U.S. patent number 3,865,894 [Application Number 04/716,190] was granted by the patent office on 1975-02-11 for process for paraffin-olefin alkylation.
This patent grant is currently assigned to Sun Oil Company of Pennsylvania. Invention is credited to David S. Barmby, Francis William Kirsch, John D. Potts.
United States Patent |
3,865,894 |
Kirsch , et al. |
February 11, 1975 |
Process for paraffin-olefin alkylation
Abstract
Olefin-paraffin alkylate is prepared by contacting C.sub.3
-C.sub.9 monoolefin with C.sub.4 -C.sub.6 iso-paraffin (which can,
if desired, be prepared in situ from other paraffin isomers) in
liquid phase with a substantially anhydrous acidic crystalline
alumino-silicate zeolite, and stopping such contacting after
substantial alkylation (which can include self-alkylation of the
isoparaffin) has occurred but before the weight rate of production
of unsaturated hydrocarbon becomes greater than the weight rate of
production of saturated hydrocarbon. The degree of conversion of
olefins and paraffins to saturate products can be increased by use
of halide adjuvants containing bromine, chlorine or fluorine.
Inventors: |
Kirsch; Francis William (Wayne,
PA), Barmby; David S. (Media, PA), Potts; John D.
(Springfield, PA) |
Assignee: |
Sun Oil Company of Pennsylvania
(Philadelphia, PA)
|
Family
ID: |
27078228 |
Appl.
No.: |
04/716,190 |
Filed: |
March 26, 1968 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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581129 |
Aug 25, 1966 |
|
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Current U.S.
Class: |
585/722 |
Current CPC
Class: |
B01J
29/061 (20130101); C07C 2/62 (20130101); B01J
29/084 (20130101); B01J 29/08 (20130101); B01J
29/088 (20130101); C07C 2/58 (20130101); C07C
2527/08 (20130101); C07C 2529/08 (20130101); C07C
2531/02 (20130101); C07C 2527/11 (20130101); C07C
2527/1206 (20130101); Y02P 20/582 (20151101) |
Current International
Class: |
C07C
2/00 (20060101); B01J 29/08 (20060101); B01J
29/06 (20060101); B01J 29/00 (20060101); C07C
2/58 (20060101); C07C 2/62 (20060101); C07c
003/52 () |
Field of
Search: |
;260/683.43,683.4,683.64
;208/120,120 ;252/455 |
References Cited
[Referenced By]
U.S. Patent Documents
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2834818 |
May 1958 |
Schmerling et al. |
3236762 |
February 1966 |
Rabo et al. |
3251902 |
May 1966 |
Garwood et al. |
3264208 |
August 1966 |
Plank et al. |
3308069 |
March 1967 |
Wadlinger et al. |
3312615 |
April 1967 |
Cramer et al. |
3352796 |
November 1967 |
Kimberlin, Jr. et al. |
3354078 |
November 1967 |
Miale et al. |
|
Primary Examiner: Gantz; Delbert E.
Assistant Examiner: Crasanakis; G. J.
Attorney, Agent or Firm: Church; George L. Hess; J. Edward
Bisson; Barry A.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of Ser. No. 581,129,
filed Aug. 25, 1966 by the present inventors, now abandoned and
assigned to the Sun Oil Company to whom the present application is
also assigned.
Claims
We claim:
1. A paraffin-olefin alkylation process which comprises contacting
monoolefin of the C.sub.2 -C.sub.9 range in admixture with paraffin
of the C.sub.4 -C.sub.6 range and with a substantially anhydrous
acidic crystalline alumino-silicate zeolite under alkylating
conditions and wherein there is present in solution in the reaction
mixture from 10.sup..sup.-5 to 10.sup..sup.-1 mole per mole of
C.sub.4 -C.sub.6 paraffin of a halide, said halide being selected
from the group consisting of HCl, carbon tetrachloride and the
aliphatic saturated monochlorides having no more than 6 carbon
atoms.
2. An isoparaffin-olefin alkylation process wherein C.sub.3
-C.sub.9 monoolefin in admixture with C.sub.4 -C.sub.6 isoparaffin
having a tertiary carbon atom is contacted with a substantially
anhydrous, acidic crystalline alumino-silicate zeolite under
alkylation conditions at a temperature below the critical
temperature of the lowest boiling hydrocarbon reactant and at a
pressure such that the reactants are substantially in liquid phase,
and wherein there is present in solution in the reaction mixture
from 10.sup..sup.-5 to 10.sup..sup.-1 mole per mole of C.sub.4
-C.sub.6 isoparaffin of a halide, said halide being selected from
the group consisting of HCl, carbon tetrachloride and the aliphatic
saturated monochlorides having 1 to 4 carbon atoms.
3. A process for the preparation of an isoparaffin-olefin alkylate
comprising contacting isobutane with monoolefin selected from the
group consisting of isobutylene, butene 2 and butene-1 and with a
substantially anhydrous acidic crystalline alumino-silicate
zeolite, at a temperature in the range of 25-120.degree.C. and at a
pressure such that each of the reactants is substantially in liquid
phase,
i. said contacting being effected utilizing sufficient agitation so
that substantially all of said zeolite is maintained in suspension
in the liquid reaction mixture,
the amount of unreacted olefin in the reaction mixture being
maintained at less than 7 mole percent based on the unreacted
isobutane, and
iii. wherein the mean weight hourly space velocity of the
hydrocarbons in the reaction mixture is in the range of 2-20 gram
hydrocarbons per hour-gram catalyst; and wherein there is present
in solution in the reaction mixture from 10.sup..sup.-5 to
10.sup..sup.-1 mole per mole of isobutane of a halide adjuvant
selected from the group consisting of HCl, carbon tetrachloride and
the aliphatic saturated monochlorides having 1 to 4 carbon
atoms.
4. Process for the preparation of an isoparaffin-olefin alkylate
comprising contacting isobutane with monoolefin selected from the
group consisting of isobutylene, butene-2 and butene-1, and with a
substantially anhydrous acidic crystalline alumino-silicate
zeolite, at a temperature in the range of 40.degree.-80.degree.C.
and at a pressure such that each of the reactants is substantially
in liquid phase,
i. said contacting being effected utilizing sufficient agitation so
that substantially all of said zeolite is maintained in suspension
in the liquid reaction mixture,
ii. the amount of unreacted olefin in the reaction mixture being
maintained at less than 7 mole percent based on the unreacted
isobutane,
iii. wherein the mean weight hourly space velocity of the
hydrocarbons in the reaction mixture is in the range of 2-20 gram
hydrocarbons per hour-gram catalyst; and
iv. wherein said contacting is in the presence of an
alkylation-promoting amount of a halide containing chlorine,
bromine or fluorine.
5. Process according to claim 4 wherein there is present in
solution in the reaction mixture from 10.sup..sup.-5 to
10.sup..sup.-1 mole per mole of isobutane of a halide, said halide
being selected from the group consisting of HCl, carbon
tetrachloride and the aliphatic saturated monochlorides having 1 to
4 carbon atoms.
6. An isoparaffin-olefin alkylation process which comprises
contacting 2,3-dimethylbutene in admixture with C.sub.4 -C.sub.6
isoparaffin having a tertiary carbon atom in the presence of an
alkylation-promoting amount of a halide containing chlorine,
bromine or fluorine with a substantially anhydrous acidic
crystalline alumino-silicate zeolite under alkylating
conditions,
i. wherein said contacting is at a temperature below the critical
temperature of the lowest boiling hydrocarbon reactant and is at a
pressure such that the reactants are substantially in liquid phase,
and
ii. wherein said product of said contacting comprises
2,3-dimethylbutane.
7. Process for the preparation of an olefin-paraffin alkylate
comprising contacting butene-1 with n-butane and with substantially
anhydrous acidic crystalline alumino-silicate zeolite, at a
temperature in the range of 40.degree.-80.degree.C. and at a
pressure such that each of the reactants is substantially in liquid
phase,
i. said contacting being effected utilizing sufficient agitation so
that substantially all of said zeolite is maintained in suspension
in the liquid reaction mixture,
ii. the amount of unreacted olefin in the reaction mixture being
maintained at less than 7 mole percent based on the unreacted
n-butane,
iii. wherein the mean weight hourly space velocity of the
hydrocarbons in the reaction mixture with the catalyst is in the
range of 2-20 gram hydrocarbon per hour-gram catalyst; and
iv. wherein said contacting of step (i) is in the presence of an
alkylation-promoting amount of a halide containing chlorine,
bromine or fluorine.
8. Process for the preparation of an olefinparaffin alkylate
comprising contacting butene-1 with n-butane and with a
substantially anhydrous acidic crystalline alumino-silicate
zeolite, at a temperature of 25-120.degree.C. and at a pressure
such that each of the reactants is substantially in liquid
phase,
i. said contacting being effected utilizing sufficient agitation so
that substantially all of said zeolite is maintained in suspension
in the liquid reaction mixture,
ii. the amount of unreacted olefin in the reaction mixture being
maintained at less than 7 mole percent based on the unreacted
n-butane,
iii. wherein the mean weight hourly space velocity of the
hydrocarbons in reaction mixture with the catalyst is in the range
of 2-20 gram hydrocarbon per hour-gram catalyst; and,
iv. wherein said contacting of step (i) is in the presence of an
alkylation-promoting amount of a halide containing chlorine,
bromine or fluorine.
Description
BACKGROUND OF THE INVENTION
This invention relates to the production of normally liquid,
saturated hydrocarbons, useful in gasoline blending, by reacting
isoparaffins with olefins in liquid phase in the presence of a
substantially anhydrous cystalline alumino-silicate zeolite. These
zeolites, in hydrated form, are chemically characterized by the
empirical formula, xM. X(AlO.sub.2).y(Si0.sub.2).zH.sub.2 0,
wherein M is H.sup.+ and/or an equivalent valence of
metal-containing cations and x, y and z are integers, the ratio x/y
being usually (but not necessarily) from 1.0 to 0.2.
The invention also comprises the use of halide catalyst adjuvants
to increase the degree of conversion of olefins and paraffins to
alkylate. Novel catalysts and novel alkylate products are also
within the scope of our invention and are described
hereinafter.
The invention will be described more particularly in connection
with a process for the preparation of an olefin-paraffin alkylate
comprising:
A. contacting C.sub.3 -C.sub.9 monoolefin with C.sub.4 -C.sub.6
isoparaffin and with a substantially anhydrous acidic crystalline
alumino-silicate zeolite, at a temperature below the critical
temperature of the lowest boiling hydrocarbon reactant and at a
pressure such that the reactants are at least partially in liquid
phase, and
B. stopping such contacting after substantial alkylation has
occurred but before the weight rate of production of unsaturated
hydrocarbon becomes greater than the weight rate of production of
saturated hydrocarbon.
It is usual in the laboratory to effect paraffin-olefin alkylation
by means of strong acids, such as AlCl.sub.3, HF, and H.sub.2
S0.sub.4 ; however, in petroleum refining, aluminum trichloride
catalysis is accompanied by equipment corrosion, cracking, sludge
formation, and other side reactions and has not proven economical,
except for ethylene-isoparaffin alkylation (for which there is no
other satisfactory catalytic process). Commerical isoparaffin
alkylation with C.sub.3 -C.sub.6 olefins to produce high octane
components for gasoline utilizes either H.sub.2 S0.sub.4 or HF as
the catalyst. These acids, although very effective as alkylation
catalysts, are highly corrosive and are potentially hazardous to
workmen; therefore, strict safety procedures must be adhered to in
their use. In addition, as for example in U.S. 2,359,119,
alkylation processes utilizing sulfuric acid normally require
reaction temperatures from about 5.degree.-15.degree.C.; therefore,
costly cooling is required.
The art has long sought to find a process for paraffin-olefin
alkylation utilizing catalyst which does not have the
above-mentioned disadvantages possessed by AlCl.sub.3, HF, or
H.sub.2 S0.sub.4. In particular, a heterogeneous process utilizing
a solid alkylation catalyst has been sought by the art since
processes using a liquid catalyst require that the acid and feed
hydrocarbons, which are mutually immiscible, be kept in homogeneous
suspension. Such "homogenization" requires expensive agitation
devices and consumes much power. In addition, emulsions can be
formed which are different and costly to "break."
Heretofore, attempts to effect paraffin-olefin alkylation utilizing
a solid catalyst have had but little success. In all such published
attempts, the bromine numbers of the reported products have been
high, indicating that olefin polymerization (or some other
competing reaction) has occurred to a substantial extent rather
than the hoped-for paraffin-olefin alkylation.
Aromatic-olefin alkylation utilizing a crystalline,
alumino-silicate catalyst has been reported (e.g., U.S. Pat. No.
2,904,607). However, the art has long recognized that
olefin-aromatic alkylation and olefin-paraffin alkylation are very
different chemical reactions and that there is no equivalency
between processes for these two dissimilar combinations.
Although the chemistry of the alkylation reactions is complex and
not completely understood, it is very probable that one major
reason for the non-equivalency of olefin-aromatic alkylation and
olefin-paraffin alkylations is that aromatic-olefin alkylation is
dependent upon proton ejection from the intermediate carbonium ion
whereas proton ejection in paraffin olefin reactions yields
unsaturated products. In contrast, the production of saturated
paraffin-olefin "alkylate" requires hydride transfer to the
intermediate carbonium ion and, thus, a catalyst and process
condition which favor hydride transfer over proton ejection.
In U.S. Pat. No. 3,251,902, claims are directed to the alkylation
of C.sub.4 and C.sub.5 isoparaffins with C.sub.2 -C.sub.5 olefins.
The examples, however, show only ethylene or propylene as feed
olefins. Ethylene-paraffin reactions do not teach how to alkylate
paraffins with C.sub.3 -C.sub.6 olefins. With propylene and
isobutane, the reported characteriszations of the products in the
examples of U.S. Pat. No. 3,251,902 are what would be expected in
view of the above-discussed prior art, particularly the art dealing
with olefin-paraffin alkylations. That is, with propylene and
isobutane as the feed hydrocarbons, the reported products of the
alkylation process of U.S. Pat. No. 3.251,902 are highly
unsaturated, and, in fact, the inventors admit that such
unsaturation indicates that "polymerization of the olefin is more
pronounced than alkylation." They attribute such polymer production
in their process to the thermal stability of the feed olefin and
the high concentration of acid sites in certain of their zeolite
catalysts. In no case do they recognize the above-discussed
importance of hydride transfer in the production of saturated
rather than unsaturated "alkylate."
SUMMARY OF THE INVENTION
As is further disclosed herein, we have discovered a process for
the production of highly saturated alkylate from C.sub.3 -C.sub.9
monoolefins which requires not only a catalyst with a large number
of acid sites of sufficient strength for hydride transfer but which
also utilizes conditions which favor hydride transfer, such as
introducing the olefin to the reactor in the liquid phase and in
intimate admixture with C.sub.4 -C.sub.6 isoparaffin and,
preferably, controlling the addition of the feed olefin such that
the unreacted olefin in the hydrocarbon-catalyst reaction mixture
is maintained at less than 12 mole percent (and most preferably
less than 7 mole percent) based on the total paraffin content of
the reaction mixture. In contrast to the process U.S. Pat. No.
3,251,902, we have also discovered that better yields of superior
products can be obtained in our process with the more highly acid
catalysts than with the less acid catalysts.
The use of dilute olefin feed streams has been suggested in
conjunction with processes for olefin-aromatic alkylation (e.g.,
U.S. Pat. No. 3,251,897); however, there is no prior art suggestion
or teaching of our liquid phase, acid zeolite-catalyzed
paraffin-olefin alkylation process wherein C.sub.3 -C.sub.9 feed
monoolefins are intimately premixed with feed paraffin, nor of our
control of the concentration of unreacted olefin in the reaction
mixture with acidic zeolite catalysts in order to obtain
paraffin-olefin alkylation rather than polymerization.
We have further discovered that the production of saturated
alkylation (and self-alkylation) products rather than unsaturated
hydrocarbons is effected when the mean residence time (or retention
or holding time) of the reaction mixture with the catalyst is in
the range of 0.05 to 0.5 hours per (gram of hydrocarbon per gram of
catalyst). More preferably, the mean residence time is 0.1-0.4
hours.
Preferably, there is present in the reactor mixture a halide
adjuvant containing fluorine, chlorine or bromine. Particularly
favorable alkylation conditions involve a temperature in the range
of 25.degree. to 120.degree.C. (more preferably
50.degree.-100.degree.C.) and sufficient pressure to maintain a
substantial part of each reactant in liquid phase (since mixed
gas-liquid phase conditions are more likely to result in poor
mixture of the feed paraffin and feed olefin, thus promoting olefin
homopolymerization).
In general, unsaturated reaction products are indicative of olefin
homopolymerization rather than paraffin-olefin alkylation. True
alkylation, including isoparaffin self-alkylation, produces
saturated hydrocarbons, However, apart from these primary
reactions, i.e., polymerization and alkylation, the acidic zeolites
catalyze many secondary reactions, such as cracking,
disproportionation, and aromatization. These reactions can
transform unsaturated "polymer" to saturated hydrocarbons and can
cause unsaturated hydrocarbons to be formed.
In our process we desire to maximize the production of saturated
hydrocarbons, and particularly the trimethylpentanes, since, as is
shown by C. R. Cupit, et al., Petrol. Chem. Eng., Dec., 1961 at
pages 204- 5, these have the more desirable antiknock
characteristics, such as low sensitivity. With C.sub.4 olefins and
isobutane, therefore, we desire to maximize the percentage yield,
based on the weight of olefin charged, of C.sub.5 .sup.+ saturates
and the yield of trimethylpentanes.
One means of maximizing this percent yield of C.sub.5 .sup.+
saturates is to prepare suitably active acid catalysts which favor
hydride transfer and to conduct the process under conditions (as
described herein) such that, as primary reactions, paraffin-olefin
alkylation and isoparaffin self-alkylation are favored over
polymerization. The reaction should also be controlled in a manner
which reduces the occurrence of undesirable reactions.
Another method of increasing C.sub.5 .sup.+ saturate yield is to
use reaction conditions which favor the secondary reaction of
octanes with isobutane to form C.sub.7, C.sub.6 and C.sub.5
paraffins.
We have found that with isobutane and butene-2 feeds, even when
such secondary reactions have occurred to some extent, the
molecular ratio of trimethylpentanes/dimethylhexanes
(TMP/DMH.sub.x) in the reaction mixture indicates the relative
degree to which the primary reaction was alkylation or
polymerization. That is, dimethylhexanes arise from olefin
dimerization followed by hydride transfer; whereas,
trimethylpentane formation is largely dependent upon
paraffin-olefin combination to form a carbonium ion species
followed by hydride abstraction from the isobutane. Therefore, the
higher the ratio TMP/DMH.sub.x, the greater the effect of
alkylation reactions, in contrast to olefin homopolymerization.
In general, the greater the tendency for the catalyst to initiate
hydride transfer, the greater the ratio TMP/DMH.sub.x. For example,
with isobutane-butene-2 feeds, AlCl.sub.3 catalyst (at
30.degree.C.) produces reaction products where TMP/DMH.sub.x is
about 2/1. With HF or with H.sub.2 S0.sub.4, alkylates can be
obtained with TMP/DMH.sub.x ratios about 8/1. commercial H.sub.2
S0.sub.4 alkylates have TMP/DMH.sub.x ratios between 3/1 and
6/1.
Prior art publications, such as those previously referred to, fail
to teach how to use solid catalyst to obtain a C.sub.4 -C.sub.6
isoparaffin C.sub.3 -C.sub.9 olefin reaction product in which
saturated products predominate rather than unsaturate. They also do
not teach how to obtain products having high TMP/DMH.sub.x ratios.
In contrast, we have discovered, and disclose herein, a
paraffin-olefin alkylation process which utilizes acidic cystalline
zeolite catalyst to obtain a predominantly saturated product in
which the TMP/DMH.sub.x ratio can be greater than 7. We further
teach how our process can be used to produce a paraffin-olefin
alkylate which contains only negligible amounts of unsaturated
reaction products. We have also discovered that maximum conversion
of olefin to saturated products can be obtained with this process
under conditions where the reaction mixture contains but a minor
amount of unsaturated reaction products.
We have further discovered, unexpectedly (in view of prior art),
that the conversion of olefin to saturated products can also be
increased by the use of halide catalyst adjuvants. That is, the
incorporation in the reaction mixture of small amounts of certain
halides containing bromine, chlorine or fluorine allows the
production of as much as 100 percent more saturated hydrocarbons
from the same quantity of olefin reactant than can be produced
under the same reaction conditions in the absence of the halide
adjuvant.
BRIEF DESCRIPTION OF THE DRAWINGS
In the attached drawings, FIG. 1 illustrates the variation in the
yield of C.sub.5 .sup.+ paraffins based on the olefin reactant as
the reaction time is increased in our process.
FIG. 2 illustrates (by the solid curve) the weight percent of
C.sub.5 .sup.+ unsaturates produced, based on the olefin reactant
(here, butene-2), as the reaction time is increased. Also
illustrated in FIG. 2, by the broken curve, is the moles of
n-butane produced per mole of butene-2 converted, as a function of
time.
FIGS. 3, 4 and 5 illustrate an apparatus which is particularly
useful for effecting the continuous production of alkylate from a
paraffin-olefin feed, utilizing the process of the present
invention. This apparatus comprises three sections, a feed-mixing
section, FIG. 3, a stirred, slurry reactor section, FIG. 4, and a
product recovery section, FIG. 5.
In the feed section (FIG. 3), C.sub.3 -C.sub.9 monoolefin is
admixed with C.sub.4 -C.sub.6 isoparaffin and transported, as by
pumping, to the reactor section. The reactor section comprises a
pressure vessel with means for maintaining the catalyst in
suspension, such as a turbine mixer and baffles, means for
introducing feed hydrocarbon and adjuvants such as a halide
promoter, and means for separating a catalyst-free portion of the
reaction mixture and transporting it from the reactor to the
product recovery section.
The reactor section (FIG. 4), also includes means for maintaining
sufficient pressure in the reaction vessel to insure that the
reactants and the reaction mixture are in liquid phase, means (such
as a differential pressure cell) for maintaining the liquid inside
the reactor at a desired level and means for maintaining the
reactor at the desired temperature (such as by a water jacket and
heating coils).
The product recovery section (FIG. 5), comprises means for cooling
the reaction mixture, means for separating gases (such as unreacted
feed isoparaffin) from the desired liquid alkylate, and means for
recycling unreacted feed hydrocarbons.
FURTHER DESCRIPTION OF THE INVENTION
Although our paraffin-olefin alkylation process requires the
control of many inter-related process variables, such as reaction
temperature, mixing rate, catalyst selection, concentration and
preparation, the more critical conditions in our process are
control of the maximum ratio of unreacted C.sub.3 -C.sub.9 olefin
to C.sub.4 -C.sub.6 isoparaffin in the reaction mixture, that all
the feed components (whether olefin or paraffin) must be well
inter-mixed and kept at least partially (preferably predominantly)
in the liquid phase, and most important, contact time of the
olefin-containing reaction mixture with the catalyst must be
controlled closely. A key measure of such contact is the mean
residence time of the olefin-containing reaction mixture with the
catalyst, in such units as mean hours per (gram of hydrocarbon per
gram of catalyst). The criticality of these conditions with respect
to obtaining a predominantly saturated alkylate has not been taught
or suggested by the prior art.
The major reaction conditions which must be controlled in order to
obtain a satisfactory product are inter-related in that they all
influence the probability that a given molecule of reactant will
collide with an active site of the zeolite catalyst and form a
desirable carbonium ion. These major variables are the initial
concentrations of isoparaffin and catalyst, the paraffin/olefin
feed ratio, the intimacy of the paraffin-olefin premixing, the feed
rate, agitation rate, temperature, pressure, catalyst type and
particle size, and the contact time (or for a continuous stirred
reactor, the mean residence time).
We have discovered that, within the operable ranges discussed
herein, if the other variables are fixed (especially those which
determine the probability that a given molecule of reactant will
collide with an active site of the catalyst), a certain minimum
contact time or induction period is required for substantial
paraffin-olefin alkylation to occur. There is also a maximum
contact time beyond which the quantity of saturated alkylate in the
reaction mixture no longer increases, and unsaturated reaction
products start to build up. We have found, in our process, that the
production of saturated alkylation products is effected when the
mean residence time of the reaction mixture with the catalyst is in
the range of 0.05 to 0.5 hours.
The published art contains no disclosure, suggestion or even
speculation of such criticality in a zeolite-catalyzed
paraffin-olefin reaction system. The best mode of practice of our
process utilizes this discovery to maximize conversion of our
prarffin-olefin feed to desirable saturated products and to
minimize, or effectively eliminate, the production of unsaturated
hydrocarbons.
A preferred embodiment of our process for the preparation of an
olefin-paraffin alkylate comprises the following steps:
1. contacting C.sub.3 -C.sub.9 monoolefin in admixture with C.sub.4
-C.sub.6 isoparaffin having a tertiary carbon atom, at a
temperature below the critical temperature of the lowest boiling
reactant and at a pressure such that the reactants are in liquid
phase, with a substantially anhydrous acidic crystalline
alumino-silicate zeolite;
2. controlling the addition of the said olefin reactant such that
the amount of unreacted feed olefin in the reaction mixture is
maintained at less than 12 mole percent and preferably less than
about 7 percent, based on the total paraffin content and of the
reaction mixture (or, more preferably, based on the unreacted
C.sub.4 -C.sub.6 isoparaffin);
3. stopping such contacting after substantial alkylation has
occurred but before the weight rate of formation of unsaturated
hydrocarbon products exceeds the weight rate of formation of
saturated hydrocarbons.
Preferably, in Step 3 above, the mean residence (or contact) time
of the olefin-containing reaction mixture with the catalyst is in
the range of 0.05 to 5 hours per (gram of hydrocarbon in the
mixture per gram of catalyst). More preferred, is a mean residence
time of 0.1 to 0.4 hours.
When our process is compared with the prior art processes for the
alkylation of aromatic hydrocarbons with olefins, it becomes
apparent that the prior art does not teach our process
(particularly in view of the above-noted differences with regard to
proton abstraction and hydride transfer between such reactions and
paraffin-olefin reactions). In fact, it is evident that the prior
art teachings relating to olefin-aromatic alkylation would lead the
ordinary man skilled in the art (particularly one who attempted to
substitute a C.sub.4 -C.sub.6 isoparaffin for the aromatic
hydrocarbon in prior art examples) to conclude that paraffin-olefin
"alkylation" catalyzed by crystalline zeolites results primarily in
the production of unsaturated hydrocarbons.
Surprisingly, in view of the prior art reports of the ability of
acidic crystalline zeolites, particularly the protonated or
decationized zeolites, to strongly catalyze the polymerization of
olefins, we have found a process, catalyzed by protonated and other
acidic zeolites, whereby polymerization and/or other reactions
which tend to produce unsaturate materials can be virtually
eliminated, or held to a well-controlled minimum, while producing a
saturated paraffin-olefin alkylate which is useful as a high octane
component for gasoline.
We have further prefected our process so that with constant product
removal and reactant recycle, saturated hydrocarbons may be
produced continuously or continually in high yields. We can also
control the molecular weight distribution of these hydrocarbons so
that the desirable high anti-knock paraffins predominate. We have
also discovered how to obtain a high degree of conversion of a
C.sub.4 olefin-isobutane feed into alkylate in which the C.sub.8
paraffin portion contains 80 percent or more of trimethylpentanes
and which has TMP/DMH.sub.x ratios greater than 5 and even as high
as 11.
As is further illustrated herein, our process can, by appropriate
selection of catalyst and conditions, be used to produce novel
paraffin-olefin alkylates, useful as motor fuels and as gasoline
blending components, comprising at least 60 mole percent C.sub.8
paraffins and less than 1 weight percent unsaturates and wherein
the C.sub.8 paraffins consist of from 5 to 20 mole percent
dimethylhexanes, from 0 to 1.5 mole percent methylheptanes, from 80
to 95 mole percent of trimethylpentanes, and wherein less than
about 30 mole percent of the trimethylpentanes is
2,2,4-trimethylpentane.
Paraffin-olefin alkylates which contain a high proportion of
trimethylpentanes have high octane ratings and good blending values
and, therefore, are highly desirable components of gasoline. In
contrast, olefinic hydrocarbons are less desirable as gasoline
components because they are gum formers, are sensitive to
oxidation, and when highly branched have poorer motor octanes than
the corresponding paraffin hydrocarbons. Aromatic hydrocarbons,
although they are generally good gasoline blending components with
high octane ratings, are not desired in our process since they can
decrease the activity of the catalyst.
The catalysts of our process are those substantially anhydrous
acidic crystalline alumino-silicate zeolites which, in hydrated
form, are chemically characterized by the empirical formula M.sub.x
(A10.sub.2).sub.x (SiO.sub.2).sub.y.sup.. (H.sub.2 0).sub.z, where
M is H.sup.+ and/or an equivalent valence of metal cations and x, y
and z are integers, the ratio x/y being usually (but not
necessarily from 1.0 to 0.2. A 10 percent aqueous suspension of the
acidic zeolite catalyst will have a pH less than 7, preferably less
than 5. For our process we prefer that the critical pore diameter
of the zeolite be at least large enough to permit adsorption of
benzene. We also prefer those acidic zeolites which contain both
H.sup.+ and polyvalent metal cations (including metal cations in
which part of the charge is balanced by oxide or hydroxyl groups),
although catalysts having only H.sup.+ or polyvalent metal
hydroxides (e.g., Ce(OH).sup.2 .sup.+or Ce(OH).sub.2 .sup.+ ) are
effective in catalyzing paraffin-olefin alkylation.
These catalysts are normally prepared from alkali metal-containing
zeolites (which in 10 percent aqueous suspension will have a pH
greater than 7, and usually greater than 9) by ionexchanging the
alkali metal ions for H.sup.+ and/or polyvalent metal cations.
Hydorgen-ion (or proton) exchange can be effected by exchange from
aqueous or non-aqueous medium with mineral acids, such as dilute
aqueous HC1, or by exchange with solutions of acids and polyvalent
metal ions (such as aqueous HN0.sub.3 and Ce(N0.sub.3).sub.3 ). For
zeolites, such as the faujasites, which can be degraded by direct
acid exchange, we prefer (as our exchange media) aqueous solutions
containing, as at least one component, ammonium salts. Polyvalent
metal exchange can be effected with solutions of salts of the
metals, such as their nitrates.
Our preferred catalysts are prepared by such ammonium ion exchange,
followed by polyvalent metal cation exchange, of an alkali metal
faujasite (such as sodium type Y zeolite) having an Si0.sub.2
/A1.sub.2 0.sub.3 molar ratio in the range of 4.0 to 5.0.
ILLUSTRATIVE EXAMPLES
The present invention may be further illustrated by the following
specific examples. Examples I-VI illustrate the preparation of
acidic, or potentially acidic, solvated crystalline zeolites by
aqueous cation exchange. Example VII illustrates the "activation"
of the solvated zeolites by removing "solvent" from the
zeolite.
The remaining examples, excepting Example XVIII, illustrate the use
of such substantially anhydrous acidic crystalline alumino-silicate
zeolites as alkylation catalysts. Of these, Examples VIII-XII show
the effect of reaction temperature on the yield and product
distribution. Examples X, XI and XIII show the unexpected, large
increase in product yield effected by the use of various halide
adjuvants. Example XII, when compared with Example IX, shows that
at a given temperature the more highly exchanged catalyst does not
necessarily produce the greatest product yield. When Example XII is
compared with Examples X and XI, it is seen that, for a given
catalyst and a given contact time, a large increase in reaction
temperature will not necessarily give the large increase in yield
which is obtainable by the use of a halide adjuvant.
Example XIV illustrates the influence of the contact time (or the
time that the feed is in contact with the catalyst) and, in
particular, shows the criticality, when maximizing saturate
production based on olefin feed, of applicants' process step of
stopping such contact after substantial alkylation has occurred but
before the weight rate of production of unsaturated hydrocarbon
becomes greater than the weight rate of production of saturated
hydrocarbon. Further shown is the 100 percent consumption of feed
olefin to produce an alkylate containing less than 0.5 percent of
unsaturates. The importance of thorough premixing of the feed and
incorporation of these steps into continuous process schemes is
also disclosed.
Example XV illustrates the effect that catalyst composition has on
the yield and product distribution. Example XVI shows the effect of
various feed olefins on yield and product distribution. Example
XVII shows the use of a fixed bed of catalyst in our process and
compares the results with our preferred process using a catalyst
slurry in a stirred reactor.
Example XVIII shows that highly unsaturated products are obtained
when process conditions analogous to those of the prior art (in
particular, the process conditions in U.S. Pat No. 3,251,902) are
used to attempt to react butene-2 with isobutane in liquid phase in
the presence of a substantially anhydrous acidic zeolite (similar
to that of Example III). Example XVIII, when compared with other
examples such as Example VIII or Example XIX, shows the importance
of our requirement that the addition of the feed olefin be
controlled such that the amount of unreacted olefin in the reaction
mixture is maintained at less than 12 mole percent (preferably less
than 7 percent) based on the unreacted C.sub.4 -C.sub.6
isoparaffin.
Example XIX illustrates a preferred embodiment of our invention
wherein we produce a highly saturated, novel alkylate, highly
desirable as a solvent and as a component of blended fuel for high
compression automobile engines, containing less than 1 percent of
unsaturates and comprising at least 60 mole percent of C.sub.8
paraffins, said C.sub.8 paraffins consisting of less than 1 mole
percent methylheptanes, 5-10 percent dimethylhexanes, and at least
90 percent trimethylpentanes, said trimethylpentanes comprising
less than 20 percent 2,2,4-trimethylpentane.
Example XX illustrates the effect of the gas used in catalyst
activation on the paraffin yield, per weight of olefin charged,
obtained from the resulting catalyst.
Example XXI illustrates the practice of our process in a continuous
production operation wherein fresh portions of the hydrocarbon
reactants (feed paraffin and feed olefin) are constantly added to
the reaction mixture and a catalyst-free alkylate is constantly
separated from the reaction mixture and withdrawn from the
reactor.
Example XXII illustrates the effect, on yield and product quality,
of the catalyst/olefin ratio.
Example XXIII illustrates the correlation between alkylate yield
and the ESR measurements of total spin count when aromatic
hydrocarbons are absorbed on the CeHY catalyst.
EXAMPLE I
This example describes the ammonium exchange of a crystalline,
alkali metal alumino-silicate zeolite which can be heated to remove
"loosely bound" water and to decompose the ammonium ion to produce
a substantially anhydrous acidic crystalline alumino-silicate
zeolite which can be used as a catalyst in our process. Preferably,
before such decomposition or "decationizing," such
ammonium-exchanged zeolites are further exchanged with polyvalent
metal cations, as is shown in EXAMPLE III hereinafter.
A kilogram of a commercially available hydrated crystalline
alumino-silicate zeolite, identified as sodium zeolite Y, was dried
in air at 125.degree.C. for 18 hrs., broken up into particles of
100 mesh or less, redried in air at 125.degree.C. for 18 hrs., and
suspended with stirring, in 1.7 liters of a 9.1% by weight aqueous
solution of ammonium chloride at 80.degree.C. After 30 minutes the
resulting ammonium-exhanged Y zeolite was separated from the liquid
by filtration and recontacted at 80.degree.C. in a similar manner
with a second 1.7 liter portion of fresh NH.sub.4 C1 solution.
After 6 more such 30-minute exchange cycles, the filtered zeolite
was washed with distilled water (pH 6.5) at 20.degree.C. until no
chloride ion could be detected in the spent wash liquid with acidic
silver nitrate reagent.
The washed ammonium-exchanged zeolite was dried for about 18 hours
in air at 125.degree.C., then ground to about 200 mesh and stored.
The dried ammonium-exchanged zeolite produced by the above series
of eight ammonium-exchanges analyzed 1.34 percent Na and 4.6
percent N, and had a loss on ignition of 26.5 percent. After the
first ammonium-exchange cycle, a similarly washed and dried portion
of the zeolite analyzed 5.5 percent Na and 2.3 percent N, and had a
loss on ignition of 25.6 percent.
The sodium Y zeolite before this ammonium exchange had a pore size
sufficiently large to enable it to absorb benzene and analyzed 7.5%
sodium and 8.86 percent aluminum, and had an A1/Si atomic ratio of
0.40. The sieve had a loss on ignition at 1,800.degree.F. of 23.8%.
All ignition losses referred to hereinafter were run at
1800.degree.F.
EXAMPLE II
This example illustrates the preparation of more highly
ammonium-exchanged zeolites than that of Example I. Example I was
repeated except that the sodium Y zeolite was subjected to 8
additional hot NH.sub.4 C1 exchange cycles before it was washed
chloride free. The washed, dried ammonium-exchanged zeolite,
resulting from this total of 16 ammonium-exchange cycles, contained
0.77 percent sodium and 4.14 percent nitrogen, and had 29.8 percent
loss on ignition.
A similar exchange for a total of 32 cycles produced a washed,
dried zeolite containing 0.21 percent Na and 4.64 percent N and
having 28.7 percent loss on ignition.
Ammonium exchange of alkali metal zeolites can also be accomplished
by suspending the zeolite in a vessel containing the exchange
solution and maintaining a flow of fresh exchange solution into the
vessel while withdrawing an equal volume of catalyst-free liquid
from the vessel. Removal of catalyst-free liquid from the vessel
can be effected by forcing the liquid with pressure or suction
through a pleated microporous, woven stainless steel screen "10 "
filter. In such continuous flow processing, the flow rate is
preferably regulated so as to maintain a relatively constant pH in
the exchange vessel. Hydrochloric acid ir nitric acid addition can
also be used for pH control. With 10 percent ammonium chloride
solutions it is preferred to maintain a pH of about 4.5 .+-. 0.3
(at 80.degree.C.). Ammonium exchange can also be effected by
percolating the exchange solution through a fixed bed of
zeolite.
EXAMPLE III
This example illustrates the further exchange of an
ammonium-exchanged zeolite with a solution containing polyvalent
metal ions in order to produce a zeolite containing both polyvalent
metal ions and ammonium ions. A portion of the dried,
ammonium-exchanged zeolite of Example I was contacted, with
stirring, for 30 minutes at 80.degree.C. with 1.7 parts by weight
of a 1.3 percent solution Ce(NO.sub.3).sub.3.sup.. 6H.sub.2 O, then
separated from the exchange solution by filtration and recontacted
for 30 minutes at 80.degree.C. with 1.7 parts by weight of fresh
cerium nitrate solution. After 6 more such exchange cycles (or a
total of 8 exchanges), the filtered Ce.sup..sup.+3
-exchanged/ammonium-exchanged zeolite was washed with water until
no nitrate ion could be detected in the spent liquor by
diphenylamine reagent. The washed Ce-NH.sub.4 .sup.+ Y zeolite was
dried for 0b 18 hours at 125.degree.C., ground, redried for 18
hours at 125.degree.C., and stored in a moisture-tight container.
The dried Ce.sup..sup.+ 3 -NH.sub.4 .sup.+-exchanged zeolite
analyzed 6.18% Ce, 1.25% Na, and 1.43% N. It had a 25.6 percent
weight loss on ignition.
EXAMPLE IV
This example illustrates the use of additional cerium exchange
cycles and a more highly ammonium-exchanged "base" zeolite in order
to obtain zeolites with a greater cerium content and a lower sodium
content than the zeolite of Example III. A portion of the washed,
dried "16 cycle" NH.sub.4 .sup.+-exchanged zeolite of Example II
was contacted according to the procedure of Example III for a total
of 16 Ce(NO.sub.3).sub.3 exchange cycles, then similarly washed and
dried. The resulting Ce.sup..sup.+3 -NH.sub.4 .sup.+ -exchanged
zeolite analyzed 10.1% Ce, 0.69% N, 0.68% Na, and had a loss on
ignition of 24.4%.
A similar series of 16 cerium exchanges performed on the "32 cycle"
ammonium-exchanged zeolite of Example II produced a washed, dried
Ce.sup..sup.+3 -NH.sub.4 .sup.+ -exchanged zeolite which analyzed
0.23% Na, 10.3% Ce, 0.8% N, and had a loss on ignition of
24.7%.
Hereinafter, sometimes, a catalyst will be identified according to
the number and type of such exchange cycles according to the code:
number of ammonium exchange cycles/number of polyvalent metal
exchange cycles. That is, the above zeolite propared by 6 cerium
exchange cycles of a 32 cycle ammonium is, by this code, a 32/16
zeolite, (or, after activation, a 32/16 catalyst).
EXAMPLE V
This example illustrates the preparation of a Ce.sup..sup.+3
-exchanged sodium Y zeolite. A portion of the commercial sodium Y
zeolite of Example I was ground and exchanged for 16 exchange
cycles with Ce(NO.sub.3).sub.3 solution in a manner similar to the
exchange of Example III, then washed and dried. The resulting
Ce.sup..sup.+3 -exchanged Na Y zeolite containted 9.6 percent
certium, 1.69 percent sodium, and had a loss on ignition of 25.1
percent.
The cerium exchanges of Examples III, IV and this example can be
effected in a continuous manner, similar to that described in
Example II for ammonium exchanges. Preferably the pH should be
about 4.5. The particular polyvalent metal salt chosen and the pH
of the exchange solution will determine whether the cationic
exchange species is the metal or a hydroxylated complex ion of the
metal. Other polyvalent metal ions, such as those referred to
hereinafter, and in particular cations of the polyvalent rare earth
metals and mixtures thereof, may be similarly exchanged with alkali
metal-containing and/or ammonium containing crystalline zeolites.
Especially preferred catalysts can be obtained from crystalline
alumino-silicate zeolites which have been so exchanged with aqueous
solutions of salts of gadolinium, such as Gd(NO.sub.3).sub.3, or
with mixtures of salts of Gd and Ce. In this specifiction the term
"rare earth metals" includes lanthanum, that is, the term "rare
earth" herein is used as a synonym for "lanthanon." The lanthonons
include La, Ce, Pr, Nd Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and
Lu.
EXAMPLE VI
This example illustrates the ammonium exchange of a Ce.sup..sup.+3
-exchanged sodium Y zeolite. A portion of a washed, dried
cerium-exchanged zeolite prepared similar to that of Example V and
containing 7.7% Ce, 0.63% Na and with 26.4% loss on ignition was
exchanged with hot aqueous ammonium chloride, for a total of 8
cycles, using the procedure of Example I. The washed, dried
NH.sub.4.sup.+ -Ce.sup..sup.+3 -exchanged Y zeolite analyzed 0.22%
Na, 2.8 N, 5.3 Ce.sup..sup.+3 and had a loss on ignition of 27.6%.
Therefore, about 30 percent of the cerium was removed from the
cerium-exchanged Na Y zeolite during the ammonium-exchange
cycle.
An alkali metal zeolite which was exchanged by the reverse
procedure, that is, 8 ammonium exchanges followed by 16 cerium
exchanges, contained 87 percent more cerium (it analyzed 9.9% Ce,
1.3% Na and 0.26% N, and had a loss on ignition of 22.5
percent).
EXAMPLE VII
This example illustrates a preferred method of "activation" of
hydrous crystalline alumino-silicate zeolites prior to their use as
catalysts in our paraffin-olefin alkylation process. In general,
hydrous crystalline zeolites are activated by controlled heating
under vacuum or in a stream of a gas, such as air, hydrogen,
nitrogen, helium or oxygen, to remove water. In the case of
ammonium-exchanged zeolites, not only is loosely bound water
removed but also the ammonium ion is decomposed to obtain a
substantially anhydrous, "decationized" or "protonated" zeolite.
Such zeolites are highly acidic and are similar catalytically to
those prepared by direct exchange with an aqueous acid.
When the hydrous ammonium zeolite also contains polyvalent metal
ions, the resulting activated zeolite will be partially protonated
or "cation deficient." Such zeolites are not only highly acidic,
but are more resistant to the detrimental effects of the activation
procedure.
The heating rate and temperatures of such "activation" will depend
to a great extent on the type of zeolite, that is, an Al/Si atomic
ration, and the type and percent of polyvalent cations and
monovalent ions such as hydrogen or ammonium ion. In any event the
hydrated zeolite is first heated at a temperature sufficiently high
to remove the bulk of the "uncombined" or "uncomplexed" water from
the pores of the zeolite. At atmospheric pressures this temperature
is preferably from 125.degree.-300.degree.C., most preferably from
125.degree.-240.degree.C.
In the case of an ammonium-exchanged zeolite the temperature is
then raised to a higher temperature than that used for such water
removal and such temperature is maintained for a sufficient time to
remove a substantial amount of the ammonium ion from the zeolite as
NH.sub.3. This removal may also involve decomposition of the
ammonium ion by such reactions as oxidation of ammonia to nitrogen
oxides or nitrogen and water.
At atmospheric pressure, with ammonium-exchanged zeolites which
also contain appreciable quanitites of exchanged polyvalent metal
cations, this higher temperature is preferably 320
-500.degree.C.
With ammonium-exchanged zeolites which contain no polyvalent metal
cations or have a low content of polyvalent cations, it is
important that the activation temperature be kept below about
400.degree.C., since at higher temperatures the intensity of the
X-ray diffraction peaks of the zeolite decreases greatly (due to a
degradation of crystalline structure) and the resulting catalyst is
less active for paraffin-olefin alkylation. In U.S. Pat. No.
3,130,007 a similar intensity measurement is used to determine the
"percent zeolite," and appears to relate to crystallinity of the
zeolite.
We have also found that, if an ammonium-exchanged crystalline
alkali metal zeolite is further exchanged with polyvalent metal
cations, the resulting polyvalent metal NH.sub.4.sup.+ -exchanged
zeolite retains a much greater proportion of its X-ray peak
intensity after activation than does the base NH.sub.4.sup.+
-exchanged zeolite. Although small quantities of polyvalent cations
will be of some benefit in this respect, for our catalysts it is
preferable that the zeolite contain at least the following quantity
of polyvalent metal cations (or a combination thereof of equivalent
valence):
1. at least one tetravalent metal, metal oxide or metal hydroxide
for every 16 atoms of aluminum in the alumino-silicate tetrahedra
of the zeolite, or
2. at least one trivalent metal, metal oxide or metal hydroxide for
every 12 atoms of aluminum in the alumino-silicate tetrahedra,
or
3. at least one divalent metal, metal oxide or metal hydroxide for
every 8 atoms of aluminum in the alumino-silicate tetrahedra.
In addition, for optimum activity, the polyvalent cation should be
selected from classes 1, 2 and 3 above (and mixtures thereof) when
the atomic ratio Al/Si of the alumino-silicate tetrahedra
comprising the zeolite is greater than 0.65, or from classes 2 and
3 above (and mixtures thereof) when the atomic ratio Al/Si is from
0.65 to 0.35, or from class 3 above when the atomic ration Al/Si is
less than 0.35. For example, the cation of our zeolite catalyst is
preferably selected from the following:
1. at least one cation selected from the class consisting of
V.sup..sup.+4, Mo.sup..sup.+4, W.sup..sup.+4, Pa.sup..sup.+4,
U.sup.115 4, VOH.sup..sup.+4, Cr(OH).sub.2.sup..sup.+4,
CrO.sup..sup.+4, MnO.sup..sup.+4, Mn(OH).sup..sup.+4,
NbOH.sup..sup.+4, MoOH.sup..sup.+4, Mo(OH).sub.2.sup..sup.+4,
MoO.sup..sup.+4, RuO.sub.2.sup..sup.+4, Ru(OH).sub.4.sup..sup.+4,
RuO.sup..sup.+4, Ru(OH).sub.2.sup..sup.+4, SbOH.sup..sup.+4,
OW.sup..sup.+4, W(OH).sub.2.sup..sup.+4, WOH.sup..sup.+4,
Re(OH).sub.3.sup..sup.+4, Re(OH).sub.2.sup..sup.+4,
ReO.sup..sup.+4, Os(OH).sub.4.sup..sup.+4, OsO.sub.2.sup..sup.+4,
OOs.sup. .sup.+4, Os(OH).sub.2.sup..sup.+4, IrO.sup..sup.+4,
Ir(OH).sub.2.sup..sup.+4, BiOH.sup..sup.+4, BiOH.sup..sup.+4,
PaOH.sup..sup.+4, UO.sup..sup.+4, U(OH).sub.2.sup..sup.+4, and
UOH.sup..sup.+4, when Al/Si is from 1.0 to 0.65,
2. at least one cation selected from the group consisting of
Al.sup..sup.+3, Ni.sup..sup.+3, TiOH.sup..sup.+3, V.sup..sup.+3,
VOH.sup..sup.+3, VO.sup..sup.+3, V(OH).sub.2.sup..sup.+3,
Cr(OH).sub.3.sup..sup.+3, Mn(OH).sub.4.sup..sup.+3,
MnO.sub.2.sup..sup.+3, Mn(OH).sub.3.sup..sup.+3,
Mn(OH).sup..sup.+3, Mn.sup..sup.+3, GeOH.sup..sup.+3,
ZrOH.sup..sup.+3, Nb(OH).sub.2.sup..sup.+3, NbO.sup..sup.+3,
Mo(OH).sub.3.sup..sup.+3, Mo(OH).sub.2.sup..sup.+3, MoO
.sup..sup.+3, MoOH.sup..sup.+3, Mo.sup..sup.+3, Ru.sup..sup.+3 ,
RuOH.sup..sup.+3, Ru(OH).sub.3.sup..sup.+3,
Ru(OH).sub.5.sup..sup.+3, Rh.sup..sup.+3, RhOH.sup..sup.+3,
PdOH.sup..sup.+3, SnOH.sup..sup.+3, Sb.sup..sup.+3,
Sb(OH).sub.2.sup..sup.+3, SbO.sup..sup.+3, La.sup..sup.+3,
HfOH.sup..sup.+3, Ta(OH).sub.2.sup..sup.+3, TaO.sup..sup.+3,
W(OH).sub.3, WO.sup..sup.+3, W(OH).sub.2.sup..sup.+3,
WOH.sup..sup.+3 W.sup..sup.+3, Re(OH).sub.4.sup. .sup.+3,
ReO.sub.2.sup..sup.+3, Re(OH).sub.3.sup..sup.+3 ReOH.sup..sup.+3,
Os.sup..sup.+3, OsOH.sup..sup.+3, Os(OH).sub.3.sup..sup.+3,
Os(OH).sub.5.sup..sup.+3, Ir.sup..sup.+3, IrOH.sup..sup.+3,
Ir(OH).sub.3.sup..sup.+3, PtOH.sup..sup.+3, PbOH.sup..sup.+3,
Bi.sup..sup.+3, Bi(OH).sub.2.sup..sup.+3, Bio.sup..sup.+3,
PoOH.sup..sup.+3, Ce.sup..sup.+3, CeOH.sup..sup.+3, Pr.sup..sup.+3,
PrOH.sup..sup.+3, Sm.sup..sup.+3, Gd.sup..sup.+3, Tb.sup..sup.+3,
TbOH.sup..sup.+3, Dy.sup..sup.+3, ThOH.sup..sup.+3,
PaO.sup..sup.+3, Pa(OH).sub.2.sup..sup.+3, PaOH.sup..sup.+3,
U(OH).sub.3.sup..sup.+3, U(OH).sub.2.sup..sup.+3 UO.sup..sup.+3,
UOH.sup..sup.+3, U.sup..sup.+3, when Al/Si is from 0.65 to 0.35,
and
3. at least cation selected from the class consisting of
Mg.sup..sup.+2, Ca.sup..sup.+2, Ba.sup..sup.+2, Sr.sup..sup.+2,
ScOH.sup..sup.+2, TiO.sup..sup.+2, Ti(OH).sub.2.sup..sup.+2,
TiOH.sup..sup.+2, V(OH).sub.3.sup..sup.+2, V(OH).sub.2.sup..sup.+2,
VO.sup..sup.+2 VOH.sup..sup.+2, V.sup..sup.+2,
Cr(OH).sub.4.sup..sup.+2, CrO.sub.2.sup..sup.+2, CrOH.sup..sup.+2,
Cr.sup..sup.+2, Mn(OH).sub.5.sup..sup.+2, Mn(OH).sub.4.sup..sup.+2,
MnO.sub.2.sup..sup.+2, Mn(OH).sub.2.sup..sup.+2, MnO.sup..sup.+2,
Mn.sup..sup.+2, MnOH.sup..sup.+2, Fe.sup..sup.+2, FeOH
.sup..sup.+2, Co.sup..sup.+2, CoOH.sup..sup.+2, Ni.sup..sup.+2,
NiOH.sup..sup.+2, GaOH.sup..sup.+2, Ge(OH).sub.2.sup..sup.+2,
GeO.sup..sup.+2, YOH.sup..sup.+2, Zr(OH).sub.2.sup..sup.+2,
ZrO.sup..sup.+2, Nb(OH).sub.3.sup..sup.+2, NbOH.sup..sup.+2,
Mo(OH).sub.4.sup..sup.+2, MoO.sub.2.sup..sup.+2,
Mo(OH).sub.3.sup..sup.+2, Mo(OH).sub.2.sup..sup.+2,
MoO.sup..sup.+2, MoOH.sup..sup.+2, Mo.sup..sup.+2, Ru.sup..sup.+2,
RuOH.sup..sup.+2, Ru(OH).sub.2.sup..sup.+2, RuO.sup..sup.+2,
Ru(OH).sub.4.sup..sup.+2, Ru(OH).sub.6.sup..sup.+2,
RuO.sub.3.sup..sup.+2, Rh.sup..sup.+2, RhOH.sup..sup.+2,
Rh(OH).sub.2.sup..sup.+2, RhO.sup..sup.+2, Pd.sup..sup.+2,
Pd(OH).sub.2.sup..sup.+2, InOH.sup..sup.+2, RuO.sub.2.sup..sup.+2,
Sn(OH).sub.2.sup..sup.+2, SnO.sup..sup.+2, Sn.sup..sup.+2,
SbOH.sup..sup.+2, Sb(OH).sub.3.sup..sup.+2, LaOH.sup..sup.+2,
Hf(OH).sub.2.sup..sup.+2, HfO.sup..sup.+2,
Ta(OH).sub.3.sup..sup.+2, W(OH).sub.4.sup..sup.+2,
WO.sub.2.sup..sup.+2,W(HO).sub.3.sup..sup.+2,
W(OH).sub.2.sup..sup.+2, WO.sup..sup.+2, WOH.sup..sup.+2,
W.sup..sup.+2, Re(OH).sub.5.sup..sup.+2, Re(OH).sub.4.sup..sup.+2,
ReO.sub.2.sup..sup.+2, Re(OH).sub.2.sup..sup.+2, ReO.sup..sup.+2,
Re.sup..sup.+2, Os.sup..sup.+2, OsOH.sup..sup.+2
Os(OH).sub.2.sup..sup.+2, OsO.sup..sup.+2,
Os(OH).sub.4.sup..sup.+2, OsO.sub.2.sup..sup.+2,
Os(OH).sub.6.sup..sup.+2, OsO.sub.3.sup..sup.+2, Ir.sup..sup.+2,
IrOH.sup..sup.+2, Ir(OH).sub.2.sup..sup.+2, IrO.sup..sup.+2,
Ir(OH).sub.4.sup..sup.+2, IrO.sub.2.sup..sup.+2, Pt.sup..sup.+2,
Pt(OH).sub.2.sup..sup.+2, PtO.sup..sup.+2, AuOH.sup..sup.+2,
TlOH.sup..sup.+2, Pb(OH).sub.2.sup..sup.+2, PbO.sup..sup.+2,
Pb.sup..sup.+2 BiOH.sup..sup.+2, Bi(OH).sub.3.sup..sup.+2
Po(OH).sub.2.sup..sup.+2, PoO.sup..sup.+2, Po.sup..sup.+2,
AcOH.sup..sup.+2, CeOH.sup..sup.+2, Ce(OH).sub.2.sup..sup.+2,
CeO.sup..sup.+2, PrOH.sup..sup.+2, Pr(OH).sub.2.sup..sup.+2,
PrO.sup..sup.+2, NdOH.sup..sup.+2, Eu.sup..sup.+2,
PmOH.sup..sup.+2, SmOH.sup..sup.+2, Sm.sup..sup.+2,
EuOH.sup..sup.+2, Gd.sup..sup.+2, GdOH.sup..sup.+2,
TbOH.sup..sup.+2 Tb(OH).sub.2.sup..sup.+2, Dy.sup..sup.+2,
DyOH.sup..sup.+2, HoOH.sup..sup.+2, EROH.sup..sup.+2,
TmOH.sup..sup.+2, Tm.sup..sup.+2, YbOH.sup..sup.+2, Yb.sup..sup.+2,
LuOH.sup..sup.+2, Th(OH).sub.2.sup..sup.+2, ThO.sup..sup.+2,
Pa(OH).sub.3.sup..sup.+2, Pa(OH).sub.2.sup..sup.+2,
PaO.sup..sup.+2, U(OH).sub.4.sup..sup.+2, UO.sub.2.sup..sup.+2,
U(OH).sub.3.sup..sup.+ 2, UO.sup..sup.+2, U(OH).sub.2.sup..sup.+2,
UOH.sup..sup.+2, when Al/Si is less than 0.35.
Thomsonite, levynite, and the Type X zeolite of U.S. Pat. No.
2,822,244 are crystalline zeolites having an Al/Si atomic ratio
greater than 0.65. Analcite, chabazite, phillipsite, and the Type Y
zeolite of U.S. Pat. No. 3,130,007 have Al/Si ratios between 0.65
and 0.35. Heulandite and the Type L zeolite of U.S. Pat. No.
3,013,984 have Al/Si ratios less than 0.35. Mordenite has an Al/Si
ratio in the range of 0.2 and some mordenites have been reported to
have an Al/Si ratio appreciably less than 0.2 (e.g., 0.13). Such
low Al content mordenites, when exchanged and activated by the
procedures taught herein, have some catalytic activity in our
process but are not among our preferred catalysts.
As catalysts in our process we further prefer substantially
anhydrous protonated alumino-silicates which are capable of
adsorbing benzene, wherein the ratio Al/Si in the tetrahedra is
from 0.65 to 0.35 and which contain at least one rare earth metal
cation for every 9 aluminum atoms in the tetrahedra since such
catalysts have high alkylation activity and retain a high degree of
X-ray peak intensity on activation or regeneration.
For example, in illustration of our preferred method of activation
of a preferred species of hydrous zeolite, the 16-cycle
Ce.sup..sup.+3 -exchanged/16-cycle NH.sub.4 -exchanged zeolite of
Example IV was heated at 230.degree.C. in a rotating kiln in a
stream of flowing air for about one hour to remove water. No loss
of ammonium ions was detected during this heating period. The
temperature of the kiln was then raised at the rate of about
10.degree.C. per minute to a temperature of 400.degree.C. During
this heating, ammonia could be detected, by MnSo.sub.4 -AgNO.sub.3
reagent, in the exhaust gases from the kiln. The kiln was
maintained at 400.degree.C. for 2 hours, at which point no ammonia
could be detected in the exhaust gases. The heat was then removed
from the kiln and the kiln was cooled rapidly in a flowing stream
of dry air. The activated catalyst was maintained overnight in a
slowly flowing stream of dry air. The resulting, substantially
anhydrous, protonated crystalline alumino-silicate had a loss on
ignition of 3.7 percent.
Summation of the intensity of the significant X-ray diffraction
peaks of the hydrous zeolite before activation and of an activated
sample showed no decrease in intensity for the activated zeolite.
In contrast, a similarly activated portion of the base 16-cycle
ammonium-exchanged zeolite showed an intensity decrease of 64
percent.
To illustrate the stabilizing effect of even small quantities of
polyvalent metal ions, a sample of the base 16-cycle
ammonium-exchanged zeolite was submitted to a 16-cycle
Ce.sup..sup.+3 exchange using one-tenth the usual cerium salt
concentration to produce a dried, washed zeolite which analyzed
1.23% Ce (ignited basis). After activation according to the above
procedure, the activated zeolite showed an intensity decrease of
47.4 percent.
The bulk density in g/ml of the "dry" (at 125.degree.C.) hydrated
zeolite is about 0.71 for sodium Y zeolite, 0.78 for highly
ammonium-exchanged sodium Y zeolite (NH.sub.4 Y), 0.90 for highly
cerium-exchanged NH.sub.4 Y (CeNH.sub.4 Y) and 0.89 for highly Gd
exchanged NH.sub.4 Y (GdNH.sub.4 Y). If one assumes no significant
volume change in activation, the calculated bulk density of the
corresponding activated or substantially anhydrous zeolite would be
in the range of 0.6 g/ml for the NaY and 0.75 g/ml for the
CeHY.
Quantitative studies of the activation of "equilibrated" highly
ammonium-exchanged sodium Y zeolite (hereinafter, sometimes
NH.sub.4 Y) and cerium exchanged, NH.sub.4 Y (hereinafter,
sometimes CeNH.sub.4 Y) have shown that, in our preferred
catalysts, even after our optimum activation, water can be evolved
from the catalyst upon ignition at 1,800.degree.F. This water is
called hereinafter sometimes, "bound," or "combined" or "complexed"
water to distinguish it from that water which is readily evolved
from the exchanged zeolite below 300.degree.C. Equilibrated zeolite
is a zeolite which has been exposed to air of about 50 percent
relative humidity, at about 68.degree.C. for about 12 hours.
We have further established that our preferred substantially
anhydrous, acidic crystalline zeolite catalyst, containing
polyvalent metal ions and, more preferably, having some degree of
protonation sometimes termed "cation deficiency", will evolve
substantially no bound water when heated for about 1 hour at
300.degree.C. but when ignited at 1800.degree.F. will evolve about
1/4 to 2 mole of water for each atom of exchanged polyvalent metal.
In particular, in our novel, activiated, cerium-containing
catalysts, for each atom of cerium in the catalyst, 0.8 to 1.2
molecules of water will be evolved upon ignition at 1,800.degree.
F.
We have concluded that in the catlyst this water is present, in the
form Ce(OH).sup.2.sup.+. To understand the basis for this finding,
one must first consider the behavior on activation of the hydrated
NaY and NH.sub.4 Y zeolites. Behavior of NH.sub.4 Y catalyst during
activation at temperatures from 150.degree.to 1292.degree.F.
(65.degree. to 700.degree.C.) and for times up to 4 hours, as is
summarized in Table 1. Two series of experiments were performed.
Experiment A being at different times at constant temperature and
Experiment B being at different temperatures at constant time.
Total water (that is, sorbed and combined) appeared to be retained
by this catalyst more firmly than ammonia.
Table 1 shows that about two-thirds of the total water present on
"dried " NH.sub.4 Y zeolite had been removed after 1 hour at
450.degree.F. This water removal is an endothermic reaction and
probably represents "loosely" held water that is in molecular form
when sorbed. Data from DTA-EGA measurements agree with this
observation.
Water removable only at 750.degree.F. and higher temperatures is
more firmly bound and is chemically combined in a form other than
molecular H.sub.2 O. Ammonia, which is largely in the form of
NH.sub.4.sup.+ ions, was removed more readily than the water which
remains after 1 hour at 450.degree.F. Furthermore, ammonia removal
releases protons (NH.sub.4.sup.+ .fwdarw. NH.sub.3 + H.sup.+ ).
When an activated NH.sub.4 Y zeolite is ignited at 1800.degree.F.,
OH groups are destroyed and H.sub.2 O is evolved in an amount
equivalent to one molecule of H.sub.2 O for every two OH
groups.
Uytterhoeven, Christner and Hall, J. PHYS. CHEM. 69, 2117-26
(1965), have proposed the following stoichiometry to account for
protonation and dehydroxylation: ##SPC1##
In an analogous manner, residual NH.sub.4.sup.+ ions can be
expected to undergo similar changes when an activated zeolite is
ignited at 1800.degree.F. Therefore, whether NH.sub.4.sup.+ groups
are intact or have been deaminated, one H.sub.2 O should be
detected upon ignition of activated catalyst for every two
NH.sub.4.sup.+ ions originally in the zeolite.
Comparing H.sub.2 O contents of activated NH.sub.4.sup.+ zeolite
with half the lattice NH.sub.4.sup.+.sup.+ -- on the basis of
Uytterhoeven's stoichiometry -- reveals the following differences
between calculated and measured H.sub.2 O: Experiment A -
activation for zero time at each temperature
______________________________________ H.sub.2 O Difference
(g.mole) Temp.,.degree.F. (Experimental-Calculated)
______________________________________ 572 0.107 752 0.071 932
0.046 1112 0.056 Experiment B - activation at 750.degree.F. H.sub.2
O Difference (g.mole) Time, min. (Experimental-Calculated) 0 0.022
60 -0.038 120 0.052 180 0.047 240 0.042
______________________________________
It is interesting to note that in most instances the excess H.sub.2
O in the preceding table is about numerically equivalent to the
residual sodium value of about 0.044 g. ion -- all on the basis of
100 g. anhydrous base. Carter, Lucchesi and Yates, J. PHYS. CHEM.,
68, 1385-1391 (1964), described IR bands on NaX zeolite at 3400 and
1655 cm.sup..sup.-1 which presisted up to 450.degree.C.
(842.degree.F.) and which they concluded were "due to residual
hydrogenbonded `polymeric` water." It is probable that the H.sub.2
O measured over and above that produced from intact and deaminated
NH.sub.4.sup.+ sites is this hydrogen-bonded water structurally
related to residual Na.sup.+ species in the lattice.
In fact, the NaY zeolite itself may contain more than one kind of
H.sub.2 O. For example, if it is assumed that the 0.414 g. ion
Na.sup.+ had one mole H.sub.2 O associated - and that this
represents strongly bound H.sub.2 O - then the H.sub.2 O equivalent
is 7.46 wt. % H.sub.2 O. This firmly bound H.sub.2 O would
represent 31 percent of the total 24.32 wt. % H.sub.2 O found
(Table 1). With NH.sub.4 Y, about 33 percent of the H.sub.2 O was
firmly bound enough to remain after one hour at 450.degree.F.
Activation studies of two ammonium-, cerium-exchanged catalysts
were made in a manner similar to those for NH.sub.4 Y.
Cerous nitrate exchange of NH.sub.4 Y catalysts replaced most of
the NH.sub.4 .sup.+ ions with cermium but removed only 20-25% of
the small residual sodium (Table 2). The Ce.sup.3.sup.+ -exchanged
product, therefore, contained residues of NH.sub.4 .sup.+ and
Na.sup.+. In contrast to NH.sub.4 Y catalyst, the subsequently
Ce.sup.3.sup.+ -exchanged material was able to lose NH.sub.4 .sup.+
during activation down to a level of 0.01 mole/100 g. or less at
750.degree.F. The NH.sub.4 Y had required temperatures above
750.degree.F. to accomplish this degree of removal.
The sum of chemical equivalents for Na.sup.+, NH.sub.4 .sup.+ and
Ce.sup.3.sup.+ after exchange was always noticeably less than the
0.414 g. ion Na.sup.+/100 g. anhydrous base found with the original
NaY zeolite. One explanation for this cation deficiency of the
exchanged catalyst is that some protons are structurally
incorporated during exchange but not directly measured by analysis.
Chemically this incorporation is possible because the pH of the
cerous nitrate solution was about 4.5, and favored cerous salt
hydrolysis.
An increase in SiOH groups and a growing cation deficiency was
observed as the catalyst became progressively deaminated during
activation. However, the SiOH groups and intact NH.sub.4 .sup.+
ions were not enough to account for all of the H.sub.2 O measured
by ignition loss at 1800.degree.F. Total H.sub.2 O measured was
0.16 to 0.10 mole/100 g. anhydrous base, but SiOH and NH.sub.4
.sup.+ could not have produced more than 0.05 mole H.sub.2 O on
ignition.
The NH.sub.4 Y study showed that residual sodium ions were
complexed at a H.sub.2 O/Na.sup.+ ratio of about 1. Continuation of
this behavior in the Ce.sup.3.sup.+ -exchanged catalyst could at
most produce 0.04 mole H.sub.2 O on ignition. Therefore, the water
not derivable from SiOH, NH.sub.4 .sup.+ and Na.sup.+ amounted to
nearly half the measured H.sub.2 O. Another source was obviously
contributing to the total.
Calculation of (H.sub.2 O)/Ce.sup.3.sup.+ ratios, are shown for two
750.degree.F. activations in Table 3. Calculation of H.sub.2 O
measured at 1800.degree.F. does not imply the existence of
associated molecular water but is equally capable of interpretation
as ce(OH).sup.2.sup.+ species according to the equation:
##SPC2##
This correspondence of measured water to the amount needed for
Ce(OH).sup.2.sup.+ formation indicates that substantially all of
the cerium in Type Y zeolite activated at 750.degree.F.
(400.degree.C.) is in this form or in an equivalent combination of
such forms as Ce.sup..sup.+3, Ce(OH).sup.2.sup.+, Ce(OH).sub.2
.sup.+ , Ce.sup..sup.+4 and Ce(OH).sup..sup.+3.
A 750.degree.F. activation with a sample of the same hydrated
CeNH.sub.4 Y zeolite in another experiment revealed in H.sub.2
O/Ce.sup.3.sup.+ ratio of 1.041 (Table 4). Continuing this
experiment at a series of temperatures up to 1292.degree.F.
(700.degree.C.) showed a steady decline of the ratio to 0.370 with
increasing temperature. Heating for up to 4 hr. at 750.degree.F.
did not lower the H.sub.2 O/Ce.sup.3.sup.+ (or Ce(OH).sup.2.sup.+
/total Ce.sup.3.sup.+) ratio effectively below 1. NH.sub.4 .sup.+
removal occurred during this time, and, thus SiOH increased
accordingly - as evidenced by the growing cation deficiency.
Ce(OH).sup.2.sup.+, however, was far more stable, and that behavior
in itself is more indicative of Ce(OH).sup.2.sup.+ than of
Ce(H.sub.2 O).sup.3.sup.+. Only by increasing temperature above
750.degree.F. could the fraction of total Ce.sup.3.sup.+ in the
Ce(OH).sup.2.sup.+ state be reduced.
Isoparaffin-olefin alkylations with NH.sub.4 .sup.+ -,
Ce.sup.3.sup.+ - exchanged Type Y gave maximum alkylate yields and
selectivity when the catalyst had been activated at about
750.degree. F. rather than at lower or higher temperatures,
Possibly, maximal Ce(OH).sup.2.sup.+ establishes the sites needed
for isoparaffin-olefin alkylation. Also, Ce.sup.3.sup.+ -exchanged
Type Y catalysts have been far more stable toward temperatures
above 400.degree.C. than NH.sub.4 Y, as measured by X-ray
diffraction. When Ce(OH).sup.2.sup.+ sites become dehydroxylated,
Ce.sup.3.sup.+ ##SPC3##
When we state that Ce(OH).sup.2.sup.+ sites are preferred for
alkylation, we do not means that these sites per se are the sole
locus of activity. Rather, these sites form an essential part of a
newtowrk or complex of sites, including ##SPC4##
species. Very possibly the entire complex is required to achieve
the carbonium ion-olefin combinations accompanied by good hydride
transfer which are vital for a highly paraffinic alkylate.
Structural considerations further suggest that only a portion of
these complexes may be effective for alkylation, even though enough
H.sub.2 O for total Ce(OH).sup.2.sup.+ formation is a necessary
ingredient of catalyst composition.
As is shown hereinafter, catalytic activity for paraffin-olefin
alkylation is related to cerium content. ESR total spin counts of
these catalysts with aromatics (such as benzene, perylene,
anthracene, etc.) sorbed on them revealed a dependence of electron
withdrawl ability upon cerium content. Calculations reveal about 5
percent of the cerium ions to be on the external catalyst surface
and the data indicated a 1:1 numerical correspondence between these
ceriums and the total spin count.
As is illustrated hereinafter in Example XXIII, there is a nearly
linear relation between the total ESR spin count of adsorbed
aromatics on our cerium catalyst (when activated at temperatures
below about 450.degree.C.) and the alkylate yield under a given set
of reaction conditions. In general the more preferred
cerium-containing catalysts have total ESR spin counts above 3
.times. 10.sup.19 /g. with anthracene. Thus, there is a correlation
between alkylation yield - with its essential dependence upon
hydride transfer - and the electron withdrawal from anthrancene by
our catalyst.
EXAMPLE VIII
This example illustrates the use of substantially anhydrous acidic
crystalline alumino-silicate zeolite as a paraffin-olefin
alkylation catalyst. The activated 16-cycle Ce.sup..sup.+3 /16
-cycle NH.sub.4 .sup.+ -exchanged zeolite of Example VII was
charged in amount of 23.3 g. into a 1-liter, stirred autoclave
containing a four-member baffle to diminish vortex formation. Then
444 milliliters of liquid isobutane was added. The stirring rate
(of a six-member, flat-blade turbine) was adjusted such that
substantially all of the zeolite was suspended in the liquid
isobutane (about 550 rpm). The temperature in the reactor was
raised to 80.degree.C. using sufficient nitrogen to produce a total
pressure of 250 p.s.i.g. Under these conditions nearly all of the
hydrocarbon is in the liquid phase. Then a liquid mixture of one
part by volume of butene-2 and five volumes of isobutane was
charged from a Jerguson gauge via a needle valve and dip tube into
the isobutane-catalyst slurry (and near the bottom of the reactor)
at the rate of one milliliter of mixture per minute for a period of
220 minutes. Nearly all of the hydrocarbon was maintained in liquid
phase. At the end of this time the reaction was stopped by cooling
the reactor to 17.degree.C., then separating the reaction mixture
from the catalyst by first removing the normally gaseous
hydrocarbons at room temperature and atmospheric pressure, and then
separating the liquid product from the catalyst by filtration. The
used catalyst analyzed 0.9% coke (non-volatile residue). Some
propane and n-butane but no methane, ethane, ethylene or propylene
were found in the normally gaseous hydrocarbons. The C.sub.5 .sup.+
paraffin yield of the reaction mixture, based on the weight of
olefin charged, was 71.4% and the C.sub.5 .sup.+ unsaturate yield
was 0.24 percent on the same basis. Hereinafter all yield data are
reported as based on the weight of olefin charged.
EXAMPLE IX
when the reaction of Example VIII was repeated except that the
temperature was 120.degree.C. and the pressure 475 p.s.i.g., the
C.sub.5 .sup.+ paraffin yield was 129.4% and the unsaturated
C.sub.5 .sup.+ hydrocarbon yield was 4.3%.
Table 5 further characterizes the C.sub.5 .sup.+ product obtained
in the reactions of Examples VIII and IX.
EXAMPLE X
This example illustrates the unexpectedly large increase in degree
of conversion of olefin reactant to saturated C.sub.5 .sup.+
hydrocarbon product when a small amount of a halide adjuvant is
present in the reaction mixture. The reaction of Example VIII was
repeated at 60.degree.C. except that the catalyst used was the
32/16 zeolite of Example IV which had been prepared by 32 NH.sub.4
.sup.+ -exchange cycles followed by 16 Ce.sup..sup.+3 -exchange
cycles. The catalyst was activated by the procedure of Example VII.
Without halide addition at 60.degree.C., the yield of C.sub.5
.sup.+ paraffins was 90 percent and the yield of C.sub.5 .sup.+
unsaturates was 11.5 percent. On a mole basis this amounted to 0.44
mole of C.sub.5 .sup.+ paraffins per mole of C.sub.4 olefin
charged. In contrast, when 2.4 .times. 10.sup..sup.-3 mole of
tertiary butyl chloride (hereinafter, sometimes, TBC) was added to
the reactor for each mole of initial isobutane, the yield of
C.sub.5 .sup.+ paraffins was 120 percent and C.sub.5 .sup.+
unsaturates 6 percent. The TMP/DMH.sub.x ratio was 6.6. The used
catalyst had no measurable coke content.
EXAMPLE XI
With the same proportion of t-butyl chloride the reaction of
Example X was repeated at 40.degree.C. (125 p.s.i.g.) and at
25.degree.C. (125 p.s.i.g.). At 25.degree.C. only 12 percent of
C.sub.5 .sup.+ paraffins was produced, and 0.49 percent of C.sub.5
.sup.+ unsaturates. At 40.degree.C. 120 percent of C.sub.5 .sup.+
paraffins was produced and 6.5 percent of C.sub.5 .sup.+
unsaturates. The TMP/DMH.sub.x ratio was 4.10 at 25.degree.C. and
7.86 at 40.degree.C.
EXAMPLE XII
When Example X was repeated at 120.degree.C. (484 p.s.i.g.) without
halide addition, 75 percent of C.sub.5 .sup.+ paraffins and 1.1
percent of C.sub.5 .sup.+ unsaturates were produced. The
TMP/DMH.sub.x ratio was 3.16.
Of commercial importance is the finding that, by practice of our
invention, we cannot only obtain good yields of alkylate which has
a high TMP/DMH.sub.x ratio and is high in trimethylpentanes but
that in these trimethylpentanes there is a low proportion of the
less desirable 2,2,4-trimethylpentane (regarding this
undesirability, see U.S. Pat. No. 2,646,453). Table 6 compares the
percent of the total trimethylpentanes which is
2,2,4-trimethylpentane (percent 2,2,4 in TMP) in the products of
Examples X, XI and XII with similar distributions reported by
Cupit, C.R. (Ibid. p. 211) for H.sub.2 SO.sub.4 alkylation and
Kennedy, R.M. (Ibid. p. 30) for HF or AlCl.sub.3 alkylation of
isobutane with butene-2. For the compositions of the products
obtained with other olefins (e.g., propylene, cyclohexane) and
H.sub.2 SO.sub.4 catalyst see J. E. Hofmann, J. ORG. CHEM., 29
(Part II), 1497-1499 (1964).
As is further illustrated herein, our process can be used to
directly product novel paraffin-olefin alkylates, useful in
gasoline blending, comprising at least 60 mole percent C.sub.8
paraffins and less thann one weight percent unsaturates and wherein
the C.sub.8 paraffins consist of from 5-20 mole percent
dimethylhexanes, from 0-1.5 mole percent methylheptanes, from 80-95
mole percent trimethylpentanes, and wherein less than 30 mole
percent of the trimethylpentanes is 2,2,4-trimethylpentane. Such
novel alkylates can also be produced using hydrogenation and/or
adsorbents to reduce the unsaturates in such products of our
process as that of Example X which is cited in Table 6.
In general, in the temperature range from about 25.degree.C. to
120.degree.C., the proportion of 2,2,4-TMP in the total TMP's
decreases (and usually the proportion of 2,3,3-TMP increases) as
the reaction temperature decreases.
Product distributions in the alkylates produced by our 32/16
catalyst (and in virtually all of the alkylates reported herein as
produced by our process) are far removed from calculated
equilibrium values. For example, the calculated equilibrium TMP
among C.sub.8 paraffins at about 60.degree.C. is only 12%l whereas,
in our process TMP usually constitute more than 80 percent of the
C.sub.8 paraffins. Among the TMP there is a similar departure from
calculated equilibrium, as shown by the following mole percent data
at 60.degree.C.:
Experimental Calculated TMP With TBC No TBC Equilibrium
______________________________________ 2,2,4- 14.8 40.4 65.4 2,2,3-
5.0 10.7 15.0 2,3,3- 44.3 27.3 8.3 2,3,4- 35.9 21.7 11.3
______________________________________
These departures from equilibrium suggest that either the published
free energies for the equilibrium calculation are seriously in
error or else that our alkylation reactions are kinetically
controlled under the conditions of our process.
Kinetic control of product distribution through specific reactions
is considered more likely for two reasons:
1. TBC promoter with solid catalyst had an evident influence upon
TMP distribution which is not characteristic of equilibrium
control.
2. Equilibrium calculations predict that the fraction of 2,2,4-TMP
decreases with rising temperature. With solid catalyst, it is
increased as temperature went up.
Alkylation with solid zeolite catalyst appears to be the result of
a sensitive balance among competing kinetic paths. Our halide
adjuvant, such as TBC, favorably alters one or more of those
paths.
Surveying temperatures with a 16/16 catalyst (under conditions as
in Examples VIII but with improved feed premixing) similarly points
out the alkylate yield gain to be realized by operating at an
intermediate temperature of about 80.degree.C. (Table 7). In a
continuous reactor residence time must be taken into account; the
same temperature with a given catalyst may not be preferred if
residence time is changed.
It is interesting to note that 60.degree.C. with the 16/16 catalyst
produced no more than half as much alkylate as 80.degree.C. with
this catalyst. The 32/16 catalyst was not so responsive to
temperature changes above 40.degree.C. Again, as temperature
decreased from 80.degree. to 60.degree.C., a shift toward a heavier
product occurred (C.sub.9 .sup.+), but the 2,2,4-TMP content was
desirably low. When this isomer decreased, the largest gain was in
2,3,3-TMP, as it has been with the 32/16 catalyst.
Temperature is a useful device in elucidating catalyst differences.
When the catalyst exchanged only with NH.sub.4 .sup.+ (32/0) was
tested at 120.degree.C. without TBC promoter, it was less active
than a 16/16 catalyst (Table 8). The C.sub.5 .sup.+ paraffin yields
were 109.5%, based on olefin charge, with 32/0 and 129.4 percent
with 16/16.
Evaluating an NH.sub.4 .sup.+-exchanged catalyst (16/0) with TBC
relative to 16/16 at 80.degree.C. revealed a more dramatic
difference in alkylate yield and product distribution.
The 16/0 catalyst produced too little C.sub.8 paraffin and too much
C.sub.9 .sup.+ and C.sub.5. These factors could also be used to
understand the importance of a polyvalent metal, such as cerium, on
the catalyst. But testing catalysts at milder conditions is even
more effective in uncovering differences between them, as shown by
the data from 32/0, 16/16, and 16/0. Therefore, low operating
tempertures can be used as a research tool in distinguishing among
alkylation catalysts that appear to be more similar at relatively
high temperatures.
EXAMPLE XIII
Table 5 reports the products obtained from similar runs at
8.degree.C. using the activated catalyst of Example VIII with
t-butyl, chloride, n-propyl chloride or n-butyl chloride as
adjuvants (at a level of 2.4 .times. 10.sup..sup.+3 mole of
adjuvant per mole of initial isobutane).
Table 9 reports the products obtained from similar runs (but with
more intimate premixing of the feed olefin and feed paraffin) using
CCl.sub.4, TBC and various other adjuvants and using either
continuous or "pulsed" addition of the adjuvant to the reaction
mixture. In this table, the amount of adjuvant is reported as
millimoles per mole of feed olefin charged (m.mole/m. OC).
In run 606 of Table 9, the catalyst was preconditioned by contact
with a solution of perylene in CCl.sub.4. The perylene was
quantitatively adsorbed by the catalyst along with some CCl.sub.4.
The catalyst developed a dark, intense, blue color upon contact
with the perylene solution. Removal of residual CCl.sub.4 by
vacuum-pumping at ambient temperature caused the catalyst color to
turn to black. This black catalyst was the catalyst used in run
606.
In run 600, the catalyst was preconditioned with carbon
tetrachloride as a control experiment for 606. The catalyst
developed an intense red color on contact with the CCl.sub.4. Upon
vacuum pumping, the red color disappeared. It is this "pumped"
catalyst which was used in run 600.
Potential catalyst adjuvants are those halides, both organic and
inorganic (e.g., AlBr.sub.3, BF.sub.3, HBCl.sub.2, AsCl.sub.3),
which are capable, under the reaction conditions, of sufficient
polarization to promote carbonium ion reactions or to have
carboniogenic properties. For precise control of the reaction
product distribution (or alkylate quality) and to prolong catalyst
life, we prefer to avoid adjuvants which contain atoms other than
hydrogen, carbon, bromine, fluorine and chlorine (although as seen
in run 632, oxyen, as in the form of alcoholic OH groups, can be
present in reaction mixture. Water, C.sub.1 to C.sub.10 saturated
alcohols (e.g., tertiary butyl alcohol, cyclohexanol) or mixtures
thereof can be used, per se, as adjuvants or in combination with
halides. To avoid accumulation of large organic molecules at the
catalyst surface, we prefer to avoid those organic halides wherein
the organic radical has a critical diameter greater than about 9A,
such as the chlorinated naphthenic waxes. Note, however, in Table
9, that perylene presorbed on the catalyst from CCl.sub.4 solution
did not act as a "poison" but allowed about 10 relative percent
more C.sub.5 .sup.+ paraffin yield than a control experiment with
carbon tetrachloride alone. This carbon tetrachloride control
experiment itself produced a better than 10 relative percent
increase in C.sub.5 .sup.+ paraffin yield over a similar experiment
with tertiary butyl chloride and without CCl.sub.4. In contrast,
NH.sub.3 presorbed on the catalyst acted as a poison, even when TBC
was added continuously to the reactor.
Our preferred halide adjuvants, when present in solution in the
reaction mixture at a level of from 1 .times. 10.sup..sup.-5 to 1
.times. 10.sup..sup.-1 mole per mole of C.sub.4 -C.sub.6
isoparaffin reactant, are HF, HC1, HBr and the saturated
halohydrocarbons containing at least one atom per molecule of
bromine, chlorine or fluorine. Mixtures of these substances can
also be used as adjuvants. Of these adjuvants we prefer carbon
tetrachloride and the aliphatic saturated monochlorides having no
more than six carbon atoms. When the isoparaffin reactant is
predominantly isobutane, we prefer to use, as halide adjuvants, the
aliphatic saturated monochlorides having 3 or 4 carbon atoms.
The adjuvant can also be added to the catalyst after the final
washing, in the exchange procedure but, more preferably, is added
to catalyst after activation, as by passing gaseous HC1 through the
catalyst at the final stage of activation (or while cooling
catalyst after activation). It can be important, especially in our
continuous process, to control the amount of adjuvant present in
the reactor vapor space since the vapor pressure of such adjuvant
affects the adjuvant concentration in the reaction mixture.
EXAMPLE XIV
This example illustrates, at a given feed rate, the influence of
"reaction time" or, more precisely, a combination of catalyst/feed
contact time and residence time (of the paraffin product) on the
yield of C.sub.5 .sup.+ saturates and C.sub.5 .sup.+ unsaturates.
This reaction time, which combines residence and contact time,
reflects both kinetic influence and the age of the
catalyst-reactant system.
The process of Example VIII was repeated at 80.degree.C., 250
p.s.i.g., using the activated catalyst of Example VIII, with 2.4
.times. 10.sup..sup.+3 mole of tertiary butyl chloride present in
the reactor initially per mole of initial isobutane (444 ml.). As
in Example VIII the rate of addition of the butene-2/isobutane feed
was 1 milliliter per minute. Four runs were made at various contact
times (60, 120, 220 and 280minutes). In each run contacting was
stopped by rapidly cooling the samples to 15-20.degree.C., then
slowly reducing the pressure to atmospheric and simultaneously
distilling off lighter gases. The remainder of the reaction
mixture, which was liquid at that temperature, was separated from
the solid catalyst by filtration.
FIG. 1 illustrates the variation in the yield of C.sub.5 .sup.+
paraffins based on the olefin reactant as the reaction time
increased.
FIG. 2 illustrates, by the solid curve, the weight percent of
C.sub.5 .sup.+ unsaturates produced, based on the olefin reactant,
as the reaction time increased. The broken curve, of FIG. 2, show
the weight percent of n-butane produced per mole of olefin
converted, as the reaction time increased.
From FIGS. 1 and 2, it can be seen that after 2 hours only
negligible amounts of C.sub.5 .sup.+ unsaturates were found in the
reaction mixture and the yield of C.sub.5 .sup.+ paraffins was 96
percent of the weight of olefin charged. Of the C.sub.5 .sup.+
paraffins, 60 mole percent was C.sub.8 and of the C.sub.8 paraffins
there was 0 mole percent methylheptanes. The ratio TMP/DMH.sub.x
was 7.18. Of the trimethylpentanes, 24.7 percent was 2,2,4-TMP. At
this point a total of 20 milliliters of butene-2 had been added to
the reactor along with an additional 100 milliliters of isobutane.
When added to the original 444 milliliters of isobutane this
amounted to a total of 544 milliliters of isobutane which had been
charged to the reactor at that time along with 20 milliliters of
butene-2 (density 0.60), which produced 11.5 grams of C.sub.5
.sup.+ paraffin.
After 220 minutes, 37 ml. of butene-2 had been charged to the
reactor along with 183 ml. of isobutane to give a total hydrocarbon
charge of 664 ml. The C.sub.5 .sup.+ paraffin yield was 142 percent
based on the weight of olefin charged (37 ml.) or a total C.sub.5
.sup.+ paraffin yield of 31.6 grams. Of the C.sub.5 .sup.+
paraffins, 60 mole percent was C.sub.8. Of the C.sub.8 paraffins, 1
mole percent was methylheptane. The ratio TMP/DMH.sub.x was 4.98.
Of the trimethylpentanes, 20.9 percent was 2,2,4-TMP.
After 280 minutes a total of 724 ml. of hydrocarbon had been
charged to the reactor of which 47 ml. was butene-2. The C.sub.5
.sup.+ paraffin yield was 110 percent of the weight of olefin
charged or 31.1 grams. The ratio TMP/DMH.sub.x was 5.44 and 21.0
percent of the trimethylpentanes was 2,2,4-TMP. At 220 minutes 0.84
grams of C.sub.5 .sup.+ unsaturates had been detected in the
reaction mixture or 3.75 percent based on the olefin charged. At
280 minutes 1.6 grams of C.sub.5 .sup.+ unsaturates were detected
in the reaction mixture, which amounted to 5.5 percent of C.sub.5
.sup.+ unsaturates based on the weight of olefin charged.
An inspection of FIGS. 1 and 2 shows that at point B of FIG. 1 and
point B' of FIG. 2, the net rate of production of unsaturated
hydrocarbon is about 2 weight percent C.sub.5 .sup.+
unsaturates/olefin charged/hour but the rate of production of
saturated hydrocarbon is about 100 weight percent C.sub.5 .sup.+
saturates/olefin charged/hour. At point C in FIG. 1 and C' in FIG.
2, the net weight rate of production of unsaturated hydrocarbon
becomes greater than the net weight rate of production of saturated
hydrocarbon per weight of olefin charge.
The broken line in FIG. 2 shows that there is a high initial
production of n-butane but that by point A" (corresponding in time
to point A' of the solid curve) the proportion of n-butane as a
function of time had become nearly constant. This behavior is
understandable if n-butane is formed as a result of olefin
protonation and subsequent hydride transfer (which is considered
necessary for initiating alkylation).
If one wishes to maximize the production of C.sub.5 .sup.+ paraffin
per olefin charged the reaction should be stopped at the point
corresponding to the letter A in FIG. 1, at which point the C.sub.5
.sup.+ product of the reaction will contain about 3.6 percent of
unsaturated hydrocarbons (see point A' of FIG. 2).
However, if one wishes to have a substantially olefin-free C.sub.5
.sup.+ product, the reaction would be stopped in the vicinity of
point B' in FIG. 2. In the latter case, the catalyst life can be
greatly prolonged in comparison with operation between points B and
A of FIG. 1 or B' and A' of FIG. 2.
Similar relations were observed at 60.degree.C. and 120.degree.C.
At 120.degree.C. (without halide addition) 28.7 grams of C.sub.5
.sup.+ paraffin were obtained after 220 minutes (129.4 weight
percent yield/olefin charged) while only 23.3 grams were obtained
after 384 minutes of reaction time (104.8% yield). When the weight
of catalyst used at 120.degree.C. (without adjuvant was doubled,
22.5 grams of C.sub.5 .sup.+ paraffin were obtained after 220
minutes (101.4% yield).
Catalyst life can be greatly prolonged at conversion ratios
approaching that at point B by constantly separating a
catalyst-free alkylate and a concomitant amount of unreacted feed
from the reaction zone while constantly adding an approximately
equal volume of fresh portions of the hydrocarbon reactants. This
constant separation and withdrawal of alkylate and unreacted feed
in conjunction with the addition of fresh reactants (including
recycle of unreacted feed) can be accomplished continuously by
adding a steady stream of reactants and withdrawing a steady stream
of the mixture, as by utilizing a continuous stirred reactor system
such that of FIGS. 3, 4 and 5.
Surprisingly, in view of U.S. Pat. No. 3,251,902, the degree of
conversion of butene-2 to paraffins is very high in our process.
For example, in the above runs, analysis of the reaction mixture
for unreacted butene-2 showed that in the 60-minute and 120-minute
runs the butene-2 conversion was 100%. In the 220-minute run 92.6
percent of the feed butene-2 was converted and 88.5% was converted
in the 280-minute run.
The most important consideration in continuous operation is to
coordinate the rate of olefin addition with the rates of feed
olefin consumption and removal in order that the amount of
unreacted olefin in the reaction mixture is maintained at less than
12 mole percent based on the unreacted C.sub.4 -C.sub.5
isoparaffin, and preferably less than about 7 percent. Also, the
preferred mean residence time of the hydrocarbons in the reaction
mixture, with the catalyst, is in the range of 0.05-0.5 hour per
gram of catalyst per gram of hydrocarbon in the reaction
mixture.
In this respect, the preferred procedure is to thoroughly premix
the feed olefin and feed paraffin. The uniformity and intimacy of
such premixing can greatly influence the character of the C.sub.5
.sup.+ product. In Table 10, for example, two runs are shown which
were identical except for the feed premixing technique. In one run
the feed was introduced through the bottom of the Jerguson gauge.
This increased the uniformity and intimacy of the premixing (by
reducing charge segregation or layering). The resulting C.sub.5
.sup.+ product contained only 0.26 percent unsaturates and was also
lower in C.sub.9 .sup.+ paraffins, higher in pentanes and had a
higher TMP/DMH.sub.x ratio than the product from the corresponding
run where the feed was introduced at the top of the mixing buret
(which, unless otherwise noted, was the technique used in all the
other examples reported herein). Note that the product from the run
with the feed introduced at the top of the mixing buret had a 685
percent greater concentration of unsaturates than the product from
the former run where the premixing was more uniform and more
complete. In these examples the runs utilizing the improved feed
premixing (from the bottom of the buret) are so noted or are
numbered in the range of 502-698 and 804-898.
For any given type of activated catalyst and feed hydrocarbon, the
rate of olefin consumption and, correspondingly, the rate of olefin
addition, will be a function of the reaction temperature, the mean
retention time of feed olefin in the reactor, the mixing rate, the
particle size and concentration of catalyst, and the rate of
product removal. One method of controlling such a "continuous"
process, under conditions of good feed olefin mixing, is to control
the rate of feed addition and the rate of reaction mixture
withdrawal such that the C.sub.5 .sup.+ component of the reaction
mixture contains substantially no C.sub.5 .sup.+ unsaturates and,
preferably, such that there is little unreacted feed olefin in the
withdrawn portion.
Another important variable to be considered in our process is the
proportion of the reactants (particularly of the feed olefin) which
can be present in the vapor space of the reactor. The proportion of
olefin in the vapor space is a function of the vapor pressure of
the olefin at the reaction temperature and of the degree of reactor
filling (that is, the vapor space in the reactor). In our
continuous stirred reactor system of FIGS. 3, 4 and 5 the degree of
reactor filling can be precisely controlled, as by means of the
differential pressure cell.
One convenient means of stopping the contact of the
olefin-isoparaffin feed with the zeolite catalyst and effecting the
concomitant removal of a portion of the C.sub.5 .sup.+ product from
the reaction mixture is to submerse a line, the opening of which is
covered by a filter device, such as a very fine screen, into the
reaction mixture and to constantly withdraw a catalyst-free portion
of the reaction mixture from the reactor to a zone where unreacted
feed olefin (if present) and feed isoparaffin are separated by
distillation from the C.sub.5 .sup.+ hydrocarbons, and recycled to
the reactor. This means can be utilized in the reactor section
(FIG. 4) of our continuous stirred reactor system (of FIGS. 3, 4
and 5) for producing an olefin-paraffin alkylate.
In the reaction illustrated by FIGS. 1 and 2, the mean residence
time in hours (per gram of catalyst per gram of hydrocarbon) of the
hydrocarbons in the reaction mixture with the catalyst was 0.089
after the first 60 minutes, 0.167 after 120 minutes, 0.236 after
180 minutes and 0.297 after 240 minutes. This is to be contrasted
with 0.62 hours in Example II, Table II, Column 3, 1.25 hours in
Example VII and 1.47 hours in Example I, Table I, Column 1 of U.S.
Pat. No. 3,251,902, previously cited herein.
In our process the preferred mean residence time is in the range of
0.05-0.45 hour, more preferably 0.1 to 0.4 hour.
An illustration of the calculation of mean residence time, for the
first 60 minutes in the reaction illustrated by FIGS. 1 and 2
herein, follows:
(444 ml. i-butane)(0.5543) = 246.11 g. isobutane for entire
time
23.3 g. of catalyst
Change 1 vol. butene-2 (density = 0.5988 g./ml.)
5 vol. isobutane (density = 0.5543 g./ml.)
(6)(D) = (5)(0.5543) + (1)(0.5988)
= 2.7715 + 0.5988 = 3.3703
d* = density of hydrocarbon mixture = 0.5617
For 60 min.
(1 hour)(23.3 grams catalyst 246.11 + (60 min.)(1 ml./min.)(0.5617
g.ml.) =
0.08861 hr./(g. Hydrocarbon)
(g. Catalyst)
EXAMPLE XV
This example illustrates the effect that catalyst composition has
on the yield of C.sub.5 .sup.+ reaction product and on the product
distribution, in particular with regard to the proportion of
C.sub.8 paraffins and the distribution of these C.sub.8 paraffins
into trimethylpentanes and dimethylhexanes.
The process of Example VIII was repeated except that the reaction
temperature was 120.degree.C. (which was close to the critical
temperature of the reaction mixture), the reaction pressure was 500
p.s.i.g., and the reaction time was 3.67 hours. Separate runs were
made with equal weights (activated basis) of zeolites of varied Na,
H and polyvalent metal contents, which were prepared similarly to
the catalysts of Examples II, III, IV and V.
Runs were also made, at 80.degree.C., 250 p.s.i.g., and 2.4 .times.
10.sup.-.sup.3 moles t-butyl chloride per mole of initial i-butane,
with catalysts prepared from the following: the 1.72 percent
(ignited) Ce zeolite of Example VII; a 16-cycle ammonium-exchanged
NaY zeolite which was further exchanged with 16 cycles of a 13.3
g./1. aqueous solution of La(NO.sub.3).sub.3.sup.. 6H.sub.2 O; a
16-cycle ammoniumexchanged NaY zeolite which was further exchanged
with 16 cycles of a 13.3 g./l. aqueous solution of hydrated mixed
rare earth nitrates (approximate salt analysis, 48% Ce.sub.2
O.sub.3, 24% La.sub.2 O.sub.3, 17% Nd.sub.2 O.sub.3, 5% Pr.sub.2
O.sub.3, 3% Sm.sub.2 O.sub.3, 2% Gd.sub.2 O.sub.3); and, a 16-cycle
ammoniumexchanged NaY zeolite which was further exchanged with 16
cycles of aqueous Ce(NO.sub.3).sub.3.sup.. 6H.sub.2 O (as in
Example IV).
All of these catalysts were activated by the procedure of Example
VII.
The yields of the C.sub.5 .sup.+ paraffin and C.sub.5 .sup.+
unsaturates, based on the weight percent of olefin charged, the
C.sub.5 .sup.+ paraffin distribution and the C.sub.8 paraffin
distribution of the products are shown in Table 11.
The yields and product distributions shown in Table 11 indicate
that, in substantially anhydrous acidic crystalline
alumino-silicate zeolites which have been prepared by ammonium
exchange of sodium zeolites with ammonium ions and polyvalent metal
ions, the catalytic activity and selectivity in paraffinolefin
alkylation are dependent upon the amount and type of exchanged
polyvalent metal and the degree of "protonation" or "cationic
deficiency" (which is related to the nitrogen content before
activation). Therefore, when other reaction variables are fixed, an
appropriate selection of the catalyst can be used to vary the yield
and product distribution in our process.
Table 12 and Table 13 illustrate the effect on the ultimate
catalyst of the type of salt used in the exchange solution.
It is evident from Table 13 that the yield differences are not
determined only by the total amount of rare earth metal present.
Therefore, it appears that different cations and their accompanying
anions can have pronounced effects on catalyst performance. Other
desirable catalysts can be prepared by exchanging NH.sub.4 Y
zeolite with salts of Gd.sup..sup.+3, Dy.sup..sup.+3 and
Sm.sup..sup.+3.
One precaution to be taken with data from Table 13 concerns the
apparent gain in selectivity for C.sub.8 paraffins with the
La(NO.sub.3).sub.3 and CeCl.sub.3 catalysts. In fact, this gain is
more in line with the selectivity gain which is typical when our
process is operated at a relatively low degree of reactant
conversion or product yield. In other words, if the
Ce(NO.sub.3).sub.3 catalyst had been used to produce only 68 to 73%
C.sub.5 .sup.+ paraffin yield (the range for La(NO.sub.3).sub.3 and
CeCl.sub.3), the molar C.sub.8 paraffin content of the C.sub.5
.sup.+ paraffins would have increased to about 80 percent instead
of remaining at the 69.0 percent actually observed at 132.0 percent
C.sub.5 .sup.+ paraffin yield.
As shown by these data, the anion in the exchange solution exerts
an influence on catalyst performance. The effect is related to the
condition of metal cations in aqueous solution as a function of
anion, cation concentration, pH and temperature. An effect such as
the following is the probable cause:
[RE(H.sub.2 O).sub.n ].sup.3 .sup.+ + X.sup.(m).sup.- .revreaction.
[RE(H.sub.2 O).sub.n-1 X].sup.(3.sup.-m).sup.+
Other cations which can affect the catalyst are the alkali metals,
such as lithium, sodium, potassium and cesium. As shown in Table
14, at comparable sodium levels, C.sub.5 .sup.+ paraffin yield
progressed from 26 to 132 wt. % olefin charge for an increase of
cerium from 2.0 to 13.5%. Even at 8.3% cerium, the C.sub.5 .sup.+
paraffin yield was only 62.7% on the same basis. The probability
that the 1.68% sodium content did not have the principal
deleterious effect upon this 62.7 % yield is supported by the
118.9% yield for a catalyst containing 2.8% sodium but 13.0% cerium
and by the 115.4% yield for another catalyst with a 1.68% sodium
and a 12.8% cerium content.
Some gain in C.sub.5 .sup.+ paraffin yield (115.4 to 132.0) can be
inferred for a reduction in sodium content from 1.68 to 0.76%.
Selectivity effects of cerium are illustrated by the relatively
high C.sub.5 .sup.+ unsaturate production with catalysts containing
less than about 12 percent cerium. Trimethylpentane/dimethylhexane
(TMP/DMX.sub.x) ratios were also comparatively low for those
catalysts, and relatively undesirable C.sub.9 .sup.+ paraffins
constituted as much as 27.2 mole % of the total C.sub.5 .sup.+
paraffins for the lowest cerium catalyst. These data show that with
less than about 12 percent cerium, alkylate will be not only lower
in yield but also poorer in quality.
A series of NH.sub.4 .sup.+-, Ce.sup.3 .sup.+-exchanged catalysts
having very similar sodium levels clarified the essential role of
cerium in producing favorable yields of high quality alkylate.
When cerium replaced ammonium on a Type Y zeolite at constant
sodium level, the following effects were observed:
1. Appreciable gains were realized in C.sub.5 .sup.+ paraffin
yield, in relative proportion of C.sub.8 paraffins, and in
selectivity for trimethylpentanes (TMP/DMH.sub.x ratio).
2. Simultaneously, desirable decreases were found in C.sub.5 .sup.+
unsaturates and in the relative proportion of C.sub.9 .sup.+
paraffins.
3. The only undesirable trned was an increase in the relative
amount of 2,2,4-TMP up to 26.4 mole % of the total TMP. However,
typical sulfuric acid alkylates have 2,2,4-TMP contents above 40
percent. This isomer has the lowest F-1 octane number of all the
TMP.
4. the largest gains in yield and selectivities occurred at values
of (Ce.sup.3 .sup.+/NH.sub.4 .sup.+) equivalent ratio below about
2.5. Higher ratios are desirable, but corresponding product
improvements become smaller.
These catalysts were prepared from the same common lot of NH.sub.4
.sup.+-exchanged Type Y zeolite. The following analytical data
establish that Ce.sup.3 .sup.+ was exchanging for NH.sub.4 .sup.+
and that no net loss of Na.sup.+ occurred from the NH.sub.4
.sup.+-exchanged zeolite:
Analysis Catalyst No. (g. equivalent/100 g. anhydrous residue)
______________________________________ Na NH.sub.4.sup.+
Ce.sup.3.sup.+ * .SIGMA. ______________________________________
FX10 0.064 0.389 -- 0.543 FX10-1-2 0.054 0.190 0.175 0.419 FX10-1-3
0.047 0.102 0.253 0.402 FX10-1-4 0.047 0.049 0.299 0.395
______________________________________ * Average of 3 analyses
The original zeolite had a sodium content of 0.426 equiv./100 g.
anhydrous residue after correction for 1,800.degree.F. ignition
loss. Residual sodium content was thus 11-13 percent of the
original.
Another interesting but undecided aspect of these catalysts is
their growing cation deficiency as cerium exchange increases. A
deficiency is said to occur when the sum of residual sodium,
ammonium and rare earth does not equal the positive charged initial
sodium. The presence of protons-bound or "solvated" -can account
for the apparent deficiency.
As has been shown in Examples I to VII, we prefer to prepare the
substantially anhydrous acidic alumino-silicate zeolites by
controlled activation of zeolites which are prepared from
crystalline sodium zeolites by first exchanging the bulk of the
sodium with ammonium ions and then exchanging the resulting
zeolite, which is low in sodium and high in ammonium ions, with
solutions of polyvalent metal cations. When the base zeolite is
sodium Y, the ammonium-exchanged zeolite should contain, on an
ignited basis, less than 3% Na and preferably less than 1.0%
Na.
In our ammonium exchange we also prefer that the sodium content of
the exchange solution be kept as low as is practicable. One means
of removing sodium ions from ammonium salt solutions is by a
separate cation exchange of the solution with a bed of
ammonium-containing ion-exchange resins or noncrystalline ammonium
zeolites. In this sodium-ion removal step, which is particularly
advantageous in continuous ammonium exchange (as in the procedures
of Example II), the sodium ion in the ammonium-ion exchange
solution exchanges with the ammonium ion in the resin and the
resulting ammonium-rich solution is recycled to the vessel
containing the crystalline zeolite for additional exchange with the
sodium in the zeolite. The ion-exchange resin bed (or
noncrystalline zeolite bed) can be regenerated by contacting the
ammonium-sodium equilibrium resin with an ammonium-rich stripping
stream. The sodium-rich effluent from the regeneration is discarded
after, if desired, residual ammonia has been recovered by flash
distillation.
Products obtained from a preferred Gd catalyst and from two other,
less preferred, catalyst types are shown in Table 15. One of the
two less preferred catalysts was obtained by activation (as in
Example VII but with 8 hours at 400.degree.C. to insure good
NH.sub.3 removal) of a highly (16 cycles) ammonium-exchanged type Y
zeolite (to produce HY catalyst). The HY catalyst produced only
about one-fourth as much alkylate, together with more C.sub.9
.sup.+ and C.sub.5 and less C.sub.8, as its cerium counterpart.
The other less preferred catalyst was prepared by activation of a
16-cycle cerium exchanged, 16-cycle ammonium-exchanged sodium X
zeolite (to produce CeHX catalyst). In comparison with CeHY
catalyst (run 664) the CeHX catalyst produced an appreciably
smaller C.sub.5 .sup.+ paraffin yield. An Analysis of this paraffin
product showed 23.9 mole % to be isopentane (which is 2 to 4 times
isopentane usually found in alkylate produced by CeHY catalyst).
Accordingly, the C.sub.8 paraffin in the alkylate produced by the
CeHX was only 59 mole % compared wth about 70% for CeHY.
Runs 628 and 674 were made with catalysts prepared by an exchange
procedure similar to that of Example IV and activated as in Example
VII (except that for the run 674 catalyst helium was substituted
for air), but wherein gadolinium nitrate was used instead of cerium
nitrate in the exchange solution. The resulting novel
Gd-alumino-silicate, upon activation, produced a novel catalyst
which is very useful for hydrocarbon conversion reactions,
particularly in our process for paraffin-olefin alkylation.
EXAMPLE XVI
This example shows the effect of feed olefins other than butene-2
on the yield of C.sub.5 .sup.+ products and their distribution.
Example VIII was repeated, with a similarly prepared catalyst,
except that the feed olefin was butene-1. The C.sub.5.sup.+
paraffin yield and the C.sub.5.sup.+ unsaturate yield were about
the same as those obtained in Example VIII with butene-2 and the
distribution of C.sub.5.sup.+ paraffins and the C.sub.8
distributions (see Table 10) were similar to those obtained in
Example IX with butene-2.
We have found that butene-1, in the presence of n-butane, is
readily isomerized to cis and trans butene-2 under our alkylation
conditions with acidic zeolite catalysts. This ready isomerization
provides the explanation for the similarity between the products
obtained when isobutane is alkylated with butene-2 and the products
obtained when butene-1 is the feed olefin. Surprisingly, a
significant quantity of highly saturated C.sub.5.sup.+ liquid
product is also obtained from this lilquid phase isomerization of
butene-1 in the presence of n-butane. A very small amount of
isobutane was also detected. An analysis of the C.sub.5.sup.+
liquid product of one such run is shown in Table 10. At least some
of this C.sub.5.sup.+ liquid appears to be the result of the
combination of the n-butane and the C.sub.4 olefin.
A similar run was made using 2-methylbutene-2 as the feed olefin
and a catalyst, prepared in a manner similar to the catalyst of
Example III, prepared from a zeolite which before activation
analyzed 5.0 percent cerium, 1.19 percent sodium, and had a loss on
ignition of 25.65%. The catalyst was activated (final temperature
400.degree.C.) as in Example VII. The C.sub.5.sup.+ paraffin yield
was 28.6 percent and the C.sub.5.sup.+ unsaturate yield was 31.2%,
based on the weight of olefin charged. The molar ratio C.sub.8
/C.sub.9 of the C.sub.5.sup.+ paraffins was 1.00.
A similar run with a somewhat more acidic catalyst produced a
C.sub.5.sup.+ paraffin yield of 49.0 percent and 15.4 percent
C.sub.5.sup.+ unsaturates based on the weight of olefin charged. Of
the C.sub.5.sup.+ paraffins 29 mole percent were C.sub.9.sup.+
paraffins and 36.6 mole percent were C.sub.8 paraffins (molar ratio
C.sub.8 /C.sub.9 was 1.25). The presence of C.sub.8 paraffins
indicates that self-alkylation of isobutane occurred during the
reaction.
A similar run using a portion of the same catalyst (activated at
500.degree.C.) and a butene-2 feed resulted in a C.sub.5.sup.+
paraffin yield of 51.8 percent of which 82.8 mole percent was
C.sub.8 and 4.2 mole percent C.sub.9.sup.+ paraffins. The
distributions of the C.sub.5.sup.+ paraffins in these two products
are shown in Table 10.
Similarly when isobutylene or propylene or a "B-B" refinery stream
(i.e., a mixture of butanes and butenes containing a minor amount
of propylene) is the feed olefin, good yields can be obtained (of a
product in which the C.sub.5.sup.+ saturates predominate over the
C.sub.5.sup.+ unsaturates) by stopping contact of the catalyst with
the reaction mixture after substantial alkylation has occurred but
before the weight rate of production of C.sub.5.sup.+ olefins
becomes greater than the weight rate of production of C.sub.5.sup.+
paraffins.
In general, our process can be used to produce (either by
alkylation, self-alkylation or both) good yields of C.sub.5.sup.+
saturated hydrocarbons from C.sub.4 -C.sub.6 isoparaffin (or
mixtures thereof) and any monoolefin having from 3 to 9 carbon
atoms, including the cyclic olefins, such as cyclohexene, and
mixtures of such monoolefins.
Table 16 reports a typical product obtained from isobutane at
60.degree.C. in our process under reaction conditions similar to
those of Example VII when propylene is the feed olefin, with and
without halide adjuvant. Table 17 details similar products obtained
in our process from isobutane and propylene under varied reaction
conditions.
Note that under the conditions of Run 544 propylene-isobutane
alkylation produced a C.sub.5.sup.+ alkylate yield of 123.3 wt. %
based on olefin charge. This number corresponds to 0.513 mole of
C.sub.5.sup.+ paraffins per mole of olefin charged to the reactor.
Close examination of the product revealed 66.0 mole % C.sub.7 among
the C.sub.5.sup.+ paraffins, and 97.2% of the C.sub.7 was
2,3-dimethylpentane.
From these results and other such studies the following
observations can be made:
1. In such batch reactions alkylation at 60.degree.C. for 2 hr.,
with attendant increases in relative amounts of promoter and
catalyst, produced the highest alkylate yield.
2. Raising or lowering temperature to 80.degree. or 40.degree.C.,
decreasing isoparaffin/olefin ratio (15/1 to 10 or 5/1), increasing
contact time at 60.degree.C. (2 to 4 hr.), and allowing more olefin
to be in the vapor phase-all had adverse effects upon yield and
selectivity. Low alkylate yields invariably were accompanied by
relatively high amounts of C.sub.9.sup.+ paraffin and low
quantities of C.sub.7.
3. Although isobutane self-alkylation is strongly indicated by
C.sub.8 paraffin in the product, the distribution of
trimethylpentanes is even more convincing. The 2,2,4-TMP content of
the C.sub.8 fraction was 61 to 70 percent for all
propylene-isobutane experiments; with butene-1 or 2 and isobutane
it is normally 15 to 25 percent for exchanged Type Y catalysts.
Mechanistic considerations show 2,2,4-IMP as a likely initial
product of self-alkylation. The reaction sequence can be formulated
in the following way: ##SPC5##
4. Comparison of Run 544 with published data on continuous H.sub.2
SO.sub.4 alkylation of propylene with isobutane shows the much
higher 2,3-DMP content in C.sub.7 product from the CeHy catalyst.
The F-1 clear value of 2,3-DMP is 91.1, while the same octane
number of 2,4-DMP is only 83.1.
Although the alkylate yield per olefin charged decreased as the
total residence time went from 2 to 4 hr., the cumulative yield of
C.sub.5.sup.+ paraffins continued to increase from 13.27 to 15.06
g. This behavior strongly indicates that the smaller rate of
alkylate production was not the result of a dead catalyst but was
more probably brought on by more product cracking and net
degradation. We have found that C.sub.6 and C.sub.8 isoparaffins
can crack to some degree under alkylation conditions and that
reaction conditions can be chosen which avoid or minimize such
cracking.
Lowering the isobutane/propylene minimum molar ratio at
60.degree.C. from 15/1 to 10/1 and 5/1 apparently decreased the
C.sub.5.sup.+ paraffin yield from 89.1 wt. percent of olefin charge
to 49.8 and 5.4 percent, respectively. This apparent effect is also
complicated by other factors. Amounts of catalyst and promoter were
chosen so that their volumetric concentration in the reaction
remained constant. Then, however, the promoter/olefin and
catalyst/olefin ratios necessarily changed. C.sub.5.sup.+ paraffin
yields were again high when these ratios were high.
Note the virtual absence of olefin polymerization as the relative
amount of olefin charge was increased. Only at a 5/1
isoparaffin/olefin ratio was a measurable amount of C.sub.5
-C.sub.8 unsaturate observed-0.07 wt. percent of olefin charged or
slightly over 1 percent of the C.sub.5.sup.+ product. This low
degree of polymerization and the implied degree of hydride transfer
are the result of our novel CeHY catalyst especially in combination
with a halide adjuvant. With a less highly exchanged (8/8) CeHY
catalyst and with no promoter significant quantities of
C.sub.5.sup.+ unsaturates will be in the product when the
isoparaffin/olefin ratio is 5.
Table 18 shows typical products obtained at 80.degree.C. when
isobutane is contacted, in our process, with various pentenes. A
report from the literature of a pentene-isobutane alkylation with a
sulfuric acid catalyst is also shown in Table 18.
Table 19 shows typical products obtained with isobutane when
isobutylene, 2,3-dimethylbutene-1 or diisobutylene is the feed
olefin. Note that diisobutylene acts like two moles of
isobutylene.
Over a 220-minute period at 500 p.s.i.g. at 120.degree.C., 9.9
liters of gaseous ethylene were introduced into a stirred slurry of
627 ml. of liquid isobutane and 23 g. of a catalyst containing
(ignited basis) 1.30 percent Na and 12.6% Ce and which was prepared
similarly to that of Example VIII. No liquid product (i.e.,
C.sub.5.sup.+ hydrocarbon) was obtained.
Similarly, when ethylene was charged to an isobutane-catalyst
slurry under pressure at 80.degree.C. no C.sub.5.sup.+ product was
found. The isobutane/ethylene molar ratio was 12.6. Ethylene feed
was cut off after 2 hr. on stream, when the reactor reached a
predetermined pressure limit of 510 p.s.i.g. However, the reactor
contents were kept at run conditions for an additional 2 hr. No
C.sub.5.sup.+ product was found. Gas analyses revealed only
ethylene and isobutane contaminated with the small amount of
n-butane originally present.
P. E. Eberly, Jr., has reported (J. PHYS. CHEM., 71, 1717-22
(1967)) that, among C.sub.2 -C.sub.6 olefins, only ethylene fails
to produce conjugated polyene structures on HY catalyst. Eberly's
report and the present example show that there is an inherent
difference in ethylene's behavior relative to that of the other
olefins when contacted in the presence of acidic alumino-silicate
zeolites.
If ethylene is charged to a reservoir of carbonium ions and active
catalysts, it is probable that ethylene reactivity for alkylation
can be enhanced; therefore, butene-2 was charged to an
isobutane-catalyst slurry for 2 hr. at 80.degree.C., at the end of
which ethylene introduction was begun and continued for an
additional 2 hr.
No sign of excess C.sub.6 paraffins was apparent in the liquid
product, and the total alkylate yield was only 51.3 percent based
on olefin charge instead of the expected 95 to 100 percent paraffin
yield. Distribution of paraffins in this alkylate an in another
from a typical 3.67 hr. run shows good resemblance between them.
The chief difference was a greater proportion of C.sub.9.sup.+
paraffins in the longer run. The relatively low alkylate yield
suggested that some cracking had occurred during the 2 hr. period
of ethylene charging.
To test the possibility of considerable alkylate cracking,
representative products were exposed to typical alkylation
conditions for 2 hr.: 12.3 g. 2,2-DMB and 8.7 g. of a C.sub.8
paraffin mixture with a high 2,2,4-TMP content. These amounts
corresponded to a 50 percent theoretical yield of 2,2-DMB and a 100
percent theoretical yield of C.sub.8 alkylate on the basis of the
preceding run. Isobutane was then charged in the same amount as in
the preceding run, and ethylene was introduced during a 2 hr. time
period in the same amount. It could not be determined whether the
isobutane had more than a diluent action and whether the ethylene
had any effect at all.
Results of this experiment, showed 77.4 percent conversion of the
2,2-DMB and 45.7% conversion of 2,2,4-TMP at only 80.degree.C. Net
destruction of C.sub.6 paraffin was 72.0 percent because 5.4
percent of the 2,2-DMB was converted to 2,3-DMB and 3-MP. Other
C.sub.8 paraffins present to the extent of 2 percent or more of the
C.sub.5.sup.+ charge were 49-75 percent cracked, and 52.3 percent
of the 2,3-DMP present was also degraded. These results suggest
that, in our process, if ethylene in the presence of isobutane is
to produce any C.sub.5.sup.+ paraffin, it will be at a temperature
in the range of 0.degree.-60.degree.C.
EXAMPLE XVII
This example illustrates use of a fixed bed of substantially
anhydrous acid zeolite to catalyze the liquid phase paraffin-olefin
alkylation. A bed of 20/60 mesh zeolite catalyst was set up in a
vertical column. The catalyst used was an acidic Y zeolite
containing 7.8 percent of mixed rare earth ions (from exchange with
a crude didymium salt) of which 41 percent was lanthanum. The
catlayst contained less than 0.6 percent of cerium, 1.6 percent of
sodium, and had an atomic ratio Al/Si of 0.44.
On an ignited basis, the rare earth content (by X-ray fluorescence
analysis) was 4.21 percent lanthanum, 0.58 percent cerium, 1.25
percent praseodymium, 3.64 percent neodymium and 0.6 percent
samarium.
The catalyst bed was activated in situ and in a manner similar to
the activation of Example VII. The catalyst was then pre-wet with
isobutane. A feed containing 1 part by weight of butene-2 and 15
parts by weight of isobutane was passed once through the column at
a weight hourly space velocity (WHSV) of 8.3 (WHSV of olefin =
0.5), at 440 p.s.i.g. and 120.degree.C., in a period of 80 minutes.
The C.sub.5.sup.+ paraffin yield was 88.5 percent. The
C.sub.5.sup.+ naphthene yield was 0.6 percent, and the
C.sub.5.sup.+ unsaturate yield was 4.5 percent. Of the
C.sub.5.sup.+ paraffins, over 78% was pentanes, and 85% of these
pentanes was n-pentane. The trimethylpentane to dimethylhexane
ratio in the C.sub.8 fraction was 1.58. Note that the maximum
possible concentration of unreacted olefin in the reaction mixture
is 6.1 mole percent.
A control reaction with the same catalyst and a similar activation
in a stirred reactor, run similar to Example VIII, at 120.degree.C.
and 480-565 p.s.i.g. for 220 minutes produced 88.0% C.sub.5.sup.+
paraffins and 6.9% C.sub.5.sup.+ unsaturates. Of the C.sub.5.sup.+
paraffins, less than 10 percent was pentanes and only 15 percent of
these pentanes was n-pentane. The trimethylpentane to
dimethylhexane weight ratio was 2.72 in the C.sub.8 paraffin
fraction.
Since the performance of a solid catalyst is in part dependent upon
reactant adsorption, we prefer the stirred slurry reactor since the
hydrocarbon to catalyst ratio can be higher than that which can be
obtained in a fixed catalyst bed of practical dimensions and
catalyst packing. However, this deficiency of a fixed bed reactor
can to some extent be overcome by using a lower olefin/isoparaffin
ratio in the feed, multiplie feed injection, specialized catalyst
distribtuion (including dilution with a relatively inactive solid,
such as acid clay), high space rates and pulsed flow.
EXAMPLE XVIII
This example illustrates the highly unsaturated products obtained
by the use of our acid Y zeolite catalysts and procedures which
would be suggested to the person having ordinary skill in the
pertinent art and who studied the previously-mentioned prior art
relating to paraffin-olefin alkylation with zeolite catalysts. That
is, the process conditions in the examples are a fair combination
of conditions taught by the prior art wich are applicable to liquid
phase reaction of butene-2 and isobutane using an acidic zeolite
catalyst. In particular, the example shows a fair combination of an
activated cerium-exchanged, ammonium-exchanged, sodium Y zeolite
and process conditions analogous to those of U.S. Pat. No.
3,251,902.
A comparison of this example with the previous examples
illustrating our process shows the undesirable results of not
controlling the addition of the olefin such that the amount of
unreacted olefin in the reaction mixture is less than 12 mole
percent (preferably less than 7 mole percent) based on the
unreacted C.sub.4 to C.sub.6 isoparaffin.
A portion of an 8-cycle cerium-exchanged/8-cycle
ammonium-exchanged-sodium Y zeolite (prepared similarly to that of
Example III) was activated by the process of Example VII except
that the maximum activation temperature was 650.degree.C. 16.8 g.
of the activated zeolite, which analyzed 1.7% Na (ignited) and 6.7%
Ce (ignited) were charged into a 1-liter stirred autoclave, to
which was added 6.1 moles of liquid isobutane. The temperature was
raised to 80.degree.C. and the pressure adjusted to 260 p.s.i.g.
with nitrogen, then 1.2 moles of liquid butene-2 was gradually
charged to the reactor, with stirring, over a period of 2.2 hours.
The total C.sub.5 .sup.+ hydrocarbon yield was 10.8 percent of the
weight of olefin charged and contained 47.3 percent saturated and
52.7 percent unsaturated hydrocarbons. Note that in this procedure
the maximum probable concentration of unreacted olefin in the
reaction mixture is 16.4 mole percent.
When the above reaction was repeated with a 22.4 gram portion of
the same zeolite which was similarly activated except that the
maximum activation temperature was 500.degree.C., the total C.sub.5
.sup.+ yield was 19.7% of the weight of olefin charged and was 47.5
volume percent saturated and 51.4 volume percent unsaturated.
With 17.0 grams of this activated zeolite and a reaction
temperature of 40.degree.C. (100 p.s.i.g.), the C.sub.5 .sup.+
yield, based on weight of olefin charged, was 4.6 percent and was
41 volume percent saturated and 59 volume percent unsaturated.
With 23.0 grams of the activated zeolite and a reaction temperature
of 120.degree.C. (450 p.s.i.g.), the C.sub.5 .sup.+ yield was 45.2%
based on the weight of olefifn charged and was 61 volume percent
saturated and 39 volume percent unsaturated.
The high degree of unsaturation in the products of this example
indicates that a major reaction was olefin polymerization as in the
general reaction
2 (gas olefins) .sup.acid zeolite 1 (liquid olefin).
EXAMPLE XIX
Example VIII was repeated except that the run was for 120 minutes
at 60.degree.C., 200 p.s.i.g., and the catalyst was prepared with
32 ammonium and 16 cerium exchanges, similar to that of Example IV.
Before activation the exchanged zeolite had a 24.74 ignition loss
and, on an ignited basis, analyzed 0.31% Na and 14.3% Ce. The
C.sub. 5.sup.+ paraffin yield was 50.1 percent and the C.sub.5
.sup.+ unsaturate yield was 0.00%. Of the C.sub.5 .sup.+ paraffins
80.5 mole percent was C.sub.8 and 0 mole percent of the C.sub.8
paraffins was methylheptanes.
This example illustrates one preferred embodiment of our invention
wherein a highly acidic Y zeolite with a halide adjuvant is used at
low temperature and with a short retention time to catalyze the
reaction of isobutane and butene-2 to produce a high yield of a
novel C.sub.5 .sup.+ alkylate containing very little C.sub.5 .sup.+
unsaturates and wherein the ratio TMP/DMH.sub.x is desirably high
and the proportion of the less desirable 2,2,4-trimethylpentane is
low. In particular, the character of this novel alkylte (which is a
highly desirable motor fuel or gasoline blending component) should
be contrasted with the undesirable products of Example XVIII (which
are illustrative of practice of the prior art).
This example, when compared with Example XVIII and Example XV (see
Table 11) shows the superiority in our process of the more highly
exchanged and highly acid catalysts (that is, those with the lower
Na and the higher polyvalent metal (contents).
Our invention can also be practiced in conjunction with the
dehydrogenation of lower paraffins to produce olefins useful as
feeds for our alkylation process. That is, the lower paraffins in
the C.sub.5 .sup.+ liquid (particularly C.sub.5 and C.sub.6
paraffins) can be separated from the higher paraffins (such as
octanes) and passed to a reactor (such as the fixed bed type)
containing a dehydrogenation catalyst at conditions favoring
monoolefin rather than diolefin formation
(500.degree.-1200.degree.F., 0.5-1.5 atm., H.sub.2 /hydrocarbon
molar ratio 0.1 to 10 and LHSV of 0.5 to 5). The resulting
monoolefins (which need not be separated from unreacted paraffins)
can be then transported to the premixing zone, diluted with
isoparaffin (if necessary) and utilized as a feed in our
paraffin-olefin alkylation process. Operable dehydrogenation
catalysts are platinum-alumina, nickel-silica, nickel-magnesia,
nickel-alumina, copper-alumina, chromia-alumina and the like.
When our fixed bed alkylation process is operated under conditions
which produce high yield of n-pentane (as in Example XIII), it is
preferred that at least some of the n-pentane is so dehydrogenated
and at least some of the resulting olefins are used as feed in the
alkylation stage.
When practiced in combination with such a dehydrogenation stage,
this process is preferably operated under conditions which favor
paraffin self-alkylation reactions, such as
2 i-C.sub.4 H.sub.10 + C.sub.5 H.sub.10 .fwdarw. i-C.sub.8 C.sub.18
+ C.sub.5 C.sub.12.
Such self-alkylation reactions are well known in sulfuric acid
catalyzed paraffin-olefin reactions (see Hofmann, J. E. and
Schriesheim, A., JACS. 84, 955 (1962)). The present process wherein
self-alkylation is combined with the dehydrogenation of C.sub.5
.sup.+ paraffins can be of great economic value to the refiner who
has a shortage of butenes and a good supply of isobutane.
Pentanes and hexenes for such self-alkylation can also be derived
from relatively inexpensive sources, as dehydrogenated natural
gasoline (see U.S. Pat. No. 3,016,344). An especially preferred
olefin is 2,3-dimethylbutene, which can be obtained from the
dimerization of propylene, since, in this isobutane
self-alkylation, it is converted to 2,3-dimethylbutane which has an
excellent blending octane number.
Although the previous examples are illustrative of practice of our
invention, the yields of many of these examples based on the weight
of olefin charged, can be improved upon since it is probable that
some of the olefin feed was not consumed in the reaction, but was
lost because of slight leakages from the reactor system. For
example, Table 20 reports two runs, at 80.degree.C., 250 p.s.i.g.
with a catalyst similar to that of Example VIII, which were
identical except that Run A utilized the same reactor system as in
the previous examples and Run B utilized the same system but
greater care was used to prevent loss of feed olefin from the
system. It can be seen that the yield in Run B was 12 relative
percent greater than Run A.
The calculated F-1 clear octane number of the alkylate of Run B
(excluding materials boiling higher than 2,2,4-trimethylhexane) was
98.0. This high octane number, in combination with the reported
yield, is one indication of the commercial promise of our
invention. Note that a similar calculation shows the novel alkylate
of Example XIX (see Table 20) to have a 99.9 octane number.
EXAMPLE XX
This example illustrates, in Table 21, the effect of the gas used
in catalyst activation on the C.sub.5 .sup.+ paraffin yield,
obtained from the resulting catalyst. Also shown below is a brief
summary of the effect on C.sub.5 .sup.+ yield of the final
activation temperature.
Activation technique of a CeNH.sub.4 zeolite to produce CeH zeolite
can be divided into three distinct parts, during each of which the
catalyst is maintained at a definite temperature for a fixed time.
First is a preliminary drying, for example, at about 65.degree.C.
Second is a dehydration, for example, at about 230.degree.C., which
removes virtually all of the adsorbed water but probably does not
affect hydroxyls or other waterforming entities more firmly
incorporated into the structure. Third is the final activation
stage, whch is characterized by NH.sub.4 .sup.+ decomposition and a
relatively small removal of water. The activated catalyst, however,
contains a definite and reproducible amount of water.
Early in the solid alkylation catalyst research program it had been
observed that 400.degree.C. appeared to be a preferred temperature
for catalyst activation in air. That observation has been verified
with current techniques and more highly exchanged catalysts. The
following yields are illustrative:
Wt. % C.sub. 5.sup.+ Yield Based Temperature of Run on Olefin
Charged Catalyst Base Air Activation No. Paraffins Unsaturates
__________________________________________________________________________
32NH.sub.4.sup..sup.+, 16Ce.sup.3.sup.+ Y 325.degree.C. 842* 29.4
0.99 do. do. 400.degree.C. 782* 119.0 5.85** do. do. 500.degree.C.
844* 113.2 1.83 16NH.sub.4.sup.+, 16Ce.sup.3.sup.+ Y 400.degree.C.
868*** 125.8 0.24 do. do. 400.degree.C. 880*** 133.8 0.36 do. do.
500.degree.C. 860*** 107.8 1.96 Catalyst Compositions (wt. %,
ignited basis) Run No. wt. % cerium wt. % sodium 782 14.0 0.31 842,
844 13.7 0.23 860, 868, 880 14.1 0.98
__________________________________________________________________________
*Operating Conditions: 60.degree.C., 200 psig., 220 min., i-C.sub.4
/C.sub.4 -ene = 14.9 min. **Use of less preferred charge stock
preparative technique for this run should not have affected
C.sub.5.sup.+ paraffin yield but probably increased the unsaturate
yield. ***Operating Conditions: 80.degree.C., 250 psig., 250 min.,
i-C.sub.4 /C.sub.4 -ene = 14.9 min.
With the 32NH.sub.4 .sup.+ -, 16Ce.sup.3.sup.+ Y-catalyst, a 5.8
percent loss of C.sub.5 .sup.+ paraffin yield was obtained after
activation at 500.degree.C. relative to 400.degree.C. With the
16NH.sub.4 .sup.+ -, 16Ce.sup.3.sup.+ Y-catalyst, a 22.0 percent
means loss of C.sub.5 .sup.+ paraffin yield was obtained by
activation at 500.degree.C. instead of 400.degree.C. The poor
result following 325.degree.C. activation may be a result of i
incompletely developed acidity in the solid or of residual
ammonium, even though a negative test for ammonia evolution had
been observed at the end of this activation. DTA and EGA
experiments have shown that ammonium decomposition occurs at
300.degree.-320.degree.C. with NH.sub.4 Y zeolite.
To some extent the bound water lost on activation at higher than
optimum temperature can be re-introduced to the catalyst. A
hydrated CeNH.sub.4 Y zeolite was activated by the procedure of
Example VII, the final heating stage being at 400.degree.C. The
resulting activated catalyst was contacted with an
isobutane-butene-2 feed to produce a 141.5 percent yield of C.sub.5
.sup.+ paraffin.
A similar alkylation with a similar catalyst which had been
activated at 600.degree.C. in the final step produced only 128.5
percent of C.sub.5 .sup.+ paraffin.
A catalyst from a similar 600.degree.C. activation was allowed to
rehydroate (by exposure to humid air) until the rehydrated zeolite
had reached equilbrium. This equilibrated zeolite was then
reactivated at 400.degree.C. When an isobutane-butene-2 feed was
contacted with this rehydrated, reactivated catalyst, at 140.5%
yield of C.sub.5 .sup.+ paraffin was obtained.
EXAMPLE XXI
FIGS. 3, 4 and 5 illustrate the three basic sections which comprise
a continuous stirred reactor system for producing an
olefin-paraffin alkylate by our process. FIG. 3 illustrates the
feed section. The valving arrangement at the top of the mixing
vessels 17 and 18 allows feed paraffin 1 or feed olefin 3 to be
placed in either vessel 17 or vessel 18 from either the top or the
bottom of the vessel. For example, paraffin can be introduced
through the bottom of vessel 17 closing valve 9, 12, 19 and 23 and
opening valves 4, 8 and 21. Then, feed olefin 3 is transported to
vessel 17 by closing valves 4, 11, 12, 14, 19 and 23 and opening
valves 7, 8, 9, 10 and 21. Alternately, the mixing of the incoming
feed olefin and feed paraffin can be effected by means of an inline
mixer; however, for precise control of the reactant proportions and
to insure intimate admixing of paraffin and olefin, we prefer that
a substantial amount of paraffin admixed with olefin be maintained
in a stirred mixing vessel as vessels 17 and 18.
Similarly, by sequencing the position of the valves, the feed
paraffin and the feed olefin can be introduced in any desired
pattern. One sequence of placing feed paraffin and feed olefin in
vessel 17 is to allow feed paraffin to enter vessel 17 toa level a.
sufficient feed olefin is then brought into vessel 17 to produce a
volume of paraffin-olefin admixture represented by level b. The
remainder of the required paraffin feed is added to vessel 17 until
the level of the total feed mixture is at c. Such a sequence of
paraffin-olefin-paraffin addition allows for better internal mixing
of the reactants in vessel 17 (n addition, uniform mixing is
insured by mixing devices 15, 16, such as, turbine blade rotary
mixers). We have also found that additional mixing can be
accomplished by brining the inert gas heat into the bottom of the
mixing vessel as through valve 21, rather than into the top of the
vessel, as through valve 12.
It is generally preferable to introduce feed components to the
mixing vessels in a number of alternate portions (except unless
when the feed components are simultaneously proportioned into an
inline mixer) to insure uniform mixing. Similarly, sequencing of
valves can be used to fill vessel 18 while the mixture in vessel 17
is being fed to the reactor 43 (of FIG. 4). In order to use vessel
17 regardless of whether vessel 18 is being filled or not,
pressure, as by an inert gas 2 (e.g., nitrogen) is imposed upon the
liquid in vessel 17, as by closing valves 12, 19 and 21 and opening
valve 5. Normally, the nitrogen head is allowed to build up until
the pressure in the mixing vessel is about 50 p.s.i. less than the
pressure in the reactor 43.
In order to allow a mixed paraffin-olefin feed to enter the reactor
43, the nitrogen head is imposed upon vessel 17 and valve 19 is
opened. A constant head pressure on vessel 17 allows the pump 31 to
pump the mixed feed through line 33 to the reactor at a constant
rate.
When valve 19 is open, the feed mixture passes through a
microfilter 24 (which protects the pump and meters from damage
caused by foreign particles), then through a high pressure
rotometer 29 (which serves as a flow indicator). The feed can then
enter the pump 31 when valve 30 is open and, when valve 32 is open
and 34 closed, the feed is pumped into the reactor 43. In the event
of a pump failure, valve 30 and valve 32 may be closed, needle
valve 34 opened and the nitrogen head increased sufficiently to
allow the feed to flow through line 35 to line 33 and, thence, to
the reactor 43.
FIG. 4 illustrates the reactor section, comprising a continuous
stirred reactor vessel and the associated lines and valving
required for introducing feed, removing reaction products, and for
operation of the differential pressure cell which is used for
liquid level control. The reactor also contains heat transfer and
control means (as a water jacket and electrical heaters, not shown)
for maintaining the desired reaction temperature. The
paraffin-olefin feed from line 33 enters the reactor 43 through
valve 34 and line 35. To insure maximum olefin dilution, we prefer
that the liquid feed be allowed to enter the reactor 43 below the
reactor liquid level 42 and in the vicinity of the mixing means
36.
The liquid level is controlled by a differential pressure cell,
hereinafter DP cell, having a high pressure section 61 and a low
pressure section 60, the differential pressure being in the range
of 5-50 inches of water column. Inert gas 49 enters the DP cell
through an inline filter 50 from which it diverges through meter 52
to the high pressure section 61 and through meter 57 to the low
pressure section 60. That is, for the high pressure section, valve
51 is open allowing the inert gas stream to flow through the high
pressure meter 52 through open valve needle 53 and valve 64 into
the high pressure side 61 of the DP cell, then through valve 62
into a line 67 which leads below the liquid level 42 in the
reactor. Pressure gauges, 54a and 54b, indicate the pressure in the
high pressure side and the lower pressure side, respectively. Other
pressure gauges, thermometers, and analytical devices, can be
advantageously incorporated into the three sections comprising the
apparatus of FIGS. 3, 4 and 5; however, for simplicity such devices
are not shown in the figures.
The inert gas can also be diverted through valve 56 to the low
pressure meter 57 through needle valve 58 to the low pressure side
60 of the DP cell and then through valve 63 and line 68 to the
vapor space above the liquid level 42 in the reactor. In operation,
the DP cell senses a differential pressure which is equal to the
height of liquid through which the inert gas from the higher
pressure side of the cell must travel from the bottom of line 67
(which must be below the liquid level) to the vapor space 39. The
difference between the pressure of the high side 61 and the
pressure of the low side 60 of the DP cell is equal to the pressure
required to push a bubble of gas through the height of the liquid.
Since the DP cell measures the mass of a column of fluid (pressure)
and not the volume, its measurement is independent of temperature
and, although at a given temperature the actual level of the liquid
will vary somewhat, the mass of the volume of liquid above the
opening line 67 can be maintained at a constant value regardless of
the temperature and pressure of the reactor.
The nitrogen (or other inert gas) which is introduced through the
DP cell can be vented through a valve system 40, which can consist
of an Annin control valve (a spline-type, highly sensitive metering
device) and a block valve ahead of the Annin valve. The Annin valve
can be actuated by a pressure transmitter (and gas meter) 38 in
order to maintain a constant pressure in the vapor space of the
reactor.
Catalyst-free reaction mixture is removed from the reactor via line
37 through valve system 69 (which can consist of an Annin valve and
a hand-block valve ahead of the Annin valve). The liquid reaction
mixture is separated from the suspended catalyst particles by means
of a submerged screen 44 and is withdrawn from the reactor through
line 37. Although screen plugging is not a frequent occurrence, if
plugging occurs the screen can be back-flushed with nitrogen. This
nitrogen back-flush can enter the reactor through line 37 and the
excess nitrogen vented through valve system 40 in order that the
reaction pressure is maintained constant. This flushing can be
effected while the catalyst particles are maintained in suspension
and the reaction mixture is maintained in contact with the catalyst
particles. In the event that catalyst must be added or removed from
the reactor, it may be accomplished through line 48, flush valve 47
and line 46. Similarly, the entire contents of the reactor can be
drained through the flush valve 47, if the reaction mixture becomes
contaminated or if for any other reason it is desired to drain the
reactor contents. For example, if scale builds up on the reactor
baffles 45, the reaction mixture can be dumped by opening valve 47,
then cleaning materials can be pumped into (and removed from) the
reactor through the same valves and lines.
The gases removed via valve 40 can be sent to a gas meter (and
pressure transmitter) 38 which can also contain devices for
chemical analysis or sampling. For example, the gases so removed
can contain HCl, from the halide adjuvant. The HCl concentration in
the vapor space is preferably maintained at a constant partial
pressure, as by adjusting the quantity of adjuvant which enters the
reactor via line 65, valve 66 and line 67. Such adjuvants can also
be introduced into the reactor if they are directly added to the
paraffin olefin feed in the mixing vessels 17 and 18.
The catalyst-free liquid reaction product (comprising C.sub.5
.sup.+ "alkylate", unreacted feed isoparaffin, some C.sub.5 -
paraffin product and, usually, a small amount of unreacted feed
olefin) which is removed from the reactor via line 37, passes
through valve 69 (where the pressure is reduced from reactor
pressure to 25 psig or less) and to condenser 72. The condensed
liquid and noncondensed gas (e.g., feed isoparaffin) and inert gas
(e.g., nitrogen) pass through valve 86 into vessel 92 or,
alternately, through valve 81 to vessel 95. We prefer to have two
such collecting vessels in order that product can be collected in
one vessel while product is removed from the other vessel. The
liquid product removed from these vessels can be transported to
product storage tanks or to a means for blending the alkylate with
other gasoline components in order to make a blended gasoline
product which can be transported to a stabilizer and then to
storage area or to tank trucks, etc.
In the product recovery section illustrated in FIG. 5, the liquid
produced by condensation of gaseous products in condenser 72 and
uncondensed gases pass through line 77 and valve 86 (valve 81 is
closed) and enter vessel 92, which is maintained at a temperature
and pressure such that liquid alkylate can be removed via valve 96
through line 98 (valve 97 is closed) to tank trucks, a blending
area, storage tanks, etc. Uncondensed gases (which consist
primarily of unreacted feed isoparaffin) leave vessel 92 via valves
93, 90 and 74 (valves 94, 89 and 73 being closed) and can be passed
to means for gas purification and separation 71 or, under some
conditions, can be recycled to the reactor or to the mixing vessels
via line 76, or via valve 73 and line 70. Minor amounts of the
halide promotor which may be present in the reaction product can be
removed as by means of an adsorbent which can be between valve 69
and the condenser 72 or at any other appropriate location in the
product recovery section. When the halide promotor is a readily
distillable gas such as HCl or methyl chloride, it can be removed
from the reaction product by an intermediate condensation.
Adjuvants, such as tertiary butyl chloride, can be added directly
to the reactor as by line 33, valve 34 and line 35, or can be added
to the one of the feed components, such as the isoparaffin, or can
be added to the paraffin-olefin mixer in the mixing vessel 17 or
18; however, in the event that the promoter can react with the
microfilter 24, or cause corrosion in the pump 31, it is preferred
that the adjuvant be added at some point after the pump as by line
65, valve 66 and line 67 (the high pressure side of the DP cell),
thus the promoter becomes dispersed in the flowing nitrogen from
the high pressure side of the DP cell and passes into the reactor
below the liquid level and bubbles up through the reactor
contents.
A liquid mixture of 17 volumes of isobutane and 1 volume of
butene-2, having a density of 0.557 g./ml., was fed, from the
mixing section, and continuously contacted, in the reactor, in the
presence of a halide adjuvant, with a CeHy catalyst (16/16) which
had been activated by the procedure of Example VII (maximum
activation temperature 400.degree.C.). The liquid level in the
reactor was maintained constant by the DP cell so that the
concentration of the catalyst in the reaction mixture was about 10
weight percent.
The feed rate and the rate of withdrawal of catalyst free reaction
mixture were continuous and controlled, such that the mean
retention time was 0.3112 hour per gram of hydrocarbon per gram of
catalyst. The catalyst was maintained primarily in suspension by
continuous stirring.
The halide adjuvant was 0.13 g. t-butyl chloride and 0.22 g.
CCl.sub.4 per gram of olefin charged. The temperature in the
reaction was maintained at 178.degree.F. and the pressure was
autogenous at the temperature (the hydrocarbon being maintained
primarily in the liquid phase).
The C.sub.5.sup.+ paraffin product recovered (continuously) from
the so withdrawn catalyst-free reaction mixture was about 100 wt.
percent based on the weight of olefin charged. The proportion of
2,2,4-trimethylpentane was about 27.5 mole percent of the
trimethylpentane fraction, and relatively constant, indicating a
continuing self-alkylation function of the catalyst. The total
trimethylpentane content in the C.sub.8 fraction of the liquid
product was also relatively constant at about 89 to 85 mole percent
of the C.sub.8 fraction of the continuously produced alkylate. Less
than 1 percent of the product was methylheptane. C.sub.5.sup.+
unsaturates in the liquid product were negligible.
EXAMPLE XXII
This example, by Table 22, illustrates the effect on yield and
product quality of the catalyst/olefin ratio.
EXAMPLE XXIII
This example illustrates the correlation between alkylate yield and
Electron Spin Resonance (ESR) measurements of total spin count when
aromatic hydrocarbons are adsorbed on the CeHY zeolite
catalyst.
Several kinds of aromatic hydrocarbons (benzene, p-xylene,
naphthene, anthracene, perylene, etc.) were adsorbed upon CeHY
catalysts prepared by varied numbers of Ce.sup.+ and NH.sub.4.sup.+
exchange cycles and with various types of activation (e.g.,
temperature, type of gas). The total ESR spin count of the adsorbed
hydrocarbon was then measured. The sorption of the aromatics
corresponded to the order of decreasing ionization potential
(benzene being first). Catalysts with a higher degree of exchange
produced larger spin counts with any particular aromatic. When
C.sub.5 .sup.+ paraffin yields obtained with similar catalysts were
plotted versus the spin count with a particular aromatic on each
catalyst, a good correlation was achieved.
The most satisfactory correlations are for compounds having
ionization potentials equal to or larger than that of naphthalene
(about 8 ev.). Spin counts of compounds with lower ionization
potential changed less than one order of magnitude while relatively
large differences in alkylate yield were being observed. These
correlations imply a relationship between radigenic nature of a
catalyst and its performance in an alkylation reaction (which is
highly dependent upon hydride transfer).
A far more exact relation between alkylate yield and anthracene
spin count was realized when a series of catalysts of increasing
cerium but constant sodium content was used. Anthracene spin count
increased less after a (Ce.sup.3.sup.+ /NH.sub.4.sup.+) equivalent
ratio of about 2.5 had been reached.
Note, for example, a nearly linear relation between alkylate yield
and anthracene spin count can be seen by plotting the data
below:
Wt. % C.sub.5.sup.+ paraffin Sorbed based on wt. of Spin Count
Hydrocarbon olefin charged (Spins/g.Cat.) .times. 10.sup..sup.-19
______________________________________ Anthracene Cat. A 91 1.2 do
B 126 2.4 do. C 150 3.8 ______________________________________
Note: Reactions at 80.degree.C., Example VIII conditions with
"improved feed premixing", isobutane-butene-2 feed. Sodium in
catalyst 11 to 13% of cation capacity of zeolite.
Poor hydride transfer, as represented by C.sub.5.sup.+ unsaturate
formation, was intensified at low (Ce.sup.3.sup.+ /NH.sub.4.sup.+)
equivalent ratio. Other aspects of product quality --low
C.sub.9.sup.+ high C.sub.8, and high TMP in the C.sub.8 -- also
improved when this composition ratio increased.
These data offer excellent support for the importance of the cerium
in CeHY catalyst for alkylation and strongly imply a relation
between hydride transfer facility of a catalyst and its electron
withdrawal ability.
TABLE 1
__________________________________________________________________________
Exchanged Zeolite Catalysts Chemical Composition of Activated
Equilibrated Ammonium-Only
__________________________________________________________________________
Catalyst Catalyst: 16 Exchange Cycles with NH.sub.4 NO.sub.3
solutes, Dry Air Medium, Rotary Kiln
__________________________________________________________________________
Activation Catalyst No. Conditions Weight Percent TIL*
Na-Equivalent Moles**
__________________________________________________________________________
Maximum Temperature .degree.F Time**** Na.sup.+ N H.sub.2 O
Na.sup.+ NH.sub.4.sup.+ .SIGMA.
__________________________________________________________________________
***Base NaY Zeolite -- -- 9.51 -- 24.32 0.414 -- 0.414 Base after
NH.sub.4.sup.+ Exchange -- -- 1.04 5.50 23.76 0.045 0.393 0.438
Experiment A Run No. A-1 150 30 1.01 5.51 24.63 0.044 0.394 0.438
A-2 450 0 1.03 5.28 24.88 0.045 0.377 0.422 A-3 450 60 1.07 4.72
25.39 0.047 0.337 0.384 A-4 750 0 1.00 2.88 26.14 0.043 0.206 0.249
A-5 750 60 1.07 1.98 26.27 0.047 0.141 0.188 A-6 750 120 1.13 0.84
27.26 0.049 0.060 0.109 A-7 750 180 1.05 0.57 27.58 0.046 0.041
0.087 A-8 750 240 1.09 0.54 27.62 0.047 0.039 0.086 Experiment B
B-1 150 30 1.03 5.42 24.54 0.045 0.387 0.432 B-2 450 0 1.03 5.04
25.07 0.045 0.360 0.405 B-3 450 60 1.16 4.74 25.17 0.050 0.339
0.389 B-4 572 0 1.14 4.41 25.44 0.050 0.315 0.365 B-5 752 0 1.15
3.33 26.17 0.050 0.238 0.288 B-6 932 0 1.17 0.48 27.43 0.051 0.034
0.085 B-7 1112 0 1.17 0.14 27.65 0.051 <0.010 <0.061 B-8 1292
0 1.14 0.13 25.19 0.050 <0.009 <0.059 B-9 1292 120 1.28 0.13
25.57 0.056 <0.009 <0.065
__________________________________________________________________________
*TIL -- True ignition loss corrected for ammonium. **Na --
Equivalent moles, moles/100 g. ignited catalyst (TIL). ***Molar
ratio Na.sub.2 O/Al.sub.2 O.sub.3 was 0.98. Molar ratio SiO.sub.
/Al.sub.2 O.sub.3 was 4.70. ****Time, in minutes, at indicated
maximum temperature.
TABLE 2
__________________________________________________________________________
Exchanged Zeolite Catalysts Chemical Composition of Activated
Ammonium Cerium Catlaysts
__________________________________________________________________________
Activation Conditions: Rotary Kiln, Dry Air, Ambient pressure,
Programed Temperatures, Air rate = 0.6SCFM
__________________________________________________________________________
Activation Conditions LOI* Moles**
__________________________________________________________________________
Run No. Max. Temp. .degree.F Time*** H.sub.2 O Na.sup.+
Ce.sup.3.sup.+ NH.sub.4 .sup.+ H.sub.2 O
__________________________________________________________________________
Experiment C C-1 150 30 17.21 0.037 0.097 0.025 0.354 0.937 C-2 450
0 10.25 0.037 0.096 0.054 0.379 0.523 C-3 450 60 5.21 0.038 0.096
0.068 0.394 0.228 C-4 750 0 4.05 0.038 0.097 0.043 0.371 0.186 C-5
750 60 3.38 0.034 0.098 0.020 0.350 0.169 C-6 750 120 3.56 0.036
0.098 0.014 0.345 0.186 C-7 750 180 3.09 0.033 0.098 <0.009
<0.336 0.163 C-8 750 240 3.40 0.035 0.098 <0.009 <0.337
0.180 Experiment D D-1 150 30 19.58 0.038 0.096 0.056 0.381 1.044
D-2 450 0 13.18 0.042 0.092 0.056 0.373 0.721 D-3 450 60 6.89 0.038
0.094 0.56 0.375 0.333 D-4 750 0 4.89 0.039 0.098 0.054 0.388 0.222
D-5 750 60 3.92 0.038 0.099 0.031 0.365 0.189 D-6 750 120 3.80
0.038 0.099 0.041 0.375 0.174 D-7 750 180 3.76 0.037 0.100 0.014
0.352 0.197 D-8 750 240 3.47 0.040 0.101 0.010 0.352 0.183
Experiment E E-1 150 30 15.09 0.037 0.096 0.051 0.376 0.796 E-2 450
0 9.76 0.043 0.098 0.051 0.387 0.497 E-3 450 60 5.08 0.042 0.090
0.057 0.370 0.230 E-4 572 -- 4.84 0.043 0.099 0.057 0.396 0.216 E-5
752 -- 4.08 0.041 0.098 0.049 0.384 0.182 E-6 932 -- 3.04 0.040
0.097 0.012 0.341 0.157 E-7 112 -- 2.70 0.043 0.098 <0.009
<0.347 0.127 E-8 1292 0 2.24 0.045 0.100 <0.009 <0.355
0.116 E-9 1292 120 1.66 0.034 0.099 <0.009 <0.340 0.083
__________________________________________________________________________
*LOI - Loss on ignition (includes ammonium) **Moles/100 g ignited
catalyst (TIL) ***Time, in minutes at indicated maximum
temperature.
TABLE 4
__________________________________________________________________________
Exchanged Zeolite Catalysts Water-cerium Ratio for Ammonium-Cerium
Exchanges Zeolite Catalysts Activated at Different Temperatures
__________________________________________________________________________
Basis of Data: Moles ion/100 g anhydrous catalyst Catalyst:
16NH.sub.4 .sup.+ exchanges followed by 16Ce.sup.3.sup.+ exchanges
Activation Conditions: Rotary kiln, Dry air, Ambient pressure,
Programed temperatures, Air Rate = 0.6
__________________________________________________________________________
SCFM Time at Total H.sub.2 O Temp Temp. Non-Ce H.sub.2 O.sup.(2)
Non-Ce Total for Ce H.sub.2 O/Ce Run No. (.degree.F) (min)
.DELTA..sup.(1) SiOH Na.sup.+ NH.sub.4 .sup.+ H.sub.2 O H.sub.2 O
Ce (moles) Ratio
__________________________________________________________________________
E-3 450 60 0.044 0.022 0.042 0.028 0.092 0.230 0.138 0.090 1.533
E-4 572 0 0.018 0.009 0.043 0.028 0.080 0.216 0.136 0.099 1.375 E-5
752 0 0.030 0.015 0.041 0.024 0.080 0.182 0.102 0.098 1.041 E-6 932
0 0.073 0.036 0.040 0.006 0.082 0.157 0.075 0.097 0.733 E-7 1112 0
0.072 0.036 0.043 0.002 0.081 0.127 0.046 0.098 0.470 E-8 1292 0
0.069 0.034 0.045 0.000 0.079 0.116 0.037 0.100 0.370 E-9 1292 120
0.083 0.042 0.034 0.000 0.076 0.083 0.007 0.009 0.077
__________________________________________________________________________
.sup.(1) .DELTA. = [(Molar equivalent Na.sup.+ in Na-Base)-(Molar
equivalents of measured ions in catalyst)] /100 g anhydrous base
.sup.(2) Non-Ce H.sub.2 O calculated as 2SiOH.fwdarw.1H.sub.2 O
& 2NH.sub.4 .sup.+ .fwdarw.1H.sub.2 O. .sup.(3) Anhydrous base
= ignited catalyst to which is added, as NH.sub.4 .sup.+, the
NH.sub.3 evolved on ignition at 1800.degree. F.
TABLE 5
__________________________________________________________________________
ISOBUTANE-BUTENE-2 ALKYLATION WITH ZEOLITE CATALYST
__________________________________________________________________________
Example No. VIII IX XIII XIII XIII* t-Butyl n-Propyl n-Butyl
Adjuvant None None Chloride Chloride Chloride
__________________________________________________________________________
Reaction Temp. 80.degree.C. 120.degree.C. 80.degree.C. 80.degree.C.
80.degree.C. Reaction Press. 250 475 250 250 250 (psig.) Wt.%
C.sub.5 .sup.+ Paraffin 71.4 129.4 142.8 129.6 117.2* Yield, based
on olefin charged C.sub.5 .sup.+ Paraffin Dist., Mole % C.sub.9
.sup.+ 4.5 10.7 14.1 5.8 10.1 C.sub.8 67.3 54.7 60.1 63.3 71.5
C.sub.7 5.1 12.0 5.9 5.7 7.1 C.sub.6 4.2 8.9 4.6 4.2 5.9 C.sub.5
19.0 13.7 15.3 21.0 5.4* Wt.% C.sub.5 .sup.+ Unsatu- 0.24 4.34 3.54
0.24 0.49 rate Yield based on olefin charged C.sub.8 Paraffin
Dist., Mole % Trimethyl- 88.2 74.0 82.4 88.1 85.0 pentanes
Dimethyl- 11.8 24.6 16.6 11.9 14.9 hexanes Methylhep- 0.0 1.5 1.1
0.0 0.1 tanes TMP/DMH.sub.x Ratio** 7.47 3.01 4.98 7.38 5.71 %
2,2,4 in TMP*** 26.9 -- 21.0 25.0 23.0
__________________________________________________________________________
In Ex. XIII halide concentration = 1.6 millimole/mole total
hydrocarbon charged. 80.degree.C., 250 psig., i-C.sub.4
-ane/C.sub.4 -ene = 14.9 mola (min.), 3.67 hr. 16NH.sub.4 .sup.+ -,
16Ce.sup.3.sup.+ -Catalyst (10.13% Ce, 0.68% Na-before 400.degree.
C max. activation) with an ignition loss 24.37% at 1800.degree.F.
Feed introduced into bottom of Jerguson guage. *One product gas
sample was lost. Some isopentane thereby not accounted for, and the
C.sub.5 .sup.+ yield and distribution are affected. **Mole ratio
trimethylpentanes to dimethylhexanes. ***Mole percent
2,2,4-trimethylpentane in total trimetylpentanes.
TABLE 6
__________________________________________________________________________
Source Cupit Kennedy Kennedy Ex. X Ex. XI Ex. XI EX. XII
__________________________________________________________________________
Cata- 96% HF AlCl.sub.3 CeHY* CeHy* CeHY* CeHY lyst H.sub.2
SO.sub.4 Reac. 7.2 20 30 60 40 25 120 Temp., .degree.C. % 2,2,4
43.9 54.3 65.3 14.8 9.1 4.0 32.3 in TMP
__________________________________________________________________________
*2.4 .times. 10.sup..sup.-3 mole t-butyl chloride adjuvant/mole
initial i-butane
TABLE 7
__________________________________________________________________________
ISOPARAFFIN-OLEFIN ALKYLATION WITH ZEOLITE CATALYSTS
__________________________________________________________________________
Temperature Effects upon Isobutane-Butene-2 Feed with a 16NH.sub.4
.sup.+ /16Ce.sup..sup.+3 Catalyst i-C.sub.4 -ane/C.sub.4 -ene-2 =
14.9 (molar min.), 220-min. time TBC = 1.6 mmole/mole hydrocarbon
Catalyst Air-activated at 750.degree.F.
__________________________________________________________________________
Temperature, .degree.C. 60 80 80 100 Run Number 560 552 566 558
C.sub.5 .sup.+ Paraffin Yield, wt. % OC 61.3 161.8 151.9 127.7
C.sub.5 .sup.+ Unsaturates, wt. % OC 0.00 0.00 0.00 0.00 C.sub.5
.sup.+ Paraffin Distribution, mole % C.sub. 9.sup.+ 12.1 6.0 7.7
6.8 C.sub.8 65.1 63.8 68.2 60.1 C.sub.7 5.1 6.8 7.7 9.6 C.sub.6 6.6
6.2 6.1 8.5 C.sub.5 11.0 17.3 10.3 15.0 C.sub.8 Paraffin
Distribution TMP 80.6 86.4 86.6 80.9 DMH.sub.x 19.4 13.6 13.4 19.1
MH.sub.p 0.0 0.0 0.0 0.0 TMP/DMH.sub.x 4.16 6.37 6.45 4.23 TMP
Distribution 2,2,4 10.3 22.3 20.5 27.0 2,2,3 5.0 5.0 5.0 5.0 2,3,4
36.6 33.5 34.0 32.9 2,3,3 48.2 39.3 40.5 35.1
__________________________________________________________________________
TABLE 8
__________________________________________________________________________
ISOPARAFFIN-OLEFIN ALKYLATION WITH ZEOLITE CATALYSTS
__________________________________________________________________________
Temperature Effects upon Isobutane-Butene-2 with NH.sub.4 .sup.+
Catalyst vs NH.sub.4 .sup.+ /Ce.sup..sup.+3 Catalyst i-C.sub.4
-ane/C.sub.4 -ene-2 = 15 (molar min.), 220-min. time Catalysts
Air-activated at 750.degree.F.
__________________________________________________________________________
Catalyst Exchange 16NH.sub.4 .sup.+ / 16NH.sub.4 .sup.+ / Cycles
32NH.sub.4 .sup.+ /O 16Ce.sup..sup.+3 16NH.sub.4 .sup.+ /O
16Ce.sup..sup.+3 TBC Adjuvant No NO Yes Yes Run Number 742 738 596
578 Temperature, .degree.C. 120 120 80 80 C.sub.5 .sup.+ Paraffin
Yield, wt. % OC 109.5 129.4 43.5 159.1 C.sub.5 .sup.+ Unsaturates,
wt. % OC 2.8 4.3 0.20 0.00 C.sub.5 .sup.+ Paraffin Distribu- tion,
mole % C.sub. 9.sup.+ 19.7 10.7 18.9 5.3 C.sub.8 42.5 54.7 54.3
69.5 C.sub.7 9.5 12.0 6.2 7.1 C.sub.6 9.7 8.9 7.0 5.9 C.sub.5 18.6
13.7 13.6 12.2 C.sub.8 Paraffin Dsitribution TMP 72.0 74.0 59.3
87.2 DMH.sub.x 27.2 24.6 38.7 12.8 MH.sub.p 0.7 1.5 2.0 0.0
TMP/DMH.sub.x 2.64 3.01 1.53 6.83 TMP Distribution 2,2,4 24.5 31.5
13.6 22.1 2,2,3 5.5 6.4 5.1 5.1 2,3,4 37.6 31.3 39.6 32.9 2,3,3
32.5 30.8 41.7 39.9
__________________________________________________________________________
TABLE 9
__________________________________________________________________________
ISOPARAFFIN-OLEFIN ALKYLATION WITH ZEOLITE CATALYSTS
__________________________________________________________________________
CCl.sub.4 as Adjuvant -80.degree.C., i-C.sub.4 -ane/C.sub.4 -ene-2
= 15 (min.), 3.67 hr., NH.sub.4 .sup.+ -, Ce.sup.3.sup.+ -Type
__________________________________________________________________________
Adjuvant Type TBC TBC TBC* TBC** CCl.sub.4 & TBC TBC &
TBA*** CCl.sub.4 Technique Continuous Pulse Pulse Pulse Continuous
Continuous Continuous Amount, mmole/m OC 42.6 28.4 30.1 30.1 30.1
CCl.sub.4 30.1 TBC 30.1 20.2 TBC 30.1 TBA Run Number 570 614 606
600 630 632 688 C.sub.5 .sup.+ Paraffin Yield, Wt.% OC 162.1 150.0
193.4 176.3 141.1 150.1 178.5 C.sub.5 .sup.+ Unsaturates, wt.% OC
0.00 0.00 0.04 C.sub.5 .sup.+ Paraffin Distribn., mole%
C.sub.9.sup.+ 9.1 4.6 7.3 5.8 4.1 5.0 5.8 C.sub.8 73.2 76.3 71.1
72.3 71.5 72.2 74.9 C.sub.7 7.3 7.3 7.1 7.1 6.8 7.0 7.5 C.sub.6 6.4
5.9 5.8 5.7 5.2 5.7 5.4 C.sub.5 4.0 5.9 12.4 10.2 6.4 C.sub.8
Paraffin Distribution TMP 86.0 88.4 87.1 87.8 88.0 88.2 87.9
DMH.sub.x 13.7 11.6 12.9 12.0 11.9 11.8 12.1 MH.sub.p 0.3 0.0 0.0
0.2 0.0 0.0 0.1 TMP Distribution 2,2,4- 19.5 24.5 22.9 27.2 29.2
28.3 26.4 2,2,3- 5.3 5.4 5.6 5.9 6.5 5.0 5.1 2,3,4- 34.2 30.9 31.8
29.1 27.1 28.7 30.9 2,3,3- 41.0 39.2 39.7 37.8 37.2 38.0 37.6
__________________________________________________________________________
*Perylene (from CCl.sub.4) presorbed on catalyst, TBC added
continuously **CCl.sub.4 presorbed on catalyst, TBC added
continuously ***TBA = t-butyl alcohol, TBC = t-butyl chloride
TABLE 10
__________________________________________________________________________
Paraffin Isobutane Isobutane Isobutane Isobutane n-Butane*
Isobutane Isobutane* *** *** 2-Methyl- 2-Methyl- *** *** **** ***
**** Olefin butene-2 butene-2 Butene-2 Butene-1 Butene-1 Butene-2
Butene-2
__________________________________________________________________________
Temperature .degree.C. 120 120 120 120 80 80 80 Pressure, psig. 460
485 455 455 250 250 250 Catalyst Wt.% Na (ignited) 1.68 1.11 1.11
1.38 0.76 0.76 0.76 Wt.% Ce (ignited) 6.8 8.7** 8.7** 12.4 13.5
13.5 13.5 C.sub.5 .sup.+ Paraffin Yield 28.6 49.0 51.8 119.7 25.6
135.0 132.0 Wt.% Olefin Chg. C.sub.5 .sup.+ Unsaturate 31.2 15.4
0.5 2.8 1.6 1.88 0.26 Yield, Wt.% Olefin Chg. C.sub.5 .sup.+
Paraffin Dist., Mole % C.sub.9.sup.+ 32.5 29.2 4.2 9.7 26.6 14.6
8.0 C.sub.8 32.6 36.6 82.8 55.0 25.6 69.3 69.0 C.sub.7 15.6 10.3
6.2 12.0 2.0 6.7 6.1 C.sub.6 15.2 10.3 5.2 11.4 2.0 5.5 5.2 C.sub.5
4.0 13.6 1.6 11.9 43.8 4.0 11.7 C.sub.8 Paraffin Dist., Mole %
Trimethyl- 71.2 74.7 63.8 75.7 33.7 85.4 88.0 pentanes Dimethyl-
26.4 24.3 36.4 23.1 65.6 14.6 12.0 hexanes Methylhep- 2.4 1.0 0.7
1.2 0.7 0.0 0.0 tanes
__________________________________________________________________________
*2.4 .times. 10.sup..sup.-3 mole tertiary butyl chloride used as
adjuvant per mole of n-butane. **Catalyst activated at
500.degree.C. (all other runs at 400.degree.C.) ***Feed introduced
at top of Jerguson gauge. ****Feed introduced at bottom of Jerguson
gauge.
TABLE 11
__________________________________________________________________________
Ex. Ex. Ex. Ex. Ex. Ex. Ex. Catalyst Prep. II IV IV VII** XV** XV**
IV**
__________________________________________________________________________
Temperature .degree.C. 120 120 120 80 80 80 80 Pressure, psig. 500
500 500 250 250 250 Wt.% Na (ignited) 0.26 1.38 0.3 0.6 0.82 0.9
0.76 Wt.% Ce (ignited) -- 12.4 13.5 1.72 -- -- 13.5 *** Wt.% La
(ignited) -- -- -- -- 12.3 **** -- Wt.% N (before 6.42 0.98 0.66
5.20 1.18 0.57 0.86 activation) Wt.% Ignition 30.25 24.24 25.84
28.41 25.25 24.95 24.70 Loss Wt.% C .sup.+ Paraf- 109.5 119.3 75.3
26.0 68.4 142.4 132.0 fin.sup.5 Yield* Wt.% C.sub.5.sup.+ Unsatu-
2.8 5.6 1.1 10.9 0.13 0.13 0.26 rate Yield* C.sub.5.sup.+ Paraffin
Dist. Mole % C.sub.9.sup.+ 19.7 11.5 11.2 27.2 5.4 3.6 8.0 C.sub.8
42.5 50.3 72.0 57.9 81.0 60.0 69.0 C.sub.7 9.5 9.0 8.6 5.8 5.9 4.1
6.1 C.sub.6 9.7 8.4 2.2 5.8 4.4 3.1 5.2 C.sub.5 18.6 20.7 6.0 3.3
3.2 29.2 11.7 C.sub.8 Paraffin Dist. Mole % Trimethyl- 72.0 73.1
75.0 55.1 89.0 88.4 88.0 pentanes do. Dimethyl- 27.2 25.7 23.8 41.4
11.0 11.6 12.0 hexanes do. Methyl- 0.7 1.2 1.2 3.5 0.0 0.0 0.0
heptanes do. TMP/DMH.sub.x 2.64 2.84 3.15 1.33 8.06 7.65 7.30
__________________________________________________________________________
*Based on weight of olefin charged. **t-Butyl chloride adjuvant.
Olefin and paraffin entered bottom of Jerguson gauge. ***Catalyst
prepared from La(NO.sub.3) solution. ****Catalyst prepared from
mixed rare earth nitrate solution and analyzed 13.8% total rare
earth metals (ignited).
TABLE 12 ______________________________________ Catalyst Content
Salt Used of Rare Earth Metals C.sub.5.sup.+ Paraffin for Exchange
(g. ion/100 g. Yield (wt. % Solution anhydrous cat.) olefin charge)
______________________________________ Ce(NO.sub.3).sub.3 0.286
132.0 CeCl.sub.3 0.272 73.1 La(NO.sub.3).sub.3 0.275 68.4
LaCl.sub.3 0.250 112.0.sup.(a) RE(NO.sub.3).sub.3 0.301 142.4
RECl.sub.3 0.236 103.1 Gd(NO.sub.3).sub.3 0.305 163.0
______________________________________ .sup.(a) Use of the magnetic
drive on the reactor possibly increased this yield as much as 15%
over what it would have been with the same packed drive used for
the other runs. Evan at (112-115 = 98%), its yield vastly exceeds
that from La(NO.sub.3).sub.3.
TABLE 13
__________________________________________________________________________
ISOPARAFFIN-OLEFIN ALKYLATION WITH ZEOLITE CATALYSTS
__________________________________________________________________________
Rare Earth Cation and Anion Effects on Catalysts 80.degree.C., 250
psig., i-C.sub.4 -ane/C.sub.4 -ene-2 = 14.9 (min.), 3.67 hr. 1.0 g.
t-Butyl Chloride
__________________________________________________________________________
Salt for Exchange Ce(NO.sub.3).sub.3 CeCl.sub.3 RE(NO.sub.3).sub.3
RECl.sub.3 La(NO.sub.3).sub.3 LaCl.sub.3 Catalyst Composition
Sodium, wt.%(ignited residue basis) 0.76 0.78 1.17 0.89 0.82 1.09
Rare Earth, wt.% (ignited residue basis) 13.5 12.9 14.2 11.2 13.1
11.9 Run Number (467-) 830 822 820 854 818 858 C.sub.5 .sup.+
Paraffin, wt.% chg. 132.0 73.1 142.4 103.1 68.4 112.0 C.sub.5
.sup.+ Unsaturates, wt. % olefin chg. 0.26 0.15 0.13 0.77 0.13 0.16
C.sub.5 .sup.+ Paraffin Distribution C.sub.9 .sup.+ , mole % 8.0
6.5 3.6 10.6 5.4 8.1 C.sub.8 , do. 69.0 78.1 60.0 66.9 81.0 61.7
C.sub.7 , do. 6.1 5.7 4.1 6.7 5.9 6.4 C.sub.6 , do. 5.2 4.1 3.1 3.9
4.4 4.4 C.sub.5 , do. 11.7 5.5 29.2 11.9 3.2 19.5 C.sub.8 Paraffin
Distribution TMP, mole % 88.0 88.6 88.4 84.8 89.0 86.2 DMH.sub.x,
do. 12.0 11.4 16.6 15.2 11.0 13.8 MH.sub.p , do. 0.0 0.0 0.0 0.0
0.0 .0 TMP/DMH.sub.x Ratio 7.30 7.74 7.65 5.09 8.06 6.25
__________________________________________________________________________
TABLE 14
__________________________________________________________________________
ISOPARAFFIN-OLEFIN ALKYLATION WITH ZEOLITE CATALYSTS
__________________________________________________________________________
Catalyst Cerium-Sodium Effects on Alkylation 80.degree.C., 250
psig., i-C.sub.4 -ane/C.sub.4 -ene-2 = 14.9 (min.), 3.67 hr. 1.0 g.
t-Butyl Chloride
__________________________________________________________________________
Catalyst Composition Sodium, wt. % (ignited residue basis ) 0.23
0.76 1.68 2.76 1.68 1.24 Cerium, wt. % ( do. ) 13.7.sup.(a)
13.5.sup.(a) 12.8.sup.(a) 13.0 8.3.sup.(a) 2.0 Run Number (467-)
852 830 848 850 846 828 C.sub.5 .sup.+ Paraffin, wt. % olefin
charge 135.2 132.0 115.4 118.9 62.7 26.0 C.sub.5 .sup.+
Unsaturates, wt. % olefin charge 0.32 0.26 0.42 0.77 4.52 10.85
C.sub.5 .sup.+ Paraffin Distribution C.sub.9 .sup.+ , mole % 8.4
8.0 10.6 10.1 19.1 27.2 C.sub.8 , do. 66.0 69.0 63.4 72.8 64.1 57.9
C.sub.7 , do. 6.6 6.1 6.7 7.2 7.4 5.8 C.sub.6 , do. 4.9 5.2 5.5 5.7
6.0 5.8 C.sub.5 , do. 14.1 11.7 13.9 4.1 3.4 3.3 C.sub.8 Paraffin
Distribution TMP, mole % 87.5 88.0 85.7 87.2 82.9 55.1 DMH.sub.x,
do. 12.4 12.0 14.3 12.8 16.2 41.4 MH.sub.p , do. 0.1 0.0 0.0 0.0
0.9 3.5 TMP/DMH.sub.x Ratio 7.08 7.30 6.00 6.80 5.10 1.33
__________________________________________________________________________
.sup.(a) By X-ray fluorescence. Others were by gravimetry.
TABLE 15
__________________________________________________________________________
Liquid Phase Isoparaffin-Olefin Alkylation with Solid Zeolite
__________________________________________________________________________
Catalysts Gadolinium versus Ammonium versus Cerium and Type X
versus Type Y Zeolite Autogenous pressure, 80.degree.C., i-C.sub.4
-ane/C.sub.4 -ene-2 = 15 (min.), 3.67 hr., 1.0 g. tertiary butyl
chloride adjuvant
__________________________________________________________________________
Catalyst Zeolite before activation GdNH.sub.4 Y GdNH.sub.4 Y
NH.sub.4 Y CeNH.sub.4 X CeNH.sub.4 Y Activation (400.degree.C.) Gas
Air He Air Air Air Run No. 628 674 596 622 642 C.sub.5 .sup.+
Paraffin Yield, wt.% OC 163.0 169.8 43.5 130.0 161.6 C.sub.5 .sup.+
Unsaturates, wt.% OC 0.00 0.05 0.2 0.0 0.00 C.sub.5 .sup.+ Paraffin
Distribution, mole % C.sub.9.sup.+ 3.7 5.8 18.9 8.3 5.4 C.sub.8
67.6 71.4 54.3 59.0 71.2 C.sub.7 5.7 7.7 6.2 4.8 7.4 C.sub.6 4.4
5.7 7.0 4.0 5.9 C.sub.5 18.5 9.3 13.6 23.9 10.0 C.sub.8 Paraffin
Distribution TMP 88.1 88.2 59.3 85.7 85.9 DMH.sub.x 11.9 11.8 38.7
14.2 14.1 MH.sub.p 0.0 0.0 2.0 0.1 0.0 TMP Distribution 2,2,4- 27.4
28.4 13.6 15.5 24.4 2,2,3- 5.9 5.4 5.1 4.1 5.6 2,3,4- 28.8 29.1
39.6 34.0 32.0 2,3,3- 37.9 37.1 41.7 46.4 38.0 Catalyst Analysis
(ignited basis, before activation) wt. % Na 9.97 0.97 1.05 0.93
0.97 wt. % Ce or Gd 14.39 Gd 14.39 Gd -- 15.5 Ce 13.99 Ce wt. % N
1.09 1.09 5.86 1.85 0.84 wt. % loss on ignition 25.35 25.35 29.67
25.47 26.28 Analysis of Base Na zeolite (before exchange, ignited
base) * * wt. % Na 9.51 9.51 -- -- 9.42 wt. % Al.sub.2 O.sub.3
16.56 16.56 -- -- 16.32 wt. % SiO.sub.2 45.29 45.29 -- -- 47.87 wt.
% loss on ignition 24.32 24.32 -- -- 25.05
__________________________________________________________________________
*Al/Si atomic ratio is 0.69 for the CeNH.sub.4 X zeolite before
activation.
TABLE 16 ______________________________________ Isoparaffin-Olefin
Alkylation with Solid Zeolite Catalysts Isobutane and Propylene
with and without Promoter ______________________________________
60.degree.C., i-C.sub.4 -ane/C.sub.3 -ene = 20 (min.), 120 min.
CeHY catalyst from 16NH.sub.4 /16 Ce Base
______________________________________ 42.3 mmole Promoter None
TBC/m OC 96% Run No., 690 544 H.sub.2 SO.sub.4 * C.sub.5 .sup.+
Paraffins, 66.1 123.3 Wt % OC C.sub.5 .sup.+ Unsaturates, 0.00 0.00
Wt. % OC C.sub.5 .sup.+ Paraffin Distribn., mole % Vol.%
C.sub.9.sup.+ 5.2 7.2 11.0 C.sub.8 12.1 11.2 9.8 C.sub.7 63.8 66.0
71.1 C.sub.6 6.9 5.9 4.2 C.sub.5 11.9 9.7 3.8 C.sub.8 Paraffin
Distribn. TMP 82.5 86.5 DMH.sub.x 16.1 13.5 MHp 1.4 0.0 TMP
Distribn. 2,2,4- 67.8 70.0 54.6 2,2,3- 1.7 0.4 0.0 2,3,4- 12.7
13.4} (45.4)** 2,3,3- 17.8 16.3 C.sub.7 Paraffin Distribn. 2,3-DMP
95.3 97.2 70.9 Other DMP 3.2 2.0 29.1 MH.sub.x 1.5 0.8 0.0
______________________________________ *At 7.degree.C., 47 Vol. %
emulsion, from Cupit, C.R.,et al, Petro Chem. Eng., p. 204
(December, 1961). **Total of 2,3,4- and 2,3,3-TMP.
TABLE 17
__________________________________________________________________________
ISOMERIZATION-OLEFIN ALKYLATION WITH SOLID ZEOLITE CATALYSTS
__________________________________________________________________________
Isobutane and Propylene Catalyst: CeHY (Base zeolite 0.35% Na,
14.19%Ce, 1.34% N) .sup.(a) Feed rate 1 ml/min. Time and
Isoparaffin/Olefin Effects
__________________________________________________________________________
Run No. 534 544 542 550 548 Temp. .degree.C. 60 60 60 60 60 Time,
hr. 3 2 4 3 3 Iso/Olefin Molar Ratio (min.) 15 20 15 10 5 Wt. TBC,
g. 1.0068 1.0018 1.0000 0.9006 0.6998 Wt. Catalyst, g. 21.99 22.54
22.04 19.95 15.83 C.sub.5 .sup.+ Paraffin Yield, wt. % OC 89.1
123.3 70.0 49.8 5.4 C.sub.5 .sup.+ Unsaturates, wt. % OC 0.41 0.00
0.00 0.00 0.07 C.sub.5 .sup.+ Paraffin Distri- bution, mole %
C.sub.9.sup.+ 16.2 7.2 22.6 21.8 28.4 C.sub.8 9.1 11.2 10.2 9.8
23.1 C.sub.7 56.3 66.0 52.4 53.9 38.6 C.sub.6 4.8 5.9 6.6 4.9 8.1
C.sub.5 13.6 9.7 8.2 9.6 1.7 TMP Distribution, mole % 2,2,4- 69.3
70.0 62.1 69.0 66.7 2,2,3- 0.3 0.4 0.6 0.0 1.1 2,3,4- 14.1 13.4
12.2 15.1 15.6 2,3,3- 16.3 16.3 15.2 15.9 16.7 C.sub.7 Paraffin
Distri- bution, mole % 2,3-DMP 98.2 97.2 95.9 97.2 92.9 Other DMP +
TMB 1.4 2.0 1.8 1.2 1.6 MH 0.4 0.8 2.3 1.6 1.5
__________________________________________________________________________
.sup.(a) Analysis on unactivated catalyst
TABLE 18
__________________________________________________________________________
Isoparaffin-Olefin Alkylation with Solid Catalyst
__________________________________________________________________________
Isobutanes and Pentenes Isopar./Olef. = 15 (min.) CeHy catalyst
Autogeneous pressure
__________________________________________________________________________
Run No. 584 582 590 586 H.sub.2 SO.sub.4 Olefin C.sub.5 -ene-1
C.sub.5 -ene-1 C.sub.5 -ene-1 3MB-ene-1 C.sub.5 -ene-1 Olefin
Vaporization Capacity (% OC) 10 10 10 10 Catalyst/Olefin (g/mole)
57.3 57.3 57.3 57.3 TBC/Olefin (mmole/mole) 28.4 28.4 28.4 28.4
Temperature (.degree.C) 60 80 100 80 Time (min.) 120 220 220 220
C.sub.5 .sup.+ Paraffin Yield, wt.% OC 57.6 67.5 64.2 115.1 C.sub.5
.sup.+ Unsaturates, wt.% OC 0.07 4.77 7.43 0.00 C.sub.5 .sup.+
Paraffin Distribution, mole % C.sub.9.sup.+ 61.3 47.8 40.6 11.1
38.2 C.sub.8 12.3 14.8 17.8 27.4 25.6 C.sub.7 4.9 3.6 6.3 4.4 0.7
C.sub.6 3.3 3.7 5.7 4.2 1.3 C.sub.5 18.1 30.0 29.6 52.8 33.9
C.sub.8 /C.sub.5 0.680 0.493 0.602 0.520 0.745 C.sub.8 Paraffin
Distribution TMP 78.7 85.2 78.2 89.1 DMH.sub.x 20.8 14.8 20.2 10.9
MHp 0.5 0.0 1.6 0.0 TMP Distribution 2,2,4- 62.6 55.9 56.3 58.4
2,2,3- 0.3 1.3 1.6 2.5 2,3,4- 17.3 20.2 22.0 18.4 2,3,3- 19.8 22.6
20.1 20.7
__________________________________________________________________________
* From J. E. Hofman, J. Orgn. Chem., 29, 1497-99 (1964)
TABLE 19
__________________________________________________________________________
Isoparaffin-Olefin Alkylation with Solid Zeolite Catalysts
Isobutane with Butene-1 and 2, Isobutylene, and Diisobutylene
__________________________________________________________________________
Isopar./Olef. = 15 (min.), CeHY (16NH.sub.4 /16Ce) Catalyst,
80.degree.C., 220 minutes Catalyst/Olefin = 57.3 g./mole,
TBC/Olefin = 28.4 mmole/mole
__________________________________________________________________________
Run No. 578 594 592 588 666 Olefin C.sub.4 -ene-2 C.sub.4 -ene-1
i-C.sub.4 -ene 2,4,4-TMP-ene-1 2,3-Dimethylbutenol Olefin
Vaporization Capacity (% OC) 22.3 22.3 22.3 1 C.sub.5 .sup.+
Paraffin Yield, Wt.% OC 159.1 168.3 123.9 120.5 87.0 C.sub.5 .sup.+
Unsaturates, Wt.% OC 0.00 0.00 {0.58 } {29.2 as C.sub.8} 0.08 {as
C.sub.8} {0.21 as C.sub.5} C.sub.5 .sup.+ Paraffin Distribn., mole
% C.sub.9.sup.+ 5.3 8.2 18.5 28.2 24.6 C.sub.8 69.5 69.2 49.3 49.5
23.0 C.sub.7 7.1 6.8 8.5 7.2 10.3 C.sub.6 5.9 5.7 7.6 6.5 31.7
C.sub.5 12.2 10.1 16.0 8.6 10.4 C.sub.8 Paraffin Distribn. TMP 87.2
85.4 88.7 87.0 83.9 DMH.sub.x 12.8 14.6 11.1 10.2 13.8 MHp 0.0 0.0
0.2 2.8 2.2 TMP Distribn. 2,2,4- 22.1 21.2 60.1 64.6 58.3 2,2,3-
5.1 5.0 2.6 1.9 2.2 2,3,4- 32.9 33.8 17.7 16.7 19.3 2,3,3- 39.9
40.0 19.6 16.8 20.2
__________________________________________________________________________
*C.sub.6 paraffin distribution, for Run 666 was 97% 2,3-DMB, 1.3%
2,2-DMB and 1.7% MP.
TABLE 20 ______________________________________ Run A* Run B* Ex.
XIX* ______________________________________ % Yield C.sub.5 .sup.+
Paraffin** 132 148 50.1 % Yield C.sub.5 Unsaturates** 0.26 0.19
0.00 C.sub.5 .sup.+ Paraffin Distribution C.sub.9 .sup.+ , Mole %
8.0 8.8 5.3 - C.sub.8 , Mole % 69.0 71.8 80.5 C.sub.7 , Mole % 6.1
6.3 3.8 C.sub.6 , Mole % 5.2 5.2 2.1 C.sub.5 , Mole % 11.7 7.9 8.4
C.sub.8 Paraffin Distribution TMP, Mole % 88.0 88.8 92.0 DMH.sub.x,
Mole % 12.0 11.2 8.0 MHp, Mole % 0.0 0.0 0.0 TMP/DMH.sub.x Ratio
7.30 7.91 11.44 Trimethylpentane Distribution % 2,2,4- 25.2 17.1 %
2,2,3- 3.7 5.0 % 2,3,4- 31.8 33.3 % 2,3,3- 39.3 44.7
______________________________________ *Feed olefin introduced at
bottom of Jerguson gauge. **Based on weight of olefin charged.
TABLE 21
__________________________________________________________________________
Helium and Hydrogen versus Air Activation at 400.degree.C. NH.sub.4
.sup.+ -, Ce.sup.3 - Type Y Base 80.degree.C, autogeneous pressure,
i-C.sub.4 -ane/C.sub.4 -ene-2 = 15 (min.), 3.67 hr., 1.0 g. TBC
__________________________________________________________________________
Activation Gas Air Air H.sub.2 He Run No. 654 656 658 660 C.sub.5
.sup.+ Paraffin Yield, wt.% OC 142.6 139.7 148.8 160.6 C.sub.5
.sup.+ Unsaturates, wt.% OC 0.00 0.05 0.00 0.14 C.sub.5 .sup.+
Paraffin Distribn., mole % C.sub.9.sup.+ 9.2 9.1 8.1 7.8 C.sub.8
66.8 66.1 69.2 70.5 C.sub.7 6.4 6.2 6.7 5.8 C.sub.6 6.2 5.8 5.7 5.9
C.sub.5 11.4 12.9 10.3 9.9 C.sub.8 Paraffin Distribn. TMP 85.6 86.4
86.7 87.5 DMH.sub.x 14.4 13.5 13.1 12.4 MHp 0.0 0.2 0.2 0.0 TMP
Distribn. 2,2,4- 22.3 23.8 25.8 26.8 2,2,3- 5.0 5.3 5.3 5.4 2,3,4-
33.9 32.3 31.1 30.4 2,3,3- 38.9 38.7 37.8 37.3
__________________________________________________________________________
TABLE 22
__________________________________________________________________________
Isoparaffin-Olefin Alkylation with Solid Catalysts
__________________________________________________________________________
Amount of Catalyst and Performance i-C.sub.4 -ane/C.sub.4 -ene-2 =
15 (molar min.) 220-min. Time 16/16 -type Catalyst
__________________________________________________________________________
Catalyst 1F7 1F1 1F8 1F9 Relative Amt. 1.0 2.0 0.5 1.0 1.0 1.5 Run
Number 738 744 564 552 566 568 TBC Promoter No No Yes Yes Yes Yes
Temperature, .degree.C 120 120 80 80 80 80 C.sub.5 .sup.+
Paraffins, wt.% OC 129.4 101.4 98.5 161.8 151.9 140.8 C.sub.5
.sup.+ Unsaturates, wt.% OC 4.3 0.81 0.00 0.00 0.00 0.00 C.sub.5
.sup.+ Paraffin Distribn., mole % C.sub.9.sup.+ 10.7 6.9 8.1 6.0
7.7 3.4 C.sub.8 54.7 43.1 70.0 63.8 68.2 66.2 C.sub.7 12.0 9.9 6.9
6.8 7.7 6.8 C.sub.6 8.9 11.7 6.5 6.2 6.1 6.0 C.sub.5 13.7 28.4 8.5
17.3 10.3 17.5 C.sub.8 Paraffin Distribn. TMP 74.0 76.1 81.6 86.4
86.6 87.5 DMH.sub.x 24.6 22.8 17.6 13.6 13.4 12.5 MHp 1.5 1.1 0.8
0.0 0.0 0.0 TMP-DMH.sub.x 3.01 3.34 4.65 6.37 6.45 7.03 TMP
Distribn. 2,2,4- 31.5 40.4 17.9 22.3 20.5 27.3 2,2,3- 6.4 10.7 4.8
5.0 5.0 5.5 2,3,4- 31.3 21.7 36.0 33.4 34.0 38.1 Grams of Catalyst
24.53 48.43 10.97 22.79 22.78 34.37
__________________________________________________________________________
* * * * *