Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
5~
This invention relates t~ the preparation of
hydrocaxbon conversion catalysts, and more particularly to the
preparation of hiyhIy active zeolite type catalysts which are
capable of converting petroleum hydrocarbons such as gas oil,
boil ng in the 400-1050F range, to lower molecular weight
derivatives such as gasoline.
For many years cation exchanged zeolites
particularly those of the rare earth exchanged type X or Y
zeolite, i.e., synthetic faujasite, have been found to be
particularly useful in the converting of petroleum feedstocks -
such as gas oil into lower molecular weight derivatives such --
as gasoline.
Prior art catalysts, while possessing a high
degree of activity and desired selectivity when compared to the
previously available amorphous type hydrogel catalysts,
are found to be relatively limited in terms of producing
desirable products other than gasoline. Substantial attempts
have been made to alter the characteristics of rare earth
exchanged faujasites so as to produce a product stream which
is higher in desirable end products such as olefins and/or
gasolines high in aromatic content. ~owever, it is found
frequently that modifications of faujasites by the exchange
with additional metals other than rare earths has frequently
led to the preparations of catalysts which tend to produce
undesirable products such as dry gas and coke.
Thus, in accordance with the present teachings, ;
a method is provided for the catalytic cracking of hydrocarbons
which method comprises contacting a hydrocarbon feedstock with
a catalyst comprising a) rare earth-hydrogen type Y zeolite,
b) a second zeolite consisting of exchanged mordenite having ~-
the general formula M-mordenite wherein M is selected from the
group consisting of hydrogen, rare earth, cobalt, nickel and
-2- ~
., , . ., . : . .. . .
~45~6~
group II cations undex catalytic cracking conditions and
recovering the pxoducts foxmed thereby.
These and still further aspects of the present
invention will become readily apparen-t from the detailed
description and specific examples.
Broadly, our invention involves cracking a
hydrocarbon feedstock using a catalyst composition which
comprises a mixture of rare earth hydrogen exchanged type Y
zeolite (RE-H-Y), and a metal or hydrogen exchanged mordenite
(H or M-Mord.), or calcium exchanged type A zeolite (CaA)
or hydrogen erionite (H-Er.).
More specifically, we have found that an `
extremely useful hydrocarbon conversion catalyst composition may
be obtained if rare earth hydrogen Y zeolite is combined with
from about 5 to 40% by weight of one of the following:
1) A transition metaI or hydrogen exchanged
mordenite which possesses the general formula M-Mord., where M
is selected from the group consisting of hydrogen and metals
such as rare earth, cobalt, nickel, group II cations, and
other di- and trivalent transition metals and Mord. represents ~;
the negatively charged mordenite.
2) A calcium exchanged type A zeolite.
3) A hydrogen exchanged erionite.
In a particularly preferred embodiment of the
present invention, the combination of rare earth hydrogen Y and
exchanged mordenite or type A zeolite or erionite is combined
-` ~O~S'J6~
with an inorganic oxide matrix such as silica, alumina, silica-
alumina hydrogel and/or clay- Such compositions ma~ be readily
formed into microspheroidal products so as to provide the -~
$o-called fluid cracking catalysts, or alternatively the
composition may he formed into relatively large sized beads
so as to provide the so-called moving bed type catalysts.
The rare earth hyarogen Y type zeolite used in the
practice of the present invention is described in U.S. Patent
No. 3,676,368 of Scherzer et al.
Briefly, the rare earth hydrogen Y zeolite
comprises faujasitic zeolite having a silica-alumina ratio
of about 3 to 6 which has been rare earth exchanged in a
particular manner to produce a zeolite which contains on the
order of 6 to 14% by weight rare earth ions measured as
rare earth oxides, and less than 0.5~ by weight alkali metal
ions measured as alkali metal oxides. The rare earth
hydrogen Y zeolite is prepared by first e~changing an alkali
metal Y zeolite, usually sodium Y zeolite having a silica-
alumina ratio on the order of 3 to 6 with a solution of rare
earth ions at a pH of from about 3.0 to 3.5 to reduce the
alkali metal oxide content to a level of less than about 4%
by weight. Subsequently, the exchanged zeolite is calcined
at a temperature of 800 to 1400F for a period of about 1
to 3 hours. Finally the product is a~nonium ion exchanged
to further reduce the alkali metal content to less than
about 0.5~ by weight.
The metal exchanged mordenite used in the practice of
the present invention is obtained by reacting sodium mordenite
which possesses a si:Lica to alumina ratio on the order of
10 to 12 and an alkali metal content on the order of about
NazO with a solution of metal cations. Moraenite used in the
-- 4 --
~ '' ' .
. ,, , , , , . . , . , : ": ,
1~4~69
practic~ o~ the ~re~.ent i~yent~Qn i~ readil~ .ayailahl~ ~rom
commercial source$ ~uch as the.~ortQn CQ. ~hich sells mordenite :~
under the commercial name o~ Zeolon.*
The exchan~e of t~e morden~te i5 conducted în conven~
tional manner using aqueous solutions of the desired metal
cation~. The exchange is conducted in a manner where~y the
alkali metal content in the morden~te i5 reduced to a level of
less than about Q.1% by weight. ~t is generally found that
thP mordenite particularly useful for the practice of the
lQ .... present invention ~ill contai.n on the order of from about 1 to :-~
:6~ by weight metal oxide selected fr~m ~he group consisting
of rare earth cobalt, nickel, group I~ cations. .
The calcium exchanged type A zeolite is obtained by
exchanging type A zeolite with calcium salts as set forth in
U.S. 2,882,243 to Milton. The resultant CaA will contain
about 18% Ca oxide a~ calcium ions
H-erionite is obtained from natural erionite by acid
treatment at boiling temperature. ~ ~ :
To prepare the catalysts contemplated herein, the rare ~-
2a earth hydrogen Y type zeolite component and the mordenite can . .
vary from about g:l to 1:1 parts by weight H or M-Mord.
Similarly, 1 part CaA, or H-Er. is mixed with 1 to 9 parts :.
by weight rare earth hydrogen Y zeolite. The precise ratio of
exchanged type Y zeolite to exchanged mordenite will depend ..
upon the:properties which are desired in the final catalyst com- ~ .
position. For.example, it is found that i$ hydrogen mordenite .~:~
is admixed with the rare earth hydrogen Y zeolite, a hydro- :.
carbon.cracking catalyst i~ o~tained which is particularly
effective for the productLon of low coke. On the other hand,
3Q if a relatively small amount of the metal exchanged mordenite
.* Trademark .
- 5 - .. .
.
1~4~ g
such as~ rare earth ex~h~n~ed mordenit~ I~ com~ined ~ith the
exchang~d type ~ z~ol~te, catalyst~ are o~tained ~hich are
part~cularly e~ect~e ~or the production of C3 and C4
hydrocar~ons.
W~en commercial catalysts are prepared using the unique
com~înation of exchanged t~pe Y zeolite and mordenite or CaA
or H-erionite contemplated herein, the zeolites are generally
formed into catalyst particles which are microspheroidal, that
is particles having a size from a~out 5Q to 300 microns which
lQ are particularly useful in the fluid catalytic cracking of
hydrocarbons. It is also contemplated that the presently
contemplated combination ~ zeolites may ~e formed into part-
icles which possess sizes on the order of up to 1/8 inch
particles which are par~icularly useful in the moving bed
ca alytic reacting of hydrocarbons.
The combination of zeolites may be formed into catalysts
using a minimum or substantially no binders so as to provide
a catalyst which comprises essentially la~% zeolite. Alter-
natively, 5 to 50~ ~y weight of thP combination of zeolites may
2Q be com~ined with from about 5~ to ~54 by weight of inorganic
oxide matrix. Typical inorganic oxide matrixes include silica,
alumina, silica-alumina hydrogel~. The preferred combination
of the catalyst is a blend of a~out 5 to 15 weight percent of
the zeolite component and a~out 95 to 85 weight percent of an
amorphous silica alumina component. It is also contemplated
that the matrix may comprise or contain clay such as kaolin and
chemical or thermally modified kaolin.
The catalysts prepared hy way of the present invention
are found to possess excellent stability for elevated temp-
3~ eratures and steam. Furthermore, it is found that the activity
and selectivity characteristics of the catalysts are exception-
ally good for the productlon of gasoline and other valuable
petroleum derivatives.
' ' . ; :
S~169
The cracking i5 carried out at a temperature of 700-1200~F,
a catalys ~ oil ratio of 0.5 to 30 and a contact time of
0.5 seconds to lO minutes. The pre~erred operating conditions
are a temperature of 800-1050F a catalyst to o~l ratio of
3~8 and a contact time of lO seconds to 5 minutes.
Having described the ~asic aspects of the present
invention, the following examples are g~ven to illustrate
specific embodiments thereof.
7 - ;.
~` ,, ~,1
.~'.' , ~ ", , jl .
069
EXA~LE 1
A. A ~a~le. ~ RE-H-~ wa~ Pxe~ared aS ~Qllows:
12 sa ml. of commercial rare earth chloride ~olution, :.
containing ~0 ~t. % REC13-6H20, was diluted with 64Q0 ml. .
of deionized ~.I.~ ~ater to form c~mponent A. Separately,
32QQ g Cdry basisl of NaY zeolite, containing 30~ H20,
~as blended into 9760 ~1. o~ D.I. ~ate.r to ~orm component `:
B. T~e two components were mixed together and the ~H of
the resulting slurry ~as ad~usted to 3.5 with HC1. The
lQ acidified ~lurry was ~eated for 45 minutes at 9Q~C, then
filtered and ~ashed w~th 80Q0 ml. of water acidified with ;
a ml. of 5 N HCl. The filter cake Was then washed chloride
free with D.I. water, dried at 105QC *or 2 hours, and calcined :~
at ~QC for 2 hours in a muffle furnace. The calcined ~:
material, which contained about 5% Na20, was ammonium exchanged
with a lQ~ ammonium sulfate solution, until the sodium level
dropped to about Q.2~. The material was washed sulfate `
free with D.I. water and dried at 105C. Analytical data
(calculated on a dry basis~: 13.5~ RE2O3, 0.2~ Na20, Surface .
2~ Area=798 m2/g. ..
B. Samples of hydrogen and metal exchanged mordenite .
were obtained as follows~
1. H-Mordenite u~ed below was a commercial product
from the Norton Co. identified as Zeolon H. The Zeolon H had a
silica-alumina ratio of 12 and a surface area of 520 m2/g. .
2. Rare earth, hydrogen mordenite (RE-H-Mord~) was
prepared from Na-mordenite, also a Norton product. The prep- .. .
aration was done by the follo~ing procedure: 50 g (dry basis)
of sodium.mordenite was blended with 20a ml. of D.I. water. 20
3~ ml. of a commercial rare earth chloride solution, containing about ;:
.:. ~ ..
, ~ , .. ............
5~69
6Q~ rar~ earth chlori~d~ cry~tal~ s~ dijluted ~ith 18~ ml. of
water. The ~rdenite was mrxe~ ~nto the rar~ earth chloride
solution, and the resulting slurry ~as refluxed at boiling
for one hour. The material ~as then ~iltered, ~ashed chloride
free, dr;ed at llQC for 2 hours, and then calcined at 540C
for 3 hours in a muffle furnace. Thls material was then
ammonium exchanged with a 1~% ammonium sulfate solution, until
the remaining sodium ~ons were removed. The product contained
5.2% rare earth oxide and had a surface area of 430 m2/g.
1~ 3. Co~alt, hydrogen mordenite ~Co-H-Mord.~ was pre- -
pared ~y co~alt exchanging an ammonium-mordenite zeolite.
Ammonium-mordenite ~as o~tained by ammonium ex~anging co~mercial
Na-mordenite with a 10% ammonium sulfate solution. To prepare
Co-H-Mord., 25 g dry ~asis of ammonium mordenite was blended - ~
into lQ0 ml. of water. This zeolite slurry was mixed with a ;
solution containing 10 g CoCl276H2O dissolved in 100 ml. of
water. The mixture ~as refluxed under boiling for one hour,
filtered, washed chloride free and dried at llaC for 2 hours.
The final product contained 2.7% CoO (on a dry ~asis) and had
2Q a surface area of 445 m2/g.
C. Samples of catalysts were prepared by combining
various quantities of the RE-H-Y & metal or H-mordenites
prepared in A ~nd B above. The catalysts were prepared by
blending 10~ by weiy~t (silica-alumina basis~ zeolite or
zeolite blend with 90~ by weight amorphous ~ilica-alumina-
clay matrix. The m~trix comprised 6a% amorphous silica-alumina
hydrogel (which contained 25% A12O3 and 75% 8ilica) and 40%
kaolin clay.
The microactivîty data ~as obtained using a reaction
,
3~ temper~ture of 9Q~F., a 16 weight hourly spaced velocity (WHSV),
and West Texa~ Devonian gas oil feedstock after steam treating
the samples of 135QF. for 8 hour~ at 15 psig steam. Comparison
"',~ '' ""''.
_ 9 _
.. . . . ... .. ..
-
~5~9
samples were prepared using a typical prior art calcined rare d
earth exchange type Y faujasite (CREY) such as is set,,forth
in U.S. 3,402,996 to Maher, et al.
The characteristics and test data developed ~or these
catalysts is summarized in the ~ables below (I and II).
"'
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~ o o ~
K c~ Lo ~ tY') D o co cn O ~1 O ~ 1--
.;, :
;~
a) .. .~
a ~r ~ er ~ ~ o co o o o ~r
. ~ ~ ,:,
X . ~,
.~ '~
~ ~ : . :
U~
o ~ o ~ o ~ oo ' ." ',
E~ ." '~: '
7I: ~ ~ .
~a
.
H I ~ ~ ~ C~ o ~ ~
(U ~ ~ o 1` ~ o .-1 o ~
~3 h ~ :t; ~
";~ ' '
1~ .,,", ~. ,
~ ~J . ' ~ .
~ ~ 1,
g :d ~ ~ o ~r ~,, '
O i~ o~ ~ I~ a~ tncn ~ ~D ~ O ~ O ~D U~ '.
~ ~ ;".':' "
.~ ~ ';''.
rl ,:,.. ...
D
O ~ " a
~ ~ O O O
a) ~ 0 ~ ~ U~
~1 ,1 1a~ 3i > O ~ ` O
~ I~ ` 11 11 C.) * + O O + +
0 0 1:~ 0 0 ~ ~ ~1 d' I ~r Ir7 ~ Lr\ U~ O `. '
en u~ K El U ~ ~ U rl C~ C.) V O ~ ~,) t ) C ) . :
.`., -:
' ~
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~09L:~69
O u~ P ~ ~ O O e~
+ + ~o ~o + + ~ m
G~ q O ~ o
n ~ 0~O
O O O ~ O O ~ ~ Z
o I~ o
~ d o~O
C ~ 0~ d~ dO
d~O , ~
C ~'"
~ ~ O ~ æ
~I ~ ~- o o co ~ o~ ~d ~
C~ .. ~ I~ o . ,
p", H
.. K~ ' '
IP .P O ~ ~J t1
t~ o 1- o a~ Ul tsl ~ ~ ,
OD . . . . ~ I J ~3
1-- a~ ~ Iv co ul (A~ O W o ~ O a~ I ~ ;' '
~ I h~ ' :
~ ~ ~ ' - ' : '
~ ~ ~ "'"' ~'
t~ ~ t~ ,', ', "
,p ~ o <S~ ` ~ ~ ..
1~ 0 CO ~,n ~ ~1 ~n ~1 ~ 13 1 ~1 ~ H . .
. ~l . . . . . . . . . . tD ~ m ~ ~ H
Ul Ip ~) ~I I.A) ~ O .IP O ~ ~I ~.n C~ ~) - l~ I I .
~ ~ .
~ ~ ~ ;
(~ t~ ::
~ ~ O 1~ 0 ~:
P ~ O O ~ I ~ '.
o ~p ~n O ~] ' .
~1 ~ ., .
t~ ~ o a~
CO . ~ I W I -: '
12
- . ; ~,~ .
~, ,
.
1~45~6~
Fro~ ~he aho~e data ~t ~ en that some. o~ the
catal~5 t~ of the present Inyent~n. ~a~ple~ 1 and 2~ are part-
icularly acti~e for the production o~ C3 and C4 hydrocarbons
~oth saturated and ole~inicl. Furthermore, it is noted that
the coke selectivity of our present catalysts is substantially
better than that of the prior art comparison catalysts. Certain ~:~
compositions sho~ also ~etter gasoline selecti~ity than the
reference catalyst CSample 6~
EXAMPLE II`
1~A. The sample o~ CaA zeolite used in the tests was a
commercial product ~rom Davi~on. Chemical Co. It contained
18.1% Ca and had a surface area of 643 m2~g.
B. Various amounts of CaA as described above were
compounded into catalyst using the technique set forth in
Example I ~C.~ a~ove. The RE-H-Y, matrix components and ,
test conditions were the same as set forth in Example I.
The results are summarized in Table III below~
2Q
"
,.. . .
.: .
~, .
:
10~5~9 :~
O Ul Ul ~ ~ .P I ~ ~ ) ~ O O t~
+ + O O + +~ t~ 11 11 `~S 1-- 1 3 j~
~ ~4 ~ ~ O ` O ~ rD I 1-
O O O ~ ~ O O .' dP
;~ j j & ~ ; c c ~ ~ ~
n n ~ dP ~ (D -
C ~ ~ S: d~ C C
~ .
~?~ I' ~.
o ~ ~ ',' ~ '
a~ . ~ o 1~ ~ o u~ I t~ ~ .
~n ~ 1-- ~ ~ ~ ~ 1- ~I cn ~ o o 1-- 1 P~' .'
It ~'
w ~v o ~ ~ ~
~ o o~ ~ ~ ~3 o ~ l ~
co . . . . . . . . . . a~ m Pi
~o ~n o ~ ~ o o ~ O ~
o ~ a~ ~ ~ ~:q
O ~ ~3. 0 ~ ~ O 1~ W ~ ~
o a~ ~o w ~ w ~ 1-- ~I ~I ~ ~ o co 1-- IJ I 1
w ~o ~ o .-1
r~ ~ o a~
00 W ~V O ~D al ~ ~I ~ ~ ~ o q ~D
00 . ~ . . . . . . a~ I w I u~
u
r~ ~ o cn u~
w . ~ o ~ o~ o o~ w ~n ~ o
1~ W ~ W ~ O
w
14
; . . ~ .
,
.
~5~69
F~om the ab~Qye~ it iS ~s~en that the cataly~ts o~ the
......
pr~sent inYent~On pusse~ ~upe~ r C3 - C4 hydrocar~on
selectiv~ty and lo~ co~ producing properties.
EX~MPL~ IV
Another example of the ad~antage of using promoter
mixtures over individual promoters~Ls;-~the-use of--a~RE-~I-Y/
Erionite mixture as promoter in a c.racking catalyst.
A. T~e RE-H-Y zeolIte was prepared a~ described in
Example I.
1~ ~. H-erionite ~as obtained fro~ natural erionite by
txeating the crushed mineral ~ith diluted hydrochloric acid
under boiling, for ~bout 3 hours. The resulting material
had a surface area of 36a m2/g and a S~02/A1203 ratio of 21.
C. Various amounts of H-erionite were compounded into
the catalyst containing RE-H-Y, as described in Example I.
The m trix and test conditions are the same as thos~ described
in previous examples.- The microactivity data obtained for
a RE-H-Y/H-erionite (4:1~ mixture as shown in Table III
~Sample 5~.
2~ The data o~tained indicates that under the test con-
ditions descri~ed, RE-H-Y/H-erionite-promoted catalyst provide
high activity and an improved gasoline and coke selectivity over
RE-H-Y or CREY promoted catalysts.
3Q
- 15 -
