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 invention relates to a liquid-liquid extraction process, comprising: the provision of a main input liquid stream, comprising at least one compound of interest and an excess compound; the provision of a liquid scrubbing stream; the extraction of the excess compound from the main input liquid stream by contact with the liquid scrubbing stream, making it possible to collect a main output liquid stream, depleted in excess compound with respect to the main input liquid stream; in which: the main input liquid stream and the liquid scrubbing stream exhibit a difference in density of less than or equal to 50 kg/m3 and also an interfacial tension of less than or equal to 3 dyn/cm; and the extraction stage is carried out in a packed contactor with a ratio by weight as input liquid scrubbing stream/main liquid stream ranging from 0.3 to 0.5.

Abstract: The invention relates to a liquid-liquid extraction process, comprising: the provision of a main input liquid stream, comprising at least one compound of interest and an excess compound; the provision of a liquid scrubbing stream; the extraction of the excess compound from the main input liquid stream by contact with the liquid scrubbing stream, making it possible to collect a main output liquid stream, depleted in excess compound with respect to the main input liquid stream; in which: the main input liquid stream and the liquid scrubbing stream exhibit a difference in density of less than or equal to 50 kg/m3 and also an interfacial tension of less than or equal to 3 dyn/cm; and the extraction stage is carried out in a packed contactor with a ratio by weight as input liquid scrubbing stream/main liquid stream ranging from 0.3 to 0.5.

Abstract: The invention relates to a method for producing a flow containing at least one alkene derivative, including the following steps: a step a) of reacting a flow containing one or more alkenes and one or more alkanes—the ratio of said alkanes to said alkenes being at least 1 by volume—with a flow containing mainly oxygen, in order to obtain at least one converted flow containing at least said alkene derivative; a step b) of separating the converted flow produced in step a) into at least said flow containing at least said alkene derivative and a residual flow containing mainly one or more hydrocarbons and one or more inert compounds; and a step c) of separating all or a portion of said residual flow by means of permeation into at least one first flow containing mainly one or more inert compounds and a second flow containing mainly one or more hydrocarbons.

Abstract: The invention relates to a method for purifying a specific gas stream containing one or more components to be recovered, one or more impurities to be eliminated and one or more poisons, for a unit for separation by means of permeation, including the following steps: a) in a unit for separation by means of absorption, separate from said unit for separation by means of permeation, the specific gas stream is placed in contact with one or more liquid solvents suitable and intended for selectively absorbing said poisons in order to obtain at least one first gas stream depleted of said poisons and a second liquid stream; and b) said first gas stream produced in step a) is separated in said unit for separation by means of permeation, at a specific absolute pressure P, into at least one third gas stream depleted of impurities and a fourth stream; the separation performed in step a) being carried out at an absolute pressure of between 50% and 200% of said specific absolute pressure P.

Abstract: The present invention relates to an improved method for preparing (meth)acrylic anhydride (A(M)A2O) by transanhydrification between (meth)acrylic acid and acetic anhydride in the presence of at least one polymerization inhibitor, in which reaction to the point of partial conversion of the reagents is carried out, followed by continuous distillation. With the method according to the invention, it is possible to produce I1A(M)A2O of very high purity under improved productivity conditions compared to existing methods while eliminating problems of reactor fouling.

Abstract: The present invention relates to an improved method for preparing (meth)acrylic anhydride (A(M)A2O) by transanhydrification between (meth)acrylic acid and acetic anhydride in the presence of at least one polymerization inhibitor, in which reaction to the point of partial conversion of the reagents is carried out, followed by continuous distillation. With the method according to the invention, it is possible to produce I1A(M)A2O of very high purity under improved productivity conditions compared to existing methods while eliminating problems of reactor fouling.

Abstract: This process for the manufacture of an aqueous solution of (meth)acryloyloxyethylbenzyl-dimethylammonium chloride ((M)ADAMQUAT BZ) by reaction, in the presence of water, of N,N-dimethylaminoethyl (meth)acrylate ((M)ADAME) with benzyl chloride is characterized in that the reaction is carried out continuously in a reactor operating according to the perfectly stirred reactor technology.

Abstract: The invention relates to a continuous method of preparing ethyl lactate by means of lactic acid esterification using ethanol in the presence of a catalyst. The inventive method consists in continuously extracting a mixture comprising ethyl lactate, ethanol, water and different heavy products from an esterification reaction medium at partial lactic acid conversion rate and, subsequently, subjecting said mixture to a reduced-pressure flash separation, thereby producing an overhead stream containing a mixture of ethyl lactate, ethanol and water, the lower part of said mixture supplying a fractional distillation column.

Abstract: The invention concerns a method for continuously producing a dimmer-rich and tri-mer rich oligomeric lactic acid composition, starting with a lactic composition by eliminating water from said lactic acid composition. The invention is characterized in that it consists in: carrying out said elimination in an adiabatic reactor provided with a recycling loop, continuously introducing a lactic acid composition in a circulating starter reaction medium being brought to a temperature ranging between 120° C. and 180° C. and in eliminating the water vapour form.

Abstract: This process for the manufacture of an aqueous solution of (meth)acryloyloxyethylbenzyl-dimethylammonium chloride ((M)ADAMQUAT BZ) by reaction, in the presence of water, of N,N-dimethylaminoethyl (meth)acrylate ((M)ADAME) with benzyl chloride is characterized in that the reaction is carried out continuously in a reactor operating according to the perfectly stirred reactor technology.

Abstract: This process for the manufacture of an aqueous solution of the unsaturated quaternary ammonium salt corresponding to the formula (I), by reaction, in the presence of water, of N,N-dimethylaminoethyl acrylate (DAMEA) with a quaternizing agent of formula (II), is characterized in that the said reaction is carried out continuously in a rotating disc agitated column, with introduction of the quaternizing agent in the column bottom and introduction of the DAMEA and the water in the column top, the said reaction being carried out at a temperature of 35 to 60° C. and under a pressure of 10 to 20 bar.  R—Cl  (II) R=methyl or benzyl radical.

Abstract: This process for the manufacture of an aqueous solution of the unsaturated quaternary ammonium salt corresponding to the formula (I), by reaction, in the presence of water, of N,N-dimethylaminoethyl acrylate (DAMEA) with a quaternizing agent of formula (II), is characterized in that the said reaction is carried out continuously in a rotating disc agitated column, with introduction of the quaternizing agent in the column bottom and introduction of the DAMEA and the water in the column top, the said reaction being carried out at a temperature of 35 to 60° C. and under a pressure of 10 to 20 bar.

Abstract: The N.sub.2 O values in gaseous effluents, notably those produced in various organic syntheses entailing nitric acid oxidation (for example the industrial scale production of adipic acid, of glyoxal and of glyoxylic acid), are catalytically decomposed at elevated temperatures over H-mordenite and ammonium mordenite catalysts, preferably the ammonium mordenites that have been exchanged with iron, cobalt or bismuth.