Note: Descriptions are shown in the official language in which they were submitted.
333~
01 --1-
OLIGOMERIZATION OF LIQUID OLEFIN OVER
A NICKEL-CONTAINING SILICACEOUS
CRYSTALLINE MOLECULAR SIEVE
05
BACKGROUND OF THE INVEN~ION
1. Field of Invention
The present invention is in the field of olefin
oligomerization. More specifically, the present invention
relates to oligomerizatlon of olefins in the liquid phase
with a nickel-containing silicaceous crystalline molecular
sieve ca~alyst.
2. escription of the Prior Art
Oligomerization and polymerization of olefins in
the gas phase over various zeolites is known in the art.
For example, ~.S. Patent Mo. 3,960,978 a process for
producing a gasoline fraction containing predominantly
olefinic compounds which comprises contacting a C2 to C5
~0 olefin with a ZSM-5 type crystalline aluminosilicate
zeolite at a temperature of from about 500F to about
900F is disclosed.
U~S. Patent No. 4,021,502 describes the
conversion of gaseous C2 to C5 olefins into gasoline
blending stock by passage over ZSM-12 at temperatures of
from about ~00F to about 1200F.
U.S. Patent Mo. 4,211,640 discloses a process
for the treatment of highly olefinic gasoline containing
at least about 50% by weight of olefins by contacting_said
oleEinic gasoline with crystalline aluminosilicate
zeolites, such as those of the ZSM-5 type, so as to
selectively react olefins other than ethylene and produce
both gasoline and fuel oil.
U.S. Patent Mo. 4,254,295 discloses a process
for the oligomerization of olefins by con~acting said
oleEins in the liquid phase with ZSM-12 catalyst at
temperatures of 80F to 400F.
U.S. Patent No. 4,227 r 992 discloses a process
for separati~g ethylene in admixture with light olefins by
contacting said olefinic mixture with a ZSM-5 catalyst and
thus producing both gasoline and fuel oil range materials.
61936-1648
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~2~33~;
The processes disclosed in these patents differ from
that of the present invention in tha-t -they employ either a
different catalyst, higher tempera-tures, or reaction in the
gaseous phase.
Also, an important feature of several of -the catalysts
used in these prior art processes is -that the catalyst must have
reduced ac-tivi-ty before oligomeriza-tion. Such catalyst of re-
duced activity may be obtained by steaming or by use in a
previous conversion process.
This deactivation step is not required in the process
of -the presen-t invention.
SUM~RY O~ THE INVENTION
In accordance wi-th the present invention, there has
been discovered a process for oligomerizing alkenes comprising:
(a) contacting a C2 to C20 olefin or mix-ture thereof in -the
liquid phase wi-th a nickel-containing silicaceous crys-talline
molecular sieve in the hydrogen Eorm selected from the group
consis-ting of HZSM-5, HZSM-ll, crystalline admixtures of HZSM-5
and HZSM-ll, silicalite, "an RE 29,948 organosilicate" (as
defined below), and CZM (as defined below) or mix-tures -thereof,
a-t a -temperature Erom abou-t ~5F -to about ~50F; (b) recovering
an effluent comprising oligomerized alkene.
I-t has been found tha-t the presen-t process provides
selective conversion o:E -the olefin Eeed -to oligomer products.
The present process effec-ts the conversion of the olefin feed
to dimer, -trimer, -tetramer, etc., product:s with high selectivity.
The product of -the present reaction thus contains primarily
olefin oligomer and li-ttle or no light cracked products, paraf~
fins, etc.
The high selectivi-t~ is in part due -to the surprising-
ly high oligomerization ac-tivi-ty of the catalys-t of the present
,J
~33~; 61936-16'18
-2a-
process, which permits high conversion at low temperatures
where cracking reactions are minimized.
The oligomers which are the products of the process
of this invention are medium to heavy olefins which are highly
useful for both fuels and chemicals. These include olefinic
gasoline, such as from propylene
~2~333~i
01 _3_
dimerization, and extremely high quality midbarrel fuels,
such as jet fuel~ Higher molecular weight compounds can
be used without further reaction as components of
functional fluids such as lubricants, as viscosity index
improvers in lubricants, as hydraulic fluids, as
transmission fluids, and as insulating oils, e.g., in
transformers to replace PCB containing oils. These
olefins can also undergo chemical reactions to produce
surfactants which in turn can be used as additives to
improve the operating characteristics of the compositions
to which they are added (e.g., lubricating oils) or can be
used as primary surfactants in highly important activities
such as enhanced oil recovery or as detergents. Among the
most used surfactants prepared from the heavy olefins are
alkyl sulfonates and alkyl aryl sulfonates.
~ significant feature of the present process is
the liquid phase contacting of the olefin feed and the
~o nickel-containing silicaceous crystalline molecular
sieves. There will be appreciated that the pressures and
temperatures employed must be sufficient to maintain the
system in the liquid phase. As is known to those in the
art, the pressure will be a function of the number of
carbon atoms of the feed olefin and the temperature.
The oligomerization process described herein may
be carried out as a batch type, semi-continuous or
continuous operation utilizing a fixed or moving bed
catalyst system.
3~ BRIEF DESCRIPTION OF THE DRAWINGS
.
Figure 1 is a graph showing the conversion of
propylene to higher molecular weight products as a
function oE time at 130F, 1600 psig and 0.5 LEISV for two
different catalysts.
Figure 2 is a graph showing the carbon number
selectivity for oligomeri~ing propylene at 130F,
1600 psig and 0.5 LHSV for two different catal~sts.
Eigure 3 i5 a graph showing a plot o~
temperature for 90% conversion of propylene to C5~ over
~3335
Ol -4_
Ni-Zn-HZSM-5 catalyst versus time under the conditions
shown.
05 ~igure 4 is a graph showing a plot of
temperature for 70% conversion of C6~Cg gasoline feed to
higher boiling product versus time over Ni-Zn-HZSM-5 and
Zn-HZSM-5 catalysts under the conditions shown.
Figure 5 is a gas chromatogram of the product of
Example 19.
Figure 6 is a graph showing a plot of temperature
for 70% conversion of C6-Cg gasoline feed to higher
boiling product versus time over Ni-Zn-HZSM-5 under the
conditions shown.
DESCRIPTION OF SPEC~FIC EMBODIMENTS
The feeds used in the process of the invention
contain alkenes which are liquids under the conditions in
the oligomerization reaction zone. Under standard
operating procedures it is normal both to know the
chemical composition of feedstocks being introduced into a
reaction zone and to set and control the temperature and
pressure in the reaction zone. Once the chemical composi-
tion of a feedstock is known, the temperature and
hydrocarbon partial pressures which will maintain all or
part of the feed as li~uids can be determined using
standard tables or routine calculations. Conversely, once
the desired temperature and pressure to be used in the
reaction zone are set, it becomes a matter of routine to
determine what feeds and feed components would or would
not be liquids in the reactor. These calculations involve
using critical temperatures and pressures. Critical
temperatures and pressures for pure organic compounds can
be found in standard reference works such as CRC Handb ok
of ChemistrY and Physlcs, International Critical Tables,
3S Handbook of Tables _or Applied Engineerin9 Science, and
Kudchaker, Alani, and Zwolinski, Chemical Reviews 6~, 659
(1968), The critica:L tem~erature for a pure compound is
that temperature above which the com~ound cannot be
li~ue~ied regardless of pressure. ~he cri~ical pressure
is the
`?.~
~333~
01 _5_
vapor pressure of the pure compound at its critical
temperature. These points for several pure alkenes are
S listed below:
Tc C (F) Pc-at~ (bar)
ethene ~.21 (43.6) 49.66 (50.3)
propene 91.3 (197.2) 45.6 (46.2)
l-butene 146.4 (295.5) 39.7 (40.2)
l-pentene 191.59 (376.9) 40 ~40.5)
iso-2-pentene 203 (39~) 36 (36.5)
l-hexene 230.83 (~47.49) 30.8 (31.2)
l-heptene 264.08 (507.34) 27.8 (28.2)
1-octene 293.4 (560~1) 25.6 ~25.9)
l-decene 342 (648) 22.4 (22.7)
It can be appreciated that at temperatures above about
~U 205C (401F), pure C5 and lower alkenes must be gaseous,
while pure C6 and higher alkenes can still be liquefied by
applying pressure. Slmilarly, above about 275C (527F)
pure C8 and higher alkenes can be maintained in the liquid
state, while pure C7 and lower alkenes must be gaseous.
Typical feeds are mixtures of compounds. But
even so, once the chemical composition of the feed is
known, the critical temperature and pressure of the mix-
ture can be determined from the ratios of the chemicals
and the critical points of the pure compounds. See for
example, the methods of Kay and Edmister in Perr~~
Chemical Engineers Handbook, 4th Edition, pages 3-214,
3-215 (McGraw Hill, 1963).
Of course, the only constraint on the alkenes
present in the feed and which are to react in the oligo-
merization reaction zone is that these alkenes be liquids
under the conditions in the reaction zone (the conditions
include a temperature of less than about 450F). The
chemical composition of the alkenes can be varied to
obtain any desired reaction mixture or product mix, 50
": :`,``
33;~5
01 -6-
long as at least some of the alkene components of the ~eed
are liquid.
05 The alkene chains can be branched~ And, even
though the nickel-containing silicaceous crystalline
molecular sieve catalysts used in this invention are
intermediate pore size molecular sieves, alkenes having
quaternary carbons (two branches on the same carbon atom)
can be used. But where quaternary carbons are present, it
is preferred that the branches are methyl.
The preferred alkenes are straight chain, or
n-alkenes, and the preferred n-alkenes are l-alkenes. The
alkenes have from 2 to 20 carbon atoms, and more prefer-
ably have from about 2 to about 6 carbon atoms.
One of the surprising discoveries of thisinvention is that under certain reaction conditions,
longer chain alkenes can be polymerized instead of being
cracked to short chain compounds. Additionally, the
oligomers produced from long n-l-alkenes are very highly
desirable for use as lubricants. The oligomers have
surprisingly little branching so they have very high
viscosity indices, yet they have enough branching to have
very low pour points.
The feed alkenes can be prepared from any source
by standard methods. Sources of such olefins can include
FCC offgas, coker offgas, synyas (by use of CO reduction
catalysts), low pressure, nonhydrogenative zeolite
dewaxing, alkanols (using high silica zeolites), and
dewaxing with crystalline silica polymorphs. Highly
suitable n-l-alkene feeds, especially for preparing
lubricating oil basestocks, can be obtained by thermal
cracking of hydrocarbonaceous compositions which contain
normal paraffins or by Ziegler polymerization of ethene.
Often, suitable feeds are prepared from lower
alkenes which themselves are polymerized. Such feeds
include polymer gasoline from bulk H3PO4 polymerization,
and propylene dimer, and other olefinic polymers in the
C~-C20 range prepared by processes known to the art.
L33;~5
01 _7_
The nickel-containing silicaceo~s crystalline
molecular sieves used in this invention are of
S intermediate pore size. By "intermediate pore size", as
used herein, is meant an effective pore aperture in the
range of about 5 to 6.5 Angstroms when the molecular sieve
is in the H-form. Molecular sieves having pore apertures
in this range tend to have unique molecular sieving
characteristics. Unlike small pore zeolites such as
erionite and chabazite, they will allow hydrocarbons
having some branching into the molecular sieve void
spaces. Unlike larger pore zeolites such as the
faujasites and mordenites, they can differentiate between
n-alkanes and slightly branched alkanes on the one hand
and larger branched alkanes having, for example,
quaternary carbon atoms.
The effective pore size of the molecular sieves
can be measured using standard adsorption techniques and
hydrocarbonaceous compounds of known minimum kinetic
diameters. See Breck, Zeolite Molecular Sieves, 1974
(especially Chapter 8) and Anderson et al, J. Catalysis
_ , 114 (1979).
Intermediate pore size molecular sieves in the
H-form will typically admit molecules having kinetic
diameters of 5.0 to 6.5 Angstroms with little hindrance.
Examples of such compounds (and their kinetic diameters in
Angstroms) are: n-hexane (~.3), 3-methylpentane (5.5),
benzene (5.85), and toluene (5.~). Compounds having
kinetic diameters of about 6 to 6.5 Angstroms can be
admitted into the pores, depending on the particular
sieve, but do not penetrate as quickly and in some cases
are effectively excluded. Compounds having kinetic
diameters in the range of 6 to 6.5 Angstroms irlclude:
cyclohexane (6.0), 2,3-dimethylbutane (6.1), m-xylene
(6.1), and 1,2,3,4 tetramethylbenzene (6.4). Generally,
compounds having kinetic diameters of greater than about
6.5 Angstroms do not penetrate the pore apertures and thus
are not absorbed into the interior of the molecular sieve
- 8 - 124333S
lattice. Examples of such larger compounds include: o-xylene
(6.8), hexamethylbenzene (7.1), 1,3,5-trimethylbenzene (7.5),
and tributylamine (8.1).
The preferred effective pore size range is from about
5.3 to about 6.2 Angstroms.
In performing adsorption measurements to determine
pore size, standard techniques are used. It is convenient to
consider a particular molecule as excluded if it does not reach
at least 95% of its equilibrium adsorption value on the zeolite
in less than about 10 minutes (p/po=0.5: 25C).
Nickel-containing HZSM-5 is described in United
States Patent Nos. 3,702,8~6 R.J. Argauer, et al, November 14,
1972 and 3,770,614 Graven, November 6, 1973.
HZSM-ll is described in United States 3,709,979
Chee, January 9, 1973. "Crystalline admixtures" of ZSM-5 and
ZSM-ll also exist, which arethought to be the result of faults
occurring within the crystal or crystallite area during the
synthesis of the zeolites. The "Crystalline admixtures" are
themselves zeolites but have characteristics in common, in a
uniform or nonuniform manner, to what the literature reports
as distinct zeolites. Examples of crystalline admixtures of
ZSM-5 and ZSM-ll are disclosed and claimed in United States
4,229,424 Kokotailo, October 21, 1980. The crystalline
admix~ures are themselves intermediate pore size zeolites and
are not to be confused with physical admixtures of zeolites in
which distinct crystal or crystallites of different zeolites
are physically present in the same catalyst composite or hydro-
thermal reaction mixture.
Silicalite is disclosed i~ United States 4,061,724
Flanegen, et al, December 6, 1977; the "RE 29,948 organo-
61936-16~8
8a-
~333~
silica-tes" are diselosed in U.S. Reissue Pa-tent RE 29,948
Dwyerl et al March 27/ 1979; chromia silicates, CZM, are
disclosed in Canadian Paten-t No. 1,165,312, filed August 22,
1980. In this pa-tent, this class of chromia silicates are
defined as follows in claim 1 and 2:
1. A crystalline chromia silica-te having a mol ratio of
oxides of SiO2:Cr2O3 of greater than about 20:1 ancd having the
followincJ random powder X-ray diffraction pattern:
Interplanar Spaeing,
d-A Relative Intensity
11.1 + 0.2 v.s.
10.0 + 0.2 v.s.
3.85 + 0.07 v.s.
3.82 ~ 0.07 s.
3.76 + 0.05 s.
3.72 + 0.05 s.
2. A erystalline chromia silicate composition expressed
in the anhydrous state in terms of mols of oxides comprising:
R2O:aM2O:bcr2o3:csio2
wherein R2O is a quaternary alkylammonium oxide, M is an alkali
metal selected ~rom the group of alkali metals consisting of
lithium, soclium, po-tassium or mixtures thereof, a is gLeater
than O but less than 1.5, c is grea-ter -than or equal -to 12,
and c/b is grea-ter than 20; and
said chromia silicate having the EollowincJ random
powder X-ray diffraetion pattern:
Interplanar Spacing,
d-A Relative Inte sity
__ _ _
11.1 ~ 0.2 v.s~
10.0 -~ 0.2 v.s.
3.85 ~ 0.07 v.s.
r--~
.~
61936-1648
-8b-
~2~33~
3.82 + 0.07 s.
3.76 + 0.05 s.
3.72 + O.OS s.
The reader is referred to the full text of this
patent for further information.
The so-called "RE 29,948 organosilicates" are
defined in both this United States Reissue Paten-t, and its
parent United S-tates Patent 3,941,871 Dwyer, et al, March 2,
1976 as follows:
61~36-1648
_g_
33~
"A crystal metal organosilicate having a composition,
in i-ts anhydrous state, in terms of mol ratios of oxides, as
follows:
0.9 ~ 0-2 [xR2O + (l-x)M2 O]: ~0.005 A12O3:~ lSio2
where M is sodium, or sodium in combination with tin, calcium,
nickel or zinc, R is a tetraalkylammonium, and x is a number
greater than zero but not exceeding 1, said organosilicate
having the X-ray diffraction lines se-t forthinTable 1 of the
specification."
Table 1 includes some 16 lines for various inter~
planar spacings. The four main ones appear to be a very
strong line for a spacing of 3.85 _ 0.07A, and strong lines
a~ 3.71 + 0.05A, 10.0 + 0.2A, and 11.1 + 0.2A. The reader
is referred to the full text of these patents for further
information.
The crystalline silica polymorphs, silicalite, and
"RE 29,~48 organosilicates", and the chromia silicate, CZM,
are essentially alumina free.
"Essentially alumina free", as used herein, is meant
the product silica polymorph (or essentially alumina-free
silicaceous crystalline molecular sieve) has a silica:alumina
mol ratio of greater than 200:1, preferably greater than
500:1. The term "essen-tia]ly alumina free" is used because i-t
is difficult to prepare completely aluminum free reaction
mixtures for synthesizing -these materials. Especially when
commercial silica sources are used, aluminum is almost always
present to a greater or lesser degree. The hydro-thermal
reaction mixtures from which the essen-tially alumina free
crystalline silicaceous molecular sieves are prepared can
also be referred -to as being substantially aluminum free. By
this usage is meant tha-t no aluminum is inten-tionally added
61936-16~8
-9a- ~243335
to the reaction mixture, e.g., as an alumina or aluminate
reagent, and that to the extent aluminum is present, it
occurs only as a contaminant in the reagent.
The most preferred molecular sieve is the zeolite
Ni-HZSM-5 and Ni containing hydrogen form of
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~1 -10-
silicalite. Of course, these and the other molecular
sieves can be used in physical admixtures.
When synthesized in the alkali metal form, the
zeolites may be conveniently converted to -the hydrogen
form by well known ion exchange reactions, for example, by
intermediate formation of the ammonium form as a result of
ammonium ion exchange and calcination of the ammonium form
to yield the hydrogen form, as disclosed in U.S. Patent
No. 4,211,640, or by treatment with an acid such as
hydrochloric acid as disclosed in U.S. Patent No.
3,702,886.
Nickel is incorporated into these silicaceous
crystalline molecular sieves according to techniques well
known in the ar~ such as impregnation and cation exchange.
For ~xample, typical ion exchange techniques would be tG
contact the hydrogen form of the particular sieve with an
aqueous solution of a nickel salt~ ~lthough a wide
~ variety of salts can be employed, particular preference is
given to chlorides, nitrates and sulfates. The amount of
nickel in the zeolites range from 0.5% to 10% by weight
and preferably from 1% to 5% by weight.
Representative ion exchange techniques are
~5 disclosed in a wide variety of patents including
U,S. Patent Nos. 3,140,249; 3,140,251; 3,960,978 and
3,140,253.
Following contact with the salt solution, the
zeolites are preferably washed with water and dried at a
3~ temperature ranging from 150F to about 500F and
thereafter heated in air at temperatures ranging from
about 500F to 1000F for periods of time ranging from 1
to 48 hours or more~
The nickel-containing silicaceous crystalline
molecular sieve catalysts can be made substantially more
stable for oligomerization by including from about 0.2% to
3~ by weight and preferably 0.5% to 2~ by weight of the
Group IIB metals, zinc or cadmium and preferably zinc. A
primary characteristic of these substituents is that they
4~ are weak bases, and are not easily reduced. These metals
~33~
0 1
can be incorporated into the catalysts using standard
impregnation, ion exchange, etc., techniques. Strongly
0~ basic metals such as the alkali metals are unsatisfactory
as they poison substantially all of the polymerization
sites on the zeolite. For this reason, the alkali metal
content of the zeolite is less than 1~, preferably less
than 0.1~, and most preferably less than 0.01%. The feed
should be low in water, i.e., less than 100 ppm, more
preferably less than 10 ppm, in sulfur, i.e., less than
100 ppm and preferably less than 10 ppm, in diolefins,
i.e., less than 0.5%, preferably less than 0.05% and most
preferably less than 0.01%, and especially in nitrogen,
i.e., less than 5 ppm, preferably less than 1 ppm and most
preferably less than 0.~ ppm.
The polymerization processes of the present
invention are surprisingly more efficient with small crys-
tallite sieve particles than with larger c-rystalline
particles. Preferably, the molecular sieve crystals or
crystallites are less than about 10 microns, more
preferably less than about 1 micron, and mos-t preferably
less than about 0.1 micron in the largest dimension.
Methods for making molecular sieve crystals in different
physical size ranges are known to the art.
The molecular sieves can be composited with
inorganic matrix materials, or they can be used with an
organic binder. It is preferred to use an inorganic
matrix since the molecul~r sieves, because of their large
internal pore volumes, tend to be fragile, and to be
subject to physical collapse and attrition during normal
loading and unloading of the reaction zones as well as
during the oligomerization processes. Where an inorganic
matrix is used, it is highly preferred that the matrix be
substantially free of hydrocarbon conversion activity. It
can be appreciated that if an inorganic matrix having
hydrogen transfer activity is used, a significant portion
of the oligomers which are produced by the molecular sieve
may be converted to paraffins and aromatics and to a large
~o degree the benefits of my invention ~ill be lost.
~33~i~
~1 -12-
The reaction conditions under which the
oligomerization reactions take place include hydrocarbon
05 partial pressures sufficient to maintain the desired
alkene reactants in the liquid state in the reaction zone.
Of course, the larger the alkene molecules, the lower the
pressure required to maintain the liquid state at a given
temperature. As described above, the operating pressure
is intimately related to the chemical composition of the
feed, but can be readily determined. Thus, the required
hydrocarbon partial pressure can range from 31 bar at
450F for a pure n-l-hexene feed to about atmospheric
pressure for a n-1-C15-C20 alkene mixture. In the process
of this invention, both reactant and product are liquids
under the conditions in the reaction zone, thus leading to
a relativel~ high residence time of each molecule in the
catalyst.
The reaction zone is typically operated below
about 450F. Above that temperature not only significant
cracking o~ reactants and loss of oligomer product take
place, but also significant hydrogen transer reactions
causing loss of olefinic oligomers to paraffins and
aromatics take place. An oligomerization temperature in
the range from about 90F to 350F is preferred. Liquid
hourly space velocities can range from 0.05 to 20,
preferably from 0.1 to about 4.
Once the effluent from the oligomerization
reaction ~one is recovered, a number of further processing
steps can be perormed.
If it is desired to use the long chain compounds
which have been formed in middle distillate fuel such as
jet or diesel or in lube oils as base stock, -the alkene
oligomers are preferably hydrogenated.
All or part of the effluent can be contacted
with the molecular sieve catalyst in further reaction
zones to further react unreacted alkenes and alkene oligo-
mers with themselves and each other to form still longer
chain materials. Of course, the longer the carbon chain,
the more susceptible the compound is to bein~3 cracked.
~l -13-
Therefore, where successive oligomerization zones are
used, the conditions in each zone must not be so severe as
05 to crack the oligomers. Operating with oligomerization
zones in series can also make process control of the
exothermic oligomerization reactions much easier.
One particularly desirable method of operation
is to separate unreacted alkenes present in the effluent
from the alkene oligomers present in the effluent and then
to recycle the unreacted alkenes back into the feed.
The following examples further illustrate this
invention.
EXAMPLES
lS Example l
HZSM-5 zeolite of 80 SiO2/Al~O3 mole ratio was
mixed with peptized Catapal alumina at a 50/50
sieve/alumina weight ratio, extruded through a 1/16" die,
dried overnight at 300F under N2, then calcined in air
~0 for 8 hours at 850F. The catalyst was exchanged ~ive
times with a 1% aqueous ammonium acetate solution, then
washed with water to give a final Na level of 100 ppm.
The catalyst of Example l was impregnated by the
pore fill method with 1% Zn using an aqueous solution of
zinc nitrate, then dried and calcined as in Example l.
Exam~le 3
The catalyst of Example l was exchanged with a
1% aqueous nickel acetate solution at 180F for five
hours, washed with water, then dried and calcined as in
Example l. The Ni content of the calcined catalyst was
3 wt %.
_ ample 4
The catalyst of Example 3 was impregnated with
1% Zn, dried, and calcined as in Example l.
Example 5
The catalyst of Example 2 (Zn-HZSM-5) was tested
for conversion of propylene to higher molecular weight
products at 130F, 1600 psig, and 0.5 LHSV. At 40 hours
33~
01 -14-
on stream, conversion to C5+ was less than 20 wt %
(Figure 1), with 32 wt % selectivity to dimer (Figure 2).
The propylene dimer distribution is given in
Table I.
TABLE I
10 C6 Olefin Composition From Propylene Oligomerization
C6 Olefin Selectivity
4-m-2-C5= 14.6
3-, 4-m-1-C5= 9.4
2-~-2-C5= 32.2
2-m-1-C5= ~.3
3-m-2-C5= 10.4
n-C6= 0.8
2,3-dm-C4= 28.3
Example 6
The catalyst of Rxample 4 (Ni-Zn-HZSM-5) was
tested for propylene conversion at the same conditions as
in Example 5. At 40 hours on stream, conversion to C5~
was over 98 wt % (Figure 1), with selectivity to dimer at
71 wt % (Figure 2). This shows the surprising benefit of
Ni addition to HZSM-5 in terms of both activity and
selectivity to dimer. The propylene dimer distribution is
given in Table II.
3~i
01 -15-
TABLE II
~5 C6 Olefin Composition From Propylene Oligomerization
C6 Olefin Selectivity '~
4-m-2-C5= 50.7
3-, 4-m-1-C5= 6.1
2-m-~-C5= 8.7
2-m-1-C5= 1.2
3-m-2-C5= 0.2
n-C6= 26.8
2,3-dm-C4= 6.3
For comparison, a 5% Ni on amorphous SiO2-A12O3
was prepared by pore-fill impregnation of a 40/60 SiO2-
A12O3 cogel with an aqueous nickel acetate solution,
drying at 300F overnight, then calcining in air for eight
hours at 850F. When tested for propylene conversion at
the conditions of Example 5, conversion to C5-~ at 40 hours
on stream was 54 wt ~, with 40 wt ~ selectivity to dimer~
Example 8
The catalyst of Example 3 (~ IZSM-5) was tested
for propylene conversion at 1600 psig and 1.0 LHSV. At 200
hours on stream, conversion to c5-t was 73 wt ~ at 120F.
~,2~
The catalyst o Example 2 (Zn-llZSM-5) was tested
for propylene conversion at 0 psig, 550E`, and 2 LHSV
under olefin gas phase conditions. After 90 hours on
streamr conversion to C5+ was 80 wt %.
Example 10
3 The catalyst of Example 3 (Ni-HZSM-5) was tested
for propylene conversion at the same conditions as in
Example 9. At 70 hours on stream, conversion to C5~ was
30 wt ~. This shows that the addition of Ni to HZ~M-5 is
only beneficial when oligomerization is carried out under
substantially liquid phase conditions.
~333~
01 -16-
Example 11
The catalyst of Example 4 (Ni-Zn-ElZSM-5) was
05 tested for propylene conversion at 0.5 LHSV and 1600 psig.
A plot of catalyst temperature for 90~ conversion to C5-~
versus time on stream is shown in Figure 3. At 430 hours
on stream, the reactor pressure was reduced to 800 psig.
The catalyst operated 800 hours before requiring a
temperature of 180F for 90% conversion to C5~. Product
inspections are shown in Table III~
TABLE III
C ~ Product Inspections from Oligomerizing
5 Propylene at 1000 psig and 0.5 LHSV
Temperature F 120
Conversion to C5+, wt % 85
Gravity, ~PI 74O0
Research Octane No., clear 94.0
Simulated TBP Distillation LV ~, F
10/20 136/139
30/50 141/154
70/go 161/2~3
Paraffins, LV% 0
Olefins, LV~ 100
Naphthenes, LV~ 0
Aromatics, LV~ 0
Examples 12-16
The catalyst of Example 1 was impregnated with
transition metals known in the art to be active for
promoting light olefin oligomerization. These include Co,
Cu, Pd, V, and Cr. The results given in Table IV show
these catalysts much less active than Ni-HZSM-5.
~0
~2~3~3~
01 -17-
TABLE IV
35Conversion of Propylene to C5+ Products
Over Transition Metal - HZSM-5 Catalyst
at 130-150E~, 0.5 LHSV, and 1600 Psig
Wt % Conversion
Example Metal ~ Loadingat 40 Hrs.
10 12 Co 2.4 12
13 Cu 0.5 < 5
14 Pd 2.5 <10
V 1.6 <10
16 Cr 5 < 5
6 Ni 3 98
Example 17
The catalyst of Example 2 (Zn-HZSM-5) was tested
for conversion of an olefinic C6-Cg gasoline feed
(Table V) to higher boiling product. The catalyst temper-
ature for 70% conversion to 350F+ as a function of time
on stream at 800 psig and 0.5 LHSV is shown in Figure 4
The catalyst fouling rate at these conditions was about
0.17F/hr.
~0
~333~;
01 ~18-
TABLE V
05Inspections of C6-Cg Olefinic Gasoline
Gravity, API 69.8
Research Octane Number, Clear 95.5
10 D-86 Distillation, LV%, F
10/20 152/156
30/50 158/162
70/90 190/348
Paraffins, LV% 0
15 Olefinsl LV% 99
Naphthenes, LV%
Aromatics, LV%
Example 1
;~U
The catalyst of Example 4 (Ni-Zn-HZSM-5) was
tested with the same feed as in Example 17 and at the same
pressure and LHSV. At 100 hours on stream, catalyst
temperature was 260F (Figure 4), about 170F lower than
needed with Zn-HZSM-5. Beyond 250 hours, the fouling rate
was only < 0.04F/hr, one-fourth or less than that for
Zn-HZSM~5, showing the benefit of Ni addition to the
catalyst with C6+ olefinic feeds. A gas chromatogram of
the product is shown in Figure 5.
Example 19
The catalyst of Example 3 (Ni-HZSM-5) was tested
with the same feed as in Example 17 and at the same
pressure but at a higher feed rate (1 and 2 LHSV). Even
at 2 LHSV~ the fouling rate was only 0.10F/hr (Figure 6),
less than that for Zn-HZSM-5 at only 0.5 LHSV.
Example 20
A Zn-silicalite catalyst was prepared in the
following manner. H-silicalite of 240 SiO2/A12O3 mole
ratio was mixed with peptized and neutralized Ca~apal
q0 alumina at a 67/33 sieve/alumina weight ratio, extruded
~3~
01 -19-
through a 1/16" die, dried overnight at 300F under N2,
then calcined in air for 8 hours at 850F. The catalyst
S was impregnated by the pore-fill method to 1 weight % Zn
using an aqueous solution of Zn(NO3)~, then dried and
calcined as done previously.
Example 21
The catalyst of Example 1 was impregnated to
3 weight % Ni by the pore-fill method using an aqueous
solution of Ni(NO3)2.6H2O. The catalyst was dried
overnight under N2 at 300F, then calcined in air for
8 hours at 850F.
Example 22
15 The Zn-silicalite catalyst of Example 1 was
tested for converting propylene to higher molecular weight
products at 150F, 1000 psig, and 0.5 LHSV. At 24 hours
onstream, conversion to C5+ was 3.2% with 38~ selectivi~y
to dimer.
~ Example 23
The Ni-Zn-silicalite catalyst of Example 2 was
tested for converting propylene at the same ronditions as
in Example 3. At 40 hours onstream, conversion to C5+ was
72.7% with 77% selac~ivity to dimer.
