Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
;t~S7
BACKGROUND OF THE INVI~:~ION
2 l. Field of the Invention
3 This invention relates to the selective conversion
4 of hydrocarbons, particularly of waxy, normal paraffin ~ype
hydrocarbons present in hydrocarbon oil feed~tocks, to lower
6 boiling hydrocarbons.
7 20 DescriPtion of the Prior Art
8 It is well known in the art to dewax wax-contain-
9 ing mineral oils, particularly the lube oil fract$ons of
0 petroleum oil, in order to remove at least a portion of the
wax therefrom to obtain a dewaxed oil of reduced pour pointO
2 For many years this wax has been removed via various solvent
3 dewaxing processes.
4 Concomitant with the worldwide decreasing supply
of naphthenic crudes heretofore used to make very low pour
16 point oils such as transformer oils, there has been an in-
7 crease in the demand for these oils due to the continuously
8 increasing demand for electrical power. Transformer oils
19 used in colder climates generally have a pour point require~
ment of around -50F. It is technologically unfeasible to
21 obtain these low pour transformer oils via solvent dewaxing
22 of paraffinic oils, because of the extremely severe refriger-
23 ation requirementsO White oils are highly refined petroleum
24 oils which must meet various requirements including haze-free
water whiteness and are generally produced from naphthenic
26 stocks which sometimes contain around l or 2~ wax. This wax
27 csn affect the pour point of the oil and results in a haze
28 which is cosme~ically ob~ectionable. It is also technolog-
ically unsound to solvent dewax these white oils. Certain
middle distillate fuels must also have low pour points so
31 that the fuels do not congeal at low temperatures. This
32 is especially true for jet fuels~
- 2 -
~ 5 7
1 In recent years, various catalytic dewaxing pro-
2 cesses have been proposed. Catalytic processes for dewaxing
3 wax-containing hydrocarbon oils wherein the normal paraffinic
4 wax constituents contsined therein are broken into lower mo-
lecular weight olefins and gases usin~ crystalline alumino-
6 silicate zeolites such as offretite, chabazite, Zeolite A,
7 analcite, erionite and mordenite have been disclosedO How-
8 ever, when higher boiling fractions such as lube oil frac-
9 tions are catalytically dewaxed using catalysts such as
lo erionite, coke very quickly builds up on the catalysts there-
11 by deactivating themO
12 More recently, it has been found that mordenite,
13 particularly the hydrogen form of mordenite commonly re-
14 ferred to in the art as decationized or H-mordenite, and
certain ZSM-type crystalline alumino~silicates are effective
16 in catalytically dewaxing the heavier petroleum oil frac-
17 tions such as lube oil fractionsO~ These zeolites preferably
18 contain a hydrogenation component selected from one or more
19 Group VI and VIII metals and oxides thereofO The wax-like
hydrocarbons, particularly the normal paraffin types, are
21 selectively hydrocracked into lower boiling hydrocarbons
22 which are primarily gases at room temperature, thereby pro-
23 ducing a dewaxed oil product having a substantially lower
24 wax content and pour point.
Additionally, a method has been disclosed for re-
26 generating H-mordenite as well as possibly other zeolites
27 such as Zeolite Y, T, L, erionite and offretite when such
28 zeolites have been deactivated during a catalytic dewaxing
29 process.
The prior art teaches that various other types of
31 crystalline alumino-silicates are not suitable for use in
32 catalytic dewaxing processes and in particular discloses
1 that large pore size crystalline alumino-silicates or zeo-
2 litic molecular sieves represented by zeolites of type X, Y
3 and L, which admit all component~ normally found in petro-
4 leum distillate charges are unsuitable for use in catalytic
dewaxing or hydrodewaxing processes and that only those
6 which have a pore size of approximately 5 A are suitable be-
7 cause they will admit only normal and/or slightly branched
8 paraffins present in a hydrocarbon feed charge.
9 SUMMARY OF THE INVENTION
-
A process for catalytically dewaxing waxy hydro-
11 carbons from wax-containing hydrocarbon oil feedstocks has
12 now been discovered, which comprises contactin~ said feed- -
13 stock at elevated temperature and pressure and in the
14 presence of hydrogen with a catalyst comprising a hydrogen
form Zeolite L molecular sieve or crystalline alumino~sili-
16 cate and recovering an oil product having a reduced wax con-
7 tent. In the process of this invention, waxy hydrocarbons
18 present in the feedstock are selec~ively hydrocracked to
19 hydrocarbons boiling below the boiling range of the feed-
stock. If the Zeolite L is not at least partially decation-
21 ized and converted to the hydrogen form it will not work ef-
22 fectively in the process of this inventionO It is pre-
23 ferred, that the hydrogen form Zeolite L contain one or more
24 catalytic metal components selected from the group consist-
ing of Group VI and Group VIII metals of the Periodic Table,
26 their oxides, sulfides and mixtureæ thereof~ It has further
27 been discovered that the selectivity of the decationized
28 Zeolite L for hydrocracking wax is greatly improved if the
29 external surface of the sieve is poisoned or made catalytic~
ally inactive. It has still further been discovered that
31 the process of this invention simultaneously reduces the
32 aromatics content of the feed.
-- 4 --
~ ~7~7
Crystalline alumino-silicates of the Zeolite L type
are well known. These materials are characterized in that
they have a one-dimensional channel system parallel to the
C - axis with a calculated free aperture size of about 7.1 ~.
U.S. Patent 3,216,789 discloses the composition, characteri-
zation and preparation of Zeolite L types of crystalline
alumino-silicates. Zeolite L has a general formula as follows:
0.9 - 1.3 ~ O:A12O3:5.2 - 6.9 SiO2: ~H2O
Wherein "M" designates at least one exchangeable cation herein-
below defined; " ~" represents the valence of "M"; and "~"may be any value from about 0 to about 9. Further, the value
of 11~ depends upon the identity of the exchangeable cations
and also upon the degree of dehydration of the zeolite.
The exchangeable cations that may be present in
æeolite L include mono-, di- and trivalent ions, particularly
those of Groups I, II and III of the Periodic Table, such as
potassium, sodium, barium, calcium, cerium, magnesium, lith-
ium, strontium, zinc ions, etc., and the like, and other
cations for which example hydrogen, ammonium and alkyl-ammonium
20 ions, which with Zeolite L behave like the metal ions mentioned
above in that they may be replaced for other exchangeable
cations without causing a substantial alteration of the basic
crystal structure of the zeolite. However, although there are
a number of cations that may be present in Zeolite L, in the
commercially available form substantially all of the exchange-
able cations are potassium ions.
As stated the synthesis of the Zeolite L catalyst is
well known in the art. For example, the zeolite may be crys-
tallized from a suitable aqueous metal alumino-silicate
57
mixture at temperatures ranging from 20 to 175C.
Zeolite L will not selectively hydrocrack wax from
petroleum oil stocks, such as white oil, jet fuel or lube oil
stocks, unless it is decationized and converted to the hydrogen
form. By decationization and conversion to the hydrogen form
is meant that the exchangeable metal cation, such as potassium,
is at least partially replaced with hydrogen. Preferably at
least about 10%, more preferably from about 15 to 75% and still
more preferably from about 40 to 60% of the exchangeable metal
cations in the sieve have been exchanged with hydrogen ion to
produce the hydrogen form Zeolite L useful in this invention.
The attached Figure is a graph illustrating the hydrodewaxing
activity of a Zeolite L catalyst as a function of the replace-
ment of potassium with hydrogen in the sieve. It has been
found that, in general, the activity or ability of the Zeolite
L catalyst to dewax the oil increases with increasing replace-
ment of potassium with hydrogen in the sieve, reaching a maxi-
mum between about 40 to 50%. Methods for replacing the metal
cations with hydrogen are well known in the art. Various
methods of decationizing Zeolite L and converting it to the
hydrogen form are described in U.S. Patent 3,130,006. The
decationization treatment i9 preferably carried out by base
exchanging a metal cation form of Zeolite L, such as the
potassium form, with ammonium cations. The ammoniumion
exchanged molecular sieve is then heated to drive off ammonia,
leaving behind the decationized or hydrogen form of Zeolite L.
As hereinbefore described, it is preferred that the
hydrogen form Zeolite L contain one or more metal hydrogenating
components selected from the group consisting of
1 Group VI and Group VIII metals, their oxides, sulfides and
2 mixtures thereof. Preferably, the catalytic metal component
3 of the catalyst is 8 platinum group metal, particularly
4 platinum or palladium, and may be added by any of the well
~ known methods such as ion-exchange or impregnation. The
6 amount of platinum group metal added to the catalyst is pre-
7 ferably within the range of 0O05 to lO wt. %, more prefer-
8 ably O.l to 5 wt. % and most preferably 0.2 to 2.0 wt. %
9 calculated as metal and based on the total weight (dry basis)
of the catalyst. Iron group metals such as nickel also give
11 useful results and they may be used in greater amounts than
12 the platinum group metals, preferably within the range of
13 O.l to 50 and more preferably loO to 20.0 wt. % calculated
14 as metal and based on the total weight (dry basis) of the
catalyst. Mixtures of certain Group VI and Group VIII metals
16 and compounds may also be used, for example, such as cobalt
17 and molybdenum. Further, it may be advantageous to incor-
18 pora~e into the catalyst multivalent metals of Groups II
19 and III in addition to one or more metals of Group VI and/or
Group VIII.
21 As hereinbefore mentioned, it has also been dis-
22 covered that still further improvements in the catalytic
23 dewaxing process of this invention may be realiæed if the
24 external exposed surfaces of the catalyst are poisoned. Any
well known methods may be employed such as coke deposition
26 or treatment with heavy metal or basic compounds. However,
27 a preferred methot is by treatment with an organic phosphor-
28 ous compound capable of inhibiting the catalytic activity
29 thereof and of such molecular size and shape as to be ex-
cluded from entering the pores in the catalyst a~d making
31 contsct with the active catalytic sites in the pores. That
32 is, greater selectivity in catalytic dewaxing resulting in
~ 1'7'~
1 higher ylelds of dewaxed oil will be realized if the outer
2 surface of the catalyst is poisoned and not the surfaces
3 inside the pores, so that only the wax-like normal paraffins
4 and perhaps the slightly branched normal paraffin hydrocar-
bons which can enter the pores are hydrocracked therein.
6 The other molecules and molecular species which are too
7 large to enter the pores will not be cracked if the external
8 surface of the catalyst is poisonedO Suitable organic phos-
9 phorous compounds useful as poisoning media for the external
o catalytic sites of the Zeolite L include organic and partic-
11 ularly cyclic phosphates, phosphites, phosphonates, phos-
2 phonites, and phosphines. Typical of such compounds are the
3 dibenzylphosphates, dibenzylphosphites, dibutylphenylphos-
14 phonites, diphenylmethylphosphates, diphenylphenylphospho-
nites, diphenylphosphites, dicresylphosphites, ethylene(bis)
16 diphenylphosphines, ethylene(bis)diphenylphosphine oxides,
7 naphthylphosphates, triphenylphosphines, triphenylphosphine
18 oxides, triphenylphosphates, triphenylphosphites, tri(di-
19 methylphenyl) phosphates, and tricresylphosphates, with tri-
cresylphosphates being particularly preferred~
21 Poisoning of the external surface of the catalyst
22 may be accomplished by addition of the organic phosphorous-
23 containing poison compound to the charge stream prior to
24 contacting with the catalyst. Alternatively, it may be de-
sirable to contact the catalyst with a suitable poisoning
26 compound prior to bringing the same into contact with the
27 charge stock. In some instances, it may be feasible to con-
28 tact the catalyst simultaneously with the poisoning com-
29 pound, and the charge stock. Pretreating the catalyst with
the poisoning compound may be accomplished by contacting
31 particles of the catalyst with the poisoning material or a
32 suitable solution containing an amount of such material suf-
- 8 -
l ficient to poison the exterior catalytic sites of said cata-
2 lyst. The particles are thereafter removed from contact with
3 the poisoning material or solution thereof and dried.
4 Suitable catalytic dewaxing process conditions in-
clude temperatures within the broad range of 450 to 950F.,
6 preferably 500 to 850F~ and still more preferably 500 to
7 750F., hydrogen pressures within the range of 100 to 5000
8 psig, preferably in the range of 200 to 2500 psig and most
9 preferably from 400 to 1500 psig, a space velocity between
0.1 to 20 liquid volumes per hour per volume of catalyst
(v/h/v), preferably 0.25 to 500 vlh/v, and hydrogen feed
2 rates in the range of 0 to 20,000 SCF/B, more preferably
3 500 to 10,000 SCF/B and most preferably 1000 to 8000 SCF/B.
4 Almost any wax containing synthetic or petroleum
oil feedstock or distillate fraction thereof which has been
16 deasphalted may be cataly~ically dewaxed employing the pro-
l7 cess of this invention. Illustrative, but nonlimiting ex-
l8 amples of such feedstocks are the middle distillate frac-
l9 tions, such as iet fuel boiling within the broad range of
300 to 650F., and lube oil stocks such as (A) distillate
2l fractions that have a boiling range within the brosd range
22 of from about 500 to 1300Fo~ with preferred stocks includ-
23 ing the lubricating oil and specialty oil fractions boiling
24 within the range of between about 550 and 1200F., and
2s (B) bright stocks and deasphalted resids having an initial
26 boiling point above about 800F. Additionally, any of these
27 feeds may be hydrocracked prior to the catalytic dewax~ng
28 process of this inventionO These stocks may come from any
~ source such as the paraffinic crudes obtained from Aramco,
Kuwait, the Pan Handle, North Louisiana, etc., the naphthenic
31 crudes obtained from Venezuela~ the U.S. Gulf Coast, Cold
32 Lake (Alberta), etc., as well as synthetic crudes derived
_ g _
5~
1 from the Athaba~ca Tar Sands, etcO
2 BRIEF DESCRIPTION OF THE DRAWING
3 The attached drawing is a graph illustrating the
4 catalytic dewaxing activity of a Zeolite L catalyst as a
function of the amount of potassium ions in the sieve that
6 have been replaced with hydrogenO
7 DESCRIPTION OF THE PREFERRED EMBODIMENTS
.
8 The following examples further illustrate the
9 present invention.
10 EXAMPLE 1
11 Zeolite L in the potassium cation form was ob-
12 tained from the Linde Division of the Union Carbide CorpO
13 designated as X-L Linde (hereinafter referred to as Zeolite
14 K-L) having the unit cell composition shown below
KgNao~ls(Alo2)g~4(sio2)27~ x H2O
16 The Zeolite K-L was supplied as a powderO In its anhydrous
17 mode (i.e., driet at about 1000Fo~ Zeolite K-L has a potas-
18 sium content of 13 wto %O However, if it is dried at about
19 250F. it has a potassium content of 12 wt. % due to the
presence of some water of hydration in the sieveO Sixty
21 grams of the catalyst were treated with one liter of an aq-
22 ueous 0.4 molar ammonium nitrate solution at reflux temper-
23 ature for eight hours followed by calcination in air at
24 1000F. for two hours to produce a partially decationized
Zeolite K-L (hereinafter referred to as Zeolite HK-L) in
26 which about 20Z of the potassium ions initially present in
27 the sieve were replaced with hydrogen ions. The powder was
28 pressed into a cake, crushed and sieved into 7 to 14 mesh
29 size particles which were used as catalysts in this experi-
ment. Palladium was deposited on both the Zeolite HK-L and
31 Zeolite K-L by soaking the catalyst particles in an aqueous,
32 mildly acid palladium chloride solution containing sufficient
- 10
~ 5 ~
1 palladium to produce a catalyst containing 0025 wt. /. palla-
2 dium. The palladium containing catalysts were then calcined
3 in air at 900 to 1000F. for two hours and reduced in a
4 stream of hydrogen at 650F. for six hours. Wax-containing
S lube oil feedstock comprising solvent extracted paraffinic
6 distillates having the properties shown in Table I were
7 passed over the catalysts in the presence of hydrogenO The
8 catalytically dewaxed product W8S then stripped to remove
9 material boiling below 500F. The results listed in Table I
show that the Zeolite K~L which was not decationized or
partially converted to the hydrogen form was ineffective in
12 reducing the wax content as reflected in the pour point,
13 whereas the decationized Zeolite HK~L removed a considerable
14 amount of wax as reflected in the low pour points of -20
and -27F.
16 EXAMPLE 2
17 In this example the effectiveness of the decat-
18 ionized or hydrogen form Zeolite HK~L from Example 1 was com-
19 pared with decationized or H-mordenite known in the art as
an effective catalyst for dewaxing lube oil fractions. Be-
21 fore the catalysts were used for catalytic dewaxing, the sur-
22 face active sites were poisoned to see if ~here would be any
23 improvement in catalyst selectivity. The catalysts were
24 soaked in a 10 wt. Z solution of tricresylphosphate (TCP) in
n-heptane for a nu~ber of hours. The TCP treated catalysts
26 were washed with heptane in order to remove any excess there-
27 from and then placed in reactors and heated in the presence
28 of hydrogen to the reaction temperature at which point the
29 liquid feed was cut inO The same type of lube oil feeds
used in Example 1 was also used in this experiment.
31 The results are in Table II and show that, com-
32 pared to the H-mordenite, not only did the Zeolite HK-L pro-
~ 5 ~
1 duce a much higher yield of dewaxed product at a comparable
2 reduction in pour point, but it did so with no significant
3 108s in VI, thereby illus~rating that decationized Zeolite L
4 can be used for catalytically dewaxing lube oil base stocks
without the need for a prior or subsequent treatment to
6 boost the VI which the art teaches is necessary when using
7 H-mordenite.
8 The beneficial effect of the TCP treatment is re-
9 flected in the much superior selectivity of the treated
catalyst. This i8 seen by comparing the data in Tables I
11 and II at 576Fo for both the TCP treated and untreated
2 Zeolite HK-Lo Thus,- ~he treated Zeolite HK-L produced a
13 product yield of 89 wto% of feed compared to 50.1 wt. %
14 for the untreated Zeolite HK-Lo
EXAMPLE 3
16 This example illustrates the effect of catalyst
17 activity as a function of replacing potassium ions in the
18 Zeolite K-L sieve wi~h hydrogen ionsO The waxy feed was
19 similar to that used in Examples 1 and 2 and had a pour
point of +7Fo The Linde Zeolite K~L was treated according
21 to the following procedure.
22 (a) 60 gO of catalyst base were treated with one
23 liter of NH Cl solution under refluxO Solution strength
24 varied from 0O05N (normal) to 2N depending on the amount of
potassium removed and replaced with hydrogen~ For the case
26 where 72~/o of the potassium ions were replaced with hydrogen
27 ions, the catalyst base was given two treats with 2N NH4Cl
28 solution~
29 (b) The treated base was calcined in air at 1000F.
for two hours to convert the NH4+ to H~ and the base was
31 then pressed into pelletsO
32 (c~ The pellets were treated by soaking in a solu-
~ 12 l~
~ 17 ~ ~ ~
1 tion of PdCl2 in a low concentration (i.e., ~ 0.5N) HCl so-
2 lution to impregnate ~he-~ieve with palladium 80 that the
3 catalyst contsined Q.25 wto% Pd based on the total catalyst
4 weight ~dry basis).
S (d) The Pd impregnated sieve was washed in water,
6 dried at 248F. and then calcined for one hour at 932F.
7 (e) The calcined catalyst was then reduced in
8 hydrogen at 752F. to produce a finished catalyst. The waxy
9 feed was passed over the catalyst at a liquid hourly space
o velocity of l.0 V/h/V, at a hyd~ogen pressure of 600 psig
11 and at temperatures of 550 and 575Fo
12 The results are plot~ed in the Figure which is a
13 graph of catalyst activity as a func~ion of potassium ion
14 replacement with hydrogen ion. By activity is meant wax
lS removal of dewaxed product (stripped to an initial boiling
16 point of 500F.) as reflected in pour pointq It is appar-
7 ent from the Figure that catalyst activity increases with
~8 increasing replacement of potassium ions with hydrogen ions,
19 reaching a maximum between about 40 to 50% replacementO It
is also obvious that for practical dewaxing activity at
21 least about lO to 15% of the potassium ions should be re-
22 placed with hydrogen ionsO
- 13 -
4S~
o~ P
. U~
O t~
U~
,_1 ", :1 h
o V'~ oo O ~
~ o. o~ O
,.. : o
~ h ~ - _
., . aJo ~ ~ C~l ~ . ,.
h o ,1 o~
~ P'
.~ ` ' ' , ~ td ~ .
,",,~ .
.,,~ ~ .
o C~ o ~ o
~5 ~ I ~ ~O h
O ,- I 0~
.' , .. ~
0 0 'O O
' ' ' ' ' ~4 ,~ cn ~ Ir)
.-, ;~,~ O
rl a ~ ~ O~ l:b
,~ ^ ~ d
. I o ~ -
~,t a) O ~ ~ v ~ p~
p~ X I ~ ~ o ~ '
lJ U ~ ~ 1 ^ O O 1~o
. I ~ ~ ~ ~ o~ ~a
I ~ P , ~ "~ 0
d E~ ~q ~ P~ ~ p O O O P~
I ~
' . '
- 1 ~ ~ . .
57
a) ~ u~ O
.~ ,~
,1 ~
~d O ~D
1: ~1 U~ ~ IJt ~ ~)
td C~l ~ ~ ~ I~
~o P. ~
~-
U~
~ ~1 ~
c~ a) o ,~ , .
"'': E~ ~ _~ .
.,
.
., ' ~ ~ ~ O~ I` o~
~'C .~
a ~ .
O 1- '.
~1~ ~ O~ D O
oo
IJ u~ ~
C~
. - . ' E~
., ,.P~ ~ O ~ ~
E~
,, . , , a
o o
~q o
o
o o
~ ~ v ~
td ~J U~ ~ ~rl JJ
'~
a~
X ~ ~ oh ,,~ ".~
u~ h J~ ~ ^ O O .C O
P' ~ d) :~ 0 ~q O P~
~ ~ ~,( o
J~ ~d O ~ P~ P
.
- . ~1 _I
- 1.5 -
~ ~7
Ex~m~le 4
1 -- !
2 This e~ample illustrates thc ability of the
3 hydrogen orm Zeolite L dewaxing catalys~ to simultaneously
4 ~educe both aromatics and wax content. ~bout 20% of the
potassium ions present in the Zeolite K~L sieve were replaced
6 with hydro~en ions via treatment with 0.5N NH4Cl for two
7 hours on a steam bath. The treated sieve was washed free of
8 excess salt and then calcined at 1004F for two hours to
9 produce Zeolite HK-L. The Zeolite HK-L was then pressed into
~0 a cake, crushed and sieved. Palladium deposition, calcining
ll and reduction o the catalyst were then carried ou~ via the
l2 procedure used in Exampl2 1. This experiment used the same
l3 type o feed as in Example 1.
14 The results are shown in Table III and are com-
pared to results obt~ined from using H~mordenite. Thus, no~
16 only did the Zeolite HKL catalyst reduce the wax content
17 and pour point lower than that obtained with H~mordenite, it
18 simultaneously produced a dewaxed product having an aromatics
19 content substantially lower than that of the feed.
.
,
~ . .
.
, . . .
- 16
5C
o t) . . .
, ~ . ~ ~o~ ,
~4 ~a o o ,l o ~a ~ 1~ ~ cr~
O ~ I .
.,, .
~ . ,_, ~
E-l N ~ . . .
z o a) r~ o a~ ~ 1
E~ a) o ~ a~
Z ~ _~ .
. ~
E~
~ .
O,
~ . ' ~C
U O _1
Z F~ ~ u~
~_~ Q~ ~ O O' ~1 0 ~a ~1 00
1-1~; V ~ 0lO 0 0
~ O ~
. , . , ~ ~V ~ . .
a: P s~
. . . ~ ~ oo.
I . O ' I _~ O 00 e~l 1
.' I Q) O
I ~ ~1 '
I
: . I
.: . I . ''
I
.' ' . ~ .
I ' '' '~
I o
. , , O
Z . u~
~ . ~ ~ O
~1 ~
g ~ ~ ~q O ~
u~ O ~o o a~ ~1 ~ ~
~ d æ ~ ~ ~
~ ~ cn
- ~q V ~ ~ ~
u~ ~ p~ ~n co
3 V V~ a) ~
t~ r~ O o ~ rl O V~ V
v ~ ~ p ~ ~,/ .~ t~
u) S~ a) u~ ~ V .~a o o Q~
P~ O ~ u~ ~ o S~
,~ ~ ~ n ~ ~ o o
J ~ O~ n
E~ ~ ~ ~ P ~ E~ v~
~ ~ . ~_
~ 1 ~ ~
4S~
1 EXAMPLE 5
2 This example illustrates the fact that the process
3 of this invention selectively hydrocracks waxy hydrocarbons
4 to lower boiling hydrocarbons. In this experiment the feed
was a wax boiling in the range of from 572 to 968F. which
6 was derived from a Western Canadian crude oil. The hydrogen
7 form Zeolite L catalyst was prepared by boiling Linde Zeo-
8 lite K-L in powder form for two hours in a 2 normal NH4Cl
9 solution. The treated sieve or catalyst base was then
o washed w~th water after which 0O5 wt. ~ palladium was added
by ion exchange with a Pd(NH3)4C12 solution at a pH of 10.
2 The ion-exchanged sieve was then washed with water and cal-
3 cined in air for two hours at a temperature of 752F. After
4 calcining the catalyst was pelletized and treated with hydro-
gen for six hours at a temperature of about 572Fo to pro-
6 duce a finished catalyst. Analysis revealed that about 44%
7 of the potassium ions remained iD the sieveO
8 Two runs were made at a temperature of 550F. and
19 a pressure of 600 psig of hydrogen, The first run was made
at a space velocity of 1.0 V/hr/V and the results are shown
21 in Table IV. The second run was made u~der a more severe
22 space velocity of 0O5 V/hr/VO In the second run all of the
23 wax feed was converted to hydrocarbons boiling below the ini-
24 tial boiling point of the feed (572F.) with a substantially
greater amount of gaseous product formed than in the first
26 run.
27 Turning to Table IV, the data show that under the
28 less severe hydrocracking conditions over 50% of the wax was
~ hydrocracked to lower boiling hydrocarbons boiling below the
initial boiling point of the wax feedO Also under the less
31 severe hydrocracking ~ nditions only 2.7 wt. % of the feed
32 wax was converted to oil (per ASTM D 721) boiling in the
- 18 -
~ 5 7
1 same range as the feed waxO
2 These data and the data from the other examples
3 show that the reaction of the present invention i~ selective
4 hydrocracking and that very little isomerization of the wax
took place.
6 TABLE IV
7ZEDLITE L SELECTIVITY FOR WAX CRACKING
8Distribution by Carbon
9Number, Wt. ~
eed* Product
11 Cl
12 C2 0
13 C3 2.3
1~ C4 9.4
6 C5 C7 24 4
19 C22 008 002
c23 208 0o9
21 C24 605 202
22 C25 10.7 3.7
23 C26 1308 4.8
24 C27 I308 4.8
.c28 12.8 405
26 C2g 1103 4.0
27 C30 807 3.0
28 C31 609 2.4
29 C32 1.6
C33 loO
31 c34 1.9 0~6
32 C35 1.0 0.3
34 C37 0 3
C38 002
36 Note: * Paraffin Wax
- 19 -
