Leuna-katalysatoren Gmbh

Buck Werke Gmbh Und Co.

Rainer Schoedel

Peter Birke

Ulrich Neumann

Klaus Weber

Reinhard Geyer

Rudolf Schumann

Hans-Dieter Neubauer

Hannelore Grundmann

Hans-Georg Friese

Werner Haertwig

Gerhard Vogel

Willi Sattelmayer

Hans-Dieter Berrouschot

Anette Hoppe

A method for the hydrodechlorination of a reaction gas primarily composed of chlorinated hydrocarbons is carried out sequentially. A first step is advantageously carried out in a tubular reactor filled with catalyst and cooled externally, to maintain a temperature within a preferred range of 80.degree. to 230.degree. C. and a radial temperature difference of not more than 40.degree. C. Hydrogen is added to the tubular reactor with a hydrogen excess in a preferred range of 1.1 to 1.5 relative to the reaction gas, based on the stoichiometric consumption. The catalyst is present in a catalyst loading in a preferred range of 0.1 to 1.5 v/vh based on the volume of reaction gas. A fixed bed reactor is advantageously used for a second step, optimally connected in straight transit with the output of the reactor of the first step. The full-space reactor is maintained at a temperature within a preferred range of 200.degree. to 300.degree. C. and a hydrogen excess relative to the stoichiometric consumption is in a preferred range of 2 to 100. Catalyst is present in a preferred amount related to a volume of catalyst in step one according to a ratio in a range of 2:1 to 10:1. The dechlorination is preferably carried out at pressures between 1 and 50 bar. A method is further provided for regenerating deactivated catalysts without accumulation of dioxin in the waste gas, achieved by a reducing treatment, followed by an oxidizing treatment at a temperature at or above the last operating temperature of the catalyst.

Method for the complete hydrodechlorination of chlorinated hydrocarbons

A new hydrodehalogenation catalyst, as well as to its use for the hydrodechlorination of chlorinated hydrocarbons. The hydrodehalogenation catalyst, which converts halogenated hydrocarbons completely under mild conditions, has a considerably longer lifetime than do known catalysts and can be regenerated. In a method of hydrogenating dechlorination the catalyst works preferably under mild reaction conditions, with lifetimes of at least 2,500 hours and leads to reaction products, which can readily be used economically and thermally without further purification. The catalyst is a palladium aluminosilicate support catalyst, which is free of chlorinated compounds, has a palladium content of 0.5 to 8% by weight and a silica content of 1 to 50% by weight. The palladium concentration over the cross section of the support passes through a maximum in the region 50 to 250 .mu.m below the outer surface of the support, the maximum palladium concentration is 1.5 to 7 times the average palladium concentration.

Hydrodehalogenation catalyst

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Halle, Germany

Rainer Schoedel