FCC catalyst prepared by a process involving more than one silica material
Process for the preparation of a catalyst and a catalyst comprising more than one silica is provided herein. Thus, in one embodiment, the invention provides a particulate FCC catalyst comprising about 5 to about 60 wt % one or more zeolites, about 10 to about 45 wt % quasicrystalline boehmite (QCB), about 0 to about 35 wt % microcrystalline boehmite (MCB), greater than about 0 to about 15 wt % silica from sodium stabilized colloidal silica, greater than about 0 to about 30 wt % silica from ammonia stabilized or lower sodium colloidal silica, and the balance clay and the process for making the same. This process results in attrition resistant catalysts with good performance.
1. A process for manufacturing an FCC catalysts comprising:
a. Adding; clay, boehmite, and a first sodium stabilized colloidal silica to form a slurry;
b. Digesting the slurry with a monoprotic acid to a pH of less than 4;
c. Adding one or more zeolites to the slurry;
d. Adding a second silica that is either an ammonia stabilized or sodium stabilized colloidal silica, wherein the sodium content is less than the first sodium stabilized colloidal silica, at any time during or after steps (a) (c) but before step (e);
e. Mixing the slurry and then destabilizing the slurry by raising the pH to above 4.0;
f. Shaping and collecting the resulting FCC Catalyst.
2. The process of claim 1 further comprising adding about 5 to about 60 wt % one or more zeolites.
3. The process of claim 1 further comprising adding greater than 0 to about 15 wt % of the first sodium stabilized colloidal silica.
4. The process of claim 1 further comprising adding greater than 0.5 wt % to about 10 wt % of the first sodium stabilized colloidal silica.
5. The process of claim 1 further comprising adding greater than 0 to about 30 wt % of the second silica.
6. The process of claim 1 further comprising adding greater than 1 wt % to about 25 wt % of the second silica.
7. The process of claim 1 further comprising adding greater than 5 wt % to about 20 wt % of the second silica.