Abstract: Unsaturated hydrocarbons may be prepared by subjecting dehydrogenatable hydrocarbon to dehydrogenation in the presence of a dehydrogenation catalyst. The effluent stream from this step, comprising unconverted hydrocarbons, dehydrogenated hydrocarbons, hydrogen and steam, may then be passed to a selective oxidation step in which the hydrogen is selectively oxidized in the presence of an oxygen-containing gas to the substantial exclusion of the oxidation of the hydrocarbons. The oxidation catalyst which is employed will comprise a Group VIII noble metal, a Group IVA metal and a Group IA or IIA metal composited on a metal oxide support. The metal oxide support such as alumina will possess a particular configuration such as a polylobular particle containing from 3 to about 8 lobes and having a ratio of exterior surface to catalyst volume greater than [4D+2L] in which D is the largest representative diameter and L is the length of the particle.

Abstract: A process is provided for converting alkanes and cycloalkanes having up to 20 carbon atoms per molecule to a product comprising hydrogen gas and dehydrogenated and/or dehydrocyclized hydrocarbons, in the presence of a catalyst composition comprising divanadium pentoxide and silica. In one embodiment, a substantially deactivated catalyst composition is regenerated by contacting it with a free oxygen containing gas under suitable regeneration conditions. In another embodiment, a catalyst composition comprising divanadium pentoxide and silica is provided.

Abstract: There is disclosed a system for measuring and controlling the concentration of hydrogen in hydrogen recycle processes used in oil refineries and petrochemical plants. The system is intended to reduce the amount of hydrogen and hydrocarbon vapor circulating in such systems, thus reducing the quantity of utilities needed to operate such systems. Specifically, there is a savings of compressor power and fuel required for heating. The system is dependent on the recognition that a decrease in cooling medium temperature results in an increase in hydrogen flow, which can be decreased to the minimum permissible without endangering catalyst activity and stability and product yield if hydrogen concentration is monitored, and that partial pressure is the key parameter.

Abstract: A process for producing 1,3-butadiene which comprises feeding a fraction comprising C.sub.4 -paraffins and C.sub.4 -olefins as the main components and being free from isobutene, 1,3-butadiene and C.sub.4 -acetylenes to a dehydrogenation or oxidative dehydrogenation step (step A), where the n-butenes contained therein is converted to 1,3-butadiene; feeding the 1,3-butadiene-containing hydrocarbon fraction thus obtained (fraction C) to an extractive distillation column (column B), in which said fraction C is distilled in an atmosphere of a selective solvent while obtaining a fraction comprising C.sub.

Abstract: The catalytic dehydrogenation of at least one dehydrogenatable organic compound which has at least one ##STR1## grouping is carried out in the presence of a zinc titanate hydrogel. The selectivity of the zinc titanate hydrogel may be improved by adding a promoter selected from the group consisting of lithium, sodium, potassium, rubidium and cesium.

Abstract: Oxide complex catalysts comprising Fe-Sb-Bi-O.sub.x promoted with a wide variety of different elements have been found to be especially useful in the ammoxidation of olefins to nitriles such as acrylonitrile and methacrylonitrile. Not only are the desired nitriles obtained with high yields when these catalysts are used, but also the production of unwanted liquid byproducts such as acrolein, acrylic acid and acetonitrile is significantly reduced.

Abstract: Dehydrogenatable hydrocarbons are dehydrogenated by contacting them, at hydrocarbon dehydrogenation conditions, with a novel attenuated superactive multimetallic catalytic composite comprising a combination of a catalytically effective amount of a pyrolyzed rhenium carbonyl component with a porous carrier material containing a uniform dispersion of catalytically effective amounts of a platinum group component maintained in the elemental metallic state, and of a manganese component. An example of the attenuated superactive nonacidic multimetallic catalytic composite disclosed herein is a combination of a catalytically effective amount of a pyrolyzed rhenium carbonyl component with a porous carrier material containing a uniform dispersion of catalytically effective amounts of an alkali or alkaline earth component, a manganese component, and of a platinum group component which is maintained in the elemental metallic state during the incorporation of a rhenium carbonyl component.