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Патент USA US2378210

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Patent-ecl June 12, ‘1945
6 ' UNITED
2,378,210 ;
STATES
PATENT , OFFICE
2,378,210
PROCESS FOR THE SYNTHESIS or TOLUENE" "
AND XYLENES
Donald L. Fuller and Bernard S. Greensfelder,
Oakland, Calif., assignors to Shell Development
Company, San Francisco, Calif., alcorporation
of Delaware
No Drawing. Application November 17, 1942,
Serial No. 465,924
(Cl. 260-668)
12 Claims.
This invention relates to a new and useful proc
processes.
In one such combination process a
ess for the synthesis of toluene and xylenes. A
particular embodiment of the invention relates
to a process for the synthesis of toluene by cata
petroleum fraction containing appreciable con
centrations of the desired non-hydroaromatic
cycloparaf?n is subjected to a dehydrogenation
lytic dehydroisomerization of dimethyl cyclo
treatment, for instance, with a dehydrogenating
pentane and/or ethyl cyclopentane.
vmetal sul?de catalyst to dehydrogenate the hy
In copending application Serial No. 449,971, _
droaromatic cycloparaf?n hydrocarbons usually
?led July 6, 1942, we have shown that molybde
present; any aromatic hydrocarbons are ex
num oxide is a unique dehydrogenation catalyst‘
tracted by known methods; and then the large
in that it is capable of e?ecting a direct dehydro 10 amounts of para?ins are reduced to a minor pro
isomerization of methyl cyclopentane to benzene
portion, ,for instance, by extraction or cracking,
and have described a method for the synthesis of
or dehydrocyclization followed by a fractionation
benzene from methyl cyclopentane utilizing this
or extraction. The residual material consisting
reaction; It is found that this unique ability of
predominantly of non-hydroaromatic cyclopar
molybdenum oxide is not con?ned to the dehy 15 a?ins is a suitable feed for the presentsynthesis. .
droisomerization of methyl cyclopentane but ex
According to another method, certain hydro
tends to the dehydroisomerization of other non
carbon fractions obtained by destructive hydro
hydroaromatic naphthene hydrocarbons’. ‘Thus,
genation processes and consisting predominantly
the dimethyl cyclopentanes, ethyl cyclopentane
of cycloparaiiinsv are subjected to the above-de
and cycloheptane may be directly dehydroiso 20 scribed dehydrogenation treatment and extrac
merized to toluene, and the trimethyl cyclopen
tanes, methyl cycloheptane and the methyl ethyl
tion treatment to remove aromatic hydrocar
bons. By this method, fractions consisting es
cyclopentanes may be directly dehydroisomer
ized to xylenes. The present application de
sentially of non-hydroaromatic hydrocarbons'
‘may be prepared.
scribes a process wherein this property of molyb 25 ' The described dehydroisomerization requires
denum oxide catalysts is used to'synthesize these
the use of speci?c catalysts. Of the many
‘methyl substituted benzenes, particularly tolu
ene.
dehydrogenation catalysts such as chromium
oxide, tungsten oxide, vanadium ‘oxide, titanium '
_
According to the process of the present inven
tion, methyl substituted benzenes such, in par
tlcular, as toluene and/or xylenes are synthesized
oxide, iron oxide, platinum, nickel, etc., the only
30, catalysts so far found to affordthe desired re
sults are molybdenum oxide and, to a lesser ex
' directly Irommon-hydroaromatic cyclopara?in
tent, molybdenum sul?de. Certain observations
hydrocarbons'having at least seven carbon atoms.
indicate that a tungsten sul?de-nickel sul?de
mixture catalyzes dehydroisomerization to a
_ The cyclop’aramn may be applied in a pure state,
in admixture with one or more other non-hydrQ
35 slight degree.
aromatic cycloparai?ns, or‘. in admixture .with
minor amounts of other hydrocarbons such as
para?ins, ole?ns and/or aromatics. The non
hydroaromatic' cyclopara?ins are, however, pref
erably present in amounts exceeding 50% by vol 40
ume. . The non-hydroaromatic cyclopara?in or
mixture consisting predominantly of non-hydro
aromatic cyclopara?ins may be derived from ‘any
source. In "some cases it is possible by careful
fractional distillation to separate a narrow boil
ing traction consisting predominantly of di
methyl~ cyclopentanes from gasolines of natural
or synthetic origin. Such fractions boil predom
inantly within the range of 185° F. and 200". F.
In many cases, however, it is impossible or im
, practical to separate a fraction consisting pre
dominantly of, the desired. non-hydroaromatic
cycloparamns from petroleum fractions by simple
fractional distillation. Suitable fractions may.‘
The catalyst may be employed
per se or- in combination with one or more pro-
,
moting and/or carrying and/or diluting sub
stances. ‘A preferred catalyst comprises an ad
sorptive support (for example, having a surface
area of 30 or more square meters per gram). im
pregnated with an effective amount of the molyb
denum oxide. Suitable adsorptive supports com
prise, for instance, active carbon, active mag
nesia, various active clays, and, especially, active
45 aluminas.
Particularly
e?ective _ molybdena
alumina, catalysts are described'and claimed in
copending applications Serial Nos. 452,552,
452,656, and 463,306, ?led July 27,, 1942, July 28, ;
1942, and October 23, 1942, respectively. E?ec
50 tive amounts of the molybdenum oxide to be ap- ,.
plied to such carrier or supporting substances
are, for instance, about 4% to about 30% ,(i. e.,
3% to 22.5% molybdenum).
-
-
The direct dehydroisomerization of theabove
however, be obtained by certain combination 55 described non-hydroaromatic cycloparaiiln hydro
.
2
2,378,210 .
Example I
carbons with the above-described molybdenum
oxide catalysts may be effected under conditions
within the following approximate limits:
A highly naphthenic straight run petroleum
fraction was carefully fractionated and a fraction
boiling between 88° C. and 93° C. (5% and 95%
points in a precision distillation over at least 20
theoretical plates) was collected. This fraction
consisted predominantly of a mixture of dimethyl
Partial pressure of hydrogen
cyclopentanes with minor amounts of para?lns
atmospheres..1 to 50
and about 17% of methyl cyclohexane. This
If molybdenum sul?de is employed instead of 10 fraction was subjected to a dehydroisomerization
molybdenum oxide, somewhat lower temperatures
treatment with a molybdenum oxide-on-alumina
between about 350° C. and 450° C. are preferred.
catalyst (14% Mo) under the following condi
By liquid hourly space velocity is meant the vol
tions:
,
umes of liquid hydrocarbon contacted (in the va
Temperature ____________ A _________ __°C__ 490
por form) per volume of catalyst per hour. Thus, 15
Pressure __________________ __atmospheres__ 10
a liquid hourly space velocity of 1 signi?es that
Contact time _____________ __seconds__ About 100
for every volume of reactor space ?lled with cat
Liquid hourly space velocity ______________ __ 0.2
alyst there is fed during one hour the vapors of an
M01 ratio of hydrogen to hydrocarbon in
equal volume of the liquid hydrocarbon feed. The
'
3
above-mentioned factors governing the conditions 20 feed
The product from the ?rst three hours of process
are interdependent as they are in most all cat
ing contained about 70% b. w. aromatic hydro
alytic reactions. The ranges given are therefore
carbons, and the product from the tenth to the
not to be taken as rigidly ?xed or absolutely lim
twelfth hour of processing contained about 59%
- ited but'only indicative of bounds outside of which
it is ordinarily unnecessary to go in practicing 25 b. w. aromatic hydrocarbons.
the invention. The conditions with respect to any
Example II
of the above governing factors which will be opti
A second portion of the material described in
mum under any given set of circumstances will
Example I was treated with the catalyst under
depend upon the conditions with respect to the
other‘ factors as well as upon the particular hy 30 the same conditions except that the pressure was
maintained at 5 atmospheres and the liquid hourly
drocarbon feed, the age of theicatalyst, etc., but
space Velocity was reduced to 0.1. The. product
will ordinarily fall within the above limits. In no
Temperature ___________________°C__ 450 to 550
Pressure ____________ "atmospheres-..
2 to 60
Liquid hourly space velocity_____ ____.__
0.1 to 2
from ten hours ‘of processing contained about
83% b. w. aromatic hydrocarbons, predominantly
case are all of the conditions made so severe that
appreciable destructive hydrogenation takes place.
The above-speci?ed conditions are hereinafter re- ‘ 35
ferred to ‘as dehydroisomerization conditions. .
One set of dehydroisomerlzation conditions which
may be advantageously employed with the pre
ferred molybdenum oxide catalyst is, for example:
toluene.
'
We claim as our invention:
1. A process for the synthesis of toluene which
comprises contacting hydrocarbon vapors consist
ing predominantly of dimethyl cyclopentanes un
40 der dehydroisomerization conditions with a cat
alyst consisting essentially of a major amount of -
Temperature _________________ __.°C__ About 490
Pressure ____________ _..atmospheres__ About 15
an adsorptive alumina impregnated with a minor '
amount of molybdenum oxide.
.
Liquid hourly space velocity ________ __ About 0.5
Partial pressure of hydrogen
_
2.- A process for the synthesis of‘ toluene which
atmospheres-.. About '1
When treating the above-described non-hy
comprises contacting hydrocarbon vapors consist
ing predominantly of non-hydroaromatic cyclo
droaromatic cyclopara?in hydrocarbons as indi
cated, the predominant reaction is the direct de
‘paraf?n hydrocarbons having seven carbon atoms ‘
‘Lesser amounts of polynuclear aromatic hydrocar
with a molybdenum oxide-alumina catalyst.
4. A process for the synthesis of toluene which
under dehydroisomerization conditions with a
catalyst consisting essentially of a major amount
hydroisomerization of the applied non-hydro
aromatic cycloparaihn hydrocarbons to the corre 50 of an adsorptive' alumina impregnated with‘ a
minor amount of molybdenum oxide.
sponding aromatic hydrocarbons. Side reactions
3. A process ‘for the synthesis of toluene which ‘
such as cracking and condensation to polynuclear
comprises contacting hydrocarbon? vapors~ con
hydrocarbons, etc., take place only to a minor
sisting predominantly of non-hydroaromatic cy
extent. The conversion products therefore con
clopara?in hydrocarbons having seven carbon
55
sist essentially of the desired alkyl benzenes with
atoms under dehydroisomerization conditions
ons.
The catalytic treatment may be effected in any
comprises contacting hydrocarbon vapors con
one of the known suitable manners for effecting
60 sisting predominantly of ethylcyclopentane un
similar reactions such as hydroforming with sim
der dehydroisomerization conditions with a mo
- ilar catalysts. Thus, the catalyst may be em
lybdenum oxide catalyst.
ployed in a granular, pelleted or ?nely divided
fc m in converters of suitable design'for such
'
-
. 5. A process for the synthesis of toluene which
comprises contacting hydrocarbon vapors consist- ‘
catalysts. One suitable method is, for example, 65 ing predominantly of dimethyl cyclopentanes un
to support the catalyst in the granular or pelleted.
der dehydroisomerization conditions with a mo
form in a reaction converter provided with heat
lybdenum oxide catalyst.
ing and temperature controlling ‘means and to
6. A process for'the synthesis of toluene which
pass the vaporized non-hydroaromatic cyclopan
comprises contacting hydrocarbon vapors con
a?ln hydrocarbons in admixture with from, for 70 sisting predominantly of non-hydroaromatic cy
clopara?in hydrocarbons having seven carbon
example, 2 to 5 volumes of hydrogen therethrough.
The catalyst is periodically regenerated by burn
ing of! deposited carbonaceous matter with oxy
atoms ' Y under
gen or an oxygen-containing gas in the known
manner.
'
'
-
>
dehydroisomerization
conditions
with a molybdenum oxide catalyst.
7. A process for the synthesis of a methyl sub
75 stituted benzene which comprises contacting hy
3
2,878,210 "
drocarbon vapors consisting predominantly oi’
non-hydroaromatic cycloparaflin hydrocarbons
having at least seven carbon atoms under dehy
_droisomerization conditions with a catalyst con
sisting essentially of a major amount of an ad
sorptive alumina impregnated with a minor
amount of molybdenum oxide.
8. A process for the synthesis of xylenes which
comprises contacting hydrocarbon vapors con
- sisting predominantly of non-hydroaromatic cy
cloparai?n hydrocarbons having eight carbon
atoms under dehydroisomerization conditions
with a molybdenum oxide catalyst.
'
non-hydroaromatic cyclopara?in hydrocarbons
having at least seven carbon atoms under dehy
droisomerization conditions with a molybdenum
oxide catalyst.
'
.'
11. A process for the synthesis of a methyl sub
stituted benzene which comprises contacting hy- ,
drocarbon vapors consisting predominantly of
non-hydroaromatic cyclopara?n hydrocarbons
having attleast seven carbon atoms under dehy
10 droisomerization conditions with a molybdenum
sul?de catalyst.
'
12. A process for. the synthesis of a methyl sub
stituted benzene which comprises contacting hy- ‘g _
9. A process for the synthesis of a methyl sub
drocarbon vapors consisting predominantly of
stituted benzene which comprises contacting hy 15 non-hydroaromatic cycloparamn hydrocarbons
drocarbon vapors consisting predominantly of
having at least seven carbon atoms under dehy
non-hydroaromatic cyclopara?in hydrocarbons
droisomerization conditions with a catalyst con-»
having at least~ seven carbon atoms under de
taining as the predominant active constituent a
hydroisomerization conditions with a molybde-'
num oxide-alumina catalyst. ‘
'
»
10. A process for the synthesis of_ a methyl su -
stituted- benzene which comprises contacting hy
. drocarbon vapors consisting predominantly of,
compound of molybdenum selected from the
v20 group consisting of molybdenum oxide and mo
lybdenum sul?de.
DONALD L. FULLER.
_
BERNARD S. GREENSF'EIDER. _
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