a process for recovering/purifying a C1-C4 (meth)acrylic ester from a crude reaction mixture comprising said ester, the process being carried out using a purification system comprising a divided wall column and a decanter, resulting in a simplification of the process and in a high productivity of the ester produced corresponding to the standards in terms of purity. The invention also relates to a process for producing C1-C4 (meth)acrylic ester comprising this recovery/purification process.

Abstract: A process for the synthesis of acrylic acid oligomer represented by formula (I): in which n is an integer ranging from 1 to 10, wherein the process comprises the step of heating acrylic acid at a temperature from 50° C. to 200° C. in the presence of a catalyst, water and at least one polymerization inhibitor. Formula (I) where n=0 is acrylic acid, the precursor for preparing the acrylic acid oligomer.

Abstract: The subject matter of the present invention is an improvement in the continuous production of methyl (meth)acrylate or of ethyl (meth)acrylate by direct esterification of (meth)acrylic acid with methanol or ethanol, under reaction conditions for which the acid is in excess relative to the alcohol, in particular with an acid/alcohol molar ratio of between 1.0 and 4, and under a pressure ranging from atmospheric pressure to 5 bar. The process of the invention makes it possible to minimize the formation of ethyl ethoxypropionate during the esterification reaction, and results in an improvement in the material balance, simplification of the purification train for the desired ester, and optimization of the energy balance.

Abstract: The present invention relates to the production of (meth)acrylic esters, and more particularly the production of C4-C10 alkyl (meth)acrylates comprising the step of membrane separation dehydration of at least one stream generated during the purification of alkyl (meth)acrylate.