FCC catalyst additive and a method for its preparation

摘要

The present invention relates to a Fluid Catalytic Cracking (FCC) additive preparation process and composition, which has high efficiency in the production of light olefins C2, C3 and C4 hydrocarbons, specifically propylene. The present invention discloses the stabilization of medium pore zeolite specifically ZSM-5 using optimum phosphate salts at a pH in the range 7-9 with synergetic combination of silica rich binder to produce FCC additive having excellent stability under severe hydrothermal conditions.

主权项

1. A zeolite based hydrothermally resistant Fluid Catalytic Cracking (FCC) catalyst additive which comprises a product obtained by spray drying and calcination of a raw material mixture having a pH ranging from 5 to 9 comprising:
ZSM-5 zeolite ranging from 40 wt % to 60 wt % that has been stabilizing with at least one phosphate source selected from the group consisting of diammonium hydrogen phosphate (DAHP) and monoammonium hydrogen phosphate, wherein the phosphate is measured in terms of P2O5 and ranges from 7 wt % to 12 wt % to provide a stabilized zeolite-phosphate slurry having a pH in the range of 7-9; clay ranging from 20 wt % to 40 wt %; and a binder ranging from 10 wt % to 40 wt %; said binder comprising silica in an amount of 75 to 100 wt % with respect to the mass of the binder, said additive being characterized by a pre-hydrothermal acidity of 200-350 μmol/g and a post-hydrothermal acidity of 25 to 150 μmol/g; silica content of above 70 % with respect to the total mass of the additive, and sodium content less than 0.5 wt % with respect to the mass of the additive.