Abstract: The present invention relates to the manufacture of bioresourced polymer-grade acrylic acid from glycerol. The polymer grade acrylic acid produced has limited content of certain impurities harmful to polymerization processes, such as, total aldehydes, protoanemonin, maleic anhydride and nonphenolic polymerization inhibitors. The invention also relates to the use of the bioresourced acrylic acid obtained for manufacture of superabsorbents or for manufacture of polymers or copolymers using amide or ester derivatives of the bioresourced acrylic acid.

Abstract: The present invention relates to a method for purifying (meth)acrylic acid obtained by catalytic or redox oxidation of a gaseous substrate constituting propane, propylene, acrolein, isobutane, isobutene, tert-butyl alcohol and/or (meth)acrolein or mixtures thereof by sending the gaseous reaction mixture to the bottom of a countercurrent absorption column (C1) which is supplied at the top with at least one type of hydrophobic heavy solvent, sending the flow (4) from the bottom of column (C1) to a separation column (C2). Column (C1) is operated at a flow rate of heavy solvent of from 3 to 5.6 times the flow rate of the (meth)acrylic acid in the gaseous reaction mixture and the rectifying column used as a separation column (C2) is operated with the feed at the top and without reflux.

Abstract: The compounds of formula (I) are provided as deposition inhibitors which prevent the deposition of compounds of polymeric nature or resulting from addition reactions to (meth)acrylic double bonds during operations for the synthesis or purification or regeneration of (meth)acrylic monomers. R1 represents a C3-C30 alkyl radical, an aryl radical or an alkylaryl radical, it being possible for these radicals to be interrupted by or connected to the oxygen of the molecule via a —(OR4)o— chain where the R4 groups each independently represent an ethylene, propylene or butylene chain and o is an integer from 1 to 50; R2 represents R1, a hydrogen atom or a counterion; and R3 represents a hydrogen atom or a counterion.

Abstract: The present invention relates to a method for purifying (meth)acrylic acid obtained by catalytic or redox oxidation of a gaseous substrate constituting propane, propylene, acrolein, isobutane, isobutene, tert-butyl alcohol and/or (meth)acrolein or mixtures thereof by sending the gaseous reaction mixture to the bottom of a countercurrent absorption column (C1) which is supplied at the top with at least one type of hydrophobic heavy solvent, sending the flow (4) from the bottom of column (C1) to a separation column (C2). Column (C1) is operated at a flow rate of heavy solvent of from 3 to 5.6 times the flow rate of the (meth)acrylic acid in the gaseous reaction mixture and the rectifying column used as a separation column (C2) is operated with the feed at the top and without reflux.

Abstract: The present invention relates to a method for purifying (meth)acrylic acid obtained by oxidizing propane, propylene, acrolein, isobutane, isobutene, ter-butyl alcohol, (meth)acrolein and mixtures thereof by sending the gaseous reaction mixture to the bottom of a countercurrent absorption column (C1) which is supplied at the top with at least one type of hydrophobic heavy solvent, sending the flow (2) from the bottom of column (C1) to a light component separation column (C2) and sending the flow from the base of column (C2), stream (4) to a separation device made up of three sections, exhaustion (S1), concentration (S2) and rectification (S3) respectively in order to extract pure (meth)acrylic acid.

Abstract: The inventive method for purifying (meth)acrylic acid by oxidising a propane and/or propylene and/or acrolein (acrylic acid production) and isobutane and/or isobutene and/or tert-butyl alcohol and/or methacrolein (methacrylic acid production) gaseous substrate consists in sending a gaseous mixture of a reaction (1) to the base of an absorption column (C1) which is supplied by the top and in counter-current by at least one type of hydrophobe absorption heavy solvent, in sending a flow (2) from the base of the column (C1) to a light component separation column (C2) and in sending a flow (4) from the base of the column (C2) to a separation device which is provided with three sections i.e. exhaustion (S1), concentration (S2) and rectification (S3), respectively in order to extract a pure desired acid, extract and advantageously recycling one or several types of heavy solvent in the absorption column (C1) and to separate intermediate heavy stabiliser-containing components from the desired (meth)acrylic acid.

Abstract: The invention concerns a method of purifying a (meth) acrylic monomer selected among (meth) acrylic acids and their esters, by distillation in the presence of at least a polymerisation inhibitor requiring input of oxygen and/or an inhibitor having better efficacy in the presence of oxygen for stabilizing the liquid phase. The invention is characterized in that the distillation is performed in the presence of a NO2 gas, with an oxygen/organic vapor (p/p) ratio ranging between 0.02 and 3%, and with a NO2 condensed organic vapor (p/p) ratio ranging between 0.01 and 50 ppm.

Abstract: The gas reaction mixture (1), formed of propylene, if the case arises, of ultimate oxidation products, of acrylic acid, of acrolein, of steam, of acetic acid and of heavy products, is sent to the bottom of an absorption column (C1) fed countercurrentwise at the top with a heavy hydrophobic absorption solvent. The gas flow (7), formed of propylene and of ultimate oxidation products, of major amounts of water and acetic acid, and of acrolein, is obtained at the top of (C1) and a flow (4), formed of acrylic acid, of the heavy solvent, of heavy products and of minor amounts of acetic acid and of water, is obtained at the bottom of (C1).

Abstract: 2-Ethylhexyl acrylate is obtained by esterification of acrylic acid (AA) with 2-ethylhexanol (2-EtHexOH), in the presence of at least one stabilizer for AA, with H2SO4 as catalyst, the crude reaction mixture (B1) obtained comprising the desired acrylate, 2-EtHexOH, AA, 2-ethylhexyl hydrogensulphate (2-EtHexSO4H), traces of H2SO4 and impurities.

Abstract: At least one nitroxide derivative is used to stabilize pure acrolein or highly concentrated solutions thereof (acrolein content ≧90% by weight), in contact with an essentially anaerobic atmosphere.

Abstract: 2-Ethylhexyl acrylate is obtained by esterification of acrylic acid (AA) with 2-ethylhexanol (2-EtHexOH), in the presence of at least one stabilizer for AA, with H2SO4 as catalyst, the crude reaction mixture (B1) obtained comprising the desired acrylate, 2-EtHexOH, AA, 2-ethylhexyl hydrogensulphate (2-EtHexSO4H), traces of H2SO4 and impurities.

Abstract: Process for purifying acrylic acid in order to remove the polymer-type impurities in those places in the distillation columns in which they have a tendency to accumulate, and more particularly a process directed towards removing the polymeric impurities which are formed during a step for removing the aldehyde impurities from acrylic acid, according to which step the medium containing the acrylic acid to be purified is distilled by adding to this medium at least one amino compound of hydrazine type and by flushing away, at the foot of the distillation column, the heavy compounds formed by the said hydrazine-type amino compound(s) with the impurities. According to the invention, the acrylic acid to be purified is also distilled in the presence of at least one compound from the class of nonionic surface agents and of at least one polymerization inhibitor. Polysaccharide ethers and acetates, in particular ethers derived from cellulose or starch, may be mentioned as nonionic surface agents.

Abstract: The method consists in extracting acrylic acid by countercurrent filtration washing of reaction gases by at least a hydrophobic absorbing heavy solvent, then recuperating the purified acrylic acid from the solution obtained at the end of this extracting step. As hydrophobic absorbing heavy solvent at least a hydrophobic aromatic compound is used having: a boiling point under atmospheric pressure between 260° C. and 380° C.; a crystallisation temperature less than 35° C. and a viscosity less than 10 mPa·s in a range of temperature between 30-80° C.

Abstract: To recover these noble products consisting of acrylic acid monomer, acrylic ester monomers and alcohols, a thermal cracking is performed in the absence of catalyst on a mixture of heavy distillation residues originating, on the one hand, from the manufacture of acrylic acid and, on the other hand, from the manufacture of the esters, the light fraction originating from the dissociation reactions is continuously vaporized during the cracking operation and this light fraction is distilled in order to recover, after condensation, the required products.

Abstract: Acrylic acid obtained by catalytic oxidation of propylene, extracted by countercurrent washing of the reaction gases which at least one hydrophobic heavy solvent in an extraction column (C1) is purified.

Abstract: An acrylic acid ester is manufactured by reaction of the said acid and an alcohol chosen from C.sub.

Abstract: In this esterification, catalysed by H.sub.2 SO.sub.4, the crude reaction mixture comprising ester, butanol, acrylic acid, BuSO.sub.4 H and traces of H.sub.2 SO.sub.4 is obtained; BuSO.sub.4 H is hydrolysed (in R2) to H.sub.2 SO.sub.4 using pure water or water generated during the reaction; after hydrolysis, the medium is separated by settling (in D2) into an organic phase containing ester, butanol and part of the unconverted acid; and an aqueous phase containing H.sub.2 SO.sub.

Abstract: An alkyl (meth)acrylate is prepared by a direct esterification (in 1) of (meth)acrylic acid by the corresponding alcohol, catalysed by H.sub.2 SO.sub.4. To the crude reaction mixture (C.sub.1) comprising the desired ester, alcohol, (meth)acrylic acid, alkyl hydrogen sulphate and traces of H.sub.2 SO.sub.4, there is added (in 3) a base to neutralize the acidic species, the resulting salts passing into the aqueous phase (A.sub.1), which is separated from the organic phase (O.sub.1) containing the desired ester. The light products (L.sub.1) containing the alcohol are recovered (in 4) from the aqueous phase, and the waste waters (W.sub.2) are expelled. A hydrolysis is carried out (in 8) of the alkyl hydrogen sulphate present in the aqueous phase (A.sub.1) obtained after the separation which is carried out after neutralization (in 3), to form the alcohol and H.sub.2 SO.sub.4 in this phase, the acidic species resulting from the hydrolysis are neutralized by introduction of a base .

Abstract: Catalytic process for the manufacture of acid fluoride selected from isobutyryl fluoride, methyl-2 butyryl fluoride, and pivaloyl fluoride from carbon monoxide, hydrogen fluoride, and an aliphatic hydrocarbon stream comprising principally an alkane having 3 to 4 carbon atoms, comprising the following series of stages:(a) introduction of at least one fluid chosen from carbon monoxide and the hydrocarbon stream into a reactor in the presence of a superacidic catalyst system comprising hydrogen fluoride, antimony pentafluoride, and at least one compound chosen from bromine, iodine, bromides, and iodides,(b) where appropriate, if it has not already been introduced during stage (a), introduction into the reactor of a fluid chosen from carbon monoxide and the hydrocarbon stream, under conditions that are suitable to permit the formation, principally, of a complex consisting of the alkyloxocarbonium cation and the anion SbF.sub.6.sup.

Abstract: Catalytic process for the manufacture of acid fluoride from carbon monoxide, hydrogen fluoride, and an aliphatic hydrocarbon stream mainly containing at least one alkane containing 3 to 4 carbon atoms, comprising the following series of stages:(a) introduction of at least one fluid chosen from carbon monoxide and the hydrocarbon stream into a reactor in the presence of a superacidic catalyst system consisting essentially of hydrogen fluoride and antimony pentafluoride,(b) where appropriate, if it has not already been introduced during stage (a), introduction into the reactor of a fluid chosen from carbon monoxide and the hydrocarbon stream, the reactor being at a temperature not above 60.degree. C. to permit the formation, principally, of a complex consisting of the alkyloxocarbonium cation and the anion SbF.sub.6.sup.-,(c) conversion of the complex into acid fluoride,(d) separation of the acid fluoride, and(e) recovery of the superacidic catalyst system.