A PROCESS FOR THE DEHYDROGENATION OF A FEED HYDROCARBON

摘要

Dehydrogenatable hydrocarbons such as alkylaromatic hydrocarbons (e.g. ethylbenzene) are catalytically dehydrogenated with minimum production of thermal by-products by using several reactors containing dehydrogenation catalyst in series flow with interstage heating being supplied by selective combustion of hydrogen produced in the process. The selective combustion of hydrogen is performed in a reactor which has a relatively small bed of dehydrogenation catalyst located adjacent to the bed of selective hydrogen oxidation catalyst and which has a flow path such that the entering hydrogen-containing stream first contacts the bed of oxidation catalyst and immediately thereafter contacts the bed of the dehydrogenation catalyst. Thus the stream passed to the reactor is heated to a relatively high temperature in the oxidation bed as exothermic combustion of hydrogen and then immediately cooled to a somewhat lower temperature in the small bed of dehydrogenation catalyst by the endothermic dehydrogenation reaction. This sequence of steps shortens the time the reactants are maintained at high temperatures which produce undesired by-products and reduces the temperature of the reactants prior to transport through a conduit to the main bed of dehydrogenation catalyst.