Aromatisation of Six-Membered Rings
Aromatization of Six-Membered Rings: Industrial Applications
Aromatic compounds, such as benzene, toluene (methylbenzene) and xylene (dimethylbenzene), are synthesized from hydrocarbons of the C6-8 gasoline fraction obtained during petroleum refining by a process called catalytic reforming. In this process, gaseous hydrocarbons are dehydrogenated to aromatic compounds at temperatures of 450-550 and hydrogen pressure of 1000-5000 with platinum on aluminum oxide as catalyst. In spite of the fact that hydrogen is a product of reforming, excess hydrogen is necessary to prevent the deposition of high-molecular compounds and carbon on the catalyst leading to deactivation.
Addition of aromatic compounds to gasoline increases the octane number and therefore the quality. Some of the aromatics also find applications as solvents or basic organic chemicals.