Cracking with cycloalkanes

For hydrocarbon reactions, metals (particularly platinum and its alloys) are frequently applied to acidic supports to catalyse hydrogen transfers. Thus platinum on a chlorinated alumina support accelerates the acid catalysed isomerization of n-alkanes (at about 150°C). In hydrocracking, the metal catalyses hydrogenation of heavy aromatic and polyaromatic components the resulting cycloparaffins (cycloalkanes) undergo zeolitic cracking, with... 

This bimolecular mechanism also applies to cycloalkanes which can be activated by intermolecular hydride transfer to small carbenium ions to form cyclohexyl cations prior to cracking. Alternately, the cyclohexyl cations can deprotonate and form cyclohexene. With two similar intermolecular hydride transfers an aromatic can also form [46]. 

Hydrogenation of fluorene Hydrogenation of fluorene provided, 34 wt % hexahydrofluorene, 6 wt % peihydrofluorene and 16 wt % cracked material as well as 44 wt % unreacted fluorene.The cracked material consisted largely of diphenyl with smaller proportions ortho methyl-substituted diphenyl. These products arise from cracking of the central five-membered ring. Compounds produced from hydrogenation of these compounds were also identified as well as small amounts of cycloalkanes. 

A further report of the oxidation ability of manganese nodules is that of Nitta.53 Several reactions were carried out with natural manganese oxide nodules including oxidative dehydrogenations of alkanes and cycloalkanes, reduction of NO, total oxidation of CO, and use in the gettering of metal and mixed metal ions. For example, nodules were found to have a tremendous capacity for adsorption of heavy metals and toxic metals like Pb2+, and Hg2+. in addition, nodules have been used to sequester metals that are present in petroleum fractions that can contain metals like V and Ni. These metals can cause degradation of the fluid cracking catalysts even at levels as low as 1 ppm. 

The catalytic reforming process is, together with catalytic cracking, one of the most important processes in modem refinery schemes. It is used to convert low octane n-alkanes and cycloalkanes with 5 to 10 carbon atoms contained in the petroleum naphtha into high-octane isoalkanes and aromatics gasoline components and hydrogen. Typically, reformer reactors operate at temperatures of 425-525 °C and hydrogen pressures of 0.5-3.0 MPa. 

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