Process of using zeolite catalyst for hydrocarbon conversion

• US 20080177119A1
• Filed: 01/22/2007
• Published: 07/24/2008
• Est. Priority Date: 01/22/2007
• Status: Active Grant

• Current Assignee: Saudi Basic Industries Corporation (Government of Saudi Arabia)
• Original Assignee: Saudi Basic Industries Corporation (Government of Saudi Arabia)
• Inventors: Smith, Robert Scott, Juttu, Gopalakrishnan G.
• Granted Patent: US 7,906,696 B2
• Time in Patent Office: Days
• US Class Current: 585/419
• CPC Class Codes: B01J 2229/20 to introduce other elements in the catalyst composition comprising the molecular sieve, but not specially in or on the molecular sieve itself
• CPC Class Codes: B01J 2229/42 Addition of matrix or binder particles
• CPC Class Codes: B01J 29/04 having base-exchange properties, e.g. crystalline zeolites B01J29/005 takes precedence
• CPC Class Codes: C07C 15/00 Cyclic hydrocarbons containing only six-membered aromatic rings as cyclic parts
• CPC Class Codes: C07C 2/76 by condensation of hydrocarbons with partial elimination of hydrogen
• CPC Class Codes: C07C 2529/74 Noble metals

Abstract

This invention is for a catalyst for conversion of a hydrocarbonaceous feed. The catalyst is a zeolite aluminosilicate with a silicon to aluminum molar ratio from about 70:1 to about 100:1 on which a noble metal has been deposited. The zeolite catalyst may contain other optional tetravalent and trivalent elements in the zeolite framework. The zeolite structure may be MFI, FAU, TON, MFL, VPI, MEL, AEL, AFI, MWW or MOR. The catalyst is synthesized by preparing a zeolite containing aluminum, silicon and, optionally, other elements, such as germanium, in the framework, depositing a noble metal, such as platinum, on the zeolite and calcining the zeolite. The catalyst may be used for aromatization of alkanes to aromatics. One embodiment is a MFI zeolite catalyst which may be used for the aromatization of alkanes having two to six carbon atoms per molecule to aromatics, such as benzene, toluene and xylenes.

Claims

1. A process for converting hydrocarbons comprising contacting a hydrocarbonaceous feed at hydrocarbon converting conditions with a catalyst comprising:

a) a zeolite having a mole ratio in the range of from about 70;

1 to about 100;

1 of an oxide of silicon (SiO₂) to an oxide of aluminum (Al₂O₃) and

b) a noble metal deposited on the zeolite.

2. The process of claim 1 wherein the noble metal is present in the range of from 0.05% to 3% by weight.

3. The process of claim 1 wherein noble metal is present in the range of from 0.2% to 2% by weight.

4. The process of claim 1 wherein noble metal is present in the range of from 0.2% to 1.5% by weight.

5. The process of claim 2 wherein noble metal is platinum.

6. The process of claim 1 wherein the zeolite has a MFI, FAU, TON, MFL, VPI, MEL, AEL, AFI, MWW or MOR structure.

7. The process of claim 1 wherein the zeolite has a MFI structure.

8. The process of claim 1 wherein the zeolite additionally comprises tetravalent elements other than silicon and trivalent elements other than aluminum in the framework of the zeolite.

9. The process of claim 8 wherein the zeolite additionally comprises germanium, tin, lead, zirconium, titanium, vanadium, chromium, gallium, boron, indium, thallium, iron, zinc or phosphorus.

10. The process of claim 8 wherein the zeolite additionally comprises germanium.

11. The process of claim 1 wherein the hydrocarbonaceous feed additionally contains sulfur.

12. The process of claim 1 wherein the catalyst additionally contains sulfur.

13. The process of claim 1, wherein prior to contact with the hydrocarbonaceous feed, the catalyst is pretreated with a sulfur compound.

14. The process of claim 12 wherein the sulfur compound is H₂S, C_nH_2n+2S where n=1-20, C_nH_2n+1S₂ where n=2-22 or C_nH_2n+1S where n=2-22.

15. The process of claim 1 wherein the catalyst is represented by the formula M[(SiO₂)(XO₂)_x(Y₂O₃)_y]Z⁺_y/n where M is a noble metal, X is a tetravalent element, Y is aluminum and, optionally, another trivalent element, Z is a cation with a valence of n, x varies from 0-0.15 and y is 0-0.125.

16. The process of claim 15 wherein M is platinum.

17. The process of claim 15 wherein X is germanium and Y is aluminum.

18. The process of claim 15 wherein Z is H⁺, Na⁺, K⁺, Rb⁺, Cs⁺, Ca²⁺, Mg²⁺, Sr²⁺ or Ba²⁺.

19. The process of claim 15 wherein Z is H⁺.

20. The process of claim 1 wherein the catalyst is of the formula |H⁺Pt|[Si₉₁Ge₄Al₁O₁₉₂]-MFI.

21. The process of claim 1 wherein the hydrocarbonaceous feed is alkanes having two to six carbon atoms per molecule.

22. The process of claim 1 wherein the process is dehydrocyclodimerization of alkanes having two to six carbon atoms per molecule.

23. The process of claim 22 wherein the dehydrocyclodimerization process operates at a temperature of about 350°

C. to 650°

C. and a relatively low pressure of about 10 to 2000 kPa gauge.

24. The process of claim 1 wherein the catalyst is bound by oxides of magnesium, aluminum, titanium, zirconium, thorium, silicon, boron or mixtures thereof.

25. The process of claim 24 wherein the catalyst is bound by an oxide of silicon (silica).