Hydrocarbon conversion process using a supported perfluorinated polymer catalyst

A process and catalyst for the conversion of hydrocarbons is disclosed. The catalyst is supported solid perfluorinated polymer containing pendent sulfonic acid groups. The processes include alkylation of isoparaffins, isomerization of normal alkanes, disproportionation of toluene, and the alkylation of benzene.

BACKGROUND OF THE INVENTION 
Hydrocarbon conversion and the isomerization of hydrocarbons in particular, 
is of special importance to the petroleum industry. In recent years, with 
the advent of catalytic converters in automobiles and the required use of 
non-leaded gasoline, a need has arisen for higher octane number gasolines. 
Natural straight-run gasolines, i.e., naphthas, contain, chiefly, normal 
paraffins, such as normal pentane and normal hexane, which have relatively 
low octane numbers. It has become essential, therefore, to convert these 
low octane components to their higher octane counterparts. The 
isomerization of these hydrocarbon components accomplish this conversion, 
i.e., the isomers resulting have a much higher octane rating. Hence, the 
facility with which this isomerization is accomplished has become of prime 
importance. 
Likewise, the need for isoparaffins, benzene, xylene, and ethyl benzene as 
building components in the petrochemical industry is increasing. 
Accordingly, the need for improved hydrocarbon conversion processes in the 
petrochemical industry is also great. 
One of the primary hydrocarbon conversion processes now employed is the 
alkylation of isoparaffins. It was thought that certain sulfonated 
fluorocarbon polymers possess sufficient activity and stability to be 
useful as alkylation catalysts. However, in a recent study by Kapura and 
Gates, Sulfonated Polymers as Alkylation Catalysts, Industrial Engineering 
Chemistry Product Research Development, Vol. 12, No. 1, pp. 62-66 (1973), 
it was found that a sulfonated fluorocarbon vinyl ether polymer was 
inactive in alkylating isobutane with propylene in the gas phase and in a 
mole ratio of 5 to 1 at 260.degree. C. The conclusion reached in that 
study was that the sulfonated fluorocarbon vinyl ether polymer catalyst 
was too weakly acidic to catalyze paraffin alkylation and that the polymer 
was not a useful catalyst. That study also showed that these same ion 
exchange resins were useful in the alkylation of benzene with propylene in 
the vapor phase to form cumene. However, the conclusion reached by Kapura 
and Gates with regard to the formation of cumene was that the sulfonated 
polymer was not "a particularly useful catalyst at temperatures greater 
than about 150.degree. C." Contrary to the conclusions reached by Kapura 
and Gates, it has now been found that a supported perfluorinated polymer 
containing pendant sulfonic acid groups is a very active catalyst in the 
preparation of ethylbenzene from benzene and ethylene, in the alkylation 
of isoparaffins, in the isomerization of normal alkanes, and in the 
disproportionation of toluene. 
SUMMARY OF THE INVENTION 
The present invention comprises an improved hydrocarbon conversion process 
which comprises contacting said hydrocarbons under hydrocarbon converting 
conditions with a supported perfluorinated polymer catalyst containing a 
repeating structure selected from the group consisting of: 
##STR1## 
where n is 0, 1 or 2; R is a radical selected from the group consisting of 
fluorine and perfluoroalkyl radicals having from 1 to 10 carbon atoms; and 
X is selected from the group consisting of: 
EQU [O(CF.sub.2).sub.m ] , [OCF.sub.2 CFY] or [OCFYCF.sub.2 ] 
where m is an integer from 2 to 10 and Y is a radical selected from the 
class consisting of fluorine and the trifluoromethyl radical. 
Also disclosed is a novel catalyst composition for the conversion of 
hydrocarbons which comprises a catalytic component dispersed on a solid, 
porous support. The catalytic component is the perfluorinated polymer 
having the structure I or II above. The solid porous support has an 
effective pore diameter of between about 50 A and about 600 A and is 
preferably selected from the group consisting of alumina, silica, 
silica-alumina and porous glass.

DETAILED DESCRIPTION OF THE INVENTION 
A. The Catalyst Composition 
The catalyst employed in the present invention is a solid at reaction 
conditions. The catalyst broadly comprises a perfluorinated polymer having 
acid groups in the amount of about 0.01 to 5 mequiv/gram catalyst. 
Preferably, the polymer contains about 0.05 to 2 mequiv/gram of catalyst. 
In a specific embodiment, the polymer catalyst contains a repeating 
structure selected from the group consisting of: 
##STR2## 
where n is 0, 1 or 2; R is a radical selected from the group consisting of 
fluorine and perfluoroalkyl radicals having from 1 to 10 carbon atoms; and 
X is selected from the group consisting of: 
EQU [O(CF.sub.2).sub.m ] , [OCF.sub.2 CFY] or [OCFYCF.sub.2 ] 
where m is an integer from 2 to 10 and Y is a radical selected from the 
class consisting of fluorine and the trifluoromethyl radical. In a 
preferred embodiment, n is 1 or 2, Y is a trifluoromethyl radical, R is 
fluorine, and m is 2. Catalysts of the above-noted structure typically 
have a molecular weight of between about 1,000 and 500,000 daltons. 
Polymer catalysts of the above-noted structure can be prepared in various 
ways. One method, disclosed in Connolly et al, U.S. Pat. No. 3,282,875 and 
Cavanaugh et al, U.S. Pat. No. 3,882,093, comprises polymerizing vinyl 
compounds of the formula: 
##STR3## 
in a perfluorocarbon solvent using a perfluorinated free radical 
initiator. Since the vinyl ethers are liquid at reaction conditions, it is 
further possible to polymerize and copolymerize the vinyl ethers in bulk 
without the use of a solvent. Polymerization temperatures vary from 
-50.degree. to +200.degree. C. depending on the initiator used. Pressure 
is not critical and is generally employed to control the ratio of the 
gaseous comonomer to the fluorocarbon vinyl ether. Suitable fluorocarbon 
solvents are known in the art and are generally perfluoroalkanes or 
perfluorocycloalkanes, such as perfluoroheptane or 
perfluorodimethylcyclobutane. Similarly, perfluorinated initiators are 
known in the art and include perfluoroperoxides and nitrogen fluorides. It 
is also possible to polymerize the vinyl ethers of structure III or IV in 
an aqueous medium using a peroxide or a redox initiator. The 
polymerization methods employed correspond to those established in the art 
for the polymerization of tetrafluoroethylene in aqueous media. 
It is also possible to prepare catalysts for the present invention by 
copolymerizing the vinyl ethers of structure III or IV with 
perfluoroethylene and/or perfluoro-alpha-olefins. A preferred copolymer 
prepared by polymerizing perfluoroethylene with a perfluorovinyl ether 
containing attached sulfonic acid groups would have the following 
structure: 
##STR4## 
where n = 1 or 2 and the ratio of x over y varies from about 2 to about 
50. The polymer of structure V is available commercially under the 
tradename of NAFION.RTM. resin. Catalysts of the above-noted structure V 
offer the advantages of high concentrations of accessible acid groups in a 
solid phase. 
The catalyst of the present invention is supported on a porous solid inert 
support. The supported catalysts possess greater activity per unit of acid 
present than do the unsupported catalysts. By porous solid support is 
meant an inert support material having a porous structure and an average 
pore diameter of between about 50 A and about 600 A or higher. Preferably, 
the average pore diameter of the support is greater than about 200 A. The 
porous solid support of the subject invention is preferably selected from 
the inorganic oxide group consisting of alumina, fluorided alumina, 
zirconia, silica, silica-alumina, magnesia, chromia, boria, and mixtures 
and combinations thereof. Other porous solid supports may also be used 
such as bauxite, kieselguhr, kaolin, bentonite, diatomaceous earth and the 
like. Other porous solid supports such as polytetrafluoroethylene, carbon, 
e.g., charcoal, polytrichlorofluoroethylene, porous glass, and the like 
may also be used. Basically, the support should be substantially inert to 
the catalyst, and be insoluble in the mixture under reaction conditions. 
The average pore diameter (also known as effective pore diameter) of the 
support, which is related to the ratio of pore volume to surface area, is 
an important consideration in the choice of support. Generally, as the 
average pore diameter of the support is increased, the activity of the 
catalyst is increased. For example, as shown in the Illustrative 
Embodiments which follow, an isomerization catalyst composition having a 
porous glass support with a 207 A average pore diameter was only about 60% 
as active as an isomerization catalyst composition having a porous glass 
support with a 310 A average pore diameter. Most preferably, the support 
should possess both a high surface area and a high average pore diameter. 
The weight ratio of catalyst to support varies from about 0.1:100 to about 
30:100, preferably from about 1:100 to about 15:100. The support is 
preferably impregnated with the catalyst by dissolving the catalyst in a 
solvent, such as ethanol, mixing the support and the catalyst solution, 
and then drying the impregnated support under vacuum at a temperature of 
between about 25.degree. C. and about 100.degree. C. so as to remove the 
solvent. 
The invention is further defined with reference to a variety of particular 
hydrocarbon conversion processes. 
B. Alkylation of Isoparaffins 
The catalytic alkylation of paraffins involves the addition of an 
isoparaffin containing a tertiary hydrogen to an olefin. The process is 
extensively used by the petroleum industry to prepare highly branched 
paraffins mainly in the C.sub.7 to C.sub.9 range, which are high quality 
fuels for ignition engines. The overall process as to chemistry is a 
composite of complex reactions, and consequently a rigorous control of 
operating conditions and of catalyst is needed to assure predictable 
results. 
Acid catalyzed hydrocarbon conversion processes comprising contacting an 
alkane with an olefin are well known. The reactants are generally 
contacted in the liquid phase and within a broad temperature range of 
about -100.degree. F. to about 100.degree. F. with an acid catalyst such 
as, for example, sulfuric acid, fluorosulfuric acid or a halogen acid, 
such as hydrofluoric acid. Typical alkylation processes are disclosed in 
U.S. Pat. No. 2,313,103, U.S. Pat. No. 2,344,469, U.S. Pat. No. 3,864,423 
and British Pat. No. 537,589. Catalyst moderators, such as water and lower 
monoethers as disclosed in U.S. Pat. No. 3,887,635, are often employed to 
improve the selectivity of the catalyst. 
The catalysts employed in the above-noted references are liquid catalysts. 
Therefore, the process equipment must be necessarily complex. The reaction 
zone typically contains elaborate hardware to ensure intimate mixing of 
catalyst and reactions. In addition, a separation chamber is required to 
separate the catalyst from the hydrocarbon product. Further, since the 
reaction typically takes place at lower than ambient temperature, 
refrigeration facilities are also a necessary part of the process. 
One means to improve the alkylation process would be to employ a solid 
catalyst instead of a liquid catalyst. However, conventional solid acid 
catalysts, such as zeolites, are not very stable in their catalytic 
activity. For example, during isobutane/butene-2 alkylation, zeolites 
undergo catastrophic decline in activity in 4 to 6 hours. Likewise, other 
solid alkylation catalysts, such an HF antimony pentafluoride catalyst as 
disclosed in U.S. Pat. No. 3,852,371, are not commercially stable 
catalysts. 
In the present invention, a C.sub.4 to C.sub.6 isoparaffin containing a 
tertiary hydrocarbon or a hydrocarbon stream containing such isoparaffins 
is contacted with a C.sub.2 to C.sub.5 monoolefin, mixtures thereof, or 
hydrocarbon streams containing such olefins, in the liquid phase and at a 
temperature of between about 80.degree. C. and about 225.degree. C. in the 
presence of the catalyst composition of the instant invention. 
The present invention has a distinct advantage over the typical alkylation 
process in that the catalyst is a solid catalyst thereby eliminating many 
of the mixing, settling, separation, and neutralization problems 
associated with catalysts such as sulfuric acid, hydrofluoric acid, or 
fluoromethane sulfuric acid. The present catalyst is also superior to the 
other solid catalysts such as zeolites in that the present catalyst is 
very stable under reaction conditions. For example, catalyst runs with the 
instant catalyst of over 200 hours have been achieved with no appreciable 
decline in catalyst activity. 
Further, contrary to prior investigations, the present catalyst is very 
active in the alkylation reaction resulting in over 90% conversion of the 
olefin and over 80% C.sub.8 selectivity. In addition, the trimethylpentane 
selectivity (basis C.sub.8 H.sub.18) of the present catalyst is over 75%. 
As shown in the Illustrative Embodiments which follow, the supported 
catalysts have a much greater activity than do the unsupported catalyst 
based on the number of grams of catalyst present. For example, the 
activity of a 1% NAFION.RTM. resin on a Johns Mansville Chromosorb T is 
2.5 times greater than a 5% Nafion resin on silica support and about 12 
times greater than an unsupported Nafion resin catalyst per unit of actual 
catalyst present. 
The olefin feed for the present invention contains olefins selected from 
the group consisting of C.sub.2 to C.sub.5 monoolefins and mixtures 
thereof. Examples of suitable olefins include propylene, isobutylene, 
butene-1, butene-2, trimethylethylene, the isomeric amylenes and mixtures 
thereof. In actual commercial use, however, these olefins will contain 
other hydrocarbons. The process of the instant invention contemplates the 
use of various refinery cuts as feedstocks. Thus, C.sub.3, C.sub.4 and/or 
C.sub.5 olefin cuts from thermal and/or catalytic cracking units; field 
butanes which have been subjected to prior isomerization and partial 
dehydrogenation treatment; refinery stabilizer bottoms; spent gases; 
normally liquid products from sulfuric acid or phosphoric acid catalyzed 
polymerization and copolymerization processes; and products, normally 
liquid in character, from thermal and/or catalytic cracking units, are all 
excellent feedstocks for the present process. 
The isoparaffin feed for the present invention comprises C.sub.4 to C.sub.6 
isoparaffins containing tertiary hydrocarbon substituents, mixtures 
thereof, and hydrocarbon streams containing such components. A preferred 
isoparaffin is isobutane. 
In order to prevent polymerization of the olefin, a large excess of 
isoparaffin is used. The weight ratio of isoparaffin to olefin varies from 
about 5:1 to about 1000:1, preferably about 20:1 to about 60:1. It has 
been found that when the isobutane to butene ratio is increased from 10:1 
to 40:1, the C.sub.8 selectivity and the total yield of greater than or 
equal to C.sub.5 products are significantly increased while the yield of 
C.sub.11 -C.sub.12 and C.sub.14 -C.sub.16 products are decreased. 
The process may be carried out either as a batch or continuous type of 
operation, although it is preferred to carry out the process continuously. 
It has been generally established that in alkylation processes, the more 
intimate the contact between the feedstock and the catalyst, the better 
the yield of saturated product obtained. With this in mind, the present 
process, when operated as a batch operation, is characterized by the use 
of vigorous mechanical stirring or shaking of the reactants and catalyst. 
When employing a continuous process, the feedstreams may be contacted with 
the supported catalyst in any suitable reactor. In one embodiment, the 
supported catalyst is packed in a vertical, tubular reactor bed with inert 
supports, such as ceramic balls or silicon carbide, above and below the 
supported catalyst to prevent entrainment of the solid catalyst. In a 
further embodiment, the supported catalyst is mixed with an inert 
material, such as quartz, and loaded in the reactor so as to improve the 
fluid dynamics of the system. The flow of the reactant feed stream may be 
upflow or downflow, with an upflow arrangement being preferred to ensure 
liquid phase alkylation. 
Reaction temperature is varied between about 80.degree. C. and about 
225.degree. C. depending upon the type of products desired. The reaction 
temperature must be kept below about 225.degree. C. due to the lack of 
stability of the catalyst at temperatures of over 250.degree. C. A 
preferred temperature range is between about 80.degree. C. and about 
130.degree. C. In general, the activity of the catalyst is greater at the 
higher temperatures. That is, as temperature increases, the conversion of 
olefin increases. 
In general, the pressure in the alkylation reaction zone is maintained to 
keep the reactants in the liquid phase, and accordingly, will vary with 
the reactants employed and the reaction temperatures. Typical reaction 
zone pressure varies from about 10 psig to about 2,000 psig. 
The weight hourly space velocity effectively measures the catalyst 
concentration employed, and hence also measures the relative activity of 
the catalyst. Weight hourly space velocity (WHSV) is defined as the weight 
per hour of olefin feed divided by the weight of catalyst (not including 
support) employed. For non-supported catalyst, the WHSV varies between 
about 0.05 and about 1.0, preferably about 0.15 and about 0.5. For a 
supported catalyst, the WHSV varies between about 0.5 to about 10.0. The 
larger WHSV employed for supported catalysts is possible because of the 
greater activity of the supported catalyst. 
In a preferred embodiment, a gas stream is introduced into the reactor 
along with the olefin and isoparaffin feed streams. Typically, the gas is 
an inert gas such as nitrogen. However, it has been found that when the 
gas stream also contains hydrogen, the total yield of C.sub.5 or greater 
products is increased without significantly increasing the n-butane 
selectivity or changing the trimethylpentane selectivity. The effect of 
including this gas stream in the alkylation reaction is to improve the 
percentage of C.sub.8 H.sub.18 in the C.sub.8 product, which improvement 
most likely occurs via hydride transfer from hydrogen to an intermediate 
C.sub.8 carbonium ion to give a C.sub.8 H.sub.18 alkane. 
The reaction products obtained are highly branched paraffins, mainly in the 
C.sub.5 to C.sub.12 range. The butenes produce mainly C.sub.8 
hydrocarbons, principally dimethylhexanes and trimethylpentanes, while 
isobutylene results in mainly trimethylpentanes. It is not necessary to 
neutralize the reaction products of the present invention, since little, 
if any, of the sulfonic acid groups on the catalyst are removed during the 
reaction. 
The principal use of the alkylate produced according to the present 
invention is in the blending of motor gasoline. Alkylate is a preferred 
gasoline blending component because of its high octane number, which 
number is enhanced by the presence of high concentrations of C.sub.8 
hydrocarbons. Trimethylpentane is a particularly valuable alkylate 
component. 
The invention is further illustrated by means of the following Comparative 
Example and Illustrative Embodiments which are given for the purpose of 
illustration only, and the invention is not to be regarded as limited to 
any of the specific materials or conditions recited therein. 
In the Comparative Example and Illustrative Embodiments, the reactor 
employed was a 17 inch stainless steel tube equipped with both a liquid 
feed upflow inlet and a nitrogen inlet. The catalyst bed occupied about 10 
inches in the center of the reactor; and on either side of the catalyst 
bed were packed about 10 grams of carborundum chips. The catalyst bed was 
intitially charged with liquified isobutane at a flow rate of 10-20 
milliliters per hour after the reactor was heated to 
80.degree.-120.degree. C. Once the reactor was completely flooded with 
isobutane, the mixture of olefin and isoparaffin were charged to the 
reactor. In all cases, the olefin employed was 2-butene and the 
isoparaffin employed was isobutane. 
In the Comparative Example and Illustrative Embodiments, the reactants were 
introduced in an upflow manner. Pressure in all cases was kept at 500 psig 
to maintain a liquid phase. In all cases, a 100% nitrogen gas was added at 
a rate of 0.3 liters per hour. 
The products were recovered at periodic intervals and analyzed by gas 
chromatography. The percentage of alkenes in the C.sub.8 fraction were 
determined by washing the fraction with 96% sulfuric acid to remove the 
alkenes. 
In the Comparative Example and Illustrative Embodiments, the catalyst 
concentration is measured by weight hourly space velocity (WHSV, 
hr.sup.-.sup.1) which is defined as the weight of the 2-butene feed per 
hour divided by the weight of catalyst employed. The weight of the support 
employed in the Illustrative Embodiments is not included in the 
calculation of WHSV. The total yield of greater than or equal to C.sub.5 
products is based on the weight of butene converted. Further, since 
2,2,5-trimethylhexane is the only significant C.sub.9 product formed and 
has a high octane number, it is included in the C.sub.8 H.sub.18 fraction 
as reported. 
Comparative Example Ia 
The catalyst for Comparative Example Ia was prepared by grinding Nafion XR 
granules with a blender to 150 micrometer or less particle size. The 
ground material was then treated twice with 30% sulfuric acid to convert 
the material from a potassium (K.sup.+) form to the H.sup.+ form. The 
treated material was collected by filtration, washed with distilled water 
until the washings were neutral, and then dried at 100.degree. C. and 3 mm 
pressure for 16 hours. The resulting catalyst contained about 0.85 
milliequivalents of acid per gram of catalyst. The structure for the 
resulting catalyst is exemplified by the following repeating structure 
where n = 1 or 2 and the ratio of x over y varies from between 2 and about 
50: 
##STR5## 
In Comparative Example Ia, the catalyst bed comprised 2.5 grams of catalyst 
plus 7.5 grams of quartz particles. The isobutane to butene-2 ratio was 
maintained at about 10 to 1, whereas the WHSV and temperature were varied 
as indicated. The total length of the run lasted over 90 hours, and the 
results are presented below in Tables 1a, 2a and 3a. 
Table 1a 
__________________________________________________________________________ 
Time, hrs 3 5 7 9 11 13 15 16 18 19 20 22 
WHSV, hr 0.4 
0.4 
0.4 
0.4 
0.4 
0.66 
0.66 
0.66 
0.66 
0.66 
0.66 
0.66 
Temperature, .degree. C. 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
100 
Butene Conversion, % 
97 97 97 98 99 96 96 96 95 95 95 96 
Total Yield .gtoreq. C.sub.5 's, %w 
150 
147 
146 
146 
147 
145 
146 
146 
146 
146 
145 
146 
Products, %w 
C.sub.5 -C.sub.7 
3 3 2 2 2.5 
2 2 2 1.5 
2 2 1.5 
C.sub.8 -C.sub.9 
65 65 65 65 64 68 68 70 71 70 71 71 
C.sub.11 -C.sub.12 
20 20 22 22 20 20 19 17 17 17 16 19 
C.sub.14 -C.sub.16 
12 12 11 11 13.5 
10 11 11 11 11 11 9.5 
Composition of C.sub.8, % 
C.sub.8 H.sub.18 
81 70 70 70 73 66 67 65 65 65 64 64 
C.sub. 8 H.sub.16 
19 30 30 30 27 34 33 35 35 35 35 36 36 
Composition of C.sub.8 H.sub.18, % 
Trimethylpentanes 
75 75 70 71 63 67 70 71 74 66 66 67 
Dimethylhexanes 
18 18 19 20 24 20 21 20 19 24 22 23 
Methylheptanes 
4 4 6 5 6 6 4 4 4 5 6 5 
2,2,5-Trimethylhexane 
4 4 5 5 7 7 5 5 3 5 6 5 
__________________________________________________________________________ 
Table 2a 
__________________________________________________________________________ 
Time, Hr. 24 26 28 30 32 33 34 36 38 39.5 
42.5 
44.5 
46 
WHSV, hr..sup.-.sup.1 
0.66 
0.66 
0.66 
0.66 
0.66 
0.66 
0.66 
0.66 
0.66 
0.66 
0.66 
0.66 
0.66 
Temperature, .degree. C. 
90 90 90 90 90 90 90 90 90 90 90 90 90 
Butene, Conversion, % 
86 85 85 87 85 85 84 87 87 88 87 85 88 
Total Yield .gtoreq. C.sub.5 's 
142 
140 
140 
140 
139 
139 
140 
143 
140 
142 
138 
139 
141 
Products, %w 
C.sub.5 -C.sub.7 
3 2 1 2 1 1 2 1 1 1 2 1 1 
C.sub.8 -C.sub.9 
74 74 73 74 73 74 73 74 74 75 74 73 74 
C.sub.11 -C.sub.12 
14 16 17 16 15 16 14 16 16 14 16 17 15 
C.sub.14 -C.sub.16 
10 9 9 9 11 9 11 9 9 10 8 9 10 
Composition of C.sub.8, % 
C.sub.8 H.sub.18 
56 58 56 58 56 57 60 58 57 56 57 57 58 
C.sub.8 H.sub.16 
44 42 44 42 44 43 40 42 43 44 43 43 43 
Composition of C.sub.8 H.sub.18, % 
Trimethylpentanes 
75 74 75 75 74 75 74 73 75 73 74 75 75 
Dimethylhexanes 
18 18 17 17 18 19 17 19 17 19 17 19 18 
Methylheptanes 
3 4 4 4 4 4 5 4 5 5 5 4 4 
2,3,5-Trimethylhexane 
4 4 4 4 4 2 4 5 3 3 4 2 3 
__________________________________________________________________________ 
Table 3a 
__________________________________________________________________________ 
Time, hrs. 50 52 56 58 60 66 70 72 90 
Temperature, .degree. C. 
90 90 80 80 80 80 90 90 90 
WHSV, hr.sup.-.sup.1 
0.33 
0.33 
0.33 
0.33 
0.33 
0.33 
0.33 
0.33 
0.33 
Butene Conversion, % 
95 95 76 73 70 68-72 
91 94 95 
Total Yield .gtoreq. C.sub.5 's 
140 
139 
138 
138 
138 140 
141 
141 
Products, %w 
C.sub.5 -C.sub.7 
1.5 
&lt;1 &lt;1 &lt;1 &lt;1 1 1.5 
1.6 
C.sub.8 -C.sub.9 
68 78 78 80 81 68 68 70 
C.sub.11 -C.sub.12 
18 13 15 13 11 19 19 17 
C.sub.14 -C.sub.16 
13 9 6 7 7 12 11.5 
12 
Composition of C.sub.8, % 
C.sub.8 H.sub.18 
60 50 49 48 50 58 58 56 
C.sub.8 H.sub.16 
40 50 51 52 50 42 42 44 
Composition of C.sub.8 H.sub.18, % 
Trimethylpentanes 
75 83 80 80 80 75 75 74 
Dimetylhexanes 18 12 14 14 15 19 18 17 
Methylheptanes 4 3 3 3 3 4 4 5 
2.2.5-Trimethylhexane 
3 2 3 3 2 2 3 4 
__________________________________________________________________________ 
Illustrative Embodiment Ia 
The catalyst for Illustrative Embodiment Ia was prepared by impregnation of 
a silica gel support (Davison 57 with a 1.0 cc/g pore volume and 300 
m.sup.2 /g surface area) with an ethanol solution of Nafion XR granules. 
The ethanol was removed from the solid on a rotary evaporator leaving a 5% 
Nafion on silica catalyst. The structure of the resulting catalyst is 
exemplified by the repeating structure designated VI. About 5 grams of 
this catalyst was mixed with 5 grams of quartz to form the catalyst bed. 
The isobutane to butene-2 ratio was kept at 10:1 and the WHSV (based on 
the number of grams of Nafion resin present) was maintained at 3.3 
hr.sup.-.sup.1. The results along with the other operating conditions are 
presented below in Table 4a. 
Table 4a 
__________________________________________________________________________ 
Time, Hrs 2 4 6 7 22.5 25.5 30.5 46.5 47.5 
Temperature, .degree. C 
100 100 100 100 110 110 110 110 110 
Butene Conv., % 
74 73 70 65 70 69 68 71 70 
Total Yield C.sub.5 's 
-- 137 139 -- 138 137 138 138 138 
Products, %w 
C.sub.5 -C.sub.7 2 2 1 2 1.5 1 1.5 
C.sub.8 -C.sub.9 72 76 73 72 74 75 76 
C.sub.11 -C.sub.12 
20 16 17 17 17 17 15 
C.sub.14 -C.sub.16 
6 6 9 9 6 7 7 
Composition of C.sub.8, % 
C.sub.8 H.sub.18 51.5 51 52 51.5 51 50 51 
C.sub.8 H.sub.16 48.5 49 48 48.5 49 50 49 
Composition of C.sub.8 H.sub.18, % 
Trimethylpentanes 
74 76 70 72 74 72 77 
Dimethylhexanes 19 17 18 21 19 21 17 
Methylheptanes 6 6 8 6 6 6 5 
2,2,5-Trimethyl- 
hexane 1 1 4 1 1 1 1 
__________________________________________________________________________ 
Illustrative Embodiment IIa 
The catalyst for Illustrative Embodiment IIa was 1.1% Nafion on a 
fluoropolymer support and was prepared by adding dropwise 5 grams of a 
5.5% solution of Nafion XR granules in ethanol to 20 grams of Chromosorb T 
(Johns-Manville teflon 6) support. After the ethanol was removed and the 
catalyst dried, it was determined that the catalyst contained 1.1% Nafion. 
The catalyst bed for Illustrative Embodiment II comprised 10 grams of the 
catalyst with no quartz being added. The catalyst structure is similar to 
that employed in Illustrative Embodiment Ia. 
The operating conditions were 110.degree. C., isobutane to butene-2 ratio 
of 10:1, and a WHSV (based on the number of grams of Nafion resin present) 
of 8.2 hr.sup.-.sup.1. The results are presented below in Table 5a. 
Table 5a 
__________________________________________________________________________ 
Time, hrs. 4 
20 24 28 
44 48 52 
68 74 
Butene Conv., % 
65 
70 70 71 
65 65 65 
68 65 
Total Yield C.sub.5 's 
-- 
138 138 -- 
137 137 -- 
137 137 
Products, %w 
C.sub.5 -C.sub.7 
-- 
2 1 -- 
1 1 -- 
1 1 
C.sub.8 -C.sub.9 
-- 
76 76 -- 
74 74 -- 
76 79 
C.sub.11 -C.sub.12 
-- 
16 14 -- 
17 17 -- 
14 14 
C.sub.14 -C.sub.16 
-- 
6 9 -- 
8 8 -- 
9 6 
Composition of C.sub.8, % 
C.sub.8 H.sub.18 
-- 
50 50 -- 
50 49 -- 
49 48 
C.sub.8 H.sub.16 
-- 
50 50 -- 
50 51 -- 
51 52 
Composition of C.sub.8 H.sub.18, % 
Trimethylpentanes 
-- 
80 80 -- 
80 80 -- 
80 80 
Dimethylhexanes 
-- 
14 15 -- 
15 14 -- 
15 15 
Methylheptanes 
-- 
5 4 -- 
4 5 -- 
4 4 
2,2,5-Trimethylhexane 
-- 
1 1 -- 
1 1 -- 
1 1 
__________________________________________________________________________ 
C. Isomerization of Normal Alkanes 
Heretofore, it has been known that the isomerization of normal paraffins, 
particularly normal hexane, to their equilibrium mixtures of branched 
chain isomers, substantially increases the octane rating of the paraffinic 
hydrocarbons. In attempting to produce such equilibrium mixtures of 
isoparaffinic hydrocarbons, several catalytic processes have been 
developed. In one lower temperature process, isomerization is effected 
over an aluminum chloride catalyst. This process is costly to operate 
because of extensive corrosion effects caused by the acidic sludge formed 
from the aluminum chloride catalyst material, thereby requiring expensive 
alloy equipment. Moreover, moisture and high-molecular weight hydrocarbons 
usually present as contaminants in the charge stock cause deterioration of 
the catalyst and necessitate its frequent replacement. One higher 
temperature process utilizes a catalyst such as platinum on a 
silica-alumina base to promote hydroisomerization of normal paraffins in 
the presence of hydrogen at temperatures of the order of 700.degree. to 
800.degree. F. At these high temperatures, the equilibrium mixture of 
isomers is such that substantial recycling of a portion of the paraffin 
feed is necessary to obtain the desired improvement in octane ratings. 
There are numerous other catalyst systems useful in the isomerization of 
normal paraffins. These catalyst systems include hydrogen mordenite and 
platinum on alumina, U.S. Pat. No. 3,432,568; hydrofluoric acid-antimony 
pentafluoride, U.S. Pat. No. 3,903,196; zeolites, U.S. Pat. No. 3,770,845; 
and SBF.sub.5 -HF on a ruthenium-promoted fluorided alumina, U.S. Pat. No. 
3,864,425. 
In the present invention, a C.sub.4 to C.sub.8 normal paraffin feedstock is 
isomerized by contacting the feed at a temperature of between about 
125.degree. C. and 225.degree. C. and a pressure of between about 0 psig 
and about 1,000 psig with the catalyst composition disclosed herein. 
The catalysts of the present invention possess an improved activity, 
selectivity and stability over many of the known isomerization catalysts. 
In addition, the present catalysts, contrasting numerous other popular 
isomerization catalysts, are not extremely sensitive to water 
contamination. For example, a water concentration of about 100-150 parts 
per million in a normal hexane feed stream had no effect on a catalyst of 
the present invention. Further, as compared to a commercial 
platinum-on-mordenite isomerization catalyst, the catalyst employed in our 
invention can catalytically promote an isomerization reaction at a 
significantly lower temperature (75.degree. C. lower). At this lower 
temperature, not only is the conversion of normal paraffins to 
isoparaffins substantially increased, but the lower temperature also 
reduces the excess cracking often encountered at the higher temperatures 
employed with other catalysts. 
The paraffin feed which can be isomerized according to the process of the 
present invention includes substantially pure normal paraffins having from 
4 to 8 carbon atoms, mixtures of such normal paraffins, or hydrocarbon 
fractions rich in such normal paraffins. The paraffin feed may also 
contain other isomerizable paraffins such as cycloparaffins (sometimes 
referred to as naphthenes). The most preferred feedstocks to the process 
of the present invention are a C.sub.5 and/or C.sub.6 normal paraffin 
feed. A particularly preferred feedstock is one containing predominantly 
(greater than 60% volume) normal hexane. 
The stability of the present catalysts in isomerizing a normal paraffin 
feedstock is greatly improved by the addition of certain hydrocarbon 
catalyst stabilizers such as isobutane and benzene. When employing 
isobutane as a stabilizer, the volume ratio of isobutane present in the 
feed to normal paraffin in the feed should be between about 0.5:1 to about 
2:1, preferably about 1:1. It has been found that a ratio of isobutane to 
normal hexane feed of about 1:1 results in a much improved catalyst 
stability and activity over a feedstock containing no isobutane. Further, 
it has been found that a 1:1 isobutane to normal hexane ratio gives better 
results than does either 0.5:1 or 2:1 ratio. When employing benzene as the 
catalyst stabilizer, the volume ratio of benzene to normal paraffin in the 
feed should be between about 0.002:1 and about 0.02:1, preferably between 
about 0.003:1 and about 0.01:1. It has been found that by increasing the 
benzene concentration in a normal hexane feed from about 0.25% to 0.5%, 
the activity of the catalyst is increased. A further increase to 1.0% 
benzene shows no advantage over 0.5% benzene. 
Reaction temperature is varied between about 125.degree. C. and about 
225.degree. C., preferably between about 175.degree. C. and about 
200.degree. C. The reaction temperature must be kept below about 
225.degree. C. due to the lack of stability of the catalyst at 
temperatures of over 250.degree. C. In general, the activity of the 
catalyst is greater at the higher temperatures. That is, as the 
temperature increases, the conversion of normal paraffin increases. 
In general, the pressure in the isomerization reaction zone is maintained 
at between about 0 psig and about 500 psig, preferably between about 50 
psig and about 100 psig. The reaction may take place in either a gaseous 
phase or a liquid phase. 
The process may be carried out either as a batch or continuous type of 
operation, although it is preferred to carry out the process continuously. 
When operated as a batch operation, the present process is characterized 
by the use of vigorous mechanical stirring or shaking of the reactants and 
catalyst. When employing a continuous process, the feed streams may be 
contacted with the catalyst in any suitable reactor. In one embodiment, 
the catalyst is packed in a vertical, tubular reactor bed with inert 
supports, such as ceramic balls or silicon carbide, above and below the 
catalyst to prevent entrainment of the solid catalyst. In a further 
embodiment, the catalyst is mixed with an inert material, such as quartz, 
and loaded in the reactor so as to improve the fluid dynamics of the 
system. The flow of the reactant feed stream may be upflow or downflow as 
desired. 
The weight hourly space velocity effectively measures the catalyst 
concentration employed, and hence also measures the relative activity of 
the catalyst. Weight hourly space velocity (WHSV) is defined as the weight 
per hour of normal paraffin in the feed divided by the weight of catalyst 
(not including support) employed. For a non-supported catalyst, the WHSV 
varies from between about 0.05 hr.sup.-.sup.1 and about 2.0 
hr.sup.-.sup.1, preferably about 0.4 hr.sup.-.sup.1 and about 1.0 
hr.sup.-.sup.1. For a supported catalyst, the WHSV varies from between 
about 0.3 hr.sup.-.sup.1 and about 10.0 hr.sup.-.sup.1, preferably about 
1.0 hr.sup.-.sup.1 and about 4.0 hr.sup.-.sup.1. The higher WHSV for the 
supported catalyst reflects the increased activity of the supported 
catalyst per unit of catalyst. 
Hydrocarbon isomers produced from our process are useful as feedstocks for 
hydrocarbon alkylation processes. Further, they find utility as a gasoline 
blending stock because of their high antiknock properties. 
The invention is further illustrated by means of the following Comparative 
Examples and Illustrative Embodiments which are given for the purpose of 
illustration only, and the invention is not to be regarded as limited to 
any of the specific materials or conditions recited therein. 
In all examples and embodiments, the reactor employed was a 17-inch 
stainless steel tube equipped with a liquid feed downflow inlet. The 
catalyst bed occupied the central portion of the reactor, with several 
grams of carborundum chips on both sides of the catalyst bed to prevent 
entrainment of the catalyst. 
In Comparative Examples Ib-IIIb and Illustrative Embodiments Ib to Xb, the 
hydrocarbon feed comprised normal hexane. The product from the reactor 
were analyzed by GLC. 
Comparative Example Ib 
The catalyst employed in Comparative Examples Ib and IIb was prepared by 
grinding Nafion XR granules with a blender to 150 micrometer or less 
particle size. The ground material was then treated twice with 30% 
sulfuric acid to convert the material from a potassium (K.sup.+) form to 
the H.sup.+ form. The treated material was collected by filtration, washed 
with distilled water until the washings were neutral, and then dried at 
100.degree. C. and 3 mm pressure for 16 hours. The resulting catalyst 
contained about 0.85 milliequivalents of acid per gram of catalyst. The 
structure for the resulting catalyst is exemplified by the following 
repeating structure where n = 1 or 2 and the ratio of x over y varies 
from between 2 and about 50: 
##STR6## 
About 2.5 grams of the resulting polymer catalyst was mixed with 7.5 grams 
of quartz and loaded in the reactor. Reaction conditions were a pressure 
of 20 psig, weight hourly space velocity (defined as the grams of 
hydrocarbon feed per hour divided by the grams of catalyst employed) of 
0.9 hr.sup.-.sup.1, and a reaction temperature of 175.degree. C. The 
results are presented below in Table 1b. 
Table 1b 
__________________________________________________________________________ 
Time, Hr. 1 2 3 4 5 6 7 
Composition of Product, %w 
C.sub.2 -C.sub.3 
3 2 1 0.8 0.6 0.4 0.2 
Isobutane 14 11 9 8 5.5 3.5 2 
Isopentane + n-pentane 
22 18 15 13 10 8 5.7 
3-Methylpentane 
8 7 7 5 4 3 1.5 
2-Methylpentane 
13 12 11 9 7 4.5 3 
2,3-Dimethylbutane 
5 4 4 3 2.5 1.5 1 
2,2-Dimethylbutane 
8 7 6 5 4 2 0.5 
n-Hexane 15 30 40 51 63 74 85 
C.sub.7 Compounds 
10 8 6 4 3 2 1 
.gtoreq.C.sub.8 Compounds 
2 1.5 1 1 0.5 0.2 0.1 
__________________________________________________________________________ 
Comparative Example IIb 
Comparative Example IIb was conducted in a similar manner to Comparative 
Example Ib except that the feed comprised a 1:1 volume ratio of isobutane 
to n-hexane. The pressure was maintained at 45-50 psig, and the WHSV 
(n-hexane feed only) at 0.47 hr.sup.-.sup.1. The temperature was raised 
from 175.degree. C. to 200.degree. C. after 54 hours. The results (on an 
iC.sub.4 free basis) are presented below in Table 2b. After 54 hours, the 
unit was shut down over a weekend period. 
Table 2b 
__________________________________________________________________________ 
Time, Hrs. 6 24 28 32 50 54 62 82 
Temperature, .degree. C. 
175 175 175 175 175 200 200 200 
Composition of Product, %w 
(iC.sub.4 free basis) 
C.sub.2 -C.sub.3 
0.5 0.3 0.3 0.3 0.3 0.3 0.3 0.3 
Isopentane + n-pentane 
1.5 0.8 0.6 0.5 0.5 0.6 0.6 0.3 
3-Methylpentane 
15 14 14 13 14 13 12 7 
2-Methylpentane 
25 25 23 23 22 20 19 12 
2,3-Dimethylbutane 
10 10 9 9 9 8 7 4 
2,2-Dimethylbutane 
16 15 13 13 12 11 3 
n-Hexane 30 34 39 40 41 45 50 73 
Methylcyclopentane 
0.2 0.05 0.05 0.05 0.05 0.05 0.03 0.02 
C.sub.7 Compounds 
0.7 0.3 0.3 0.25 0.2 0.25 0.2 0.1 
.gtoreq.C.sub.8 Compounds 
0.3 0.1 0.1 0.1 0.1 0.1 0.05 0.05 
__________________________________________________________________________ 
Illustrative Embodiment Ib 
Illustrative Embodiments Ib to Xb disclose the use of the catalyst of the 
present invention on various supports. In all cases, the supported 
catalyst was placed in a round-bottomed flask and a 5.5% solution of 
Nafion XR resin in ethanol was added dropwise. The resulting mixture was 
vigorously stirred with a mechanical stirrer during the impregnation, and 
stirring continued for 30 minutes thereafter. The ethanol was removed from 
the resulting supported catalyst by evaporation on a rotary evaporator at 
25.degree. C. and 1 mm pressure for 2 hours and at 60.degree. C. and 1 mm 
pressure for an additional 4 hours. The dried, supported catalyst was then 
ground to a sufficient size so as to pass through a number 60 sieve. The 
resulting active catalyst structure is the same as that shown in 
Comparative Example Ib. 
In Illustrative Embodiment Ib, the support employed was a high surface area 
silica having a 1.65 ml/g pore volume, 300 m.sup.2 /g surface area and a 
210 A average pore diameter. Nine grams of the resulting catalyst (6% 
catalyst on support) were loaded in the reactor. Reaction conditions were 
20 psig pressure, 175.degree. C. temperature, and a WHSV of 3.0 
hr.sup.-.sup.1. Note that in all embodiments and claims, WHSV is measured 
on a support-free basis. The results are presented below in Table 3b. 
Table 3b 
______________________________________ 
Time, Hrs. 2 4 5 6 6.5 7.5 8.5 
Composition of Product, %w 
C.sub.2 -C.sub.3 1.5 1.5 1.0 0.6 0.6 0.4 0.2 
Isobutane 8 6 6 4 5 3 2 
Isopentane + n-pentane 
12 10 10 7 8 4 2 
3-Methylpentane 12 11 10 9 9 7 5 
2-Methylpentane 20 18 16 16 15 14 10 
2,3-Dimethylbutane 
8 7 6 5 4 4 2 
2,2-Dimethylbutane 
12 11 10 7 5 4 1 
n-Hexane 20 30 37 42 50 62 77 
Methylcyclopentane 
0.2 0.2 0.2 0.1 0.1 0.1 0.05 
C.sub.7 Compounds 
6 4 3 2 2 1 0.5 
.gtoreq.C.sub.8 Compounds 
0.5 0.4 0.3 0.3 0.3 0.2 0.1 
______________________________________ 
Illustrative Embodiment IIb 
An identical catalyst to that employed in Illustrative Embodiment Ib was 
employed in Illustrative Embodiment IIb. However, in Illustrative 
Embodiment Ib, the feed stream comprised isobutane and n-hexane in a 1:1 
volume ratio. Reaction conditions included a 40-50 psig pressure and a 
WHSV of 2.2 hr.sup.-.sup.1. The temperature was increased from 175.degree. 
C. to 200.degree. C. after 124 hours. Note that in all embodiments, WHSV 
is measured on basis of the n-hexane feed only, i.e., moderators such as 
isobutane or benzene are not included. The results are presented below in 
Table 4b. 
Table 4b 
__________________________________________________________________________ 
Time, Hours 4 28 70 98 124 
148 
177 
Temperature, .degree. C. 
175 
175 
175 
175 
175 
200 
200 
Composition of Product, %w 
(iC.sub.4 free basis) 
C.sub.2 -C.sub.3 
0.5 
0.3 
0.3 
0.3 
0.2 
0.5 
0.2 
Isopentane + n-pentane 
2 0.6 
0.5 
0.4 
0.4 
0.6 
0.3 
3-Methylpentane 
12 12 12 12 12 13 7 
2-Methylpentane 
20 20 20 20 20 21 13 
2,3-Dimethylbutane 
8 8 8 8 8 8 4 
2,2-Dimethylbutane 
12 12 11 12 12 16 4 
n-Hexane 46 48 49 48 48 39 70 
Methylcyclopentane 
0.1 
0.05 
0.05 
0.05 
0.05 
0.1 
0.05 
C.sub.7 Compounds 
0.3 
0.2 
0.2 
0.2 
0.2 
0.3 
0.1 
.gtoreq. C.sub.8 Compounds 
0.1 
0.1 
0.05 
0.05 
0.05 
0.1 
-- 
__________________________________________________________________________ 
Illustrative Embodiment IIIb 
Illustrative Embodiment IIIb was conducted in a similar manner to 
Illustrative Embodiment IIb except that the isobutane to n-hexane ratio 
was maintained at 0.5:1. Other operating conditions included a pressure of 
40 psig, temperature of 175.degree. C. and a WHSV of 2.9 hr.sup.-.sup.1. 
The results are presented below in Table 5b. 
Table 5b 
______________________________________ 
Time, Hrs. 4 22 27 46 51 70 
Composition of Product, %w 
(iC.sub.4 free basis 
C.sub.2 -C.sub.3 0.9 0.6 0.5 0.5 0.5 0.3 
Isopentane 3 1.5 1.5 1.5 1.5 1.0 
3-Methylpentane 8 8 8 7 7 4 
2-Methylpentane 13 14 14 13 13 8 
2,3-Dimethylbutane 
5 5 5 5 4 3 
2,2-Dimethylbutane 
7 7.5 6 6 5 1.5 
n-Hexane 62 63 64 66 68 82 
Methylcyclopentane 
0.1 0.1 0.1 0.1 0.05 0.05 
C.sub.7 Compounds 
0.4 0.4 0.4 0.4 0.3 0.2 
.gtoreq.C.sub.8 Compounds 
0.1 0.1 0.1 0.1 0.1 0.05 
______________________________________ 
Illustrative Embodiment IVb 
Benzene acts as does isobutane in improving the selectivity and stability 
of the catalysts of the present invention. In Illustrative Embodiment IVb, 
an identical catalyst to that employed in Illustrative Embodiments Ib, IIb 
and IIIb was used. The normal hexane feed, however, contained 0.5% volume 
benzene and no isobutane. Other reaction conditions included a pressure of 
20 psig, WHSV of 2.3 hr.sup.-.sup.1, and a temperature of 175.degree. C. 
The results are presented below in Table 6b. 
Table 6b 
______________________________________ 
Time, Hrs. 5 21 45 69 77 98 
Composition of product, %w 
C.sub.2 -C.sub.3 0.2 0.2 0.4 0.3 0.1 0.05 
Isobutane 0.3 0.3 0.3 0.3 0.2 0.1 
Isopentane + n-pentane 
0.4 0.4 0.3 0.3 0.3 0.1 
3-Methylpentane 12 12 12 12 10 4 
2-Methylpentane 20 20 20 20 18 8 
2,3-Diemthylbutane 
8 8 8 8 7 2 
2,2-Dimethylbutane 
11 12 11 12 10 2 
n-Hexane 48 47 48 47 53 82 
Methylcyclopentane 
0.1 0.1 0.1 0.05 0.05 0.05 
C.sub.7 Compounds 
0.2 0.2 0.2 0.2 0.2 0.05 
.gtoreq.C.sub.8 Compounds 
0.05 0.05 0.05 
0.05 0.05 Trace 
Benzene 0.3 0.4 0.45 
0.4 0.45 0.45 
______________________________________ 
Illustrative Embodiment Vb 
Illustrative Embodiment Vb differs from Illustrative Embodiment IVb only in 
that the pressure was maintained at 18 psig, and the percentage of benzene 
in the normal hexane feed was reduced to 0.25% volume. The results are 
presented below in Table 7b. 
Table 7b 
______________________________________ 
Time, Hrs. 4 24 46 70 78 97 
Composition of Product, %w 
C.sub.2 -C.sub.3 0.2 0.2 0.2 0.2 0.2 0.1 
Isobutane 0.5 0.5 0.5 0.5 0.5 0.3 
Isopentane + n-pentane 
0.7 0.7 0.6 0.7 0.7 0.3 
3-Methylpentane 10 8 9 8 7 4 
2-Methylpentane 17 16 15 15 13 7 
2,3-Dimethylbutane 
6.5 6 6 6 5 2 
2,2-Dimethylbutane 
9 8 8 7 6 1.5 
n-Hexane 56 59 59 62 67 85 
Methylcyclopentane 
0.1 0.1 0.1 0.1 0.1 0.05 
C.sub.7 Compounds 
0.3 0.3 0.3 0.3 0.3 0.2 
.gtoreq.C.sub.8 Compounds 
0.1 0.1 0.1 0.1 0.1 0.05 
Benzene 0.1 0.15 0.15 0.1 0.1 0.15 
______________________________________ 
Illustrative Embodiment VIb 
The only change from Illustrative Embodiment Vb is that in Illustrative 
Embodiment VIb, the benzene concentration in the n-hexane feed is 
increased to 1.0% volume. The results are found below in Table 8b. 
Table 8b 
______________________________________ 
Time, Hrs. 4 23 28 47 52 71 
Composition of 
Product, %w 
C.sub.2 -C.sub.3 
0.1 0.1 0.1 0.1 0.1 0.05 
Isobutane 0.2 0.2 0.2 0.2 0.2 0.1 
Isopentane 0.3 0.2 0.2 0.2 0.2 0.1 
3-Methylpentane 
9 8 8 8 7 4 
2-Methylpentane 
15 15 15 14 13 6 
2,3-Dimethylbutane 
6 5 5 5 4.5 2 
2,2-Dimethylbutane 
7 6 6 6 5 1.5 
n-Hexane 61 64 64 65 68 85 
Methylcyclopentane 
0.1 0.1 0.1 0.1 0.05 0.05 
C.sub.7 Compounds 
0.1 0.1 0.1 0.1 0.1 0.1 
.gtoreq.C.sub.8 Compounds 
0.05 0.05 Trace Trace Trace -- 
Benzene 0.6 0.9 0.8 0.90 0.90 0.90 
______________________________________ 
Illustrative Embodiment VIIb 
In Illustrative Embodiment VIIb, the catalyst of the present invention was 
supported on a silica-alumina base (MSA-3) having a 1.0 ml/g pore volume, 
510 m.sup.2 /g surface area, and an 80 A average pore diameter. About 12 
grams of the resulting inpregnated catalyst having a catalyst to support 
weight ratio of 4.5:100 was loaded in the reactor. Operating conditions 
included 40 psig pressure, 175.degree. C. temperature, WHSV of 2.12 
hr.sup.-.sup.1, and an isobutane to n-hexane feed ratio of 1:1. The 
results are presented below in Table 9b. 
Table 9b 
______________________________________ 
Time, Hrs. 4 20 25 28 44 50 
Composition of Product, %w 
(iC.sub.4 free basis) 
C.sub.2 -C.sub.3 
1 0.4 0.2 0.2 0.3 0.2 
Isopentane 2 0.5 0.4 0.4 0.3 0.12 
3-Methylpentane 7 7 7 6 6 5 
2-Methylpentane 11 11 10 10 10 8 
2,3-Dimethylbutane 
4 4 3 3 3 2 
2,2-Dimethylbutane 
4 4 4 3 3 1.5 
n-Hexane 71 73 75 77 77 83 
Methylcyclopentane 
0.1 0.05 0.05 0.05 0.05 0.05 
C.sub.7 Compounds 
0.3 0.2 0.2 0.2 0.2 0.11 
.gtoreq.C.sub.8 Compounds 
0.1 0.05 0.05 0.05 0.05 0.05 
______________________________________ 
Illustrative Embodiment VIIIb 
In Illustrative Embodiment VIIIb, the support was a porous glass (98% 
SiO.sub.2 and 2% B.sub.2 O.sub.3) having a pore volume of 1.2 ml/g, 
surface area of 154 m.sup.2 /g, and an average pore diameter of 310 A. The 
impregnated catalyst had a catalyst to support weight ratio of 5:100. 
About 4.5 grams of the supported catalyst was loaded in the reactor. 
Reaction conditions were a 40 psig pressure, WHSV of 5.3 hr.sup.-.sup.1, 
175.degree. C. temperature, and an isobutane to n-hexane ratio of 1:1. The 
results are presented below in Table 10b. 
Table 10b 
______________________________________ 
Time, Hrs. 1 23 45 53 77 98 
Composition of Product, %w 
(iC.sub.4 free basis) 
C.sub.2 -C.sub.3 0.3 0.3 0.4 0.4 0.3 0.3 
Isopentane + n-pentane 
3.0 1.0 1.1 1.0 0.9 0.9 
3-Methylpentane 15 15 15 14.5 15 14.5 
2-Methylpentane 25 25 25 25 25 25 
2,3-Dimethylbutane 
10 10 10 9.5 10 9.5 
2,2-Dimethylbutane 
16 16 16 16 15 15 
n-Hexane 30 32 32 33 33 34 
Methylcyclopentane 
0.1 0.1 0.1 0.1 0.1 0.1 
C.sub.7 Compounds 
0.5 0.3 0.3 0.3 0.3 0.3 
.gtoreq.C.sub.8 Compounds 
0.2 0.1 0.1 0.1 0.1 0.1 
______________________________________ 
Illustrative Embodiment IXb 
In Illustrative Embodiment IXb, the support employed was a porous glass 
having a pore volume of 1.5 ml/g, surface area of 292 m.sup.2 /g, and an 
average pore diameter of 207 A. The catalyst to support ratio was 4.5:100, 
and 4.5 grams of supported catalyst were employed. Reaction conditions 
included 40 psig pressure, WHSV of 4.4 hr.sup.-.sup.1, temperature of 
175.degree. C., and an isobutane to n-hexane ration of 1:1. The results 
are presented below in Table 11b. 
Table 11b 
______________________________________ 
Time, Hrs. 2 21 26 47 53 74 
Composition of Product, w% 
(iC.sub.4 free basis) 
C.sub.2 -C.sub.3 0.3 0.3 0.3 0.2 0.2 0.2 
Isopentane + n-pentane 
2.0 0.6 0.6 0.6 0.6 0.6 
3-Methylpentane 12 
12 12 12 12 12 
2-Methylpentane 20 20 20 20 20 20 
2,3-Dimethylbutane 
8 8 8 8 8 7 
2,2-Dimethylbutane 
12 12 11 11 12 11 
n-Hexane 45 47 48 48 47 49 
Methylcyclopentane 
0.1 0.1 0.1 0.1 0.1 0.1 
C.sub.7 Compounds 
0.4 0.3 0.3 0.3 0.3 0.3 
.gtoreq.C.sub.8 Compounds 
0.1 0.1 0.1 0.1 0.1 0.1 
______________________________________ 
Illustrative Embodiment Xb 
In Illustrative Embodiment Xb, the support employed was a Pechiney alumina 
having a pore volume of 0.55 ml/g, surface area of 60 m.sup.2 /g, and an 
effective pore diameter of 370 A. Catalyst to support ratio was 2.8:100. 
About 12 grams of the supported catalyst were loaded in the reactor. 
Reaction conditions included a 40 psig pressure, 175.degree. C. 
temperature, WHSV of 3.5 hr.sup.-.sup.1, and an isobutane to n-hexane feed 
ratio of 1:1. The results are presented below in Table 12b. 
Table 12b 
______________________________________ 
Time, Hrs. 5 26 50 71 77 96 
Composition of Product, %w 
(iC.sub.4 free basis) 
C.sub.2 -C.sub.3 0.3 0.3 0.2 0.2 0.2 0.2 
Isopentane 1.0 0.8 0.8 0.8 0.8 0.5 
3-Methylpentane 15 15 15 15 15 10 
2-Methylpentane 25 25 25 24.5 25 17 
2,3-Dimethylbutane 
10 10 10 9.5 9.5 6.5 
2,2-Dimethylbutane 
15 15 15 14.5 14.5 9 
n-Hexane 33 33 33 34.5 34.5 56.5 
Methylcyclopentane 
0.1 0.1 0.1 0.1 0.1 0.1 
C.sub.7 Compounds 
0.3 0.3 0.3 0.3 0.3 0.2 
.gtoreq.C.sub.8 Compounds 
0.1 0.1 0.1 0.1 0.1 0.05 
______________________________________ 
Illustrative Embodiment XIb 
In Illustrative Embodiment XIb, the support was a low pore diameter CCI 
alumina having a pore volume of 0.85 ml/g, a surface area of 250 m.sup.2 
/g, and an effective pore diameter of 136 A. Catalyst to support ratio was 
about 3.7:100, and about 15 grams of supported catalyst were loaded in the 
reactor. Reaction conditions included a pressure of 40 psig, temperature 
of 175.degree. C., WHSV of 2.2 hr.sup.-.sup.1, and an isobutane to 
n-hexane ratio of 1:1. The results are presented below in Table 13b. 
Table 13b 
______________________________________ 
Time, Hrs. 2 23 44 66 74 95 100 
Composition of 
Product, %w 
(iC.sub.4 free basis) 
C.sub.2 -C.sub.3 
0.5 0.2 0.2 0.2 0.3 0.1 0.1 
Isopentane 3 0.4 0.4 0.4 0.5 0.2 0.2 
3-Methylpentane 
13 12 12 12 12 4 2 
2-Methylpentane 
21 20 20 20 20 8 4 
2,3-Dimethylbutane 
8 8 8 8 8 2 1 
2,2-Dimethylbutane 
13 12 12 12 12 2 1 
n-Hexane 40 48 48 48 48 83 91 
Methylcyclopentane 
0.1 0.1 0.05 0.05 0.05 0.05 0.05 
C.sub.7 Compounds 
0.3 0.2 0.2 0.2 0.2 0.1 0.1 
.gtoreq.C.sub.8 Compounds 
0.1 0.05 0.05 0.05 0.05 Trace -- 
______________________________________ 
Comparative Example IIIb 
Comparative Example IIIb was run with an identical catalyst and loading as 
that employed in Comparative Example IIb. However, in Comparative Example 
IIIb, the feed comprised n-pentane instead of n-hexane. Other operating 
conditions included a 45 psig pressure, WHSV of 0.45 hr.sup.-.sup.1, and 
an isobutane to n-pentane ratio of 1:1. The temperature was increased from 
175.degree. C. to 200.degree. C. after 30 hours. Results are presented 
below in Table 14b. 
Table 14b 
______________________________________ 
Time, Hrs. 5 26 32 52 60 82 84 
Temperature, .degree. C. 
175 175 200 200 200 200 200 
Composition of 
Product, %w 
(iC.sub.4 free basis) 
C.sub.2 -C.sub.3 
0.2 0.2 0.2 0.2 0.2 0.1 0.1 
Isopentane 25 25 30 32 30 15 12 
n-pentane 75 75 70 68 70 85 88 
C.sub.6 Compounds 
0.1 0.2 0.2 0.2 0.2 0.1 0.1 
.gtoreq.C.sub.7 Compounds 
0.05 0.05 0.5 0.05 0.05 0.05 0.05 
______________________________________ 
D. Preparation of Ethylbenzene 
As is well known to those skilled in the art, ethylbenzene is a desirable 
article of commerce since it is the starting material for the production 
of styrene. Generally, styrene is produced through the steam 
dehydrogenation of ethylbenzene. Ethylbenzene does occur, to some extent, 
in petroleum fractions and may be obtained from such fractions through the 
technique of super-distillation. However, the demand for styrene in recent 
times has far surpassed the availability of naturally occurring 
ethylbenzene. Accordingly, the prior art has resorted more and more to the 
alkylation of benzene with ethylene using various types of catalyst. Among 
the catalysts employed in the prior art are aluminum chloride, U.S. Pat. 
No. 3,848,012; phosphoric acid, U.S. Pat. No. 3,478,119; boron 
trifluoride-modified alumina, British patent No. 905,051; silica-alumina, 
U.S. Pat. No. 2,419,796; and zeolites, U.S. Pat. No. 3,751,504. 
It is also known that certain sulfonated fluorocarbon vinyl ether polymers 
are useful in the alkylation of benzene with propylene in the vapor phase 
to form cumene. See the recent study by Kapura and Gates, supra. However, 
the conclusion reached by Kapura and Gates in their study was that the 
sulfonated polymer was not "a practically useful catalyst at temperatures 
greater than about 150.degree. C." Contrary to the conclusions reached by 
Kapura and Gates for employing sulfonated polymers to prepare cumene from 
benzene and propylene, it has now been found that catalysts of the instant 
invention are very active in the preparation of ethylbenzene from benzene 
and ethylene. This finding is especially surprising since it is well known 
that propylene is more reactive than ethylene. 
In the present invention, ethylene is reacted with benzene in the liquid 
phase over the present catalyst composition and at a temperature of 
between about 125.degree. C. and 225.degree. C. The catalysts and process 
of the present invention produce an ethylbenzene product containing very 
little (less than 0.1%) cumene, and with a relatively high percentage of 
ethylbenzene in the reaction zone effluent. 
The ethylene feed stream suitable for use in the practice of the present 
invention may be either of high purity or of a lower purity. High purity 
ethylene streams comprise at least 90 mol percent ethylene, preferably 
over about 95 mol percent ethylene. However, it is often useful to employ 
lower purity ethylene streams. Preferred ethylene streams contain between 
about 35 and about 75 percent ethylene, usually less than about 50 percent 
ethylene, with the balance of the stream being largely inert gases such as 
ethane, methane and hydrogen. However, with either high or low purity 
ethylene, the ethylene feed stream should be substantially free from 
aromatics, acetylene, and other olefins. 
The benzene to be used in the present invention should be of relatively 
high purity. However, the benzene is typically obtained from storage 
facilities and, therefore, will often be saturated with water. Contrary to 
the detrimental effect of water on the commercially used aluminum chloride 
and silica-alumina catalysts, water levels of as high as 100ppm have no 
detrimental effect on the catalysts of the present invention. 
In order to prevent polymerization of the ethylene, an excess of benzene is 
used. The mole ratio of benzene to ethylene varies from about 1.5:1 to 
about 10:1, preferably about 2.1 to about 5:1. 
The process may be carried out either as a batch or continuous type of 
operation, although it is preferred to carry out the process continuously. 
It has been generally established that the more intimate the contact 
between the feedstock and the catalyst, the better the yield of desired 
product obtained. With this in mind, the present process, when operated as 
a batch operation, is characterized by the use of vigorous mechanical 
stirring or shaking of the reactants and catalyst. 
When employing a continuous process, the feed streams may be contacted with 
the catalyst in any suitable reactor. In one embodiment, the catalyst is 
packed in a vertical, tubular reactor bed with inert supports, such as 
ceramic balls or silicon carbide, above and below the catalyst. The 
catalyst can be mixed with an inert material, such as quartz, and loaded 
in the reactor so as to improve the fluid dynamics of the system. The flow 
of the reactant feed stream may be upflow or downflow, with an upflow 
arrangement being preferred to ensure liquid phase alkylation. 
Reaction temperature is varied between about 125.degree. C. and about 
225.degree. C. The reaction temperature must be kept below about 
225.degree. C. due to the lack of stability of the catalyst at 
temperatures of over 250.degree. C. A preferred temperature range is 
between about 150.degree. C. and about 210.degree. C. In general, the 
activity of the catalyst is greater at the higher temperatures. That is, 
as temperature increases, the conversion of ethylene increases. 
In general, the pressure in the reaction zone is maintained to keep the 
reactants in the liquid phase, and accordingly, will vary with the 
particular reactants employed and the reaction temperatures. Typical 
reaction zone pressure varies from about 10 psig to about 2,000 psig. 
The weight hourly space velocity effectively measures the catalyst 
concentration employed, and hence, also measures the relative activity of 
the catalyst. Weight hourly space velocity (WHSV) is defined as the weight 
per hour of total combined feed (benzene plus ethylene) divided by the 
weight of catalyst (including support) employed. For a supported catalyst, 
the WHSV varies between about 0.5 hr.sup.-.sup.1 and about 20 
hr.sup.-.sup.1, preferably about 2 hr.sup.-.sup.1 and about 10 
hr.sup.-.sup.1. 
The invention is further illustrated by means of the following Comparative 
Example and Illustrative Embodiments which are given for the purpose of 
illustration only, and the invention is not to be regarded as limited to 
any of the specific materials or conditions recited therein. 
In Comparative Example Ic and Illustrative Embodiments Ic to IVc, the 
reactor employed was a 17-inch stainless steel tube equipped with a liquid 
feed upflow inlet. The catalyst bed occupied the central portion of the 
reactor, with several grams of carborundum chips on both sides of the 
catalyst bed to prevent entrainment of the catalyst. All reactions took 
place in the liquid phase. 
Comparative Example Ic 
The catalyst employed in Comparative Example Ic was prepared by grinding 
Nafion XR granules with a blender to 150 micrometer or less particle size. 
The ground material was then treated twice with 30% sulfuric acid to 
convert the material from a potassium (K.sup.+) form to the H.sup.+ form. 
The treated material was collected by filtration, washed with distilled 
water until the washings were neutral, and then dried at 100.degree. C. 
and 3 mm pressure for 16 hours. The resulting catalyst contained about 
0.85 milliequivalents of acid per gram of catalyst. The structure for the 
resulting catalyst is exemplified by the following repeating structure 
where n = 1 or 2 and the ratio of x over y varies from between 2 and about 
50: 
##STR7## 
About 4.0 grams of the resulting polymer catalyst was mixed with 5.0 grams 
of quartz and loaded in the reactor. Reaction conditions were a pressure 
of 500 psig, a temperature of 175.degree. C. and an approximate 
benzene/ethylene mole ratio of 5:1. The weight hourly space velocity, WHSV 
(defined as the grams of total feed per hour divided by the grams of 
catalyst -- including support -- employed), varied from 1.0 hr.sup.-.sup.1 
to 8.0 hr.sup.-.sup.1 as indicated in the results presented below in Table 
1c. 
Table 1c 
______________________________________ 
Time, hours 4 24 44 50 74 78 
Temperature, .degree. C. 
175 175 175 175 176 175 
WHSV 1.0 1.0 1.0 2.0 4.0 8.0 
Ethylene Conversion, % 
100 100 100 100 100 100 
Ethylbenzene, %w 
15.6 15.4 15.5 16.3 16.9 17.5 
in product 
Selectivity, %w 
Ethylbenzene 80 80 80 84 86 88 
Butylbenzene 1 1 1 1 1 1 
Diethylbenzene 15 15 14.5 12.5 11 10 
Triethylbenzene 
3.6 3.1 3.5 2.1 1.8 1.5 
Tetraethylbenzene 
1.0 1.0 1.0 0.5 0.3 -- 
______________________________________ 
Illustrative Embodiment Ic 
Illustrative Embodiments Ic to IVc disclose the use of the catalyst of the 
present invention on various supports. In all cases, the supported 
catalyst was prepared by placing the support in a round-bottomed flask and 
adding, dropwise, a 5.5% solution of Nafion XR resin in ethanol. The 
resulting mixture was vigorously srirred with a mechanical stirrer during 
the impregnation, and stirring continued for 30 minutes thereafter. The 
ethanol was removed from the resulting supported catalyst by evaporation 
on a rotary evaporator at 25.degree. C. and 1 mm pressure for two hours 
and at 60.degree. C. and 1 mm pressure for an additional four hours. The 
dried, supported catalyst was then ground to a sufficient size so as to 
pass through a number 60 sieve. The resulting active catalyst structure is 
the same as that shown in Comparative Example Ic. 
In Illustrative Embodiment Ic, the support employed was a high surface area 
silica having a 1.65 ml/g pore volume, 300 m.sup.2 /g surface area and a 
210 A average pore diameter. Ten grams of the resulting catalyst (6% 
catalyst on support) were loaded in the reactor. Reaction conditions were 
500 psig pressure and a benzene to ethylene ratio of about 5:1. WHSV and 
temperature were changed as indicated with the results below in Table 2c. 
Note that in all embodiments and claims, WHSV is measured on the total 
catalyst employed including the support. 
Table 2c 
______________________________________ 
Time, hours 18 23.5 46.5 50.5 70.5 77 
Temperature, .degree. C. 
175 175 175 185 185 195 
WHSV 0.5 0.9 0.9 1.8 3.6 3.6 
Ethylene Conversion, % 
100 100 100 99 90 98 
Ethylbenzene, %w 
16.2 16.7 16.9 17.4 16.1 17.8 
in product 
Selectivity, %w 
Ethylbenzene 86 88 89 91 93 93 
Butylbenzene 1.6 1.5 1.3 1.0 0.8 0.6 
Diethylbenzene 11 9.5 9.0 8.0 6.0 6.5 
Triethylbenzene 
1.0 1.0 0.8 0.4 0.2 0.2 
______________________________________ 
Illustrative Embodiment IIc 
An identical catalyst to that employed in Illustrative Embodiment Ic was 
employed in Illustrative Embodiment IIc. However, in Illustrative 
Embodiment IIc, the reactor was charged with 4.5 grams of the supported 
catalyst and 4.5 grams of quartz; the benzene to ethylene mole ratio was 
decreased to about 3:1; and the WHSV was maintained at about 3.0 
hr.sup.-.sup.1. The temperature was varied as indicated in Table 3c below. 
Table 3c 
__________________________________________________________________________ 
Time, hours 4 20 28 51.5 
117 
123 
169 
189 
Temperature .degree. C. 
193 
193 
193 
195 
197 
199 
215 
220 
Ethylene Conversion, % 
98 98 98 99 96 100 
66 20 
Ethylbenzene %w product 
28.5 
28 28.5 
28.8 
28 28 13.4 
8.8 
Selectivity, %w 
Ethylbenzene 88 87 87 85 87 85 89 91 
Butylbenzene 1.0 
1.2 
1.3 
1.3 
1.3 
1.2 
1.1 
1.0 
Diethylbenzene 
9 9 9 11 9 11 9 8 
Triethylbenzene 
2 2 2 2.2 
2 2.1 
1.1 
0.2 
Tetraethylbenzene 
0.6 
0.6 
0.6 
0.6 
0.6 
0.6 
-- -- 
__________________________________________________________________________ 
Illustrative Embodiment IIIc 
In Illustrative Embodiment IIIc, the support was a porous glass (98% 
SiO.sub.2 and 2% B.sub.2 O.sub.3) having a pore volume of 1.2 ml/g, 
surface area of 154 m.sup.2 /g, and an average pore diameter of 310 A. THe 
impregnated catalyst had a catalyst to support weight ratio of 5:100. 
About 4.5 grams of supported catalyst was loaded in the reactor along with 
4.5 grams of quartz. Reactor pressure was maintained at 750 psig, WHSV at 
3.0, and the benzene to ethylene ratio at 3:1. The results are presented 
below in Table 4c. 
Table 4c 
______________________________________ 
Time, hours 3 22 46 51 75 97 
Temperature, .degree. C. 
188 188 188 195 200 201 
Ethylene Conversion, % 
95 99 95 100 100 99 
Ethylbenzene, %w 
in product 27.6 28.7 27.6 29 29 28.7 
Selectivity, %w 
Ethylbenzene 86.5 86 87 85.5 85.5 86 
Butylbenzene 1.3 1.2 1.2 1.2 1.2 1.2 
Diethylbenzene 10 10 9.5 10.5 10.5 10 
Triethylbenzene 
2 2.2 1.9 2.1 2.1 2.1 
Tetraethylbenzene 
0.6 0.5 0.5 0.6 0.6 0.5 
______________________________________ 
Illustrative Embodiment IVc 
In Illustrative Embodiment IVc, the support employed was Pechiney alumina 
having a pore volume of 0.55 ml/g, surface area of 60 m.sup.2 /g, and an 
effective pore diameter of 370 A. Catalyst to support ratio was about 
2.8:100. About 10 grams of the supported catalyst was loaded in the 
reactor. Reaction conditions included a 750 psig pressure and a WHSV of 
about 3.0. The results are presented below in Table 5c. 
Table 5c 
______________________________________ 
Time, hours 5 28.5 50 72 93 98 
Temperature, .degree. C. 
190 195 200 205 205 210 
Ethylene Conversion 
73 89 99 100 73 55 
Ethylbenzene, %w 
in product 21.2 25.7 28.7 29 21 16 
Selectivity, %w 
Ethylbenzene 88 87 85.5 85 87.5 88.5 
Butylbenzene 1.1 1.1 1.2 1.2 1.0 1.1 
Diethylbenzene 10 10 11 11 9.5 9.5 
Triethylbenzene 
1.3 1.5 1.8 2.1 1.6 1.1 
Tetraethylbenzene 
0.2 0.4 0.6 0.6 0.2 -- 
______________________________________ 
E. Disproportionation of Toluene 
Recently, with the increase in the production of synthetic fibers, demand 
for benzene and xylene has increased. Therefore, the so-called 
disproportionation process for converting toluene to benzene and xylene 
has been examined for industrial applications. Most of these processes 
employ Friedel-Crafts catalysts. Other reported processes employ 
silica-alumina, alumina-boria, or crystalline zeolites as catalysts. See, 
e.g., U.S. Pat. No. 3,576,895 and U.S. Pat. No. 3,553,277. 
However, most of these known catalysts exhibit only a low catalytic 
activity for the disproportionation reaction of toluene, and further, 
these catalysts have such shortcomings as a relative short catalyst life 
and problems with extreme carbon deposition on the catalyst. 
In the present invention, a toluene-containing stream is contacted with a 
catalyst of the instant invention in the liquid phase and at a temperature 
of between about 150.degree. C. and 225.degree. C. In a preferred 
embodiment, a hydrogen gas-containing stream is also employed in the 
reaction. 
The toluene feed for the present invention is typically obtained as a 
refinery process stream from an extraction process. Accordingly, the 
stream typically contains some benzene and xylene in addition to the 
toluene. Toluene concentrations of greater than about 50% volume are 
preferred, however. 
The process may be carried out either as a batch or continuous type of 
operation, although it is preferred to carry out the process continuously. 
It has generally been established that the more intimate the contact 
between the feedstock and the catalyst, the better the yield of desired 
product obtained. With this in mind, the present process, when operated as 
a batch operation, is characterized by the use of vigorous mechanical 
stirring or shaking of the reactant and catalyst. 
When employing a continuous process, the feedstocks may be contacted with 
the supported catalyst in any suitable reactor. In one embodiment, the 
supported catalyst is packed in a vertical, tubular reactor bed with inert 
supports, such as ceramic balls or silicon carbide, above and below the 
supported catalyst to prevent entrainment of the solid catalyst. In a 
further embodiment, the supported catalyst is mixed with an inert 
material, such as quartz, and loaded in the reactor so as to improve the 
fluid dynamics of the system. The flow of the reactant feed stream may be 
upflow or downflow, with an upflow arrangement being preferred to ensure a 
liquid phase reaction. 
Reaction temperature is varied between about 150.degree. C. and 225.degree. 
C. The reaction temperature must be kept below about 225.degree. C. due to 
the lack of stability of the catalyst at temperatures of over 250.degree. 
C. A preferred temperature range is between about 175.degree. C. and 
210.degree. C. 
In general, the pressure in the reaction zone is maintained to keep the 
toluene in liquid phase, and accordingly, will vary with the particular 
feedstock employed and the reaction temperatures. Typical reaction zone 
pressure varies from about 10 psig to about 2,000 psig. 
The weight hourly space velocity effectively measures the catalyst 
concentration employed, and hence, also measures the relative activity of 
the catalyst. Weight hourly space velocity (WHSV) is defined as the weight 
per hour of toluene feed divided by the weight of catalyst (not including 
support) employed. For a non-supported catalyst, the WHSV varies between 
about 0.05 hr.sup.-.sup.1 to about 1.0 hr.sup.-.sup.1. For a supported 
catalyst, the WHSV varies from between about 0.5 hr.sup.-1 to about 10.0 
hr.sup.-.sup.1. The larger WHSV employed for supported catalysts is 
possible because of the greater activity of the supported catalysts. 
In a preferred embodiment, a gas stream is introduced into the reaction 
zone along with the toluene feed stream. Typically, the gas is an inert 
gas such as nitrogen. However, it has been found that when the gas stream 
also contains some hydrogen, the conversion of toluene is increased while 
the production of unwanted products such as C.sub.3 -C.sub.5 cracked gases 
and non-volatile aromatic products is decreased. A preferred gas 
composition contains between about 2% to 95% hydrogen with the remainder 
being an inert gas such as nitrogen. The volume ratio of gas to toluene 
varies from about 0.5:1 to about 20:1. 
The invention is further illustrated by means of the following Comparative 
Example and Illustrative Embodiments which are given for the purpose of 
illustration only, and the invention is not to be regarded as limited to 
any of the specific materials or conditions recited therein. 
In the Comparative Example and Illustrative Embodiments, the reactor 
employed was a 17-inch stainless steel tube equipped with both a liquid 
feed upflow inlet and a nitrogen inlet. The catalyst bed occupied about 10 
inches in the center of the reactor; and on either side of the catalyst 
bed were packed about 10 grams of carborumdum chips. 
In all cases, the reactants were introduced in an upflow manner, pressure 
was kept at 300 psig to maintain a liquid phase, and the feed stream was 
100% toluene. Catalyst concentration is measured by weight hourly space 
velocity (WHSV, hr.sup.-.sup.1) which is defined as the weight of the 
toluene feed divided by the weight of catalyst (excluding support). 
Comparative Example Id 
The catalyst employed in Comparative Example Id was prepared by grinding 
Nafion XR granules with a blender to 150 micrometer or less particle size. 
The ground material was then treated twice with 30% sulfuric acid to 
convert the material from a potassium (K.sup.+) form to the H.sup.+ form. 
The treated material was collected by filtration, washed with distilled 
water until the washings were neutral, and then dried at 100.degree. C. 
and 3 mm pressure for 16 hours. The resulting catalyst contained about 
0.85 milliequivalents of acid per gram of catalyst. The structure for the 
resulting catalyst is exemplified by the following repeating structure 
when n = 1 or 2 and the ratio of x over y varies from between 2 and about 
50: 
##STR8## 
In Comparative Example Id, the catalyst bed comprised 5 grams of the 
catalyst plus 5 grams of quartz particles. A stream of 100% nitrogen in a 
volume ratio of 1:1 with the toluene feed was maintained. The WHSV was 
maintained at 0.43 hr.sup.-.sup.1. The results are presented below in 
Table 1d. 
Table 1d 
______________________________________ 
Time, hr 5 26 46.5 68.5 72.5 91.5 
Temperature, .degree. C. 
200 200 200 200 225 225 
Composition of Product 
%w 
C.sub.3 -C.sub.5 
0.8 0.8 0.8 0.8 1.0 0.4 
Toluene 78 78.5 79 84 84 90 
Benzene 9.9 9.9 9.5 7.3 7.3 4.6 
o-Xylene 2.2 2.0 1.9 1.5 1.4 1.0 
p-Xylene 2.6 2.4 2.3 1.8 1.8 3.7 
m-Xylene 5.8 5.5 5.4 4.0 4.0 
Trimethylbenzenes 
0.5 0.5 0.5 0.4 0.3 0.3 
Non-Volatile Aromatics 
0.5 0.5 0.5 0.5 0.5 0.4 
______________________________________ 
Illustrative Embodiment Id 
In the Illustrative Embodiments Id and IId, the catalyst was prepared by 
impregnating a silica support with an ethanol solution of Nafion XR 
granules, and then removing the ethanol from the solid on a rotary 
evaporator leaving a 6% catalyst on support composition. The support was a 
high surface area silica having a 1.65 ml/g pore volume, 300 m.sup.2 /g 
surface area and a 210 A average pore diameter. Ten grams of the resulting 
catalyst were loaded in the reactor. A stream of 100% hydrogen in a volume 
ratio of 2:1 with the toluene feed was maintained. The WHSV was kept at 
3.6. The results are presented below in Table 2d. 
Table 2d 
______________________________________ 
Time, hour 3 6 22 25 28 30 
Temperature, .degree. C. 
200 200 200 200 200 225 
Composition of Product, 
%w 
C.sub.3 -C.sub.5 
0.1 0.1 0.1 0.1 0.1 0.2 
Toluene 86.5 87 87.5 87.5 87.5 81 
Benzene 6.4 6.3 6.0 6.0 6.0 9.3 
o-Xylene 1.3 1.2 1.2 1.1 1.1 1.9 
p-Xylene + m-Xylene 
5.4 5.2 5.2 5.2 5.0 7.3 
Trimethylbenzenes 
0.3 0.3 0.3 0.3 0.3 0.4 
Non-Volatile Aromatics 
0.05 0.05 0.05 0.05 0.05 0.1 
______________________________________ 
Illustrative Embodiment IId 
This Embodiment was conducted in a similar manner to Ilustrative Embodiment 
Id except that the gas stream employed comprised 6% volume hydrogen and 
94% volume nitrogen. The results are presented below in Table 3d. 
Table 3d 
______________________________________ 
Time, hour 4 25 46 68 76 96 
Temperature, .degree. C. 
200 200 200 200 225 225 
Composition of 
Product, %w 
C.sub.3 -C.sub.5 
0.2 0.2 0.2 0.2 0.4 0.3 
Toluene 79 79 80 81 72.5 90 
Benzene 10 10.0 9.8 9.3 13.2 4.6 
o-Xylene 2.1 2.1 2.0 1.9 2.7 1.0 
p-Xylene 2.6 2.6 2.5 2.3 3.3 3.7 
m-Xylene 5.7 5.5 5.3 5.0 7.1 
Trimethylbenzenes 
0.4 0.5 0.4 0.4 0.6 0.2 
Non-Volatile 
Aromatics 0.1 0.1 0.1 0.1 0.1 -- 
______________________________________