Abstract: The invention relates to a method for producing carboxylic esters by converting a carboxylic acid or a carboxylic acid anhydride or a mixture thereof with an alcohol in a reaction system comprising one or more reactors, wherein reaction water is distilled as alcohol-water-azeotrope with the vapors, the vapors are at least partially condensed, the condensate is separated into an aqueous phase and an organic phase and said organic phase is supplied at least partially back into said reaction system. Components boiling lower than the alcohol are at least partially removed from said returned organic phase such as wherein components boiling lower than alcohol are evaporated and/or distilled off. An enrichment in the reaction system of by-products boiling lower than alcohol is avoided. Alcohol losses can be minimized by discharge currents.

Abstract: The invention relates to a method for producing carboxylic esters by converting a carboxylic acid or a carboxylic acid anhydride or a mixture thereof with an alcohol in a reaction system comprising one or more reactors, wherein reaction water is distilled as alcohol-water-azeotrope with the vapors, the vapors are at least partially condensed, the condensate is separated into an aqueous phase and an organic phase and said organic phase is supplied at least partially back into said reaction system. Components boiling lower than the alcohol are at least partially removed from said returned organic phase such as wherein components boiling lower than alcohol are evaporated and/or distilled off. An enrichment in the reaction system of by-products boiling lower than alcohol is avoided. Alcohol losses can be minimized by discharge currents.

Abstract: The invention relates to a method for producing carboxylic acid esters by reacting a reaction mixture, comprising a carboxylic acid and/or a carboxylic acid anhydride, and an alcohol in a reaction system having one or more reactors, wherein reaction water is distilled off as an alcohol/water azeotrope with the exhaust vapor. In addition, the reaction mixture is treated with superheated alcohol vapor. The method allows the production of esters having a low acid number.

Abstract: The invention relates to a method for producing carboxylic esters by converting a carboxylic acid or a carboxylic acid anhydride or a mixture thereof with an alcohol in a reaction system comprising one or more reactors, wherein reaction water is distilled as alcohol-water-azeotrope with the vapors, the vapors are at least partially condensed, the condensate is separated into an aqueous phase and an organic phase and said organic phase is supplied at least partially back into said reaction system. Components boiling lower than the alcohol are at least partially removed from said returned organic phase such as wherein components boiling lower than alcohol are evaporated and/or distilled off. An enrichment in the reaction system of by-products boiling lower than alcohol is avoided. Alcohol losses can be minimized by discharge currents.

Abstract: The invention relates to a raw ester of an esterification reaction catalyzed by a metal-containing esterification catalyst generated by a) mixing the raw ester at a temperature T of more than 100° C. under a pressure p that is equal to or greater than the vapor pressure of water at the temperature T with an aqueous base, b) relaxing the ester-base mixture and evaporating water, c) mixing the obtained fluid phase with water forming a water-in-oil emulsion, d) distilling water out of said emulsion and e) filtering the ester. Said method results in esters having low acid value and residues accrue in easily filterable form in the solid catalyst residues.

Abstract: The invention relates to a method for producing carboxylic acid esters by reacting a reaction mixture, comprising a carboxylic acid and/or a carboxylic acid anhydride, and an alcohol in a reaction system having one or more reactors, wherein reaction water is distilled off as an alcohol/water azeotrope with the exhaust vapor. In addition, the reaction mixture is treated with superheated alcohol vapor. The method allows the production of esters having a low acid number.

Abstract: The invention relates to a method for producing carboxylic esters by converting a carboxylic acid or a carboxylic acid anhydride or a mixture thereof with an alcohol in a reaction system comprising one or more reactors, wherein reaction water is distilled as alcohol-water-azeotrope with the vapors, the vapors are at least partially condensed, the condensate is separated into an aqueous phase and an organic phase and said organic phase is supplied at least partially back into said reaction system. Components boiling lower than the alcohol are at least partially removed from said returned organic phase such as wherein components boiling lower than alcohol are evaporated and/or distilled off. An enrichment in the reaction system of by-products boiling lower than alcohol is avoided. Alcohol losses can be minimized by discharge currents.

Abstract: A process is described for preparing mixtures of diesters of phthalic acid with decanols and tridecanols by reacting phthalic acid or a reactive derivative of phthalic acid with a mixture made from at least one decanol and at least one tridecanol. Mixtures obtainable in this way are also described, as is their use as plasticizers for molding compositions, and also mixtures of isomeric tridecanols suitable for preparing the mixtures of diesters.

Abstract: Process for removal of the esterification catalyst by separation from a crude plasticizer ester obtained by reacting a dicarboxylic acid with C8–C13 alcohols, by treating the crude ester with an aqueous alkali solution in the range from 10 to 100° C. and then separating the aqueous alkaline phase comprising the hydrolyzed esterification catalyst by gravitational phase separation, by treating the crude ester, prior to or during the phase separation, with a salt of a di- or polyvalent metal, or with a mixture of these salts.

Abstract: Process for removal of the esterification catalyst by separation from a crude plasticizer ester obtained by reacting a dicarboxylic acid with C8-C13 alcohols, by treating the crude ester with an aqueous alkali solution in the range from 10 to 100° C. and then separating the aqueous alkaline phase comprising the hydrolyzed esterification catalyst by gravitational phase separation, by treating the crude ester, prior to or during the phase separation, with a salt of a di- or polyvalent metal, or with a mixture of these salts.

Abstract: The invention relates to a method for the production of phthalic anhydride to a specification, using a distillative purification of crude phthalic anhydride, by introduction of crude phthalic anhydride into a distillation column, operating at reduced pressure, withdrawal of the low-boiling fraction from the head, or near the head of the column and withdrawal of the phthalic anhydride, which meets the specification, from a side-tap on the column, whilst operating the column at a reflux ratio x, with 1:1.7<x<1:3.

Abstract: A process is described for preparing mixtures of diesters of phthalic acid with decanols and tridecanols by reacting phthalic acid or a reactive derivative of phthalic acid with a mixture made from at least one decanol and at least one tridecanol.

Abstract: A process for the continuous production of 1,3-dioxolan-2-ones such as ethylene carbonate or propylene carbonate by reacting a corresponding oxirane with carbon dioxide in the liquid phase in the presence of a catalyst comprises conducting the reaction in a two-part reactor in whose first part the reaction is taken with backmixing to a conversion of not less than 80% of the oxirane II and in whose second part the reaction is completed under nonbackmixing conditions, and passing the carbon dioxide in countercurrent to the oxirane II in the entire reactor.