Hoechst Aktiengesellschaft

Eitel Goedicke

Wilhelm Vogt

Hermann Glaser

Heinz Erpenbach

Winfried Lork

Gerhard Mietens

Heribert Tetzlaff

In a process for the purification and recovery of a contaminated catalyst solution produced during carbonylation of methanol and/or methyl acetate and/or dimethyl ether and containing carbonyl complexes of rhodium, organic and/or inorganic promoters, undistillable organic impurities and acetic acid, acetic anhydride and ethylidene diacetate, the organic impurities and acetic acid, acetic anhydride and ethylidene diacetate are removed from the contaminatd catalyst solution by extraction at pressures from 35 to 450 bar and temperatures from 0.degree. to 120.degree. C. with a liquefied or supercritical gas, and the phase of the liquefied or supercritical gas is separated from the purified, promoter-containing catalyst solution, the phase of the liquefied or supercritical gas is separated by flash vaporization, the recovered gas is re-employed for extraction, acetic acid, acetic anhydride and ethylidene diacetate are separated off from the component which remains liquid, and are combined with the purified catalyst complex to prepare fresh catalyst solution and, finally, the organic impurities remaining as the residue on separation of the phase of the liquefied or supercritical gas is purged.

Process for the purification and recovery of the contaminated solution

A carrier-supported catalyst is made by applying one or more non-noble metal and noble metal components on to a ceramic honeycomb structure coated with a layer of a heat-resistant metal oxide. To this end, the ceramic honeycomb structure is dipped at least once into an aqueous suspension of pseudoboehmite and zirconium oxide hydrate, the honeycomb structure so treated is dried at temperatures of up to 250.degree. C. and calcined at temperatures of up to 1000.degree. C.; next, the honeycomb structure is impregnated with an aqueous solution of at least one iron salt, and, if desired, nickel and cerium salts, dried at temperatures of up to 250.degree. C. and annealed at temperatures of up to 600.degree. C.; next, the honeycomb structure is impregnated with an aqueous solution containing at least one soluble compound of platinum, rhodium or palladium, and, if desired cerium, one of the solutions under (b) or (c) being required to contain cerium; the honeycomb structure so treated is ultimately dried at temperatures of up to 250.degree. C. and annealed at temperatures of up to 600.degree. C.

Process for making a carrier-supported catalyst

A carrier-supported catalyst is prepared by applying a noble metal on to a ceramic honeycomb structure coated with an aluminum oxide layer. To this end, the ceramic honeycomb structure is impregnated with an aqueous solution containing nitrilotriacetic acid or ethylenediaminotetraacetic acid, ammonia and at least one noble metal compound.

A carrier-supported catalyst is made by impregnating a ceramic honeycomb structure having a layer of a heat resistant metal oxide applied to it with the aqueous solution of at least one metal selected from platinum, rhodium and palladium, drying the impregnated honeycomb structure and annealing it. More particularly a drying gas regularly distributed across the entire cross-sectional area of the impregnated honeycomb structure is passed therethrough at 20.degree. to 400.degree. C. The temperature and quantity of drying gas are selected so that water ceases to be evaporated from the impregnated honeycomb structure after 30 to 300 seconds and the dried impregnated honeycomb structure is heat-treated over a period of 1 to 3 hours at temperatures up to 1000.degree. C.

A converter for catalytic conversion of exhaust gas from an internal combustion engine comprising a double-shelled housing, of which the outer shell is spaced apart from the inner shell. The two shells are slidable with respect to one another and have a heat-retaining layer disposed there-between. The housing is provided with a gas inlet and gas outlet. Slidably mounted in the interior of the housing is at least one receptacle which has exhaust gas passage ways disposed in its upper and lower end portions. The receptacle(s) is (are) filled with granular catalyst forming a bed.

Converter for catalytic conversion of exhaust gas from an internal

Device for holding a granular catalyst suitable for use in the decontamination of the exhaust gas of an internal combustion engine. The device comprises a housing which comprises a jacket closed by means of end plates and which is provided with a gas inlet and gas outlet, and which has disposed therein a sleeve having an annular cross-section and having perforated walls, this sleeve being disposed substantially concentrically with respect to the gas inlet. In the device at least one end-plate-facing terminal portion of the sleeve, and also the lateral wall of the sleeve, are slidably mounted relative to the jacket of the housing, so as to accommodate axial relative movements.

Device for holding a granular catalyst

Device for holding a granular catalyst suitable for use in the decontamination of exhaust gas from an internal combustion engine. The device comprises a housing which is closed by means of end plates and provided with a gas inlet and gas outlet and in which there is disposed a sleeve having perforated walls which are substantially circular in cross-section, this sleeve being disposed therein substantially concentrically with respect to the gas inlet. The device is provided with one or more flow-defining means which are accommodated in the housing, the gas flow-defining means causing gas admitted to the housing to be at least partially directed in a substantially axial direction so as to form a stream flowing under increased static pressure towards one of the end regions of the sleeve.

Catalytic converter for exhaust gases

Apparatus adapted to receive one or more catalysts for the decontamination of exhaust gas of internal combustion engines. The apparatus, which includes a closed container for one or more beds of catalyst, is provided with an inlet for introducing exhaust gas thereinto and with an outlet for removing decontaminated exhaust gas therefrom. The catalyst beds are maintained in position by means of a spring-actuated clamping device which comprises a thrust rod, a mounting therefor and a spring element. The spring element, which bears against the mounting, urges the thrust rod into close contact with the catalyst beds.

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Bergheim, Germany

Eitel Goedicke