CATALYST SYSTEM AND PROCESS FOR CONVERSION OF A HYDROCARBON FEED UTILIZING THE CATALYST SYSTEM

Abstract

The present invention relates to a catalyst system comprising: i. a first layer of a hydrocarbon conversion catalyst, the hydrocarbon conversion catalyst comprising: a first composition comprising a platinum group metal on a solid support; and a second composition comprising a transition metal on an inorganic support; ii. a second layer comprising a cracking catalyst; and to a process for conversion of a hydrocarbon feed utilizing this catalyst system.

Claims

1. A catalyst system comprising: i. a first layer of a hydrocarbon conversion catalyst, the hydrocarbon conversion catalyst comprising: a first composition comprising a dehydrogenation active metal on a solid support; and a second composition comprising a transition metal on an inorganic support; and ii. a second layer comprising a cracking catalyst.

2. The catalyst system according to claim 1, wherein the cracking catalyst comprises a molecular sieve.

3. The catalyst system according to claim 2, wherein the molecular sieve is zeolite and/or silicalite.

4. The catalyst system according to claim 3, wherein the zeolite is selected from ZSM-5, ZSM-11, SAPO-11, and mixtures thereof.

5. The catalyst system according to claim 1, wherein a weight ratio of the first layer to the second layer is from 50:1 to 1:20.

6. The catalyst system according to claim 1, wherein the dehydrogenation active metal is selected from platinum, palladium, iridium, chromium, and mixtures thereof.

7. The catalyst system according to claim 1, wherein the solid support is selected from aluminium oxide, silicon dioxide, zirconium dioxide, titanium dioxide, magnesium oxide, calcium oxide, and mixtures thereof.

8. The catalyst system according to claim 1, wherein the transition metal is selected from molybdenum, tungsten, rhenium, and mixtures thereof.

9. The catalyst system according to claim 1, wherein the inorganic support is selected from aluminium oxide, silicon dioxide, zirconium dioxide, titanium dioxide, zeolite, and mixtures thereof.

10. The catalyst system according to claim 1, wherein the second composition further comprises a mixed magnesium-aluminium oxide or a mixed calcium-aluminium oxide.

11. A process for conversion of a hydrocarbon feed comprising a saturated hydrocarbon compound to olefin products comprising contacting a hydrocarbon feed stream with the catalyst system according to claim 1.

12. The process according to claim 11, wherein the hydrocarbon feed stream comprises a paraffin selected from ethane, propane, butane, pentane, and mixtures thereof.

13. The process according to claim 11, wherein the process is carried out at a temperature in the range of 200-800? C.

14. The process according to claim 11, wherein the hydrocarbon feed stream is passed through the catalyst system by contacting the hydrocarbon conversion catalyst first and the cracking catalyst second.

15. The process according to claim 11, wherein the catalyst system is pretreated by contacting the catalyst system with an inert gas, an oxidizing gas, a reducing gas, or mixtures thereof, at a temperature in the range of 250? C. to 850? C., prior to contacting with the hydrocarbon feed stream.

Description

[0085] Example 1 (comparative): No cracking catalyst was used

[0086] Example 2 (comparative): a mixture of SiO.sub.2 and Al.sub.2O.sub.3 was used

[0087] Example 3: a ZSM-5 zeolite with Si/Al ratio of 500 was used

[0088] Example 4: a silicalite was used

[0089] Example 5: a SAPO-34 zeolite was used

[0090] Example 6: a SAPO-11 zeolite was used

[0091] Example 7: a ?-zeolite was used

TABLE-US-00001 TABLE 1 Result C3H8 Selectivity (% wt) Conversion Total Example (% wt) Olefins CH4 C2H4 C2H6 C3H6 C4H8 C4H10 C5+ Example 1 21.842 61.034 0.721 1.462 21.991 41.241 16.496 14.361 2.979 Example 2 22.353 65.496 0.867 3.302 20.870 41.910 19.052 11.570 1.230 Example 3 21.812 55.365 0.946 4.125 23.048 35.939 13.996 12.507 2.307 Example 4 21.574 47.887 1.074 3.939 24.368 30.365 11.611 17.197 4.051 Example 5 23.127 57.680 0.891 2.835 23.072 37.907 15.330 13.479 2.601 Example 6 23.028 56.044 0.978 3.283 23.354 37.236 13.916 12.453 2.559 Example 7 21.401 60.015 0.964 3.292 22.557 38.708 16.903 12.329 2.049

[0092] It can be seen from the results above that when the catalyst system include zeolite or silicalite as a downstream layer, butenes selectivity was decreased while ethylene selectivity was increased comparing to when no cracking catalyst was used or a normal mixture of SiO.sub.2Al.sub.2O.sub.3 was used as a downstream layer of the catalyst system.

[0093] It can be further noticed that when ZSM-5 was used as a cracking catalyst, the increase of ethylene selectivity was highest. When ?-zeolite was used, ethylene selectivity was increased but butenes selectivity was not reduced. When silicalite was used, butenes selectivity was decreased, and ethylene selectivity was increased, however, more of C5+ which is usually an undesired by-product was also produced. The features disclosed in the foregoing description and in the claims may, both separately and in any combination thereof, be material for realizing the invention in diverse forms.

[0094] The features disclosed in the foregoing description and the claims may, both separately and in any combination thereof, be material for realizing the invention in diverse forms thereof.