AU669543B2 - Catalytic cracking catalysts and additives - Google Patents

Description

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION NAME OF APPLICANT(S): W. R. Grace Co.-Conn.

ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

INVENTION TITLE: Catalytic cracking catalysts and additives The following statement is a full description of this invention, including the best method of performing it known to me/us:o o e -2- The present invention relates to catalytic cracking catalysts, and more particularly, to cracking catalyst/additive compositions which are capable of converting metals-containing hydrocarbon feedstocks into valuable products such as gasoline and diesel fuel.

When zeolite-containing cracking catalysts are used to process feedstocks which contain metals such as vanadium and nickel the metals are deposited on the catalyst in amounts that eventually cause loss of activity and the increased production of undesirable products such as hydrogen and coke.

15 The prior art discloses various methods for improving the catalytic cracking activity and selectivity of catalytic cracking catalysts in the presence of V when a rare-aarth component is added to the catalyst.

U.S. 3,930,987 describes zeolite containing cracking catalysts which are impregnated with a solution of rare-earth salts. The soluble rare-earth salts which may be used to prepare the catalysts include rare earth chlorides, bromides, iodides, carbonates, bicarbonates, sulfates, sulfides, thiocyanates, peroxysulfates, .acetates, benzoates, citrates, fluorides, nitrates, formates, propionatas, butyrates, valerates, lactates, malanates, oxalates, palmitates, hydroxides, tartrates, and the like-.

U.S. 4,515,683 discloses a method -for-passivating vanadium on catalytic cracking catalysts wherein lanthanum is nonionically precipitated on the catalyst prior to ordinary use. In a preferred-embod-iment -3lanthanum is precipitated by the addition of ammonium hydroxide or oxalic acid to a catalyst which has been previously impregnated with a rare-earth chloride solution.

U.S. 4,921,824 discloses an improved catalytic cracking catalyst which contains separate and discrete particles of lanthanum oxide. The lanthanum oxide particles are added separate from and along with the catalyst during the cracking process. The lanthanum oxide additive may include an- inert matrix such as clay, silica and/or a metal oxide.

Great Britain 2 140 791 discloses the preparation of SOx gettering agents which comprise lanthanum oxide dispersed essentially as a monolayer on the surface of alumina. The lanthanum oxide-alumina compositions may be admixed with or incorporated in FCC catalysts that comprise zeolite, clay and an alumina sol binder such as aluminum chlorhydroxide.

U.S. 4,843,052 and U.S. 4,940,531 disclose acid- 20 reacted metakaolin.catalysts. The catalysts can be used for the catalytic cracking of hydrocarbon feedstocks that contain high levels of metals such as Ni and V.

U.S. 4,465,779 discloses modified cracking catalyst compositions which include a diluent that contains a magnesium compound. The compositions are used to process-feedstocks having very high metals (Ni V) content.

It is an object of the present invention to provide improved catalytic cracking catalyst and additive compositions that are highly effective for controlling the adverse effects of metals such as V and Ni.

1 I, F p 1" Af'T V I 'I k I'I 1 .NW II0 0 i.tl Broadly, the invention contemplates a particulate rare-earth-containing catalyst/additive composition which comprises discrete particles of rare-earth, preferably lanthanum/neodynium (La/Nd), oxide and/or oxychloride, dispersed in an inorganic oxide matrix that comprises an acid reacted ;neta'aolin, and preferably, an alkaline metal oxide and/or a catalytically active zeolite/molecular sieve component.

According to a first aspect of the present invention there is provided a composition comprising discrete particles of a rare-earth compound selected from the group consisting of a rare-earth oxide, oxychloride and mixtures thereof dispersed in an acid reacted metakaolin matrix.

Further according to the first aspect of the present invention, there is provided a catalytic cracking catalyst composition comprising a zeolite containing cracking catalyst admixed with a composition as described in the immediately preceding paragraph.

Still further according to the first aspect of the invention there is provided a method for the catalytic cracking of hydrocarbons which comprises reacting a vanadium-containing hydrocarbon in the presence of the catalyst composition of as described in the immediately preceding paragraph under catalytic cracking conditions.

In a preferred embodiment, we have found that the catalytic performance of zeolitecontaining cracking catalysts in the presence of Ni and V may be improved by combining the catalyst with a particulate rare-earth containing additive which is obtained by combining finely divided rare-earth oxalate with acid reacted metakaolin having the mole composition 0.8 to A1 2 0 3 *2 SiQ and a surface area of above about 150 m 2 and optionally, calcium and/or magnesium oxide, and/or a zeolite/molecular sieve component, and/or an aluminum hydroxychloride sol, and forming and calcining the mixture to obtain hard, dense attrition resistant particles comprising rare-earth oxide and/or oxychloride dispersed in a catalytically .z.

Vr n, iD-~ l ~BYIIC- 1 H Wl K w (J I t.v% active acid-reacted metakaolin/alumina matrix.

According to a second aspect of the present invention there is provided a method for preparing a particulate rare-earth-containing catalyst/additive composition which comprises: preparing a slurry of rare-earth oxalate and acid reacted metakaolin; spray drying the mixture; and calcining the spray dried mixture at a temperature of 425 to 870 0

C.

In a preferred practice of the method of the invention, the catalyst additive composition is prepared as follows: Preparing an aqueous slurry which contains finely divided rare-earth oxalate and acid reacted metakaolin; and optionally calcium and/or magnesium oxide (CaO and/or MgO), a zeolite/molecular sieve component and acid aluminum sol.

Spray drying the aqueous slurry which has a solids content of about 25 to weight percent at a temperature of about 300 to 350 0 F to obtain particles having a size range of to 150 microns in which rare-earth oxalate particles are dispersed throughout an acid reacted metakaolin/aluminum sol matrix; and Calcining the spray dried particles at a temperature of 1000 to 1200°F for about 1 hour to convert the rare-earth oxalate to particles of rare-earth oxide and/or oxychloride, and to transform the spray dried particles into dense attrition resistant catalyst/additive particles.

Subsequent to calcination, the preferred compositions of the first aspect of the invention contain the following components (expressed as weight percent dry basis): Acid-reacted metakaolin 10 to 90, preferably 50 to Rare-earth oxychloride/oxide 1 to 35, preferably 1 to Alumina binder or sol 0 to 10, preferably 2 to Calcium/Magnesium oxide 0 to 10, preferably 2 to I 1 I I III IW% i' 4V'%H Zeolite/molecular sieve component 0 to 50, and preferably 0 to The catalyst/additive composition of the first aspect of the invention and/or prepared by the method of the second aspect of the invention advantageously possesses the following catalytic and physical properties: a microactivity of 15 to 80 as determined by ASTM 3907; a Davison attrition Index of 0 to 30, preferably 1 to a density of 0.6 to 1.0 g/cc; a surface area of 50 to 200 m/g.

The Davison Index (DI) is determined as follows: A sample of catalyst is analyzed to determine the 0 to 20 micron size content. The sample is then subjected to a 1 hour test in a Fluid Catalyst Attrition Apparatus using a hardened steel jet cup having a precision bored orifice. An air flow of 21 liters a minute is used. The Davison Index is calculated as follows: Davison Index wt. 0-20 micron material formed during test wt. original 20 micron fraction The acid reacted metakaolin used in the present invention may be as described in U.S.

4,843,052 (incorporated herein by reference), and may be obtained by heating kaolin at a temperature of about 700 to 910°C for at least one minute to obtain reactive metakaolin. The reactive kaolin may then be reacted with an acid, preferably hydrochloric, in amounts of up to about 1.5 moles of acid per mole of reactive metakaolin to obtain a reaction mixture that comprises acid-reacted metakaolin dispersed in an aqueous solution of acid leached alumina, i.e.

aluminum chloride.

I i 4 K H 0it 1" 41 (N L".V -7- This acid reacted metal binder preferably has the molar composition of about 0.8 to Al120,2 SiO., a surface area of about 150 to 500 m 2 and a total nitrogen pore volume of about 0.15 to 0.50 cc/g as determined by ASTM-4222 and 4691.

In a preferred practice of the method of the invention, the acid reacted metakaolin reaction mixture is combined with metallic aluminum powder to obtain an aluminum hydroxychloride sol binder. Alternatively, the acid reacted metakaolin may be recovered from the reaction mixture and used without an additional sol binder or may be combined with an aluminum hydrochloride sol such as Chlorhydrol, having the formulation Al 2 0 3 ,,Ci wherein u about 4 to 12.

In another preferred embodiment the catalyst/additive composition will contain up to weight percent and prefereably 2 to 5 weight percent CaO and/or MgO which may be conveniently included in the rare earth oxalate slurry to maintain a slurry pH of above about and preferably 3.5 to 4.5. Preferably, MgO is combined with the rare-earth oxalate before the rare earth oxalate is mixed with the acid reacted meta-kaolin to form the slurry.

The rare-earth oxalate used in the present invention may contain essentially 100 percent I /7.

N> K- n- -8lanthanum/neodynium oxalate or may comprise oxalates wherein lanthanum/neodynium is present in combination with up to about 60 weight percent of other rareearths such as cerium. The rare-earth oxalate may be conveniently prepared by reacting rare-earth hydrate (oxide, hydroxide, etc.) such as Molycorp Grade 5210 rare-earth hydrate having the rare-earth analysis expressed as weight percent oxide: LazO 3 46 Ce 2 0 3 12 PrFO 2 6 Nd 2 0 3 16 Other (Cl, H0O, etc.) with oxalic acid to obtain precipitated rare-earth 15 oxalate having a particle size range of 2 to 100 microns.

The catalyst/additive may be combined with commercial zeolite-containing fluid cracking catalysts (FCC), such as Octacat, Super-D, DA and XP catalysts manufactured and sold by the Davison Chemical Division of W. R. Grace Co.-Conn. as a separate or an integral component. These catalysts typically comprise a zeolite/molecular sieve such as type X, Y, ultrastable Y (USY), rare earth exchanged Y (REY), Beta, and/or ZSM-5 dispersed in silica, alumina or silica-alumina clay matrix. Preferred zeolites are disclosed in U.S. 3,402,996 (CREX and CREY), U.S.

3,293,192, U.S. 3,449,070 (USY), U.S. 3,595,611, 3,607,043, 3,957,623 (PCY) and 3,676,368 (REHY). The FCC catalyst may be prepared in accordance with the I' (II R I'iIlit 4sw"-lNo 4/i6 teachings of U.S.A 3,957,689, CA 967,136, U.S. 4,499,197, U.S. 4,542,118 and U.S. 4,458,023.

It is also contemplated that the above-noted zeolite/molecular sieves, for example up to wt may be incorporated in the catalyst/additive composition to enhance the cracking activity.

The catalyst/additive composition of the present invention is preferably combined with the conventional zeolite containing FCC catalyst in amounts ranging from 5 to 25 weight percent, and more preferably 5 to 15 weight percent. The catalyst/additive composition may be combined with the FCC catalysts as a separate particular component before or during use in a catalytic cracking process. Alternatively, the catalyst/additive composition may be incorporated in conventional FCC catalyst particles during manufacture.

The FCC/additive compositions may be used in FCC processes conducted at cracking reaction temperatures of 500 to 600 0 C and regeneration temperatures of 600 to 850 0 C using hydrocarbon feedstocks that may contain up to 100 ppm or more of V and Ni. It is found that the presence of the additive during the FCC process passivates the adverse effects of metals such as vanadium and decreases the formation of hydrogen and coke. It is anticipated that use of the catalyst/additive composition will permit the successful use of FCC regeneration catalysts that contain as much as 10,000 to 20,000 ppm V.

Having described the basic aspects of the invention, the following examples are given, without including any limitation, to illustrate specific embodiments.

oT.9 r Y nn 9^

V^OC)

Example 1 Preparation of Acid Reacted Metakaolin/Alumina Sol Binder A 100 lb. sample of kaolin clay was calcined to 1680 0 F and then reacted with 9.4 lbs of HC1 (100% acid basis) and 280 lbs of H20 at 214°F for a period of 8 hours. Subsequently, 4.6 lbs of aluminum metal powder (Alcoa grade 120) was added and the reaction continued at 214 0 F for 6 hours.

10 Example 2 Preparation of Rare-Earth Oxalate Precipitated rare-earth oxalate was prepared by combining 117.4 Ibs of deionized water with 18.5 lbs oxalic acid (C 3 04H 2 2H 2 0) and heating the mixture to 100°F. Then 20.1 lbs rare-earth hydrate (Molycorp 5210) was added and the mixture was agitated for 1 hour. The resulting precipitated rare-earth oxalate slurry had a pH of below -11- Prepaa~no Rare-Earth Oxalate/MQ Slurry 100 lbs (dry basis) of a rare-earth oxalate slurry prepared by the method of Example 2 was combined with 5.8 lbs of MgO. The resulting mixture had a pH of Preartioi f Catalyst/Additive 158 lbs of MgO treated rare-earth oxalate slurry of-Example-3 was mixed with 207.1 lbs of the acidreacted metakaolin/binder slurry of Example 1, mixed thoroughly) spray dried at a temperature of 300OF (control), and calcined at a material temperature of 1000OF for 1 hour.

yflvALR -12- Large Batch Preparation Oxalic acid solution was prepared by adding 0.214 lbs C 2 04HzO2H 2 0 per 1 lb H 2 0 and heating to 45°C. 9820 lbs of rare-earth hydrate, which contained 46 weight percent LazO 3 was then combined with 51460 Ibs of the oxalic acid solution. The pH of the mixture was adjusted by adding 1000 lbs MgO to obtain a pH 4.0. The resulting slurry comprised: Rare-earth oxalate: 17360 lbs (27.9%) MgO: 1000 Ibs (1.61%) Water: 43920 Ibs (70.5%) Total: 62280 Ibs 50,900 lbs of acid reacted metakaolin/aluminum 15 sol binder slurry prepared as described in Example 1 (22.2 wt.% Solids) was added to 31,140 lbs of the oxalate/MgO slurry prepared above. The slurry was then spray dried at 350 0 F and calcined at 1100-1200°F S• for abour 1 hour.

o -13- Example 6 Chemical/Physical Properties and Evaluation of Catalyst/Additive Test samples were prepared which comprised 15 weight percent of the products of Examples 4 and 5, and weight percent of a commercial zeolite-containing FCC catalyst (Orion 822 manufactured and sold by the Davison Chemical Division of W. R. Grace Co.-Conn.).

A base case (comparison) sample comprising 100% Orion 822 was also prepared.

The samples were calcined 3 hours at 1250 0

F,

impregnated with V-naphthenate to a level of 5,000 ppm V, calcined 1 hour at 1450 0 F to remove carbon, then steam deactivated at 1450 0 F, 80% steam-in-air for hours. The steamed samples were evaluated for catalyst zeolite surface area retention and catalyst cracking activity and selectivity (MAT). The MAT tests were conducted at 980 0 F, 30 second contact time with a typical gas oil feedstock.

The test results using 100% Orion 822 catalyst as a control (base case) are summarized in Tables I and II. The results show that the compositions of Examples 4 and 5 produced higher retained zeolite S"surface areas after deactivation and substantially lower coke and H 2 compared with the base case catalyst.

-14- TABLE I Chemical/Physical Properties Cat&lyst Orion 822 (loo100%) Composition of Example 4 (100%) 5 Chemical Analysis

RE

2 0 3

W%

MgO: W% A1 2 0 3

W%

1.43 33.0 26.7 2.7 33.7 Physical Analysis SA: m 2 /g

H

2 0 PV: cc/g

DI:

ABD: g/cc *m Catalytic Properties* "i2 Catalyst 286 0.41 7 0.74 Orion 822 (100%) o ee a eeo 153 0.46 7 0.75 Blend of Orion 822 Ex. 4 78 61.5 0.47 42.0 Zeolite SA: m 2 /g 46 MAT: 5 cat. to oil ratio, 30 WHSV, 980* Cony. W% 48.0 Coke: W% 5.1 Hz: W% 0.70 Gasoline: W% 33.3 *Subsequent to impregnation with 5000 ppa V and deactivation with 1450"F, 80% steam/20% air for 5 hrs.

TABLE II Chemical /Phys ical1 Properties Catalyst Orion 822 (100%) Composition of Example Chemical Analysis

RE

2 0 3

W%

MgO: W% A1 2 0 3

W%

Physical Analysis SA: m 2 */g

H

2 0 PV: cc/g

DI:

ABD: g/cc .:catalytic Privertjes* 1.43 26.2 3.1 33.5. 33.3 286 0.41 7 0.74 57 0.26 4 0.98 Catalyst Orion 822 (100%) Bland of Orion 822 sk. 5 Zeolite SA: m 2 /g 57 M4AT: 4 cat. to oil ratio, 30 WH8V, 98007 Cony. W% 50 Coke: W% 5.1

H

2 W% 0.68 Gasoline: W% 24.5 7 1/68 57.0 4.2 0.59 -3-9-5s *Subsequent to impregnation with 5000 ppm V and deactivation with 14500F, 8-0% steauj20% air for S hrs.

-16- Example 7 Preparation of Zeolite-Containing Crackingr Catalyst Samples of zeolite-containing catalysts A and B were prepared which contain the following components: Catalys:' (Control)catalyst B (invention) wt.% Component wt.% Component USY Zeolite USY Zeolite A1.0 3 from A1 2 (OH) 5 C1 (2 5H 2 0) 10 7 A1 2 0 3 from P1 2 (OH) 5 Cl1(2. 5H 2 0) 38 Acid Reacted Metakaol in/Alumina Sol Binder Kaolin 38 Acid Reacted Hetakaolin/Alumina Sol Binder 28.9 Kaolin 1.1 REA0 from La/Nd Oxalate Catalysts A B were made by spray drying an aqueous slurry of USY zeolite, aluminum hydroxychioride sol, acid reacted metakaclin (of the type prepared in Example 1) and kaolin (which contained about 27 weight percent solids). -Catal-yst B, (Invention) included rare earth oxalates which possessed a La 1

O

3 /Nd 2

O

3 ratio of 6.86. The spray dried catalysts were then calcined -for 30 minutes at 370-OC.

The catalysts were washed with aqueous (NH4) 2

SO,

solution to reduce the soda level to 0.5 weight percent Na 2 O. The catalysts were then oven dried at-, 1200 C.

-17- Example 8 Chemical/Physical Properties Evaluation of Zeolite-Containing Cracking Catalyst The chemical/physical/catalytic properties of Catalysts A B of Example 7 were determined and are summarised below: Chemical/Physical Properties: A (Control) B (Invention La 2

O

3 wt.% 0.01 0.96

RE

2 0 3 wt.% 0.03 1.11 Na 2 O wt.% 0.27 0.30 A1 2 0 3 wt.% 42.9 41.9 Cl wt.% 0.06 0.09 TV 1750°F wt.% 13.9 13.7 ABD, g/cc 0.73 0.70 S DI 5 7 Unit cell size, A 24.58 24.59 :Zeolite SA, m/g 152 157 Catalytic Properties* O0 1700 ppm Ni 3300 ppm V MA wt.% 52 59 Hz wt.% 0.87 0.77 Coke wt.% 6.4 9.2 2500 pm Ni 5000 ppm V MA wt.% 45 S* H 2 wt.% 0.86 1.15 Coke wt.% 6.1 9.7 Subsequent to impregnation with Ni V and deactivation with 1400 0 F, 100% steam, 5 psig for 6 hours.

Claims (7)

18- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:- 1. A composition comprising discrete particles of a rare-earth compound selected from the group consisting of a rare-earth oxide, oxychloride and mixtures thereof dispersed in an acid reacted metakaolin matrix. 2. The composition of claim 1 which contains up to about 10 weight percent alumina binder. 3. The composition of claim 1 wherein the acid reacted metakaolin has the mole composition 0.8 to 1.0 AI 2 0 3 -2 SiO 2 and a surface area of above 150 m 2 /g. 4. The composition of claim 1 wherein the rare-earth component comprises at least about weight percent lanthanum/neodynium expressed as La 2 03/Nd 2 O 3 5 The composition of claim 1 which contains up to 10 weight percent alkaline earth metal oxide. 6. The composition of claim 5 wherein the alkaline earth oxide is magnesium oxide. 7. The composition of claim 1 which contains up to 50 weight percent zeolite/molecular sieve. 8. The composition of claim 1 having a particle size of 10 to 150 microns. 9. A catalytic cracking catalyst composition comprising a zeolite-containing cracking catalyst admixed with the composition of claim 1. A method for the catalytic cracking of hydrocarbons which comprises reacting a vanadium-containing hydrocarbon in the presence of the catalyst composition of claim 9 under catalytic cracking conditions. 11. A method for preparing a particulate rare-earth-containing catalyst/additive composition 7 4y V 'N1111 .1VA 91 01 V.V)(

19- which comprises: preparing a slurry of rare-earth oxalate and acid reacted metakaolin; spray drying the mixture; and calcining the spray dried mixture at a temperature of 425 to 870 0 C. 12. The method of claim 11 wherein the slurry is spray dried to obtain particles in the size range of about 10 to 150 microns, and an attrition index of 0 to 30 DI. 13. The method of claim 11 wherein the slurry contains up to 10 weight percent alumina sol. 14. The method of claim 13 wherein the alumina sol is obtained by reacng acid reacted metakaolin slurry with aluminum metal powder. The method of claim 13 wherein ite alumina sol has the formula Al 2 )3,Cl 6 wherein about 4 to 12. 16. The method of claim 11 wherein the slurry includes an alkaline earth oxide. 17. The method of claim 16 wherein the alkaline earth oxide is magnesium oxide. 18. The method of claim 17 wherein the magnesium oxide is combined with the rare-earth oxalate before the rare earth oxalate is mixed with the acid reacted meta-kaolin to form the slurry. 19. The method of claim 11 wherein a zeolite/molecular sieve is included in said slurry. A catalyst/additive composition substantially as hereinbefore described with reference to Examples 1 to

21. A method for preparing a catalyst/additive composition substantially as hereinbefore described with reference to Examples 1 to I I l I lil nv 4 1 111-1* -20

22. A catalytic cracking catalyst composition according to claim 9 and substantially as herein described with reference to Example 6.

23. A catalyst/additive composition substantially as herein described with reference to catalyst B in Examples 7 and 8.

24. A method of preparing a catalyst/additive composition substantially as herein described with reference to catalyst B in Examples 7 and 8.

25. A catalytic cracking catalyst composition substantially as herein described with reference to catalyst B in Examples 7 and 8. DATED this 4th day of April, 1996. W. R. GRACE CO.-CONN. By its Patent Attorneys DAVIES COLLISON CAVE Abstract Catalytic cracking catalysts/additives which comprise rare-earth, preferably lanthanum, oxide and/or oxychloride dispersed in an acid reacted metakaolin matrix. The catalysts/additives may be combined with zeolite-containing cracking catalysts to enhance catalytic activity/selectivity in the presence of metals (Ni and V). ee e