Isomerization Behavior Comparison of Single Hydrocarbon and Mixed Light Hydrocarbons over Super-Solid Acid Catalyst Pt/SO42−/ZrO2/Al2O3

The hydroisomerization reaction of light alkanes was used to improve their octane value. Industrial light alkane feeds usually contain a certain amount of cycloalkanes and aromatics (known as hydrocarbon impurities). In this study, the influence of hydrocarbon impurities on the isomerization activity of n-alkanes over Pt/SO42−/ZrO2/Al2O3 (PSZA) was investigated in a continuous flow fixed-bed reactor, TPSR, and pulse reactor. The reason for the influence of hydrocarbon impurities on the isomerization activity of n-alkanes was also discussed by using in situ adsorption–desorption and temperature-programmed reactions. The catalyst was characterized by XRD, PyIR, N2 adsorption–desorption, TEM, and XRF. The results showed that the prepared catalyst contained mainly tetragonal zirconia and possessed a large amount of strong B and L acid sites. A certain amount of hydrocarbon impurities obviously inhibited the isomerization conversion of n-alkanes. The extent of the inhibition was very dependent on the kind of hydrocarbon impurities, n-alkane carbon number, and reaction temperature. Lighter n-alkane isomerization conversion was influenced to a greater extent. And the increase of reaction temperature could weaken its inhibitory effect. The results provided a reference and base for the industrial application of light alkane hydroisomerization over PSZA.