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Star - Steam active reforming
196 Please note that after 1 July, 1982, all contributions should be addressed to Dr. J.R.H. Ross Department of Chemical Technology, Twente University of Technology, P.O. Box 217, 7500 AE Enschede, The Netherlands STAR - Steam Active Reforming Phillips Petroleum have announced a new catalysed process for the dehydrogenation of isobutane to isobutene, used, for example, as a precursor for methvl-t-butvl ether (MTBE), the replacementFor lead in gasoline. The isobutane is diluted with steam and is passed into a series of furnace tubes containing a proprietary solid catalyst. Coke is deposited and so the process requires two or more parallel reactors with coke burn-off every eight hours. The yield is high, reaching about 47.5% of isobutene and 2.5% of light gases are also produced. Phillips do not olan to build a comnercial plant at present but are willing to iicence the process. New Steam Reforming Catalysts Imperial Chemical Industries have recently disclosed (European Application 81, 302484.1) a new catalyst for the production of hydrogen by the reaction of a carbonaceous feed-stock with steam or, where appropriate, carbon dioxide. Catalysts for such processes have most commonly been supported on a refractory material such as alumina or hydraulic cement and should be mechanically strong with a high porosity and surface area. The patent application proposes the use of a low-pore volume "primary" support(for strength) and a coating of a high surface area porous "secondary" support. The most suitable primary supports are hollow cylinders with transverse internal partitions, preferably chordal and non-radial, prepared from e.g. alumina fired at i3bO1800°C, with an area of less than 1.0 m2g-1.. The secondary support may be prepared by forming a colloidal suspension of the material to be used (e.g. Al2O3), suspending further of the same material in the dispersion and applying
the suspension to form a thin coating (less than 1 mn thick) over the surface of the primary support; a grain growth inhibitor, especially 0.1 to 5% by weight of a rare earth oxide such as cerium oxide, may be added at the same time. The active component is then incorporated by impregnation techniques (possibly by repeated impregnations)to give the required content; platinum group metals may be used, either alone or with other metals such as nickel or cobalt as the active component. The patent application gives example of the processes for which the catalyst may be used and typical results obtained with materials prepared according to the invention. Oxidation Catalyst for Cigarettes Gallaher Ltd., the cigarette manufacturer, have disclosed (British Patent aoolication 1.604.0811 a catalyst'for the oxidation ot cigarette smoke. This consists of palladium, platinum or rhodium supported on a preformed alumina or zeolite carrier. (The catalyst can also be used for purification of the exhaust gases from internal combustion engines.) Is there not a danger, if the catalyst is very efficient, of removing all those nasty things for which cigarette smokers seem to crave? Presumably, there must be a happy medium. Homogeneous Reduction of Nitro Compounds to Amines The catalytic hydrogenation of organic nitro compounds is of importance as the organic amines produced are important starting materials for many organic syntheses. Although a series of heterogeneous catalysts are known for this purpose, they are susceptible to poisoning and are not totally selective. -A recent paper by Biemer, Dexheimer and Madeja (J. Prakt. Chem., 323 (1981) 857) describes the use of cobalt complexes with tetradentate chelating agents (dimethvlolioximate anion or one of th other closely related lisands with sliaht chemical modification of the internal ligand spheres) together with carbon monoxide and water to catalyse the reduction reaction at room temperature and atmospheric pressure with high specificity.
the suspension to form a thin coating (less than 1 mn thick) over the surface of the primary support; a grain growth inhibitor, especially 0.1 to 5% by weight of a rare earth oxide such as cerium oxide, may be added at the same time. The active component is then incorporated by impregnation techniques (possibly by repeated impregnations)to give the required content; platinum group metals may be used, either alone or with other metals such as nickel or cobalt as the active component. The patent application gives example of the processes for which the catalyst may be used and typical results obtained with materials prepared according to the invention. Oxidation Catalyst for Cigarettes Gallaher Ltd., the cigarette manufacturer, have disclosed (British Patent aoolication 1.604.0811 a catalyst'for the oxidation ot cigarette smoke. This consists of palladium, platinum or rhodium supported on a preformed alumina or zeolite carrier. (The catalyst can also be used for purification of the exhaust gases from internal combustion engines.) Is there not a danger, if the catalyst is very efficient, of removing all those nasty things for which cigarette smokers seem to crave? Presumably, there must be a happy medium. Homogeneous Reduction of Nitro Compounds to Amines The catalytic hydrogenation of organic nitro compounds is of importance as the organic amines produced are important starting materials for many organic syntheses. Although a series of heterogeneous catalysts are known for this purpose, they are susceptible to poisoning and are not totally selective. -A recent paper by Biemer, Dexheimer and Madeja (J. Prakt. Chem., 323 (1981) 857) describes the use of cobalt complexes with tetradentate chelating agents (dimethvlolioximate anion or one of th other closely related lisands with sliaht chemical modification of the internal ligand spheres) together with carbon monoxide and water to catalyse the reduction reaction at room temperature and atmospheric pressure with high specificity.