Titania-bound zeolite EU-2 composition and method of making and using such composition

Abstract

Catalyst composition useful in the catalytic dewaxing of a waxy hydrocarbon feedstock which catalyst composition includes a mixture of zeolite EU-2 and titania and may further include a noble metal. The zeolite EU-2 has a molar bulk ratio of silica-to-alumina (SAR) of greater than 100:1. The zeolite or mixture may have been dealuminated such as by acid leaching using a fluorosilicate salt or by steam treating.

Claims

1. A catalyst composition comprising a mixture comprising titania and zeolite EU-2 having a molar bulk ratio of silica-to-alumina (SAR) of greater than 115:1; wherein said zeolite EU-2 is present in said composition in an amount of at least 10 wt. % and at most 60% wt and said titania is present in said composition in an amount of no more than 90% wt, with such % wt being based on the dry weight of said composition; and wherein said titania has a high surface area greater than 105 m.sup.2/gm.

2. A catalyst composition as recited in claim 1, further comprising a noble metal selected from the group consisting of platinum and palladium.

3. A catalyst composition as recited in claim 1, wherein said mixture contains zeolite EU-2 particles of which the average aluminum concentration is at least 1.1 times the aluminum concentration at the surface of the EU-2 particles.

4. A catalyst composition as recited in claim 1, wherein said catalyst composition is substantially free of silica other than the silica contained in said zeolite EU-2 framework.

5. A catalyst composition as recited in claim 1, wherein said catalyst composition is substantially free of alumina other than the alumina contained in said zeolite EU-2 framework.

6. A catalyst composition as recited in claim 1, wherein said zeolite EU-2 has a molar bulk ratio of silica-to-alumina greater than 120:1 and said titania has a B.E.T. surface area greater than 125 m.sup.2/gm.

7. A catalyst composition as recited in claim 1, wherein more than 60 wt % of said titania is in the form of anatase titania.

8. A catalyst composition as recited in claim 1, wherein said zeolite EU-2 content of said composition is at least 25 wt % and at most 55 wt % and the titania content of said composition is at least 30 wt % and no more than 75 wt %.

9. A catalyst composition as recited in claim 1, wherein said zeolite EU-2 has a molar bulk ratio of silica-to-alumina greater than 130:1 and said titania has a B.E.T. surface area greater than 150 m.sup.2/gm.

10. A catalyst composition as recited in claim 1, wherein said zeolite EU-2 content of said composition is at least 30 wt % and at most 60 wt % and the titania content of said composition is at least 40 wt % and at most 90 wt %.

11. A catalyst composition as recited in claim 1, further comprises a noble metal selected from the group consisting of platinum and palladium; and wherein said zeolite EU-2 has a molar bulk ratio of silica-to-alumina greater than 130:1 and less than 500:1; said titania has a B.E.T. surface area greater than 175 m.sup.2/gm and less than 700 m.sup.2/gm; said zeolite EU-2 content of said composition is at least 10 wt % and at most 55 wt %; and said titania content of said composition is at least 45 wt % and no more than 70wt % of said composition.

12. A catalyst composition as recited in claim 11, wherein said titania includes more than 60 wt % titania in the anatase form and less than 40 wt % in the rutile form.

13. A method for preparing said catalyst composition of claim 1, wherein said method comprises: preparing a mixture comprising at least 40 wt. % and no more than 80 wt. % titania, having a high surface area greater than 105 m.sup.2/gm, ant at most 60wt. % zeolite EU-2 having a molar bulk ratio of silica-to-alumina (SAR) of greater than 115:1 and forming said mixture into a particle.

14. A method as recited in claim 13, further comprising: drying and calcining said particle to thereby provide a calcined particle.

15. A method as recited in claim 14, further comprising: subjecting said calcined particle to dealumination to thereby provide a dealuminated particle comprising dealuminated zeolite.

16. A method as recited in claim 15, further comprising: incorporating a noble metal into said dealuminated particle to thereby provide a catalyst composition comprising zeolite EU-2, titania and said noble metal.

17. A process for the catalytic dewaxing of a hydrocarbon oil feed, wherein said process comprises: contacting under catalytic dewaxing conditions said hydrocarbon oil feed with the catalyst composition of claim 1.

18. A process for the catalytic dewaxing of a hydrocarbon oil feed, wherein said process comprises: contacting under catalytic dewaxing conditions said hydrocarbon oil feed with the catalyst composition of claim 2.

19. A process for the catalytic dewaxing of a hydrocarbon oil feed, wherein said process comprises: contacting under catalytic dewaxing conditions said hydrocarbon oil feed with the catalyst composition of claim 3.

20. A process for the catalytic dewaxing of a hydrocarbon oil feed, wherein said process comprises: contacting under catalytic dewaxing conditions said hydrocarbon oil feed with the catalyst composition of claim 4.

21. A process for the catalytic dewaxing of a hydrocarbon oil feed, wherein said process comprises: contacting under catalytic dewaxing conditions said hydrocarbon oil feed with the catalyst composition of claim 5.

22. A process for the catalytic dewaxing of a hydrocarbon oil feed, wherein said process comprises: contacting under catalytic dewaxing conditions said hydrocarbon oil feed with the catalyst composition of claim 6.

23. A process for the catalytic dewaxing of a hydrocarbon oil feed, wherein said process comprises: contacting under catalytic dewaxing conditions said hydrocarbon oil feed with the catalyst composition of claim 7.

24. A process for the catalytic dewaxing of a hydrocarbon oil feed, wherein said process comprises: contacting under catalytic dewaxing conditions said hydrocarbon oil feed with the catalyst composition of claim 8.

25. A process for the catalytic dewaxing of a hydrocarbon oil feed, wherein said process comprises: contacting under catalytic dewaxing conditions said hydrocarbon oil feed with the catalyst composition of claim 9.

26. A process for the catalytic dewaxing of a hydrocarbon oil feed, wherein said process comprises: contacting under catalytic dewaxing conditions said hydrocarbon oil feed with the catalyst composition of claim 10.

27. A process for the catalytic dewaxing of a hydrocarbon oil feed, wherein said process comprises: contacting under catalytic dewaxing conditions said hydrocarbon oil feed with the catalyst composition of claim 11.

28. A process for the catalytic dewaxing of a hydrocarbon oil feed, wherein said process comprises: contacting under catalytic dewaxing conditions said hydrocarbon oil feed with the catalyst composition of claim 12.

Description

(1) Example I

(2) This Example I describes the preparation of the comparative Composition I (zeolite EU-2 /silica) and the inventive Compositions II and III (zeolite EU-2/titania). The zeolite EU-2 used in the preparation of the compositions had a SAR of 158 and was made by the method described in U.S. Pat. No. 4,741,891.

(3) Composition I (Comparison)

(4) An extrudable mass was prepared by combining 50 wt % zeolite EU-2, 25 wt % of amorphous precipitated silica powder (Sipernat-50 as obtained from Evonik) and 25 wt % of an ammonium stabilized commercially available silica sol (sold under the trade name Bindzil 30NH.sub.3/220 by Eka Chemicals). The weight amounts are basis dry components. The mass was extruded to give extrudates having a cylinder shape and an average diameter of 1.6 mm. These extrudates were dried at 120° C. and calcined at 625° C. for 1 hour resulting in white calcined extrudates.

(5) These extrudates were treated at a temperature of 90° C. for 5 hours with 0.01 M aqueous ammonium hexafluorosilicate (AHS) solution. The weight ratio of solution to extrudates was 5:1. Subsequently, the extrudates were separated from the solution, washed with deionized water, and dried at 120° C. for 2 hours followed by calcination at 500° C. for 1 hour.

(6) Thereafter, 0.7% wt/wt platinum was incorporated into the composition by pore volume impregnation during about 10 minutes with an aqueous solution containing tetramine platinum nitrate (Pt(NH.sub.3).sub.4(NO.sub.3).sub.2) (3.37% w/w Pt).

(7) The impregnated composition was not washed, but it was equilibrated during 1.5 hours on a rolling bed, dried for 10 minutes at 180° C. (temperature incrementally increased at a rate of 15° C./minute). The temperature was raised again at an incremental rate of 30° C./minute to 290° C. (internal 270° C.) and held stable during 12 minutes. Then, the catalyst was cooled down to room temperature.

(8) Composition II (zeolite EU-2 and titania)

(9) An extrudable mass was prepared by combining 50 wt % zeolite EU-2 and 50 wt % 100% anatase titania powder sold by Millenium Specialty Chemicals Inc. identified as Millenium's G5 grade titania having a nitrogen B.E.T. surface are of 293 m.sup.2/g and a bulk density of 0.56 g/ml. The weight amounts are basis dry components. The mass was extruded to give extrudates having a cylinder shape and an average diameter of 1.6 mm. These extrudates were dried at 120° C. and calcined at 625° C. for 1 hour to provide calcined extrudates.

(10) These extrudates were treated at a temperature of 90° C. for 5 hours with 0.01 M aqueous ammonium hexafluorosilicate (AHS) solution. The weight ratio of solution to extrudates was 5:1. Subsequently, the extrudates were separated from the solution, washed with deionized water, and dried at 120° C. for 2 hours followed by calcination at 500° C. for 1 hour.

(11) Thereafter, 0.7% wt/wt platinum was incorporated into the composition by pore volume impregnation during about 10 minutes with an aqueous solution containing tetramine platinum nitrate (Pt(NH.sub.3).sub.4(NO.sub.3).sub.2) (3.37% w/w Pt).

(12) The impregnated composition was not washed, but it was equilibrated during 1.5 hours on a rolling bed, dried for 10 minutes at 180° C. (temperature incrementally increased at a rate of 15° C./minute). The temperature was raised again at an incremental rate of 30° C./minute to 290° C. (internal 270° C.) and held stable during 12 minutes. Then, the catalyst was cooled down to room temperature.

(13) Composition III (zeolite EU-2 and titania)

(14) This composition was prepared in the same manner as described above for Composition II with the exception that the titania powder is Degussa (Evonik) P25 80 wt % anatase and 20 wt % rutile titania.

(15) Example II

(16) This Example II describes the performance testing of the compositions of Example I in the catalytic dewaxing of a waxy raffinate feed and presents the results thereof.

(17) The catalyst under scrutiny was dried at 250° C. for 3 hours. Subsequently, the catalyst was mixed with sufficient inert material to assure proper plug flow conditions and loaded into a single tube test reactor of down flow mode. Subsequently, a hydrogen partial of 40 bar was applied and the temperature was increased from room temperature to 125° C. at a rate of 20° C./h, and held for two hours. The temperature was then increased further to 300° C. at a rate of 50° C./h, and held for 8 hours to ensure proper reduction of the metallic phase.

(18) The reactor was cooled to 200 ° C. and then the feed having the properties presented in Table 1 was introduced at a weight hourly space velocity of 1.0 kg feed per liter catalyst per hour, together with hydrogen at a rate of 500 Nl per kg of feed. After feed break through, the temperature was increased to 250° C. in 4 hours, and held overnight. The temperature was then adjusted to obtain a liquid product cloud point of −30° C. The cloud points were measured according to ASTM D 2500.

(19) The performance of catalysts I, II and III is shown in Table 2. The expression % w of stands for the weight percent on feed, 400° C.+ stands for product having a boiling point above 400° C. measured according to ASTM D-2887. The yield of 400° C.+ product can be considered equivalent to the base oil yield. T.sub.req is the temperature required to reach the target total liquid product pour point (TLP PP) of −30° C.

(20) TABLE-US-00001 TABLE 1 Waxy Raffinate Feed Properties Feed Density at 70/4° C. g/ml 0.7844 Carbon content % w 85.28 Hydrogen content % w 14.72 Sulphur content, ppmw <10 Nitrogen content, ppmw <1 UV Mono-aromatics Aromatics mmol/100 g 0.30 Pour Point ° C. +48 Cloud Point ° C. +56 TBP-GLC 0.5% w recovery (IBP) ° C. 289 10% w recovery ° C. 405 50% w recovery ° C. 461 90% w recovery ° C. 520 98% w recovery ° C. 548 99.5% w recovery ° C. 567

(21) TABLE-US-00002 TABLE 2 Catalyst Performance Results Waxy Raffinate @ TLP PP = −30° C. Yield 400° C.+ Catalyst T.sub.req (° C.) (% wof) I 358 74.4 II 330 73.2 III 329 75.5

(22) As may be seen from the data presented in Table 2, the Catalysts II and III with the titania binder exhibits significantly better catalytic dewaxing activity than the comparative Catalyst I that uses a silica binder with the activity gain being approximately 28 to 29° C. It is theorized that an interaction between the silica and zeolite of Catalyst I in some way impacts the catalytic activity of the composition.