Hydrocarbon conversion catalyst composition
A hydrocarbon conversion catalyst composition which comprises dealuminated ZSM-48 and/or EU-2 zeolite and a refractory oxide binder essentially free of alumina, processes for preparing such composition and processes for converting hydrocarbon feedstock with the help of such compositions.
1. A catalytic dewaxing process for reducing the pour point of a wax-containing feedstock, said catalytic dewaxing process comprises:
contacting under dewaxing conditions said wax-containing feedstock, having a 10% distillation point at 200° C. as measured by ASTM D-2887-93, with a dewaxing catalyst composition, wherein said dewaxing conditions include a contacting temperature in the range of from 250 to 400° C., a contacting pressure in the range of from 5×10 5 to 200×10 5 Pa, and a liquid hourly space velocity in the range of from 0.1 to 10 hr −1 , and thereby providing a reduction of the pour point of said wax-containing feedstock by at least 10° C.;
wherein said dewaxing catalyst comprises a dealuminated dried and calcined extrudate, wherein said extrudate, before drying and calcination, comprises a binder that is essentially free of alumina and which comprises both a silica powder, wherein said silica powder comprises powder particles having a mean diameter between 10 μm and 200 μm, and a silica sol; EU-2 zeolite, wherein said EU-2 zeolite has a silica-to-alumina molar bulk ratio before the dealumination of said dried and calcined extrudate in the range of from 100 to 210; a plasticising agent; and water in an amount of at least 35% and not exceeding 60% by weight of the extrudate before drying and calcination; and
a catalytic metal selected from the group consisting of platinum, palladium and nickel;
wherein the dealumination of said dried and calcined extrudate is done by contacting said dried and calcined extrudate with an aqueous solution of fluorosilicate salt having a concentration of at least 0.005 mole of fluorosilicate salt/liter and at most 0.5 mole of fluorosilicate salt/liter and at a temperature in the range of from 10° C. to 120° C., and
wherein the amount of said EU-2 zeolite present in said catalyst composition is at least 15% wt. of said catalyst composition; and
wherein the EU-2 zeolite is in the form of EU-2 zeolite particles, where the average aluminum concentration of the EU-2 zeolite particles is at least two times the aluminum concentration at the surface of the particles.
2. The process as recited in claim 1 , wherein the EU-2 zeolite content in said catalyst composition, on a dry basis, is in the range of from 20 to 70 wt. % as calculated on the total weight of said catalyst composition.
3. The process as recited in claim 2 , wherein said fluorosilicate salt of said fluorosilicate salt solution is represented by the formula:
( A )2/ b SiF6
wherein ‘A’ is a metallic or non-metallic cation other than H+ having the valence ‘b’.
4. The process as recited in claim 3 , wherein the plasticizing agent is selected from the group consisting of dextrose, gelatin, glucose, glues, gums, salts, waxes, starch and cellulose ethers.
5. The process as recited in claim 4 , wherein said binder contains at most 2% wt. alumina, based on dry weight of the binder.
6. The process as recited in claim 5 , wherein said binder contains at most 1.1% wt. alumina, based on dry weight of the binder.
7. The process as recited in claim 6 , wherein said extrudate further comprises zeolite ZSM-12 that is present therein in an amount of at most 50% wt., based on the weight of said EU-2 zeolite present in said catalyst composition.
8. The process as recited in claim 7 , wherein the amount of EU-2 zeolite is at least 25% wt. and at most 65% wt.
9. The process as recited in claim 8 , wherein said plasticizing agent is methylcellulose or a methylcellulose derivative.
10. The process as recited in claim 9 , wherein said binder contains at most 0.2% wt. alumina, based on dry weight of the binder.
11. The process according to claim 10 , wherein said contacting temperature is in the range of from 275 to 350° C. and said contacting pressure is in the range of from 15×10 5 to 170×10 5 Pa.
12. The process according to claim 11 , wherein said wax-containing feedstock has a wax content of at least 50% by weight as determined by ASTM method D3235.
13. The process according to claim 12 , wherein said reduction of the pour point of said wax-containing feedstock is at least 20° C.
14. The process according to claim 13 , wherein said wax-containing feedstock has a wax content of at least 80% by weight.