Coking causes of boiling-bed isobutane dehydrogenation reactor

The formation of disperse metal particles and existing dead spaces in reactors were found to cause intense coking in boiling-bed dehydrogenation reactors. These disperse metal particles result from abrasive wear of the reactor construction parts with corundum particles existing in the IM-2201 catalyst due to jet flows accounted for by the geometry of the reactor interior devices. On these disperse metal particles, hydrocarbons are catalytically decomposed into hydrogen and carbon nanofibers of two types: fibers with a pile arrangement of graphene layers and bamboo-like tubes. The amount of formed carbon exceeds by two orders of magnitude the amount of metal resulting from abrasive wear. It was recommended to redesign the reactor in order to minimize abrasive wear of its parts, to line the reactor parts with ceramic materials, and to use a corundum-free catalyst. The results of this work can be used to prevent coking in boiling-bed reactors for the synthesis of isobutylene, isoamylenes, and n-butylene at Sibur Open Joint-Stock Company, Nizhnekamskneftekhim Open Joint-Stock Company, etc.