Hoechst Aktiengesellschaft

Hans-Klaus Kubbeler

Klaus Gehrmann

Heinz Erpenbach

Winfried Lork

Peter Horstermann

Georg Kohl

Klaus Schmitt

Klaus Schmitz

George Kohl

The disclosure relates to a process for separating the catalyst system from reaction mixtures which are obtained by reacting methyl acetate and/or dimethylether with carbon monoxide and optionally hydrogen at elevated temperatures to acetic anhydride and optionally ethylidene diacetate in the presence of a catalyst system consisting of carbonyl complexes of noble metals belonging to group VIII of the Periodic System, acetic acid, an organophosphorus or organonitrogen compound, methyl iodide and optionally compounds of carbonyl-yielding common metals, and which issue from the reaction zone under a pressure of 25 to 150 bars at a temperature of 100.degree. to 250.degree. C. More particularly, the reaction mixture coming from the reaction zone is introduced into a separator heated to 60.degree. to 140.degree. C. and released to a pressure of 0.5 to 3.5 bars with spontaneous evaporation of the bulk of volatile constituents; the stream of liquid matter coming from the separator is delivered to a distilling zone and the bulk of still volatile constituents is distilled off therein under a pressure of 0.05 to 1 bar at a base temperature of 70.degree. to 170.degree. C.; and catalyst solution retained as base product is recycled to the reaction zone.

Process for separating the catalyst system from the reaction mixtures of

The invention provides a process for making acetic anhydride, wherein methyl acetate and/or dimethylether is (are) reacted with carbon monoxide under substantially anhydrous conditions, at temperatures of 350 to 575 K and under pressures of 1 to 300 bars in the presence of a catalyst system comprised of noble metals belonging to group VIII of the periodic system of the elements, or their compounds and iodine and/or its compounds. More specifically, an aliphatic carboxylic acid with 1 to 8 carbon atoms and at least one heterocyclic aromatic compound, in which at least one hetero atom is a quaternary nitrogen atom are used as promoters.

Production of acetic anhydride

The invention relates to an improved process for making acetic anhydride by reacting methyl acetate and/or dimethylether with carbon monoxide under practically anhydrous conditions, at temperatures of 350 to 575 K., under pressures of 1 to 300 bars, and in the presence of a catalyst system containing noble metals belonging to group VIII of the periodic system of the elements, or compounds thereof, iodine and/or its compounds, and an aliphatic carboxylic acid having 1 to 8 carbon atoms. The improved process is effected in the presence of a catalyst system containing, as additional ingredients, a heterocyclic aromatic compound, in which at least one hetero atom is a quaternary nitrogen atom, or a quaternary organophosphorus compound, and a zirconium compound being soluble in the reaction mixture.

The invention relates to an improved process for making 1,1-diacetoxyethane by reacting methyl acetate and/or dimethylether with carbon monoxide and hydrogen under practically anhydrous conditions, at temperatures of 350.degree. to 575.degree. K., under pressures of 1 to 300 bars, and in the presence of a catalyst system containing noble metals belonging to group VIII of the periodic system of the elements, or compounds thereof, and iodine and/or its compounds. The improved process is effected in the presence of a catalyst system containing, as additional ingredients, an aliphatic carboxylic acid having 1 to 8 carbon atoms, a heterocyclic aromatic compound, in which at least one hetero atom is a quaternary nitrogen atom, and a manganese or rhenium compound.

Production of 1,1-diacetoxyethane

Alkyl acrylates free from ether are made continuously by reacting acrylic acid with a C.sub.1 -C.sub.4 -alkanol, in a molar ratio of 1:1 to 1:2, in liquid phase, at 80.degree. to 130.degree. C., under 100 to 760 mm Hg, in the presence of an acid catalyst.

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Swisttal, Germany

Hans-Klaus Kubbeler