METATHESIS CATALYST ON MIXED METAL OXIDE-ZEOLITE SUPPORT AND PROCESS FOR USE THEREOF

Abstract

The present invention relates to catalyst comprising at least one transition metal selected from Group VIA and Group VITA metals and a support containing a mixture of 0.1 to 60 percent by weight of zeolite, based on total weight of the support, with at least one other inorganic or organic material, wherein the at least one other inorganic or organic material is selected from silicon dioxide, titanium dioxide, zirconium dioxide and activated carbon, preferably silicon dioxide; and a process for olefin metathesis utilizing that catalyst.

Claims

1. A catalyst comprising at least one transition metal selected from Group VIA and Group VIIA metals and a support containing a mixture of 0.1 to 60 percent by weight of .sub.Lzeolite, based on total weight of the support, with at least one other inorganic or organic material, wherein the at least one other inorganic or organic material is selected from the group consisting of silicon dioxide, titanium dioxide, zirconium dioxide and activated carbon.

2. The catalyst according to claim 1 wherein the at least one transition metal is selected from the group consisting of rhenium, molybdenum and tungsten.

3. The catalyst according to claim 1 wherein the catalyst comprises the at least one transition metal in an amount of 1 to 12 percent by weight (calculated as elemental metal) of the total catalyst.

4. The catalyst according to claim 1 wherein the zeolite is selected from the group consisting of ZSM-5, Ferrierite, X-zeolite, Y-zeolite, beta-zeolite, MCM-22.

5. The catalyst according to claim 1 wherein the support comprises the zeolite in an amount of 0.1 to 30 percent by weight of the total support.

6. The catalyst according to claim 1 wherein the zeolite has silica to alumina ratio in the range of 2 to 500.

7. The catalyst according to claim 1 wherein the catalyst comprises a lanthanide metal.

8. A process for olefin metathesis reaction comprising: contacting the catalyst of claim 1 with a feed stream comprising at least a first olefin.

9. The process according to claim 19 wherein activating the catalyst comprises treating the catalyst at a temperature in the range of 200° C. to 700° C.

10. The process according to claim 8 wherein contacting the catalyst and the feed stream is carried out at a temperature in the range of 200° C. to 600° C.

11. The process according to claim 8 wherein the feed stream further comprises at least a second olefin.

12. The process according to claim 11 wherein the first olefin is ethylene and the second olefin is selected from the group consisting of 2-butene, 2-pentene, and a mixture thereof.

13. The process according to claim 8, further comprising, following contracting the catalyst with the feed stream regenerating the catalyst.

14. The catalyst of claim 1, wherein the at least one other inorganic or organic material is silicon dioxide.

15. The catalyst of claim 2, wherein the at least one transition metal is tungsten.

16. The catalyst of claim 4, wherein the zeolite is selected from the group consisting of Ferrierite, X-zeolite, Y-zeolite, and mixtures thereof

17. The catalyst of claim 16 wherein the zeolite is Y-zeolite.

18. The catalyst of claim 5 wherein the support comprises the zeolite in an amount of 1 to 10 percent by weight of the total support.

19. The process of claim 8, further comprising activating the catalyst, prior to contacting it with the feed stream.

20. The process of claim 12, wherein the second olefin is 2-butene.

Description

EXAMPLES

[0050] The following examples are intended to be illustrative of this invention only. They are not to be taken in any way limiting on the scope of this invention. Numerous changes and modifications can be made without departing from the scope of the invention as disclosed in the accompanying claims

Example 1

Catalyst Preparation

[0051] A catalyst according to the present invention was prepared by first physically mixing 90 wt % of silica gel with 10 wt % of HY-zeolite and then impregnating an aqueous solution containing a pre-calculated amount of ammonium metatungsten tetrahydrate onto the mixture of silica gel and HY-zeolite. The obtained mixture was left for 2 hours at ambient atmosphere prior to drying at 110° C. in an oven overnight. The final dried mixture appeared as a white solid. Next, the white solid mixture was calcined in air at 500° C. for 8 hours to obtain the final catalyst ready to be used in metathesis reaction.

Example 2

Conversion and Selectivity Test

[0052] Catalyst samples were subjected to conversion and selectivity test. The samples include:

[0053] Sample A which comprises tungsten oxide on a support comprising a mixture of 90 wt % of silica and 10%wt of Y-zeoltie,

[0054] Sample B which comprises tungsten oxide on a silica support, and

[0055] Sample C which comprises tungsten oxide on a silica support modified with 0.5 wt % of lanthanum,

[0056] wherein all samples A to C contain the same amount of tungsten oxide.

[0057] Sample A, Sample B and Sample C were treated prior to testing by packing 3 grams of catalyst in a reactor then heating the catalyst to 500° C. for 1 hour under nitrogen flow. Subsequently, the metathesis reaction of ethylene and another feed stream containing 1-butene, 2-butene, isobutene and other paraffins was performed over the catalyst mixture at temperature 350° C.

[0058] Effluents from the reaction were directed to GC-FID (Agilent) to measure their chemical composition. The measured compositions of effluents were used to calculate butene conversion and propylene selectivity. Percent butene conversion was calculated from weight of 1-butene and 2-butene converted during reaction divided by weight of 1-butene and 2-butene in feed stream and then multiplies by one hundred. And percent propylene selectivity was calculated from weight of propylene produced from the reaction divided by weight of all product produced from the reaction and then multiplies by one hundred. The results are shown in Table 1.

TABLE-US-00001 TABLE 1 Sam- % butene conversion % propylene selectivity ple SOR* EOR** % decrease SOR* EOR** % decrease A 75.9 75.0 1.18 92.4 92.8 −0.43 B 38.4 32.8 14.58 74.1 65.1 12.15 C 70.4 40.0 43.18 86.8 77.6 10.6 *SOR = Start of Run (2 hours from start of reaction) **EOR = End of Run (24 hours from start of reaction)

[0059] As demonstrated by the result above, Sample A, which is the catalyst according to the present invention, provides higher butene conversion and higher propylene selectivity than Sample B and C. Moreover, catalytic stability of Sample A evidently shows less decrease of conversion and selectivity from SOR to EOR than other samples.

Example 3

Effect of Zeolite Content and Si/Al of Zeolite used in the Support

[0060] Catalyst samples containing a fixed amount of tungsten oxide on supports containing silica and Y-zeolite were prepared from Y-zeolite with various ratios of silica to alumina and at different amount of Y-zeolite in the support. These samples were tested at reaction condition described in Example 2. The results of this test are shown in Table 2.

TABLE-US-00002 TABLE 2 Amount of Y-zeolite Si/Al of in support Y-zeolite % butene % propylene Catalytic (wt %) in support conversion selectivity stability 0 (100 wt % 0 Poor Poor Poor silica) 5 10 Excellent Moderate Moderate 5 15 Excellent Excellent Excellent 5 200 Moderate Excellent Excellent 10 10 Excellent Moderate Excellent 10 15 Excellent Excellent Excellent 10 200 Moderate Excellent Excellent 20 10 Excellent Moderate Moderate 20 15 Excellent Moderate Moderate 20 200 Moderate Moderate Moderate

[0061] Poor butene conversion implies that less than 30 percent by weight of butene in the feed stream was consumed in the reaction. Moderate butene conversion implies that 30 to 60 percent by weight of butene in the feed stream was consumed in the reaction. And excellent butene conversion implies that more than 60 percent by weight of butene in the feed stream was consumed in the reaction.

[0062] Poor propylene selectivity implies that propylene produced from the reaction was less than 30 percent by weight of the total product. Moderate propylene selectivity implies that propylene produced from the reaction was between 30 and 60 percent by weight of the total product. And excellent propylene selectivity implies that propylene produced from the reaction was more than 60 percent by weight of the total product.

[0063] Poor catalytic stability implies that butene conversion dropped greater than 60 percent from start of run to end of run. Moderate catalytic stability implies that butene conversion dropped between 20 to 60 percent from start of run to end of run. And excellent catalytic stability implies that butene conversion dropped less than 20 percent from start of run to end of run.

[0064] Evidently, results displayed in Table 2 show that adding zeolite to the silica support has favorable effect on conversion, selectivity and stability of the catalyst for metathesis of olefin. Moreover, it can also be seen that amount and property of zeolite added should be carefully chosen in order to achieve the best result.

[0065] The feature 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 thereof.

INDUSTRIAL APPLICABILITY

[0066] This has been described in the Description of Embodiments.