Catalyst composition for treating heavy feedstocks

Abstract

The present invention provides a catalyst and a process for its preparation and its use in cracking heavy feedstocks. The catalyst comprises one or more zeolites having a controlled silica to alumina ratio and preferably treated with alkali in the presence of a matrix component selected from the group consisting of clays, synthetic matrix other than pillared clay, and mixtures thereof. The catalyst are particularly useful in treating heavy feedstock such as residues from oil sands processing.

Description

BRIEF DESCRIPTON OF THE DRAWINGS

FIG. 1 is an x-ray diffraction pattern of an alkali treated shape selective zeolite (alkaline treated ZSM5-sodium form).

FIG. 2 shows nitrogen adsorption and desorption isotherms at 77 K for an alkaline treated shape selective zeolite (alkali treated ZSM-5, proton form).

FIG. 3 is a BJH pore size distribution of an alkaline treated shape selective zeolite (alkaline treated ZSM-5 proton form).

Claims

1. A process for preparing a modified zeolite catalyst comprising forming a slurry of from 15 to 55 weight % of a matrix component selected from the group consisting of clays, synthetic matrix other than pillared clay, and mixtures thereof and from 10 to 20 weight % of a sol or gel of a binder selected from the group consisting of oxides of aluminum, silicon, and mixtures thereof and from 0 to 15 weight % of an oxide of a group IVB or VB metal adding thereto from 10 to 75 weight % of a mixture of one or more zeolites selected from the group consisting of: (i) an alkaline treated shape selective zeolite having a structure in which the silica to alumina ratio is less than 45 and a meso-large pore BET surface area of greater than 50 m2/g;(ii) an olefin selective zeolite having a structure in which the silica to alumina ratio is less than 70;(iii) a beta zeolite having a structure in which the silica to aluminum ratio is less than 100;(iv) a Y-faujasite type zeolite having a structure in which silica to alumina ratio is less than 30;

2. The process according to claim 1, wherein zeolite component (i) has a silica to alumina ratio less than 40.

3. The process according to claim 2, wherein zeolite component (i) is present in an amount from 10 to 90 weight % of the total zeolite content.

4. The process according to claim 3, wherein the phosphorus content in the catalyst is from 0.2 to 15 weight % based on the total weight of the catalyst.

5. The process according to claim 4, wherein said zeolite, said catalyst or both are treated with a phosphorus compound selected from the group consisting of ammonium dihydrogen phosphate and diammonium hydrogen phosphate, ammonium hypophosphate, ammonium orthophosphate, ammonium dihydrogen orthophosphate, ammonium hydrogen orthophosphate, triammonium phosphate, phosphine halides and organic phosphates, phosphines, and phosphates, and combinations thereof.

6. The process according to claim 5, wherein zeolite component (i) is selected from the group consisting of ZSM-5, ZSM-8, ZSM-11, ZSM-12, ZSM-35, ZSM-38 and mixtures thereof.

7. The process according to claim 6, wherein the group VB, VIB, VIIB and VIII elements are selected from the group consisting of V, Cr, Mn, Co, Ni, Cu, and mixtures thereof.

8. The process according to claim 7, wherein zeolite component (i) has a meso-large pore BET surface area greater than 80 m2/g.

9. The process according to claim 8, wherein zeolite component (ii) has a meso-large pore BET surface area less than 40 m2/g.

10. The process according to claim 8, wherein zeolite component (ii) is selected from the group consisting of ZSM-5, ZSM-8, ZSM-11, ZSM-12, ZSM-35, ZSM-38 and mixtures thereof.

11. The process according to claim 1, wherein zeolite components (ii), (iii) and (iv) or a mixture there of are present in a total amount from 10 to 90 weight % of the zeolite components.

12. The process according to claim 1, wherein said catalyst is formed into particles by one or more processes selected from the group consisting of: (i) spray drying the resulting slurry at a temperature from 100° C. to 650° C., followed by calcining the resulting solid at a temperature from 500° C. to 800° C.;(ii) drying the resulting slurry at a temperature from 100° C. to 150° C.; calcining the resulting solid at a temperature from 500° C. to 800° C. and subjecting it to a comminution step; and(iii) by extruding the resulting slurry and drying the resulting extrudate.

13. The process according to claim 1, wherein the final particle size for the catalyst is from 0.005 to 0.150 mm.

14. The process according to claim 1, wherein the resulting catalyst is further treated with from 0 to 15 weight % of a phosphorus compound calculated as P2O5 based on the weight of the catalyst.

15. A catalyst suitable for cracking a hydrocarbon feedstock having a boiling point above 300° C. at a temperature from 500° C. to 800° C. and a pressure from 103.3 kPa to 6.89×103 kPa to produce more than 15% of C2-4 olefins, and gasoline and diesel cuts as co-products, having a coke make of less than 18% prepared according to claim 1.

16. A process for the fluidized cracking of a hydrocarbon feedstock having a boiling point above 300° C. at a temperature from 500° C. to 800° C. and a pressure from 103.3 kPa to 6.89×103 kPa to produce more than 15% of C24 olefins, and gasoline and diesel cuts as co-products, and having a coke make of less than 18% in the presence of a catalyst according to claim 1.

17. The process according to claim 16, wherein the temperature is from 530° C. to 770° C.

18. The process according to claim 17, wherein the process is continuous and is conducted in a reactor having at least one side riser to introduce fresh catalyst, regenerated catalyst or a mixture thereof into the reactor and a regenerator with cyclones to decoke the catalyst and separate the catalyst from the off gases.