Hoechst Aktiengesellschaft

Hoechst Agteingesellschaft

Peter M Roth

Siegfried Rewitzer

Erhard Leistner

Wolfgang Wendel

Hans Haverkamp

Karl Heinrich

Georg-Emerich Miess

Michael Kleiber

Wolfgang Schick

Werner Kraus

Norbert Schadler

Joachim Burschapers

Thomas Vernaleken

Regina Witt

A process for the separation of dimethyl ether and chloromethane in mixtures A process for the separation of dimethyl ether and chloromethane in mixtures by two distillation steps. In the first step, the mixture is subjected to an extractive distillation with water, aqueous salt solutions or organic liquids as extractant, the top product being chloromethane. In the second step, the dimethyl ether is separated from the extractant.

Process for the separation of dimethyl ether and chloromethane in

The invention relates to a process for the purification of an inert gas by subjecting the inert gas to a sorption treatment, especially gas scrubs. The invention comprises compressing the inert gas to a higher pressure before the sorption treatment, performing the sorption treatment at this higher pressure, and then expanding the purified inert gas. The advantages of the process of the invention can be seen to be essentially that, for example, streams of waste air which contain as impurities volatile solvents such as methyl chloride, isopropyl chloride, or dichloromethane, can be cleaned up with low consumption of energy and scrubbing liquid. Correspondingly, the equipment can have smaller dimensions.

Process for purifying inert gases

A process for the preparation and fractionation of a mixture of dimethyl ether and chloromethane by extractive distillation with water as extractant. The mixture is prepared by reacting methanol with hydrogen chloride. It is then subjected to an extractive distillation with water as extractant, resulting in chloromethane as top product. In the next step, the dimethyl ether is removed by distillation and, in another step, the extraction water is separated from the methanol which is still present.

Process for the preparation and fractionation of a mixture of dimethyl

This invention relates to a process for the preparation and fractionation of a mixture of dimethyl ether and chloromethane by extractive distillation with methanol as extractant. The mixture is prepared by reacting methanol with hydrogen chloride. The mixture is then distilled to remove water and is subsequently subjected to an extractive distillation with methanol as extractant, with chloromethane resulting as top product. In another distillation step, the remaining dimethyl ether is separated from the methanol.

An apparatus is described for recovery and reuse of liquids which are used as solvents and for the specific dilution of the solvent in the chemical reaction and/or the processing of substances. The process includes:

Process for solvent recovery and apparatus suitable therefor

A process for recovery and reuse of liquids used as solvents and diluents in a chemical reaction and/or the processing of substances, the process include the introduction of a solvent, a diluent, and a substance to be reacted and/or processed into a processing plant, feeding a used mixture of solvent, diluent and residues into a recovery plant, separating the solvent, diluent and residue resulting from the chemical reaction and/or processing of substances, recycling the solvent and diluent back to the processing plant, ejecting residues, and ejecting the treated substances. The apparatus for carrying out the process is also described.

Process for solvent recovery

The invention relates to a process for separating out hydrogen chloride from a gas mixture forming in the chlorination of methane, which gas mixture contains unreacted methane, its chlorination products and hydrogen chloride formed in the reaction, by cooling and compression of the gas mixture and subsequent scrubbing with a scrubbing liquid which comprises at least one liquid chlorination product of methane. The gas mixture is separated into a methane-containing gas phase and a liquid phase containing hydrogen chloride and methane chlorination products, and the hydrogen chloride is then desorbed from the liquid phase by heating.

Process for separating out hydrogen chloride

Column having integrated heat exchanger A column is described including a column body (1) and at least one heat exchanger (2) installed directly on the column head. This heat exchanger is a plate heat exchanger which is specially arranged so that the condensing vapors and the condensate (12) generated on the exchanger surface move in one direction. A further embodiment of the invention relates to a column which contains a column body (1) and at least one plate heat exchanger installed between two trays and/or packing beds within the column, which plate heat exchanger is operated as a condenser and is situated within a collecting vessel (29) open at the top. A third embodiment of the invention relates to a column which includes a column body (1) and at least one plate heat exchanger (2), which is operated as an evaporator, and which is installed within the column between two trays and/or packing beds and/or in the bottom. The column according to the invention is distinguished by a space-saving construction.

Column having integrated heat exchanger

Reprocessing mixtures which contain organic solvents and constituents of low volatility and may contain water: includes introducing the mixture into a concentration apparatus of a solvent recovery system, concentrating the mixture in the concentration apparatus by evaporating off a portion of a readily volatile fraction and feeding this readily volatile fraction to a separation column. A portion of the concentrated mixture from the concentration apparatus is conducted away into a separation apparatus where the constituents of low volatility are separated off from the concentrated mixture and ejected from the solvent recovery system. The concentrated mixture is conducted away, freed from the constituents of low volatility, from the separation apparatus.

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Eppstein, Germany

Peter M Roth