Effect of the method of introduction of rhenium into a zeolite on the dynamics of its deactivation during upgrading of straight-run gasoline

Catalysts containing rhenium introduced by various methods are prepared on the basis of a high-silica zeolite of the Zeolite Socony Mobil 5 (ZSM-5) pentasil family with a silicate module 40. The catalytic activity of the prepared samples and the rate of their deactivation are investigated in the course of a conversion of a straight-run oil gasoline fraction. It is shown that the greatest decrease in catalytic activity, which is estimated by the concentration of aromatic hydrocarbons in the gasolines formed, is revealed by the initial ZSM-5. In all cases modification of zeolite with rhenium promote an increase in the time of stable operation of the resulted catalysts. Depending on the method of introduction of rhenium into zeolite, the rate of deactivation of the catalysts decreases in the following series: ion exchange–mixing with ultrafine powder–impregnation–dry mixing with ammonium perrhenate.