Intensification of butane dehydrogenation on a granular catalyst by hydrogen removal through palladium alloy membranes

A commercial Cr2O3-Al2O3 catalyst was placed in one of two zones of a plug flow reactor with a palladium alloy membrane. The oxidation of hydrogen diffusing from the zone of butane dehydrogenation gave higher butadiene yields than hydrogen removal by an argon flow. The magnitude of the effect depended on the nature and content of the second palladium alloy component. The most efficient membrane for the synthesis of butene and butadiene from butane was a palladium-tin alloy

Reconstruction of the surface layer of platinum group metals in the thermal treatment in various gases and propane hydrogenolysis

The enrichment with ruthenium of the surface layer of a Pd-Ru alloy tube during the propane hydrogenolysis was observed. Metal particles immobilized within carbonaceous deposits and filamentous crystals of the metals with a carbon cover are formed on the Rh and Ir wires. Thermal treatment in gases free of carbon compounds does not cause such a deep reconstruction. The deep reconstruction occuring during the propane hydrogenolysis is the stronger, the greater the amount of carbon this metal dissolves

Membrane-catalyst systems for selectivity improvement in dehydrogenation and hydrogenation reactions

Variation in the selectivity of dehydrogenation and hydrogenation reactions was observed as a result of the conditions of hydrogen transfer from the zone of paraffin, olefin or cyclohexane dehydrogenation into the zone of diene hydrogenation through a hydrogen permeable membrane in the form of foil, thin-walled tube or a dense palladium alloy layer on the thermostable porous support. Industrial granular catalysts Pt-Re/Al2O3 and alumina-chromia were used for dehydrogenation, and hydrogenation was performed by palladium-containing membrane catalysts. The dependence of the selectivity of cyclopentadiene (CPD) hydrogenation into cyclopentene (CPE) was measured by an increase in the thickness from 20 to 80 nm of the palladium-ruthenium (Pd-Ru) alloy layer on the polydimethylsiloxane film which was inert towards CPD hydrogenation. Cyclopolyolefines C7-C12 of different structure differ in the rate of their reaction with hydrogen diffused through the membrane catalysts or mixed with the polyolefin. © 2001 Published by Elsevier Science B.V

Intensification of butane dehydrogenation on a granular catalyst by hydrogen transfer through palladium alloy membranes

МАТЕРИАЛЫ ВТОРОЙ МЕЖДУНАР. КОНФ. ПО КАТАЛИЗУ В МЕМБРАННЫХ РЕАКТОРАХ, МОСКВА, РОССИЯ, 24-26 СЕНТ., 199

Intensification of butane dehydrogenation on a granular catalyst by hydrogen transfer through palladium alloy membranes

МАТЕРИАЛЫ ВТОРОЙ МЕЖДУНАР. КОНФ. ПО КАТАЛИЗУ В МЕМБРАННЫХ РЕАКТОРАХ, МОСКВА, РОССИЯ, 24-26 СЕНТ., 199

Intensification of butane dehydrogenation on a granular catalyst by hydrogen removal through palladium alloy membranes

A commercial Cr2O3-Al2O3 catalyst was placed in one of two zones of a plug flow reactor with a palladium alloy membrane. The oxidation of hydrogen diffusing from the zone of butane dehydrogenation gave higher butadiene yields than hydrogen removal by an argon flow. The magnitude of the effect depended on the nature and content of the second palladium alloy component. The most efficient membrane for the synthesis of butene and butadiene from butane was a palladium-tin alloy

Changes in the catalytic activity and hydrogen permeability of a palladium-ruthenium alloy membrane catalyst under the influence of reagents

1. In the course of catalytic hydrogenation reactions of cyclopentadiene, cyclooctadiene, and isoprene; and in the catalytic hydrogenolysis of propane, all of which proceed at 373-573 K, a.catalytic etching of a palladium-ruthenium membrane catalyst is taking place; it is determined by the nature of the reagents. 2. An oxidative-reductive treatment changes the surface structure, the catalytic activity, and the hydrogen permeability to a much lesser degree than when such a treatment is alternated with actual catalytic reactions. 3. A heat treatment followed by a subsequent rapid cooling from temperatures above the recrystallization temperature, increases significantly the activity of a palladium-ruthenium membrane catalyst in the hydrogenolysis of propane. © 1988 Plenum Publishing Corporation

Effect of reaction products on dehydrogenation rate of isoamylenes on a membrane catalyst

The dehydrogenation of isoamylenes on a membrane catalyst composed of a Pd catalyst with 5.9% Ni under nongradient conditions is inhibited by isoprene, while the reaction rate passes through a maximum when the partial pressure of hydrogen in the starting mixture is increased. © 1977 Plenum Publishing Corporation