CA2049928A1 - Reforming naphtha with boron-containing large-pore zeolites - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Catalytic reforming processes using boron-containing large-pore zeolites.

Description

2~

01REFORMING NAPHT~A WI~H BORON-CONTAINING

04BAC~GROUND OF THE_INVENTION

06 Catalytic reforming is a process for treating naphtha 07 fractions of petroleum di~tillates to improve their octane OB rating by producin~ aromatic components and isomeriz~ng ~9 paraffins from component~ pre ent in naphtha feed~tocks.
Included among the hydrocarbon reactions occurring in 11 reforming processes are: dehydrogenation of naphthenefi to 12 aromaties, dehydrocyclization of parafins to aromatics, and 13 hydrocracking of paraffins to lighter gases with a lower 14 boiling point than gasoline. Hydrocracking reactions which produce light paraffin gases are not desirable as they 16 reduce the yield of products in the gacoline range.

18 Natural and 6ynthe~ic zeolitic crystalline aluminosilicates 19 and borosilicates are useful as catalysts. The u6e of ZSM-type catalysts and processes are described in U.S.
21 Patent Nos. 3,546,102, 3,679,575, 4,D18,711 and 3,574,092.
22 Zeolite L is also used ln reforming proce ses as described 23 in U.S. Patent Nos. 4,104,320, 4,447,316, 4,347,394 and 24 4,434,311.

2S 30rosilicate zecli~es are especially use~ul in catalytic 27 refor~ing. Methods for preparing high silica content 28 zeolites that contain framework boron are described i~ U.S.
29 Patent No. 4,269,313.

31 The use of int~rmediate pore borosilicate zeolite~ for 32 catalytic reforming is described in European Patent 33 Appl$cation No. 188,913. In this application, ZSM-5, 1-- , 01 ZSM-ll, ZSM-12, ZSM-23, ZS~-35, ZSM-38, ZSM-48 and zeolite 02 beta have been identified as lntermedi~te pore boro~ilicate 03 zeOlites-05 A method for controlling catalytic activity of large-pore 06 boron-containing zeolites i~ described in European Patent 07 Application No. 234,759-09 SUMMARY OF INVENTIOI~

11 According to the present invention, a proce~s i~ provided 12 for catalytic reforming. The process compri~es contacting a 13 hydrocarbon feedstream under cataly~ic reforming conditions 14 with a composition comprising large-pore borosilicate zeolites having ~ pore 8iZ~ b~tween 6 and 8 angstroms.
16 Preferably, th~ large-pore borosilicate zeolites ar~ boron 17 beta zeolite, (~)SSZ-24, SSZ-31 and SSZ-33.

19 Boron beta zeolite is described in co~monly assigned co~pending applicatio~ U.S. Serial No. 377,359 ~Docket No.
21 B-3924~, filed concurrently herewith, and entitled 22 nLow-Aluminum ~oron aeta Zeolite", the di~closure of which 23 is incorporated herein by reference.

(B)SSZ-24 is de~cribed in commonly assigned co-pending 26 application U.S. Serial No. 377,357 (Docket No. B-3952), 27 filed concurrently herewith, and ~ntitled "Zeolite 28 (B)Ssz-24n~ the disclosure of which is incorporated herein 29 by reference.

31 SSZ-33 is described in commonly assigned co-pending 32 application U.S. Serial No. 377,358 (Docket No. B-3889), 33 filed concurrently herewlth, and entitled "Zeolite S5Z-33", 34 the disclosure of which is incorporated herein by reference.

01 SSZ-31 is described in commonly a~signed co-pending 02 application U.S. Serial ~o. _ (Docket No. 2-3986~, 03 filed concurrently herewith, and entitled "~ew Zeolite 04 SSZ-31", the disclosure of which is incorporated herein by 05 re~erence.

07 According to a pref~rred embodiment, the largs-pore 08 borosilicate zeolites may be used ln a multi-stage catalytic 09 reforming proce~s. These zeolites may be located in one or more of the reactQrs, with conventional platinum and rhenium 11 catalyst located in the remaining reactors.

13 The reforming process may be acco~plished by using fixed 14 beds, fluid beds or moving beds ~or cGntacting the hydrocarbon feedstream with the catalyst6.

17 Among other factors, the present invention is based on our 18 finding that large-pore borosilicates including boron beta 19 zeolite [(B)Betal, SSZ-33, (B)SSZ-24 and SSZ-31 have unexpectedly outstanding reforming properties. These 21 include high sulfur tol~rance, high catalyst stability, and 22 high catalyst activity.

24 DETAIL15D DESCR~PTION OF THE INVENTION

26 The present invention relates ~o refor~ing processes 27 employinq large-pore borosilicate zeolites. A large-pore ~8 zeolite is defin~d herein as a zeolite having a poce ~ize 29 between 6 and 8 angstroms. A method of determining this pore size is described in Journal o~ Catalysis (1986);

3~ Vol. 99, p. 335 (D. S. Santilli). A large-pore zeolite may 32 be identlfied by using the pnre probe technique de~crlbed in 33 Journal of Catalysis (1986); Vol. 99, p. 335 (D. S.
34 Santilli). This method allows measurement of the 01 steady-state concentrations of compounds within the pores of 02 materials. 2,2-dimethylbutane (22D~3~ enters the large 03 pores and the concentration in the pores i6 measured using 04 this technique.

06 According to preferred embodiments of our invention, SSZ-~3, 07 (B)SSZ-24, SSZ-31 and low-aluminum boron beta zeolite 08 I(B)betal are large-pore borosilioate æeolltes with high 09 catalyst activity in th@ reforming process.
11 SSZ-33 is defined as ~ zeolite having a mole ratio of an 12 oxide selected from silicon, germanium oxide and mixtures 13 thereof to an oxide selected from boron oxide or mixtures of 14 boron oxide with aluminum oxide, gallium oxide or iron oxide, greater than about 20:1 and having the x-ray 16 diffraction lines of Table 1. The X-ray diffraction lines 17 of Table 1 correspond to the calcined SSZ-33.

19 Table 1 21 2 ~ d/n lO0 x I/Io 22 . 7 86 11.25 90 23. 20.48 4.336 100 24 21.47 4.139 40 22.03 4.035 90 26 23.18 3.837 64 27 ~6.83 3.323 40 (B)SSZ-24 is defined as a zeolite havin~ a mole ratio o~ an oxide selected from silicon oxide, germanium oxide, and mixtures thereof to an oxide selected from boron oxide or mixtures of boron oxide with aluminum oxide, gallium oxide, 01 and iron oxide, between 20:1 and lQ0:1 and having the X-ray 02 diffraction lines of Table 2. The X-ray diffraction lines 03 of Table 2 correspond to the caleined (B)SSZ-24.

05 Table 2 0~ 2 ~ d/n 100 x I/Io og 7.50 11.79 100 13.00 6.B1 16 11 15.03 5.~94 8 12 lg.93 4.455 35 13 21.42 4.148 48 14 22.67 3.922 60 lS 25.15 3.541 3 16 26.~0 3.401 22 17 29.38 3.040 12 18 30.43 2.947 12 lg Boron beta zeolite is a zeolite having a mole ratio of an 21 oxide selected from silicon oxide, germanium oxide, and 22 mixtures thereof to an oxide selected from boron oxide, or 23 mixtures of boron oxide with aluminum oxide, gallium oxide 24 or iron oxide, greater than 10:1 and wherein the amount of aluminum is less than 0.10% by weight and having the x-ray 26 diffraotion lines of Table 3. The x-ray diffraotion lines 27 of Table 3 correspond to the calcined boron beta zeolite.

01 Table 3 03 2 ~ d/n100 x I/I Shape 04 o 05 7.7 11.5 85 sroad 06 13.58 6.52 9 07 14.87 5.96 12 sroad 08 18.50 4.80 3 Very ~road 09 ~ 3 4.07 15 22.87 3.89 100 ~road 11 27.3~ 3.26 10 12 29.30 3.05 6 Broad 13 30.08 2.97 8 SSZ-31 is defined as a zeolite having a mole ratio of an 16 oxide selected from silicon oxide, germanium oxide, and 17 mixtures thereof to an oxide selected from aluminum oxide, 18 gallium oxide, iron oxide, and mixtures thcreof greater than 19 about 50:1, and having the X-ray diffraction lines of Table 4. The X-ray diffraction lin~s of Table 4 correspond 21 to the calcined SSZ-31.

23 Table 4 2 ~ d/n100 x I/~o Shape , ,, 26 6.08 14.54 9 27 7.35 12.03 9 28 a.oo 11.05 7 Broad 29 18.48 4.80 11 20.35 4.36 9 ~oad 31 21.11 4.21 100 32 22O24 4.00 56 33 24.71 3.60 21 34 30.R8 2.90 7 , 01 The large-pore borosilicates can be used as reforming 02 catalysts to convert light straight run naphtha6 and similar 03 mixtures to highly aromat~c mixtures. Thus, nor~al and 04 slightly branched chained hydrocarbons, preferably having a 05 boiling range above about 40C and less than about 250C, 06 can be converted to products having a subs~antial aromatics 07 content by contacting the hydrocarbon feed with the zeolite 08 at a temperature in the range of from about 400C to 600~C, 09 at pressures ranging from atmospheric to 20 atmosph2res, 10 LHSV ranging from 0.1 to 15, and a recycle hydrogen to 11 hydrocarbon ratio of about 1 to 10.

13 The reforming cataly6t preferably contains a ~roup YIII
14 metal compound to have suffioient activity for commercial use. sy Group VIII metal compound as used herein is meant 16 the metal itself or a compound thereofO The Group VIII
17 noble metals and their compounds, platinum, palladium, and 18 iridium, or combinations thereof can be used. The most 19 preferred metal is platinum. The amsunt of Group VIII metal present in the conversion catalyst should be within the 21 normal range of use in reforming catalysts, from about 0.05 22 to 2.0 wt. percent, preferably 0.2 to 0.~ wt. percent. In 23 addition, the catalyst can also contain a seoond Group VII
24 metal. Especially preferred is rhenium.

26 The zeolite/Group VIII metal cataly6t can be used with or 27 without a binder or matrix. The preferred inorganic matrix, ~8 where one is used, is a silica-based binder such as 29 Cab-O Sil or Ludox. Other matrices such as alumina, magnesia and titania can be used. The preferred inorganic 31 matrix is nonacidic.

z~ Y3~,~

01 It is critical to the selective production of aromatics in 02 useful quantities that the conversion catalyst be 03 substanti~lly free of acidity, for example, by exchanging 04 the sites in the zeolite with metal ions, e.g., ~roup I and 05 Group II ions. The zeolite is usually prepared from 06 mixtures containing alkali metal hydroxides and thus, have 07 alkali metal contents o~ about 1-2 wt~ %. These high levels ~ of alkali metal, usually sodium or potassium, are 09 unacceptable for most other catalytic applications because they greatly deactivate the catalyst for cracking reactions 11 by reducing catalyst acidity. Therefore, the alkali metal 12 is removed to low levels by ion exchange with hydrogen or 13 ammonium ions. ~y alkali metals as used herein is meant 14 ionic alkali metals or their basic compounds. Surprisingly, unless the zeolite itself is substantially free of acidity, 16 the alkali metal is required in the present process to 17 reduce acidity and improve aromatics production. Alkali 18 metals are incorporated by impregnation or ion exchange 19 using nitrate, chloride or carbonate salts.

21 The amount of alkali metal necessary to render the zeolites 22 substantially free of acidity can be calculated using 23 standard techniques based on the aluminum, gallium or iron 24 content of the zeolites. If a zeolite free of alkali metal is the ~tartin~ material, alkali metal ions can be ion 26 exchanged into the zeolite to substantially eliminate the 27 acidity of the zeolite. An alkali metal content of about 28 100%, or gr~ater, of the acid sites calculated on a molar 29 basis is suf~icient.

31 Where the metal ion content is less than 100% of the acid 32 sites on a molar basis, the test described in UOS. Patent 33 No. 4,34~,394, which patent is incorporated totally herein 01 by reference, can be used to determine if the zeolit~ is 02 substantially free of acidity.

04 The preferred alkali metals are sodium, potassium, and 05 ~esium, as well as other Groups IA and IIA metalR. The 06 zeolites can be substantially free of acidity only at very 07 high silica:alumina mole ratios; by "zeolite consisting 08 essentially of silica" i8 meant a zeolite which is 09 substantially free of acidity without base poisoning.

11 A low sulfur feed is preferred in the reforming pcocess; but 12 due to the sulfur tolerance of these catalysts, feed 13 desulfurization does not have to be as complete as with 14 conventional reforming catalysts. The feed shculd contain less than 10 parts per million sulfur. In the case of a 16 feed which is not low enough in sulfur, acceptable levels 17 can be reached by hydrogenating the feed with a 18 hydrogenating catalyst which is resistant to sulfur 19 poisoning. An ex~mple of a suitable catalyst for this hydrodesulfurization process is an alumina-containing 21 support and a minor catalytic proportion of molybdenum 22 oxide, cobalt oxide and/or nickel oxide. A platinum on 23 alumina hydrogenating catalyst can also work. In which 24 case, a sulfur fiorber is preferably placed downstream of the hydrogenating catalyst, but upstream of the present 26 reforming catalyst. Examples of sulfur sorbers ar~ alkali 27 or alkaline earth metals on porous refractory inorganic 28 oxides, zin~, etc. Hydrodesulfur1zation is typically 29 conducted at 315-455C, at 200-2000 psig, and at a LHSV of 1-5.

01 It is preferable to limit the nitrogen level and the water 02 content of the feed. Catalysts and processes which are 03 suitable for these purposes are known to those skilled in 04 the art.

n6 After a period of operation, the catalyst oan become 07 deactivated by coke. Coke can be removed by contacting the 08 catalyst with an oxygen-containing gas at ~n elevated 09 temperature. If the Group VIII ~etal(~) have agglomerated, then it can be redispersed by contacting the catalyst with a 11 chlorine gas under conditions effective to redisperse the 1~ metal(s). The method of regenerating the catalyst may 13 depend on whether there is a fixed bed, moving bed, or 14 fluidized bed operation. Regeneration methods and conditions are well known in the art.

17 The reforming catalysts preferably contain a Group VIII
18 metal oompound to have su~ficient activity for commercial 19 use. ~y Group VIII metal ~ompound as used herein is meant the metal it~elf or a compound thereof. The Group VIII
21 noble metals and their compounds, platinum, pallad~um, and 22 iridium, or oombinations~thereof can be used. Rhenlum and 23 tin may also be used in conjunction with the noble metal.
24 The most preferred metal is platinum. The amount of Group VIII metal present in the conversion catalyst should be 26 within the normal range of use in reform~ng catalysts, from 27 about 0.05-2.0 wt~ %.

29 Example 1 31 Preparation of Platinum-(B)SSZ-24 33 The borosilicate version of (B)SSZ-24 was prepared for use 34 as a reforming catalyst. The zeolite powder was impregna~ed 01 with Pt~NH3)4-2No3 to give 0.8 wt. % Pt. ~he material was 02 calcined up to 550F in air and maintained at thi~
03 temperature for three hours. The powder was pelletized on a 04 Carver press at 1000 psi and broken and meshed to 24-40.

06 Example 2 08 Reforming Test_Results (B)SSZ-24 from Example 1 was tested as a reforming catalyst.
11 The conditions for the re~orming tect were as follows.
12 The catalyst was prereduced for 1 hour in flowing hydrogen 13 at 950F and atmospheric pressure. Test conditions were:

Total Pressure ~ 200 psig 16 H2/HC Molar Ratio ~ 6.4 17 WHSV - 6 hr 1 19 The catalyst was initially tested at 800F and then at 900~F. The feed was an iC7 mixture supplied by Philips 21 Petroleum Company. The catalyst from Example 1 was ~ested 22 with these results.

24 Feed Products _ 26 Temperature, F 800~F 900F
27 Con~ersion % 0 79.6 100 28 Toluene, wt. ~ 0.5 22.1 21.9 2Q C5-C8 Octane, RON 63.7 86.8 105.2 C5~ Yield, wt. % 100 54.9 35.
31 Aromatization 32 Selectivity, % 32.1 30.2 33 Toluene in the 34 C5+ ~romatics % 86.6 72.7 2~

01 As shown by the complete conversion, this catalyst is 02 capable of converting all types of feedstock molecule6.

04 Exam~le 3 06Preparation and Testing of a 07Neutralized Platinum-Aluminum-Boron SSZ-24 09 Aluminum was substituted into the borosilicate version of (B)SSZ-24 by refluxing the zeolite with an equal mass o~
11 Al(NO3)3 9H2O overnight. Prior to use, the aluminum nitrate 12 was dissolved in H2O a~ a ratio of 50:1. The product 13 contained acidity due to the aluminum incorporation, and 14 this would lead to unacceptable cracking los~es. Two back ion exchanges with KNO3 were performed and the catalyfit was 16 calcine~ to 1000F. Next, a re~orming catalyst was prepared 17 as in Example 1. It was tested as in Example 2.

19 Feed_ Products 21 Temperature, F 800 900 22 Conversion % 0 53O0 95.1 23 Toluene, wt. % 0.5 22.6 26.6 24 C5-C8 Octane, RON 63.7 78.1 99.6 C5~ Yield, wt. ~ 100 81.5 46.2 26 Aromatization 27 Selectivity, % 47.1 35.7 28 Toluene in the 29 C5~ Aromatics % 90.6 78.1 31 By comparison with Example 2, the incorporation of aluminum, 32 accompanied by its neutralization, gives a less active, but 33 more sel~ctive catalyst.

01 Example 4 03 Preparation and Testin~ of a Platinum-Boron-Bet ~5 The borosilicate version of boron beta was impregnated with 06 Pt(NH3)4'2NO3 to give 0.6 wt. ~ Pt. The material was 07 calcined up to 550~F in air ~nd maintained at this 08 temperature for three hours. The powder was pelletized on a 09 Carver press at 1000 psi and broken and meshed to 24-40.
The catalyst was te6ted as shown in Example 2 with the 11 exception that opera~ion at both 200 and 50 psig were 12 explored.

14 Pressure, psiq 200 50 200 Temperature, F 800 800 900 16 Conversion ~ 88.8 77.0 100 17 Toluene, wt. % 19.1 39.3 16.9 18 C5-C8 Octane, RON 89.5 90.S 104.3 19 C5+ Yield, wt. % 46.9 77.4 ~0.2 Aromatization 21 Selectivity, % 25.4 54.5 25.3 22 Toluene in the 23 C5+ Aromatics % 84.9 93.7 67.8 The catalyst is quite stable and the values are averaged 26 over at least 20 hours of run time.
2~

~9 30Preparation and Testing of a 31Platinum-Cobalt-Boron-Beta Catalyst 33 Cobalt was incorporated into the boron beta as described in 34 Exa~ple 3 with Co(NO3)2 6H2O as the cobalt source replacing 01 Al(NO3)3-9H2O as the aluminum source in Example 3. The 02 catalyst was cal~ined to 1000F, and a Platinum reforming 03 catalyst was prepared as described in ~xample 1. It was 04 tested as described in Example 2 except the wHsv was 12 and 05 operation at both 200 and 100 psig was evaluated.

07 Pressure, psig 200 100 08 Temperature, ~F 800 300 09 Conversion % 83.3 86.0 Toluene, wt. % 18.8 27.3 ll C5-C8 Octane, XON 85.3 90.3 12 C5~ Yield, wt. ~ 59~8 63.7 13 Aromatization 14 Selectivity, % 27 37 Toluene in the 16 C5+ Aromatics % 83.3 85.9 ~8 By comparison with Example 4, the incorporating of cobalt 19 gives a more active catalyst. The catalyst has good stability a~ 800F.

22 Example 6 2~
24 Preparation of Pt-SSZ-33 26 SSZ-33 was prepared for use as a reforming catalyst. The 27 zeolite powder was impregnated with Pt(NH3)4-2NU3 to give 2~ 0.8 wt. % Pt. The material was caleined up to 550~F in alr 29 and maintained at this temperature for three hours. The powder was pelletized on a Carver press at 1000 psi and 31 broken and screened to 24-40 mesh.

01 Example 7 03 Preparation of Pt-Zinc-SSZ-33 05 Zinc was incorporated into the novel large-pore borosilicate 06 SSZ-33 by refluxing Zn(Ac)2 H2O as described in Example 3.
07 The product wa~ washed, dried, and calcined to 1000F, and 08 then impregnated with Pt~NH3)4 2NO3 to give 0.8 wt.% Pt.
09 The material was calcined up to 550F in air and maintained at this temperature for three hours. The powder was 11 pelletized on a Carver press at 1000 psig, broken, and 12 meshed to 24-40. It was tested as described in Example 2.
13 Resul~s are as follows:

Pres ure, psig 200 16 Temperature, F 900 17 Conversion % 71.1 18 Toluene, wt. % 2~
19 C5-C~ Octane, RON 85 C5+ Yield, wt. % 74.2 21 Aromatization 22 Selectivity, ~ 44.5 23 Toluene in the 24 C5+ Aro~atics % 88.5 01 Example 8 03 Testing of Pt-SSZ-33 and Pt-Zinc-SSZ-3 05 The catalysts of ~xamples 6 and 7 were tested with a 06 partially reformed naphtha at:

08 Total Pressure - 50 psig 09 H2/~C Molar Ratio ~ 3 LHSV ~ 2 hr 1 12 These conditions simulate use of the catalyst in the last 13 reactor of a ~ulti-stage reforming process. An analysis of 14 the feed and products is shown below.
16 FeedProducts 18 Molecular Sieve Pt-SSZ-33 Pt-Zn-SSZ-33 19 ~emperature, F 780 860 21 Composition, wt. %
22 C4- 13.4 9.4 23 C5's Total 0 8.3 7.0 24 C6 Paraffins 8.7 8.3 7.7 C6 Naphthenes 1.0 0.9 0.9 ~6 Benzene 1.6 3.5 2.6 2g 01 Feed Products 03 C7 Paraffins8.6 2.9 4.5 04 C7 Naphthenes 0.2 0.1 0 S Toluen~ 8.9 13.3 11.6 07 Ca Paraffins5.8 0.5 0 08 C8 Naphthenes 0.1 0 0 09 C8 Aromatics21.1 22.7 23.
11 Cg Paraffins2.1 0 13 Cg+ Aromatics 32.3 26.9 31.4 Octane, RON94.6 101.0 101.0 17 C5+ Yiqld, LV~ 100.0 86.0 89.0 18 of the Feed These examples illustrate the ability of both cataly~t~ to 21 upgrade partially reformed naphtha. Incorporation of zinc 22 improves the liguid product selectivity, apparently by 2~ reducing dealkylation of exi~ing aromatlc~.

Example 9 2~Comparison of Unsulfided and Sulfided 28Platinum ~oron ~eta The borosilicate version o~ Beta was impregnated with 31 Pt(NH3)4-2NO3 as in Example 4. The catalyst was ~ulfided at 32 950E for 1 hour in the presence of hydrogen.

01 Test conditions were:

03 Temperature ~ 800F
04 H2/HC Molar Ratio - 6.4 S WHSV ~ 6 07 U~sulfided Pt/tB)beta Sulfided Pt~(B)beta 09 Pressure, psig200 200 200 200 10 Time, hrs- 3 18 3 18 11 Feed ~onversion~ ~ 96.9 95.8 79.1 81.~
12 C5+ Yield, wt. % 37.6 40.2 59.4 57.0 13 Calculated RON93.0 92.8 87.5 88.4 14 Aromatization19.4 21.3 35.2 34.0 Selectivity, 17Example 10 l9Comparison of Sulfided Pt/~B)beta and 20Sulfided Pt/(B)beta with 52% SiO2 Binder 22800~, 200 psig, 6 WHSV, 6.4 ~l2:~C

Pt/(B)beta ~ound Pt/~B)beta 27 Time, hr~. 3 18 3 18 2a Feed Conversion, ~ 79.1 81.6 52.7 57.7 29 C5+ Yield, w~. %59.4 57.0 86.5 82.1 30 Calculated RON 87.5 88.4 79.5 80.2 31 Aromatization 35.2 34.0 52.9 47.0 32 Sele~tivity 01 800F, 50 psig, 6 WHSV, 6.4 H2:HC

04 Pt/(B~beta Bound Pt/(B)beta 06 Time, hrs. 3 18 3 18 07 Feed Conversion, ~ 87.9 86.5 62.6 61.5 08 C5+ Yield, wt. % 64.3 66.0 84.4 85.0 09 Calcul~ted RO~97.8 96.5 84.4 83.7 Aromatiz~tion 50.8 Sl.S 56.3 55.5 11 Selectivity l3 . Example 11 1~
15Comparison of 5ulfided Pt/(B~beta 16and Sulfided Pt/Cs-(Al)-(B)beta 18800F, 200 psig, 6 W~SV, 6.4 H2:HC*

Pt/tB?beta Pt/Cs-(Al)-~B)beta 22 Feed Convorsion, ~ 79.6 48.0 23 C5~ Yield, wt. % 59.7 93.7 24 Calculated RON 87.9 77.0 Propane ~ Butanes, 18.8 2.3 2~ wt. %
27 ~oluene, wt. % 25.6 ~5-9 2~ Aro~. Selectivity 35.7 56.0 30*Data averaged for first five hours.

.

2~

01800F, 50 psi~, 6 W~SV, 6.4 H2:HC~
02 _ __ Pt/~)Beta Pt/Cs-~Al)-~B)beta O ~

06 Time, hrs. 3 18 3 lB
07 Feed Conversion, % 87.9 86.5 46.0 40.0 0~ C5+ ~ield, wt. %64.3 66.0 95.0 96.0 09 Calculated ~ON g7.8 96.5 77.0 74.5 Arom. Selectivity 50.R 51.5 59.5 58.0 11 Propane + ~utanes, 31.4 28.1 3.3 2.5 12 wt. %
l3 Toluene, wt. % 42.0 41.8 26.0 22.0 **Interpolated data.

17Example_12 Pre aration and Testin~ of P~-Boron-SSZ-31 19 P - - .
21 The borosilieate version of SSZ-31 was prepared for u~e as a 22 reforming catalyst. The zeolite powder was impregnated with 23 Pt(NH3)4'2NO3 to give 0.7 wt. ~ Pt. The material wa~
24 calcined up to 600~ in air and maintained at this temperature for three hours. The powder was pelletized on a 26 Carver press at 1000 psi, broken, and ~creened ~o:24-40 27 mesh.

29 Pt-Boron-SSZ-31 wa~ tested for reforming using an iC7 feed mixture (Ph$1ips Petroleum Company) as fol}ow~:

01 Reaction Conditions Run 1 Run 2 02 Temperature, F 800 800 03 Total pressure, psig 200 50 04 H2/Hydrocarbon Mole Ratio 6 . 4 6 . 4 05 Feed rate, WHSV, hr l 6 6 0~
07 Results Feed Run 1 Run 2 08 Conversion, % 0 68.1 69.7 09 Aromatization Select . 0 39 . 4 54 . 7 Toluene, wt . ~ 0 . 7 24 . 6 36 . 0 11 C5-C8 Octane, RON 6 3 . 9 B2 . B 87 . 6

Claims (24)

1. . -22-WHAT IS CLAIMED IS:
   
   l. A catalytic reforming process which comprises contacting a hydrocarbonaceous feedstream under catalytic reforming conditions with a composition comprising large-pore borosilicats zeolites having pore size greater than 6 and less than 8 angstroms.
2. 2. A process in accordance with Claim 1 wherein said large-pore borosilicate zeolites contain less than 1000 parts per million aluminum.
3. 3. A process in accordance with Claim 2 wherein said large-pore borosilicate zeolites are boron beta zeolite, boron SSZ-24, boron SSZ-31, and SSZ-33.
4. 4. A process in accordance with Claims l, 2 and 3 wherein the boron in the large-pore borosilicate zeolites is partially replaced by a Group IIIA metal, or a first row transition metal.
5. 5. A process in accordance with Claim 4 wherein the replacing metal is cobalt, zinc, aluminum, gallium, iron, nickel, tin and titanium.
6. 6. A process in accordance with Claims l, 2, 3 and 4 wherein the hydrogenation/dehydrogenation component of said large-pore borosilicate zeolites is a Group VIII
   metal.
7. 7. A process in accordance with Claim 6 wherein the hydrogenation/dehydrogenation component of said large-pore borosilicate zeolite comprises platinum.
   
   WO91/11501 . PCT/US90/03765
8. 8. A process in accordance with Claim 6 wherein said large-pore borosilicate zeolite contains an alkali metal component.
9. 9. A process in accordance with Claims 1, 2, 3 and 4 wherein the hydrogenation/dehydrogenation component of said large-pore borosilicate zeolite comprises rhenium and platinum.
10. 10. A process in accordance with Claims 1, 2, 3 and 4 wherein the hydrogenation/dehydrogenation component of said large-pore borosilicate zeolites comprises platinum and tin.
11. 11. A process in accordance with Claim 1, 2 and 3 comprising using a fixed, moving or fluid bed reformer.
12. 12. A process in accordance with Claims 1, 2 and 3 which is a multi-stage catalytic reforming process.
13. 13. A process in accordance with Claim 12 where the large-pore borosilicate zeolite is used in the last reactor to convert the remaining light paraffins not converted by the Pt Re/Al2O3 or Pt Sn/Al2O3 catalysts used in the upstream reactors.
14. 14. A process in accordance with Claim 12 where the large-pore borosilicate zeolite is used in the last stage of a multi-stage catalytic reforming process where the operating pressure of the last stage is much lower than the upstream stage.
15. 15. A process in accordance with claim 1 wherein the feedstream contains less than 1 part per million sulfur.
16. 16. A process in accordance with claim 1 wherein said large-pore borosilicate zeolites comprise:
    i) a Group VIII metal and a metal selected from the group of metals consisting of Group IA metals and Group IIA metals;
    ii) said selected Group IA metals and/or Group IIA
    metals reducing acidity of said catalyst.
17. 17. A process in accordance with claim 16 wherein said selected Group IA and/or Group IIA metals rendering said catalyst substantially free of acidity without introducing base poisoning to said catalyst.
18. 18. A process of claim 16 wherein said selected metal is a Group IA metal.
19. 19. A process of claim 16 wherein said selected metal is selected from the group consisting of sodium, potassium and calcium.
20. 20. A process of claim 19 wherein sufficient selected metal is incorporated into said catalyst to neutralize substantially all acid sites in said borosilicate zeolites.
21. 21. A process of claim 19 wherein said Group VIII metal is selected from the group consisting of platinum, palladium and iridium.
22. 22. A process of claim 21 wherein said catalyst comprises 0.05 to 2.0% by weight of said selected Group VIII metal.
23. 23. A process of claim 22 wherein said catalyst comprises 0.2 to 0.8% by weight of said selected Group VIII metal.
24. 24. A process of claim 23 further comprising a binder for said Group VIII metal selected from the group consisting of a silica-based binder, alumina, magnesia and titania.