Petro-Tex Chemical Corporation

Harold E Manning

Michael C Ellis

The isobutene in C.sub.4 hydrocarbon streams containing 5 to 60 mole % isobutene and n-butenes may be reduced to a level of 0.2 mole % or less by passing the feed stream at LHSV 0.5 to 12 in liquid phase through a fixed bed cation exchange resin catalyst in a tubular reactor with a water heat exchange medium maintained at a temperature of 30.degree. to 80.degree. C., whereby the isobutene is oligomerized and easily separated from the remaining C.sub.4 by fractionation.

Isobutene removal from C.sub.4 streams

A process for the oligomerization of normal C.sub.2 -C.sub.10 olefins, for example n-butenes by passing a feed containing said olefins in liquid phase through a fixed bed of acid, cation exchange resin at a temperature in the range of 40.degree. to 185.degree. C. at LHSV of 0.10 to 10 and recovering the oligomer product. In the case of n-butenes the principal component of the oligomer product is C.sub.8 dimer.

Process for oligomerization of C.sub.2 to C.sub.10 normal olefins

The isobutene in C.sub.4 hydrocarbon streams containing from 0.5 to 5% isobutene and n-butenes is reduced preferably to a level of 0.2 mole % or less by passing the feed stream at LHSV 2.5 to 12 in liquid phase through a fixed-bed cation exchange resin catalyst in a tubular reactor with a water heat exchange medium maintained at a temperature of 50.degree. to 80.degree. C., whereby the isobutene is oligomerized and easily separated from the remaining C.sub.4 's by fractionation.

Isobutene removal from C4 streams

Magnesium chromite dehydrogenation catalysts are improved by incorporation therein up to about 10% of an alkali metal.

Dehydrogenation process and catalyst

Magnesium chromites promoted with aluminum have been found to be superior to chromia-alumina type dehydrogenation catalysts, for example, in the dehydrogenation of n-butane. The aluminum is either added to the preformed magnesium chromite or is incorporated into the spinel structure of the chromite itself or added in both ways. The aluminum will be present in the catalyst from all sources in an atomic ratio of Al:Cr of 0.0004 to 1.2:1. The atomic ratio will more usually be 0.04 to 0.8:1, Al:Cr.

Dehydrogenation catalyst

Dehydrogenation process

Magnesium chromite dehydrogenation catalyst are improved by preparation in oxygen deficient or essentially inert calcination atmospheres and in the presense of halogen, either singularly or in combination.

Magnesium chromites promoted with B, Si, Sn, Pb and Se have been found to be superior to chromia-alumina type dehydrogenation catalysts, for example, in the dehydrogenation of n-butane. The promoter is either added to the preformed magnesium chromite or is incorporated into the spinel structure of the chromite itself or added in both ways. The promoter will be present in the catalyst from all sources in a mol ration of promoter : MgCr.sub.2 O.sub.4 of 0.001 to 0.25. The ratio will more usually be 0.03 to 0.08 : 1 promoter : MgCr.sub.2 O.sub.4.

Magnesium chromites promoted with B, Si, Sn, Pb and Se have been found to be superior to chromia-alumina type dehydrogenation catalysts, for example, in the dehydrogenation of n-butane. The promoter is either added to the preformed magnesium chromite or is incorporated into the spinel structure of the chromite itself or added in both ways. The promoter will be present in the catalyst from all sources in a mol ratio of promoter: MgCr.sub.2 O.sub.4 of 0.001 to 0.25:1. The ratio will more usually be 0.03 to 0.08 : 1 promoter : MgCr.sub.2 O.sub.4.

Magnesium chromites promoted with B, Si, Sn, Pb and Se have been found to be superior to chromia-alumina type dehydrogenation catalysts, for example, in the dehydrogenation of n-butane. The promoter is either added to the preformed magnesium chromite or is incorporated into the spinel structure of the chromite itself or added in both ways. The promoter will be present in the catalyst from all sources in a mol ratio of promoter: MgCr.sub.2 O.sub.4 of 0.001 to 0.25:1. The ratio will more usually be 0.03 to 0.08:1 promoter: MgCr.sub.2 O.sub.4.

The presence of 0.05 to 0.4 atom of chromium per atom of manganese in a manganese ferrite oxidative dehydrogenation catalyst improves the yields from oxidative dehydrogenation reactions employing such catalyst. A chromium modified manganese ferrite catalysts containing from 1 to 20 weight percent carbon is also disclosed.

Chromium modified manganese ferrite oxidative dehydrogenation catalysts

Metal chromite dehydrogenation catalysts are made by preparing an aqueous solution of CrO.sub.3, dissolving a second metal compound, such as MgO, therein adding a reducing agent, precipitating a substantially insoluble oxide of Mg and Cr, recovering the precipitate and calcining it to produce a Mg chromite dehydrogenation catalyst.

Method of metal chromite preparation

Magnesium chromite dehydrogenation catalysts are improved by incorporation therein up to about 10 % of an alkali metal. The effect of the addition of lithium is shown in the dehydrogenation of isopentane, n-butane and ethylbenzene.

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Houston, TX, United States of America

Harold E Manning