J E u r o p a i s c h e s

Patentamt

European Patent Office © Publication number: 0 1 5 6 5 9 5

Office europeen des brevets A 2

© EUROPEAN PATENT APPLICATION

© Application number: 85301772.1 © Int. CI.4: C 01 B 3 3 / 2 6

© Date of filing: 14.03.85

@ Priority: 21.03.84 US 591723 © Applicant: MOBIL OIL CORPORATION 150 East 42nd Street New York New York 10017IUS)

© Date of publication of application: 02.10.85 Bulletin 85/40 © Inventor: Rosinski, Edward Joseph

BoxA © Designated Contracting States: Pedricktown New Jersey 08067(US)

BE DE FR GB IT NL SE © Inventor: Chu.Pochen

1173 0llerton Road West Deptford New Jersey 08066(US)

© Representative: West, Alan Harry Mobil Court 3 Clements Inn London WC2A2EBIGB)

(sj) Process for preparing discrete, zeolite-containing particles. Discrete particles, for example, extrudates and micro- spheres, comprising up to 60% by weight of high-silica zeolite in a matrix are obtained by in situ seeded crystallization of the zeolite in the absence of organic cations.

This i n v e n t i o n r e l a t e s to the p r e p a r a t i o n of d i s c r e t e

p a r t i c l e s c o n t a i n i n g c r y s t a l l i n e a l u m i n o s i l i c a t e z e o l i t e s , and

e s p e c i a l l y z e o l i t e s having a s i l i c a to alumina mole r a t i o g r e a t e r

than 12 and a C o n s t r a i n t Index from 1 to 1 2 .

Many c r y s t a l l i n e z e o l i t e s are known. Some occur (at l e a s t

so far) only in n a t u r e , for i n s t a n c e p a u l i n g i t e and m e r l i n o i t e ; some

occur only as a r e s u l t of s y n t h e s i s , for i n s t a n c e z e o l i t e s A and

ZSM-5: and some occur in both n a t u r a l and s y n t h e t i c forms, f o r

i n s t ance morden i t e , a s y n t h e t i c c o u n t e r p a r t of which is known a s

zeolon, and f a u j a s i t e , s y n t h e t i c c o u n t e r p a r t s of which are known a s

z e o l i t e s X and Y. C o u n t e r p a r t s are of course demons t ra t ed as s u c h

by co r re spondence of t h e i r X-ray d i f f r a c t i o n da ta , the i n d i c i a by

means of which the i n d i v i d u a l i t y of a z e o l i t e is e s t a b l i s h e d . Such

data are a m a n i f e s t a t i o n of the p a r t i c u l a r geometry of t h e

t h r e e - d i m e n s i o n a l l a t t i c e , formed of 5i04 and, o p t i o n a l l y , A104 t e t r a h e d r a c r o s s l i n k e d by the sha r ing of oxygen atoms and i n c l u d i n g

s u f f i c i e n t c a t i o n i c complement to ba lance the r e s u l t i n g n e g a t i v e

charge on the AI04 t e t r a h e d r a , of which a z e o l i t e c o n s i s t s . The

r a t i o of t o t a l aluminum and s i l i c o n atoms to oxygen atoms i s

t h e r e f o r e 1 : 2 .

Z e o l i t e s have a c r y s t a l s t r u c t u r e t h a t is capable o f

r e g u l a t i n g the access to and egrees from the i n t r a c r y s t a l l i n e f r e e

space. This c o n t r o l , which is e f f e c t e d b y t h e c r y s t a l s t r u c t u r e

i t s e l f , is dependent both upon the molecular c o n f i g u r a t i o n of t h e

ma te r i a l which is or, a l t e r n a t i v e l y , i s not, to have access to t h e

i n t e r n a l s t r u c t u r e or pores of the z e o l i t e and a lso upon t h e

s t r u c t u r e of the z e o l i t e i t s e l f . The pores of the z e o l i t e are i n

the form of channe l s formed by the r egu la r d i s p o s i t i o n of t h e

t e t r a h e d r a making up the an ion i c framework of the c r y s t a l l i n e

z e o l i t e . A c o n v e n i e n t measure of the e x t e n t to which a z e o l i t e

p r o v i d e s t h i s c o n t r o l for molecules of vary ing s i z e s to i t s i n t e r n a l

s t r u c t u r e is p rov ided by the C o n s t r a i n t Index of the z e o l i t e :

z e o l i t e s which p r o v i d e h igh ly r e s t r i c t e d access to and egrees f rom

the i n t e r n a l s t r u c t u r e have a high value for the C o n s t r a i n t I n d e x

and z e o l i t e s of t h i s kind u s u a l l y have pores of small s i ze . I n

c o n t r a s t , z e o l i t e s which provide r e l a t i v e l y f r ee access to t h e

i n t e r n a l z e o l i t e s t r u c t u r e have a low value for the C o n s t r a i n t I n d e x .

C o n s t r a i n t Index va lues for some t y p i c a l z e o l i t e s are a s f o l l o w s :

The method by which C o n s t r a i n t Index is determined i s

d e s c r i b e d f u l l y in U.S. Pa tent 4 ,016,218 to which r e f e r e n c e is made

for d e t a i l s of t h a t me thod .

Because C o n s t r a i n t Index is r e l a t e d to the c r y s t a l l i n e

s t r u c t u r e of the z e o l i t e but is n e v e r t h e l e s s de te rmined by means o f

a t e s t which e x p l o i t s the c a p a c i t y of the z e o l i t e to engage in a

c r a c k i n g r e a c t i o n , t h a t i s , a r e a c t i o n dependent upon the p o s s e s s i o n

of a c i d i c s i t e s and f u n c t i o n a l i t y in the z e o l i t e , the sample o f

z e o l i t e used in the t e s t should be r e p r e s e n t a t i v e of z e o l i t i c

s t r u c t u r e whose C o n s t r a i n t Index is to be de termined and should a l s o

possess r e q u i s i t e a c id i c f u n c t i o n a l i t y for the t e s t . A c i d i c

f u n c t i o n a l i t y may, of cour se , be va r i ed by a r t i f i c e s i n c l u d i n g b a s e

exchange, s teaming or c o n t r o l of s i l i c a : a l u m i n a r a t i o .

The s i l i c a : a l u m i n a r a t i o of a z e o l i t e is to be c o n s i d e r e d

as the s t r u c t u r a l framework r a t i o , t h a t i s , the r a t i o of the S i o 4 to the A104 t e t r a h e d r a which t o g e t h e r c o n s t i t u t e the s t r u c t u r e o f

which the z e o l i t e is composed. This r a t i o may vary from t h e

s i l i c a : a l u m i n a r a t i o de te rmined by va r ious p h y s i c a l and c h e m i c a l

methods. For example, a gross chemical a n a l y s i s may i n c l u d e

aluminum which is p r e sen t in the form of c a t i o n s a s s o c i a t e d with t h e

a c i d i c s i t e s on the z e o l i t e , t h e r eby g iv ing a low s i l i c a : a l u m i n a

r a t i o . S i m i l a r l y , i f the r a t i o i s - d e t e r m i n e d by t h e r m o g r a v i m e t r i c

a n a l y s i s (TGA) of ammonia d e s o r p t i o n , a low ammonia t i t r a t i o n may be

o b t a i n e d i f c a t i o n i c aluminum p r e v e n t s exchange of the ammoniuum

ions onto the a c i d i c s i t e s . These d i s p a r i t i e s are p a r t i c u l a r l y

t r o u b l e s o m e when c e r t a i n t r e a t m e n t s such as d e a l u m i n i z a t i o n r e s u l t

in the p resence of ion ic aluminum f ree of the z e o l i t e s t r u c t u r e .

Due care should t h e r e f o r e be taken to ensure tha t the f ramework

s i l i c a : a l u m i n a r a t i o is c o r r e c t l y d e t e r m i n e d .

Methods for the s y n t h e s i s of z e o l i t e s are d e s c r i b e d in t h e

l i t e r a t u r e and are summarized in Breck, Z e o l i t e Molecular S i e v e s ,

John Wiley & Sons, 1974, at Chapter 4. G e n e r a l l y , a l u m i n o s i l i c a t e

z e o l i t e s c r y s t a l l i z e from aqueous systems of high pH c o n t a i n i n g

sources of s i l i c a and a lumina, a source of a s u i t a b l e c a t i o n ,

t y p i c a l l y sodium, and g e n e r a l l y a source of organic c a t i o n s . The

system is ma in ta ined under hyd ro the rma l c o n d i t i o n s , for example ,

from room t e m p e r a t u r e to 200°C or more, under autogenous p r e s s u r e , u n t i l the c r y s t a l l i n e p roduc t has fo rmed .

When the z e o l i t e s have been prepared in the p resence o f

o rgan ic c a t i o n s , they are c a t a l y t i c a l l y i n a c t i v e , p o s s i b l y b e c a u s e

the i n t r a c r y s t a l l i n e f ree space is occupied by organic c a t i o n s from

the forming s o l u t i o n . They may be a c t i v a t e d by h e a t i n g in an i n e r t

a tmosphere at 540°C for one hour, for example, fo l lowed by b a s e

exchange with ammonium s a l t s fo l lowed by c a l c i n a t i o n at 540°C i n

a i r . The p r e sence of o rgan ic c a t i o n s in the forming s o l u t i o n may

not be a b s o l u t e l y e s s e n t i a l to the format ion of the z e o l i t e but i t

does appear to favor i t s f o r m a t i o n .

Some z e o l i t e s e x h i b i t ex t remely high s i l i c a - a l u m i n a

r a t i o s . One such z e o l i t e is ZSM-5 d e s c r i b e d in U.S. P a t e n t

3 , 7 0 2 , 8 8 6 . That p a t e n t d e s c r i b e s c r y s t a l l i z a t i o n of ZSM-5 by

h y d r o t h e r m a l t r e a t m e n t of a r e a c t i o n mixture c o n t a i n i n g sources o f

s i l i c a and a lumina, and an a l k a l i metal oxide p lus a q u a t e r n a r y

ammonium compound such as t e t rapropylammonium s a l t . A somewhat

s i m i l a r z e o l i t e is ZSM-11 d e s c r i b e d in U.S. Pa t en t 3 ,709 ,979 , where

a q u a t e r n a r y ammonium compound is a lso employed. U.S. P a t e n t

3 , 9 4 1 , 8 7 1 is concerned with the s p e c i a l case of ZSM-5 in which t h e

a lumina c o n t e n t is v a n i s h i n g l y smal l , ap t ly c a l l e d

" o r g a o o s i l i c a t e " . Other z e o l i t e s , s i m i l a r in s t r u c t u r e to ZSM-5,

i n c l u d e ZSM-11, ZSM-12 (U.S. P a t e n t 3 , 8 3 2 , 4 4 9 ) , ZSM-23 (U.S. P a t e n t

4 , 0 7 6 , 8 4 2 ) , ZSM-35 (U.S. Pa t en t 4 , 0 1 6 , 2 4 5 ) , ZSM-38 (U.S. P a t e n t

4 , 0 4 6 , 8 5 9 ) , ZSM-48 (U.S. P a t e n t 4 ,397 ,827) and z e o l i t e beta (U.S .

P a t e n t 3 , 3 0 8 , 0 6 9 ) .

Z e o l i t e s are o f ten combined with a porous mat r ix to p r o v i d e

a c a t a l y s t compos i t i on . The mat r ix tends to improve the a c t i v i t y

and /o r s e l e c t i v i t y of the c a t a l y s t in c e r t a i n o rgan i c c o n v e r s i o n

p r o c e s s e s . I n e r t m a t e r i a l s which serve as the porous matr ix act a s

d i l u e n t s to c o n t r o l the amount of conve r s ion in a p a r t i c u l a r p r o c e s s

so t h a t p r o d u c t s can be o b t a i n e d economica l ly and in an o r d e r l y

manner w i thou t employing o the r means for c o n t r o l l i n g the r a t e o f

r e a c t i o n . The m a t e r i a l employed as the porous mat r ix may be a c t i v e

or i n e r t . The porous matr ix a l so f u n c t i o n s as a b inder for t h e

z e o l i t e to p rov ide a compos i t i on having a good c rush s t r e n g t h .

I n o r g a n i c m a t e r i a l s , e s p e c i a l l y those of a porous na tu re a r e

p r e f e r r e d . Of these m a t e r i a l s i n o r g a n i c oxides such as c l a y ,

c h e m i c a l l y t r e a t e d c lay, a lumina , s i l i c a , s i l i c a - a l u m i n a and t h e

l ike are p a r t i c u l a r l y p r e f e r r e d because of the s u p e r i o r p o r o s i t y ,

a t t r i t i o n r e s i s t a n c e and s t a b i l i t y they p rov ide to the z e o l i t i c

compos i t ion . The z e o l i t e can be combined, d i s p e r s e d or o t h e r w i s e

i n t i m a t e l y mixed with the porous matr ix m a t e r i a l in such p r o p o r t i o n s

tha t the r e s u l t i n g product con ta in s from 1 to 95% by weight, and

p r e f e r a b l y from 1 to 70% by weight , of the z e o l i t e . For most

commercial a p p l i c a t i o n s , the z e o l i t e - p o r o u s matr ix composite i s

provided as a hard aggrega te of d i s c r e t e p a r t i c l e s in the form o f

e x t r u d a t e s , m i c r o s p h e r e s , t a b l e t s , p e l l e t s , g r a n u l e s and the l i k e

which s u b s t a n t i a l l y r e t a i n t h e i r shape and s t r e n g t h in u s e .

Techn iques for i n c o r p o r a t i n g z e o l i t e s in a matrix a r e

conven t iona l in the art as set fo r th in U.S. Pa t en t 3 , 1 4 0 , 2 5 3 .

U.S. Pa ten t 4 ,091,007 d e s c r i b e s a method of p r epa r ing ZSM-5

z e o l i t e as a d i s c r e t e p a r t i c l e having a c r y s t a l l i n i t y of g r e a t e r

than 40 p e r c e n t by p re forming the r e a c t i o n mixture in to p e l l e t s o r

e x t r u d a t e s which r e t a i n t h e i r shape and a c q u i r e s u b s t a n t i a l s t r e n g t h

during the c r y s t a l l i z a t i o n p rocess . That r e a c t i o n mixture c o n t a i n s

a source of a l k a l i metal c a t i ons and t e t r aa lky lammonium c a t i o n s ,

s i l i c a , alumina and water . The c r y s t a l l i z e d p roduc t can be h a n d l e d

in subsequent chemical p r o c e s s i n g such as ion exchange, w i t h o u t

n e c e s s i t a t i n g cumbersome p roces se s such as f i l t r a t i o n . F u r t h e r ,

these d i s c r e t e p a r t i c l e s can be used d i r e c t l y as adso rbe r s o r

c a t a l y s t s a f t e r a p p r o p r i a t e p r o c e s s i n g but wi thou t the need of any r e f o r m u l a t i o n or p e l l e t i z i n g s ince the n o n - c r y s t a l l i n e po r t ion o f

the d i s c r e t e p a r t i c l e serves as a porous m a t r i x .

U.S. Pa t en t 4 ,175,144 s t a t e s tha t z e o l i t e s such as ZSM-5

and ZSM-11 can be formed hydro the rma l ly from r e a c t i o n mixtures o f

e l eva ted pH c o n t a i n i n g sources of s i l i c a and alumina and a l k a l i

metal oxide in the absence of qua te rna ry ions . In one p a r t i c u l a r

embodiment, t ha t r e s u l t is achieved by supp ly ing seeds of t h e

z e o l i t e to a mixture of sources as above d e s c r i b e d .

European Patent App l i ca t i on 110,650 d e s c r i b e s t h e

p r e p a r a t i o n of ZSM-5 z e o l i t e in the form of a powder from a r e a c t i o n

mixture c o n t a i n i n g ZSM-5 seeds and c o l l o i d a l s i l i c a but which i s

s u b s t a n t i a l l y f r ee of o rgan ic c a t i o n s .

None of t he se p r i o r p u b l i c a t i o n s d e s c r i b e s an in s i t u

method for p r e p a r i n g d i s c r e t e p a r t i c l e s in p e l l e t or e x t r u d a t e fo rm

c o n t a i n i n g s u b s t a n t i a l q u a n t i t i e s of high s i l i c a z e o l i t e p r e p a r e d

wi thou t employing o rgan i c compounds in the r e a c t i o n m i x t u r e .

Al though z e o l i t e s have been d e s c r i b e d above in terms o n l y

of a l u m i n o s i l i c a t e z e o l i t e s , i t is well known t h a t z e o l i t e s t h a t a r e

i somorphous with the a l u m i n o s i l i c a t e s but c o n t a i n o ther e lements i n

p lace of the s i l i c o n and/or aluminum, e x i s t a l s o . Thus, germanium

is a wel l r e c o g n i z e d s u b s t i t u t e for s i l i c o n in the c r y s t a l f ramework

of t e t r a h e d r a l i n k e d by shared oxygen a t o m s - see, for example, U . S .

P a t e n t 3 , 7 0 2 , 8 8 6 and 3 ,709 ,979 which a l so d e s c r i b e how g a l l i u m o x i d e

may take the p lace of a lumina. Breck has a l so r e p o r t e d s u c h

s u b s t i t u t i o n of i r o n , t e t r a h e d r a l l y c o o r d i n a t e d phosphorus in t h e

c r y s t a l framework, and g a l l i u m . B o r o s i l i c a t e z e o l i t e s have a l s o

been d e s c r i b e d . F u r t h e r , a method for p r e p a r i n g v a r i o u s z e o l i t e s ,

i n c l u d i n g ZSM-5, which c o n t a i n t e t r a h e d r a l l y c o o r d i n a t e d t r a n s i t i o n

meta l s in the c r y s t a l framework, is d e s c r i b e d in U.S. P a t e n t

3 , 5 3 0 , 0 6 4 .

The e x t e n s i v e s u r f a c e area p rov ided by the pores o f

z e o l i t e s has been shown to have p o t e n t c a t a l y t i c e f f e c t s ,

p a r t i c u l a r l y towards hyd roca rbons . For many types of c o n v e r s i o n s ,

advan tage can be taken of the s i m u l t a n e o u s mo lecu la r s ieve e f f e c t

and unique c a t a l y t i c c a p a b i l i t i e s to ach ieve shape s e l e c t i v e

c a t a l y s i s not a v a i l a b l e with o the r c a t a l y s t s . As the s i l i c a / a l u m i n a

(or e q u i v a l e n t ) r a t i o is i n c r e a s e d , the z e o l i t e s become d i s t i n c t l y

h y d r o p h o b i c , p e r m i t t i n g chemical c o n v e r s i o n s and a d s o r p t i o n s b a s e d , in whole or in p a r t , on f u n c t i o n a l i t y of the molecules in a m i x t u r e

under t r e a t m e n t .

Z e o l i t e ZSM-5 has been shown to be a p a r t i c u l a r l y u s e f u l

c a t a l y s t in r e a c t i o n s i n v o l v i n g a roma t i c compounds, with emphasis on

those having a s i n g l e c a r b o c y c l e . Thus ZSM-5 e x h i b i t s u n i q u e

s e l e c t i v i t y in the c o n v e r s i o n of o l e f i n s , n a p h t h e n e s , a l c o h o l s ,

e t h e r s and a lkanes in to a romat i c compounds and in such r e a c t i o n s a s

i s o m e r i z a t i o n , a l k y l a t i o n , d e a l k y l a t i o n and t r a n s a l k y l a t i o n o f

a r o m a t i c s . That f a v o r a b l e i n f l u e n c e on aromat ic c o n v e r s i o n

r e a c t i o n s is found also in the forms of ZSM-5 in which ano the r m e t a l

appears in i somorphic s u b s t i t u t i o n for aluminum, as d e s c r i b e d i n

U.S. Pa t en t 4 ,163 ,028 . The o the r high s i l i c a z e o l i t e s d e s c r i b e d

above have also been shown to be p a r t i c u l a r l y u s e f u l c a t a l y s t s ,

u s u a l l y in the same type of c o n v e r s i o n s in which ZSM-5 has b e e n

u s e f u l l y employed .

The p r e s e n t i n v e n t i o n seeks to provide a p rocess for t h e

p r e p a r a t i o n of d i s c r e t e , h i g h - s i l i c a z e o l i t e - c o n t a i n i n g p a r t i c l e s

s i m i l a r to tha t d e s c r i b e d in U.S. Pa ten t 4 ,091,007 r e f e r r e d t o

above, but wi thout the use of an o rgan ic compound in t h e

z e o l i t e - f o r m i n g r e a c t i o n mix tu re . By employing high s i l i c a z e o l i t e

seeds in p r e p a r i n g the preformed composite p a r t i c l e s , a h i g h l y

c r y s t a l l i n e product is ob t a ined by means of an in s i t u

c r y s t a l l i z a t i o n in the absence of the organic compounds r e q u i r e d i n

o ther h i g h - s i l i c a z e o l i t e s y n t h e s e s . Following the p r e f o r m i n g

o p e r a t i o n , the d i s c r e t e p a r t i c l e s are c a l c ined and then c o n t a c t e d

with an a l k a l i metal hydroxide s o l u t i o n to achieve the d e s i r e d

degree of c r y s t a l l i z a t i o n . The i n t e g r i t y of the composi te p a r t i c l e s

is r e t a i n e d dur ing the c r y s t a l l i z a t i o n to provide a z e o l i t e

compos i t ion in p a r t i c u l a t e form which is a t t r i t i o n r e s i s t a n t and

h ighly s t a b l e .

According to the i n v e n t i o n , t h e r e is provided a p rocess f o r

p r e p a r i n g d i s c r e t e p a r t i c l e s c o n t a i n i n g a c r y s t a l l i n e z e o l i t e h a v i n g

a s i l i c a to alumina mole r a t i o g r e a t e r than 12 and a C o n s t r a i n t

Index of 1 to 12 by r e a c t i n g t o g e t h e r under hydro thermal c o n d i t i o n s

a mixture compr i s ing water and sources of s i l i c a , alumina and a l k a l i

c a t i o n s , which c o m p r i s e s : (a) mixing t o g e t h e r seeds of a z e o l i t e having a

s i l i c a to alumina mole r a t i o g r e a t e r than 12 and a C o n s t r a i n t I ndex

of 1 to 12, a source of s i l i c a , a source of alumina and water and

forming the mixture in to d i s c r e t e p a r t i c l e s ;

(b) t h e r m a l l y t r e a t i n g the d i s c r e t e p a r t i c l e s to form

hard, dry, a t t r i t i o n r e s i s t a n t p a r t i c l e s ;

(c) mixing the a t t r i t i o n r e s i s t a n t p a r t i c l e s with a

source of a l k a l i c a t i o n s to form an aqueous r e a c t i o n mix ture h a v i n g

a c o m p o s i t i o n e f f e c t i v e to form the z e o l i t e of the s e e d s ;

(d) m a i n t a i n i n g the aqueous r e a c t i o n mixture u n d e r

hyd ro the rma l c o n d i t i o n s to form the z e o l i t e in the d i s c r e t e

p a r t i c l e s ; and

(e) r e c o v e r i n g d i s c r e t e p a r t i c l e s having the z e o l i t e

formed t h e r e i n .

In the p r o c e s s of the i n v e n t i o n no o rgan ic c a t i o n i s

employed in the c r y s t a l l i z a t i o n r e a c t i o n . D i s c r e t e p a r t i c l e s a r e

formed i n c l u d i n g a source of s i l i c a , a source of a lumina , water and

high s i l i c a z e o l i t e seeds . These p a r t i c l e s , in the f o r m o f

e x t r u d a t e s , m i c r o s p h e r e s , t a b l e t s , p e l l e t s or the l i k e , are t h e n

t h e r m a l l y t r e a t e d to remove excess water and to p r o v i d e hard, d r y

p a r t i c l e s having high a t t r i t i o n r e s i s t a n c e and good c rush s t r e n g t h .

To form the high s i l i c a z e o l i t e ; these hard d i s c r e t e p a r t i c l e s a r e

c o n t a c t e d with an a l k a n i z i n g s o l u t i o n under c o n d i t i o n s to e f f e c t t h e

d e s i r e d c r y s t a l l i z a t i o n . This p roces s enables a c a t a l y s t

c o m p o s i t i o n to be o b t a i n e d , c o n t a i n i n g a maximum of 60% by w e i g h t

h i g h - s i l i c a z e o l i t e in a porous m a t r i x .

The source of a lumina may be an a l u m i n a - c o n t a i n i n g clay o r

an a l u m i n o s i l i c a t e m a t e r i a l such as a n a t u r a l z e o l i t e which becomes

amorphous upon c a l c i n a t i o n . The gene r i c term "clay" is meant t o

i nc lude a l u m i n a - c o n t a i n i n g c l ays such as k a o l i n i t e , h a l l o y s i t e ,

m o n t m o r i l l o n i t e , i l l i t e , d i c k i t e , a t t a p u l g i t e , and o t h e r s . A l though

the z e o l i t e c r y s t a l l i n e a l u m i n o s i l i c a t e can be p r e p a r e d using e i t h e r

the raw clay or a t h e r m a l l y or hyd ro the rma l ly t r e a t e d c lay , i t i s

p r e f e r r e d t h a t the clay is given a thermal t r e a t m e n t at a

t e m p e r a t u r e of 5400C or more. I t is a lso in tended t h a t c h e m i c a l l y

t r e a t e d c l ays may be u t i l i z e d in t h i s p r o c e s s .

All of the alumina r e q u i r e d in the r e a c t i o n mixture may be

provided by a c lay or, where d e s i r e d , an a d d i t i o n a l source o f

a lumina, such as sodium a lumina t e , aluminum s u l f a t e or o t h e r

aluminum s a l t , may be p r o v i d e d .

The source of s i l i c a in the r e a c t i o n mix ture may c o n s i s t o f

both a clay and a non-c l ay m a t e r i a l or a clay a lone . T y p i c a l

non-c lay m a t e r i a l t h a t can be employed are Ludox, aqueous

d i s p e r s i o n s of c o l l o i d a l s i l i c a , water g l a s s , s a n d , s i l i c a g e l ,

fumed s i l i c a , s i l i c a hydrosol and f i n e l y - d i v i d e d p r e c i p i t a t e d

s i l i c a s such as H i - S i l , Quso, and Z e o s y 1 . 1 0 0 .

The a l k a l i c a t i o n s employed may be ammonium, sod ium,

po tass ium, l i t h i u m , rubid ium, cesium or mix tu res of t h e r e o f w i t h

ammonium and sodium being p r e f e r r e d . S o l u t i o n s of a l k a l i m e t a l

hydroxide and ammonium hydroxide may be e s p e c i a l l y u s e f u l l y employed

to supply the r e q u i r e d c a t i o n s .

The water c o n t e n t of the forming mixture wi l l depend on t h e

f i n a l p h y s i c a l form of the p a r t i c l e s d e s i r e d . I t is p r e f e r r e d t o

have l e s s than 50 weight pe rcen t of water in the r e a c t i o n m i x t u r e

when p r e p a r i n g a g g r e g a t e s in the form of e x t r u d a t e s , t a b l e t s ,

s p h e r o i d s , or g r a n u l e s . For each form of the a g g r e g a t e , some

ad jus tment in water c o n t e n t , below 50 weight p e r c e n t , w i l l be made

to impart the bes t p h y s i c a l p r o p e r t i e s to the m ix tu r e . For example ,

l e s s water is d e s i r e d for t a b l e t i n g the mixture than for e x t r u d i n g

i t . On the o ther hand, i f the mixture is to be spray d r i ed to form

m i c r o s p h e r e s , enough water has to be added to p r epa re a s l u r r y t h a t

is s u f f i c i e n t l y f l u i d to be pumped through the sp ray ing n o z z l e .

Water in the forming mixture wi l l be comple te ly evapo ra t ed d u r i n g

the drying and ha rden ing s tep . Add i t iona l water has to be added t o

cover the formed p a r t i c l e s and to d i s s o l v e hydrox ides of ammonium

and a l k a l i meta ls dur ing the f i n a l c r y s t a l l i z a t i o n s t e p .

This water used in the c r y s t a l l i z a t i o n s tep c o n s t i t u t e s the w a t e r

r equ i r ed by the s p e c i f i c mole r a t i o s for the p a r t i c u l a r z e o l i t e

being formed.

For some c a t a l y t i c or a d s o r p t i o n a p p l i c a t i o n s , i t wi l l b e

d e s i r a b l e to i n c o r p o r a t e s u b s t a n t i a l l y n o n r e a c t i v e s o l i d powders

in to the r e a c t i o n mix tu re . These powders are s e l e c t e d on the b a s i s

of the p a r t i c u l a r p h y s i c a l p r o p e r t y t h a t i t is d e s i r e d to impart t o

the f i n a l p r o d u c t . For example, s o l i d powders may be added t o

i n c r e a s e d e n s i t y , modify c a t a l y t i c a c t i v i t y , i n c r e a s e heat c a p a c i t y

or modify p o r o s i t y of the f i n a l p a r t i c l e , or act as a d i l u e n t f o r

the c r y s t a l l i n e a l u m i n o s i l i c a t e in the p r o d u c t . Examples of s o l i d

powders which may be used i n c l u d e a lpha a lumina , t i t a n i a , z i r c o n i a ,

z i r c o n , barium s u l f a t e , and m e t a l l i c n i c k e l . I t is to be u n d e r s t o o d

t h a t s u b s t a n t i a l l y i n a c t i v e " w e i g h t i n g a g e n t s " such as i n a c t i v e

a l u a i n a ( fo r example, alpha a lumina) and sand may a l so be u s e d .

Z e o l i t e ZSM-5, in i t s anhydrous s t a t e , is i d e n t i f i e d in t h e

l i t e r a t u r e in terms of mole r a t i o s of i t s c o n s t i t u e n t ox ides , a s

f o l l o w s :

(0 .9 + 0.2)M2/n 0:Al2O3: x SiO2 in which M is a mix tu re of a l k a l i m e t a l , e s p e c i a l l y sodium, and

t e t r a a l k y l a m m o n i u m the a lky l groups of which p r e f e r a b l y c o n t a i n 2 t o

5 carbon atoms, n is the va lence of-M and x is at l e a s t 5 .

The ZSM-5 s y n t h e s i z e d in the p roce s s of the i n v e n t i o n w i l l

have the same c h a r a c t e r i s t i c formula but in which M is an a l k a l i

me ta l , ammonium or mix ture t h e r e o f , and X is at l e a s t 12 .

The h i g h - s i l i c a z e o l i t e s with which the i n v e n t i o n i s

conce rned , such as ZSM-5, possess a d e f i n i t e d i s t i n g u i s h i n g

c r y s t a l l i n e s t r u c t u r e whose X-ray d i f f r a c t i o n p a t t e r n h a s

s i g n i f i c a n t l i n e s from which the f o l l o w i n g i n t e r p l a n a r spac ings d

(in Angstroms) and r e l a t i v e i n t e n s i t i e s can be d e r i v e d :

These values were de te rmined by s t a n d a r d t e c h n i q u e s . The r a d i a t i o n

was the K-alpha doub le t of copper, and a s c i n t i l l a t i o n c o u n t e r

spec t rome te r with a s t r i p cha r t pen r e c o r d e r was used. The p e a k

he igh t s , I, and the p o s i t i o n s as a f u n c t i o n of 2 t imes t h e t a ,

where t he t a is the Bragg angle , were read from the s p e c t r o m e t e r

cha r t . From t h e s e , the r e l a t i v e i n t e n s i t i e s , 100 I / I o , where I o is the i n t e n s i t y of the s t r o n g e s t l i n e or peak, and d, t h e

i n t e r p l a n a r spac ing in A, co r r e spond ing to the recorded l i n e s ,

were c a l c u l a t e d . In Table 2, the r e l a t i v e i n t e n s i t i e s are given i n

terms of symbols s = s t r o n g , w = weak and vs = v e r y

s t r o n g .

O n e of the h i g h - s i l i c a z e o l i t e s , ZSM-5, has been p r e p a r e d

h i t h e r t o from a r e a c t i o n mix ture c o n t a i n i n g t e t r ap ropy l ammon ium

hydrox ide , sodium ox ide , an oxide of a luminum,

an oxide of s i l i c a , and water and having a compos i t i on f a l l i n g

wi th in the f o l l o w i n g r a n g e s :

in which R is p r o p y l , by m a i n t a i n i n g the mix ture u n t i l c r y s t a l s o f

the z e o l i t e are formed. Tetrapropylammonium ions can be supp l i ed by

the a d d i t i o n of t e t r ap ropy lammonium h a l i d e . If an excess o f

t e t rapropy lammonium hydrox ide is used which would r a i s e the value o f

OH-/SiO2 above the r anges set f o r th above, the excess h y d r o x i d e

can be n e u t r a l i z e d by adding an a p p r o p r i a t e amount of acid t o

ma in ta in the OH-/SiO2 r a t i o wi th in the r e q u i r e d r ange . The

r e s u l t i n g c r y s t a l s a re then s e p a r a t e d from the l i q u i d and

r ecove red . T y p i c a l r e a c t i o n c o n d i t i o n s c o n s i s t of h e a t i n g t h e

r e a c t i o n mix ture to a t e m p e r a t u r e of 75 to 205°C for a period o f

time of one hour to 60 days. A more p r e f e r r e d t e m p e r a t u r e is 90 t o

175°C with the amount of time at a t e m p e r a t u r e in such range b e i n g

from 1 hour to 20 d a y s .

Other h i g h - s i l i c a z e o l i t e s have been p repa red in a s i m i l a r

f a sh ion employing m i x t u r e s having compos i t i ons whose mole r a t i o s o f

components f a l l w i t h i n s p e c i f i c ranges d e s c r i b e d in the a r t .

Early s y n t h e s i s of ZSM-5 z e o l i t e and o ther h i g h - s i l i c a

z e o l i t e s was accompl i shed by i nc lud ing amines, q u a t e r n a r y ammonium

compounds, q u a t e r n a r y phosphonium compounds or the l i ke in t h e

r e a c t i o n m ix tu r e . These have been cons ide r ed to be " t e m p l a t e s "

which d i r e c t e d the course of c r y s t a l l i z a t i o n to the p a r t i c u l a r

des i r ed c r y s t a l framework. Such compounds are c a t i o n i c in n a t u r e

and occupy p o s i t i o n s in the c r y s t a l l i n e product to ba lance t h e

e l e c t r o n e g a t i v e c h a r a c t e r of t e t r a h e d r a l l y c o o r d i n a t e d aluminum o r

o ther element s u b s t i t u t e d for aluminum. On d e h y d r a t i o n of t h e

z e o l i t e , these bulky c a t i o n s occupy spaces which i n h i b i t flow o f

f l u i d s (gases or l i q u i d s ) in the pores for a d s o r p t i o n , c a t a l y s i s o r

ion exchange. T y p i c a l l y , t e t r a p r o p y l ammonium c a t i o n s have been

removed from ZSM-5 z e o l i t e s by combustion in a i r at e l e v a t e d

t empera tu re to f a c i l i t a t e removal of sodium c a t i o n s by ion e x c h a n g e .

Such o r g a n i c t empla te compounds are not i nc luded in t h e

r e a c t i o n mix tu res of the inven t ion s ince t h e i r use would involve an

unnecessary expense and would impose unnecessa ry p r o c e s s i n g s t e p s .

According to the i n v e n t i o n , the r e a c t i o n mixture i s

s u b s t a n t i a l l y f r ee of organic compounds of n i t r o g e n or p h o s p h o r u s ,

p a t i c u l a r l y those which form ca t i ons in aqueous s o l u t i o n . The

r e a c t i o n mixture t h e r e f o r e c o n s i s t s e s s e n t i a l l y of i n o r g a n i c

r eagen t s in the sense t ha t any organic m a t e r i a l p r e s e n t i s

a d v e n t i t i o u s and /o r does not enter in to or d i r e c t t h e

c r y s t a l l i z a t i o n p r o c e s s . The products ob ta ined acco rd ing to t h e

i n v e n t i o n are t h e r e f o r e s u b s t a n t i a l l y f ree of o rgan ic c a t i o n s .

The h i g h - s i l i c a z e o l i t e s p repared by the p rocess of t h e

i n v e n t i o n possess a s i l i c a to alumina mole r a t i o of at l e a s t 12 .

P r e f e r a b l y , however, t h a t r a t i o is g r e a t e r than 30 and may be

c o n s i d e r a b l y h i g h e r .

In accordance with the i n v e n t i o n , the r e a c t i o n m i x t u r e

obta ined by a d d i t i o n of the source of a l k a l i c a t i o n s and water t o

the dry, hard, a t t r i t i o n r e s i s t a n t p a r t i c l e s , s u i t a b l y has a

composi t ion in terms of mole r a t i o s , for each of the d e s i g n a t e d

h i g h - s i l i c a z e o l i t e s , as f o l l o w s :

The h i g h - s i l i c a z e o l i t e seed c r y s t a l s inc luded in t h e

d i s c r e t e p a r t i c l e s may be a po r t i on of the wet product as s e p a r a t e d

from a h i g h - s i l i c a z e o l i t e s y n t h e s i s performed according to any o f

the p r i o r a r t p rocedures or may be c r y s t a l s which have been i o n

exchanged and /o r c a l c i n e d in any d e s i r e d manner. The q u a n t i t y o f

seeds employed may vary wi th in wide l i m i t s , but wi l l g e n e r a l l y be a t

l e a s t 0.01 weight pe rcen t of seeds based on the t o t a l weight o f

s i l i c a , alumina and seeds . Although the presence of h i g h - s i l i c a

z e o l i t e seeds is c r i t i c a l to the success of the s y n t h e s i s , t h e

q u a n t i t y of the seeds employed is not per se c r i t i c a l . However,

t h i s l a t t e r f a c t o r does become impor t an t in c o n t r o l l i n g the s ize o f

the h i g h - s i l i c a z e o l i t e fo rmed .

In g e n e r a l i t has been found t ha t lower r e a c t i o n

t e m p e r a t u r e s f a v o r p roduc t ion of z e o l i t e s of smal ler c r y s t a l s ize i n

the p r a c t i c e o f the i n v e n t i o n . A f u r t h e r c o n t r o l can be imposed by

c o n t r o l of q u a n t i t y of seed c r y s t a l s . At r e l a t i v e l y s m a l l

p r o p o r t i o n s of seed, about 1 to 5% by weight , the p rocess y i e l d s a

product of l a r g e r s i ze than the seeds . At l a rge r q u a n t i t i e s o f

seed, in the approximate range of 3 to 10%, the p rocess tends t o

y ie ld a p roduc t of about the same c r y s t a l s ize as the seed c r y s t a l s .

In the p rocess of the i n v e n t i o n , the mixture of s e e d s ,

sources of s i l i c a and alumina and water is preformed in to d i s c r e t e

p a r t i c l e s by p r o c e d u r e s such as e x t r u s i o n , spray d ry ing , t a b l e t t i n g

and the l i k e . The d i s c r e t e p a r t i c l e s are then s u b j e c t e d to a

thermal t r e a t m e n t , for example, at about 540°C, such as c a l c i n i n g ,

to provide a dry, hard p a r t i c l e . Temperatures of 1000°C and above

may be employed. These p a r t i c l e s r e t a i n t h e i r shape and a c q u i r e s u b s t a n t i a l s t r e n g t h in the c r y s t a l l i z a t i o n p r o c e s s .

The d i s c r e t e p a r t i c l e s are then added to an a l k a l i n e

aqueous s o l u t i o n c o n t a i n i n g s u f f i c i e n t a l k a l i hydroxide t h a t t h e

mixture with blended s o l i d s wi l l have a pH between 7.5 and 13.0. I n

a d d i t i o n to the f u n c t i o n of c o n t r o l l i n g pH, the a l k a l i z i n g a g e n t

a l so s e r v e s to supp ly the n e c e s s a r y c a t i o n s to b a l a n c e s u c h

e l e c t r o n e g a t i v e c h a r a c t e r as may be found in the c r y s t a l f ramework.

The r e a c t i o n mix ture c o n t a i n i n g the d i s c r e t e p a r t i c l e s i s

a g i t a t e d to promote mixing and r a i s e d in t e m p e r a t u r e to h y d r o t h e r m a l

c o n d i t i o n s c o n d u c i v e to fo rma t ion of the d e s i r e d h i g h - s i l i c a

z e o l i t e , in the g e n e r a l range of 75 to 200°C. A g i t a t i o n i s

c o n t i n u e d whi le the mix tu re is ma in ta ined under au togenous p r e s s u r e u n t i l the z e o l i t e c r y s t a l s are formed in the d i s c r e t e p a r t i c l e s , a

pe r iod of a few hours to s e v e r a l d a y s .

The c r y s t a l l i z e d p roduc t can then be r e a d i l y handled in a n y s u b s e q u e n t chemica l p r o c e s s i n g , such as ion exchange , w i t h o u t

n e c e s s i t a t i n g such cumbersome p r o c e s s e s as f i l t r a t i o n . F u r t h e r m o r e ,

the d i s c r e t e p a r t i c l e s can be d i r e c t l y used as a d s o r b e n t s o r

c a t a l y s t s a f t e r the a p p r o p r i a t e p r o c e s s i n g but w i thou t need of any r e f o r m u l a t i o n or p e l l e t i z i n g s ince the n o n - c r y s t a l l i n e p o r t i o n o f

the p a r t i c l e s e r v e s as the m a t r i x .

The p a r t i c u l a r h i g h - s i l i c a z e o l i t e formed depends upon t h e

c o m p o s i t i o n of the d i s c r e t e p a r t i c l e s be fo re c r y s t a l l i z a t i o n and t h e

n a t u r e of the z e o l i t e s e e d s c o n t a i n e d in those p a r t i c l e s . The

compos i t i on of the d i s c r e t e p a r t i c l e s and the source of the a l k a l i .

metal c a t i o n shou ld p r o v i d e a compos i t ion e f f e c t i v e to form t h e

p a r t i c u l a r h i g h - s i l i c a z e o l i t e d e s i r e d and the seeds employed s h o u l d

be of t h a t same z e o l i t e . Thus i f the z e o l i t e in the f i n a l d i s c r e t e

p a r t i c l e p r o d u c t i s to be ZSM-12, ZSM-12 z e o l i t e seeds should b e

i n c l u d e d in the c o m p o s i t i o n of the d i s c r e t e p a r t i c l e s when they a r e

i n i t i a l l y formed and the t h e r m a l l y t r e a t e d d i s c r e t e p a r t i c l e s ( p r i o r

to c r y s t a l l i z a t i o n ) t o g e t h e r with the source of a l k a l i metal c a t i o n s

should p rov ide a c o m p o s i t i o n wi th in the mole r a t i o range for ZSM-12

as they appear in Table 4 a b o v e .

In the p r o c e s s of t h i s i n v e n t i o n , the r e a c t i o n mixture i s

e s s e n t i a l l y f r e e of o r g a n i c r e a g e n t s such as the amines and

q u a t e r n a r y ammonium compounds used in many p r i o r a r t p r e p a r a t i o n s .

Thus, the i n v e n t i o n avo ids the consumption of expens ive o r g a n i c

r e a g e n t s and avo ids the downstream p r o c e s s i n g s t ep s necessa ry t o

remove o rgan ic c a t i o n s from the p r o d u c t .

H i g h - s i l i c a z e o l i t e s p r e p a r e d accord ing to the i n v e n t i o n

can be employed in the form in which they are s y n t h e s i z e d or can be

c o n v e r t e d in to forms through ion exchange in accordance with known

t e c h n i q u e s , to p repare c a t a l y t i c a l l y a c t i v e c o m p o s i t i o n s . These

z e o l i t e compos i t i ons can be ion exchanged to remove a t l e a s t a

p o r t i o n of the a l k a l i metal c a t i o n s and conver ted in to forms which

tend to be more c a t a l y t i c a l l y a c t i v e and s t a b l e . The a l k a l i m e t a l

c a t i o n s , e s p e c i a l l y the sodium and potass ium c a t i o n s , can be

exchanged for hydrogen ions by t r e a t i n g the z e o l i t e with a c i d s .

A l t e r n a t i v e l y , the z e o l i t e can be t r e a t e d with a source of ammonium,

alkylammonium or arylammonium, p rov ided tha t s t e r i c h inde rance does

not p r even t the ca t ion from e n t e r i n g the pores of the z e o l i t e . I f

the a l k a l i metal is r ep laced by an ammonium c a t i o n or complex, t h e

hydrogen form is prepared t he r e f rom by hea t ing the exchanged

c o m p o s i t i o n to a t empera tu re above 200°C causing e v o l u t i o n o f

ammonia and r e t e n t i o n of a proton in the compos i t ion , at the s i t e

p r e v i o u s l y occupied by the ammonium i o n .

Other r e p l a c i n g c a t i o n s i n c l u d e c a t i o n s of Groups IB- V I I I

of the P e r i o d i c Table, e s p e c i a l l y meta ls of Groups II and I I I ,

i n c l u d i n g the ra re ea r th meta l s , t i n , lead , Group IVB c o m p r i s i n g

t i t a n i u m , z i rconium, and hafnium; meta ls of the a c t i n i d e s e r i e s ,

antimony., bismuth, chromium, a lso Group VIIB and Group V I I I .

R e g a r d l e s s of the c a t i o n s r e p l a c i n g the a l k a l i metal c a t i o n s in t h e

f r e s h l y s y n t h e s i z e d form of the z e o l i t e s , the s p a t i a l a r rangement o f

the aluminum, s i l i c o n and oxygen atoms, which form the b a s i c c r y s t a l

l a t t i c e of the z e o l i t e , remains e s s e n t i a l l y unchanged by t h e

r e p l a c e m e n t of sodium, as de te rmined by X-ray d i f f r a c t i o n a n a l y s i s

of the ion exchanged m a t e r i a l .

Ion exchange of the z e o l i t e s can be a c c o m p l i s h e d

c o n v e n t i o n a l l y by c o n t a c t i n g the z e o l i t e with a s o l u t i o n , s u i t a b l y

an aqueous s o l u t i o n , of a s a l t of the exchanging c a t i o n .

A d d i t i o n a l l y , the composi t ion can undergo so l id s t a t e exchange t o

remove sodium and s u b s t i t u t e ano the r ca t ion t h e r e f o r .

P r e f e r a b l y , s o l u t i o n exchange is employed .

While water w i l l o r d i n a r i l y be the s o l v e n t in the i o n

exchange s o l u t i o n employed, o ther s o l v e n t s , a l t h o u g h g e n e r a l l y l e s s

p r e f e r r e d , can be used. Thus, in a d d i t i o n to an aqueous s o l u t i o n ,

a l c o h o l s o l u t i o n s of the exchange compounds can be employed i n

p r o d u c i n g a c a t a l y s t compos i t i on . G e n e r a l l y , the a l k a l i m e t a l

c o n t e n t i s reduced to l e s s than 3 weight p e r c e n t . When t h e

exchanged a l u a d n o s i l i c a t e is p r e p a r e d , i t is g e n e r a l l y , t h e r e a f t e r ,

t r e a t e d with a s u i t a b l e s o l v e n t , for example, wate r , to wash out any of the an ions which may have become t e m p o r a r i l y e n t r a i n e d or c a u g h t

in the pores or c a v i t i e s of the c r y s t a l l i n e c o m p o s i t i o n .

C a l c i n a t i o n of the high s i l i c a z e o l i t e s of t h i s i n v e n t i o n

may be u t i l i z e d to p lace the z e o l i t e in an a c t i v a t e d form. The

z e o l i t e be ing c a l c i n e d may be in i t s f r e s h l y p r e p a r e d form or in i t s

i o n - e x c h a n g e d form. C a l c i n a t i o n may be conducted in a i r or o t h e r

i n e r t gas at t e m p e r a t u r e s of 260 to 820°C for p e r i o d s of time from 1

to 48. hours or more .

The h i g h - s i l i c a z e o l i t e s p r epa red by the p roces s of t h e

i n v e n t i o n are v a l u a b l e c a t a l y s t s in v a r i o u s o rgan ic compound

c o n v e r s i o n p r o c e s s e s . Such p r o c e s s e s i n c l u d e , for e x a m p l e ,

a l k y l a t i o n of a roma t i c s with o l e f i n s , a r o m a t i z a t i o n of n o r m a l l y

gaseous o l e f i n s and p a r a f f i n s , a r o m a t i z a t i o n of normal ly l i q u i d low

m o l e c u l a r weight p a r a f f i n s and o l e f i n s , i s o m e r i z a t i o n of a r o m a t i c s ,

p a r a f f i n s and o l e f i n s , d i s p r o p o r t i o n a t i o n of a r o m a t i c s ,

t r a n s a l k y l a t i o n of a r o m a t i c s , o l i g o m e r i z a t i o n of o l e f i n s and

c r a c k i n g and h y d r o c r a c k i n g . Other c a t a l y t i c p r o c e s s e s where t h e s e

z e o l i t e s may be employed are d e s c r i b e d in the a r t . The z e o l i t e i s

u s u a l l y employed in i t s c a l c i n e d form and may have b e e n

i o n - e x c h a n g e d before the c a l c i n a t i o n .

The f o l l owing Examples i l l u s t r a t e the i n v e n t i o n . ZSM-5 i s

the h i g h - s i l i c a z e o l i t e t h a t is the s u b j e c t of the Examples . D i s c r e t e p a r t i c l e s c o n t a i n i n g any of the o ther h i g h - s i l i c a z e o l i t e s

may be p r e p a r e d and employed in a s i m i l a r f ash ion by making

a p p r o p r i a t e m o d i f i c a t i o n s to the compos i t ion of the r e a c t i o n m i x t u r e

and employing seeds of the h i g h - s i l i c a z e o l i t e of i n t e r e s t .

Example 1

A base c a t a l y s t in the shape of an e x t r u d a t e was p r e p a r e d

by mul l ing 1000 g of kaol in clay (S.A.F. type, 85% s o l i d ) , 977 g o f

a commercial brand of f i ne ly d iv ided so l i d s i l i c a known as H i - S i l

(EP type, 87% s o l i d ) , 90 g of ZSM-5 seeds ( 0 . 0 2 j U m , 100% so l id ) and

1500 g of H20 for about 30 minutes and then ex t rud ing the m i x t u r e

into 3.2 mm e x t r u d a t e s . The seeds c o n s t i t u t e d 5 wt.% of the t o t a l

s o l i d s . The d r i ed e x t r u d a t e s were hardened by c a l c i n a t i o n at 9800C

for 3 hours in a i r . One hundred p a r t s of the c a l c i n e d e x t r u d a t e s

were added to a s o l u t i o n of 220 p a r t s of H20 and 4 p a r t s of NaOH.

The mix ture was then heated in an au toc l ave at 100°C for 16 h o u r s

and at 150°C for 4 days. The r e s u l t a n t e x t r u d a t e was water washed,

d r ied and c rushed to de termine i t s c r y s t a l l i n i t y . The p roduc t was

de t e rmined , by x-ray d i f f r a c t i o n a n a l y s i s , to be 40% by w e i g h t

ZSM-5. The d r i ed e x t r u d a t e had a c rush ing s t r e n g t h of 690 kPa .

Pore volume was 0.43 ml/g. The NH4 exchangbed, a i r c a l c i n e d (3

hours at 540°C) e x t r u d a t e had an alpha a c t i v i t y of 154 .

Example 2

The same ca l c ined e x t r u d a t e s and s o l u t i o n d e s c r i b e d i n

Example 1 were heated in an a u t o c l a v e at 100°C for 14 days. The

r e s u l t a n t washed and dried e x t r u d a t e s con ta ined about 10% ZSM-5

c r y s t a l s .

Example 3

A base c a t a l y s t in the shape of an e x t r u d a t e was p r e p a r e d

by the method desc r ibed in Example 1 except tha t ZSM-5 seeds were

not added. The e x t r u d a t e s were c a l c ined and s u b j e c t e d t o

c r y s t a l l i z a t i o n by the p rocedure desc r ibed in Example 1. The f i n a l

e x t r u d a t e s con ta ined no ZSM-5 but some u n i d e n t i f i e d c r y s t a l l i n e

m a t e r i a l .

Example 4

A m i c r o s p h e r i c a l form of t h e ZSM-5 a g g r e g a t e was p r e p a r e d

by spray d ry ing a m ix tu re of 5000 gm of kao l in (U.F. g r ade ) , 4800 gm

of 30% c o l l o i d a l SiO2, 283 gm of ZSM-5 seeds (5% weight based on

t o t a l s o l i d s ) and 1000 g of H2O. The r e s u l t a n t ZSM-5 m i c r o s p h e r e s

were a l so p r e c a l c i n e d at 980°C for 3 hours . The c r y s t a l l i z a t i o n o f

m i c r o s p h e r e s to ZSM-5 fo l lowed the c o n d i t i o n s d e s c r i b e d in Example 1

for the e x t r u d a t e s . The m i c r o s p h e r e product was ana lyzed by x - r a y

d i f f r a c t i o n a n a l y s i s and found to c o n t a i n 35% by weight ZSM-5.

Example 5

The same c a l c i n e d m i c r o s p h e r e s and s o l u t i o n d e s c r i b e d i n

Example 4 were hea ted in an a u t o c l a v e at 100°C for 14 days. The

f i n a l washed and d r i e d e x t r u d a t e s c o n t a i n e d about 10% ZSM-5 m a t e r i a l .

Example 6

A m i c r o s p h e r i c a l form of the ZSM-5 a g g r e g a t e was p r e p a r e d

by spray d ry ing the c o m p o s i t i o n d e s c r i b e d in Example 4 except t h a t

ZSM-5 seeds were not added. The c a l c i n a t i o n and c r y s t a l l i z a t i o n o f

these m i c r o s p h e r e s fo l low the c o n d i t i o n s d e s c r i b e d in Example 1 .

The f i n a l p roduc t c o n t a i n e d only some u n i d e n t i f i e d c r y s t a l l i n e m a t e r i a l .

Example 7

The d i s c r e t e p a r t i c l e p roduc t of Example 4 was s t e a m

a c t i v a t e d and e v a l u a t e d in a s e r i e s of runs where a gas o i l was

c a t a l y t i c a l l y c r a c k e d . The gas o i l employed was a sour heavy ga s

o i l . In Run 1, t h i s gas o i l was c racked with a c o m m e r c i a l

z e o l i t e - c o n t a i n i n g c r a c k i n g c a t a l y s t supp l i ed by F i l t r o l

C o r p o r a t i o n . In Run 2, 0.5 wt.% of the steam a c t i v a t e d product o f

Example 4 was added to the commercial z e o l i t e c r a c k i n g c a t a l y s t

while in Run 3, 2 wt.% of the steam a c t i v a t e d p r o d u c t of Example 4

was added to the commercial z e o l i t e c r ack ing c a t a l y s t . The r e s u l t s

of t hese t h r e e runs are p r e s e n t e d in Table 5 .

1. A p rocess for p r e p a r i n g d i s c r e t e p a r t i c l e s c o n t a i n i n g

a c r y s t a l l i n e z e o l i t e having a s i l i c a to alumina mole r a t i o g r e a t e r

than 12 and a C o n s t r a i n t Index of 1 to 12 by r e a c t i n g t o g e t h e r u n d e r

h y d r o t h e r m a l c o n d i t i o n s a mix tu re compr i s ing water and sources o f

s i l i c a , a lumina and a l k a l i c a t i o n s , which c o m p r i s e s :

(a) mixing t o g e t h e r seeds of a z e o l i t e having a s i l i c a to aulmina mole r a t i o g r e a t e r than 12 and a C o n s t r a i n t I ndex

of 1 to 12, a source of s i l i c a , a source of alumina and water and

forming the mix tu re in to d i s c r e t e p a r t i c l e s ;

(b) t he rma l ly t r e a t i n g the d i s c r e t e p a r t i c l e s to form

ha rd , d ry , a t t r i t i o n r e s i s t a n t p a r t i c l e s ;

(c) mixing the a t t r i t i o n r e s i s t a n t p a r t i c l e s with a

sou rce of a l k a l i c a t i o n s to form an aqueous r e a c t i o n mix ture h a v i n g

a c o m p o s i t i o n e f f e c t i v e to form the z e o l i t e of the s e e d s ; (d) m a i n t a i n i n g the aqueous r e a c t i o n mix tu re u n d e r

h y d r o t h e r m a l c o n d i t i o n s to form the z e o l i t e in the d i s c r e t e

p a r t i c l e s ; a n d

(e) r e c o v e r i n g d i s c r e t e p a r t i c l e s having the z e o l i t e

formed t h e r e i n .

2. A p rocess a cco rd ing to Claim 1, i n c l u d i n g the f u r t h e r

s t ep of c a l c i n i n g the d i s c r e t e p a r t i c l e s .

3. A p roce s s a cco rd ing to Claim 1 or Claim 2 i n c l u d i n g

the f u r t h e r s t e p of s u b j e c t i n g the z e o l i t e wi th in the d i s c r e t e

p a r t i c l e s to ion exchange to r e p l a c e the a l k a l i c a t i o n s at l e a s t i n

pa r t by c a t i o n s of a metal or h y d r o g e n .

4. A p roces s acco rd ing to any one of Claims 1 to 3 ,

where in the source of alumina is an a l u m i n a - c o n t a i n i n g clay s e l e c t e d

from k a o l i n , h a l l o y s i t e and m o n t m o r i l l o n i t e , or an a l u m i n o s i l i c a t e .

5. A p roce s s accord ing to any one of Claims 1 to 4 ,

wherein the source of s i l i c a comprises a s i l i c a - c o n t a i n i n g c l a y ,

fumed s i l i c a or s i l i c a h y d r o s o l .

6. A p rocess acco rd ing to any one of Claims 1 to 5 ,

wherein the r e a c t i o n mixture of s t eps (c) and (d) is e s s e n t i a l l y

f ree from organic c a t i o n s .

7. A p rocess acco rd ing to any one of Claims 1 to 6 ,

wherein the f i n a l d i s c r e t e p a r t i c l e s have a z e o l i t e content of n o t

more than 60% by w e i g h t .

8. A p rocess accord ing to any one of Claims 1 to 7 ,

wherein the d i s c r e t e p a r t i c l e s are in the form of e x t r u d a t e s ,

p e l l e t s , t a b l e t s or m i c r o s p h e r e s .