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Патент USA US2406967

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Patented Sept. 3, i946
» 2,406,967
; UNITED STATES PATENT OFFICE ‘
2,406,967
ISOMERIZATION 0F sATURA'rnn
HYDROCARBONS
‘
..
'
Herman Pines, Riverside, 111., assig‘nor to Uni; .
versal Oil Products Company,' Chicago," 111., a '
corporation of Delaware
* ‘ ‘
No Drawing. Application ‘November 19, 1943,
Serial No. 510,915
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;
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1'2‘ alias. (o1. zed-sass) 71 ‘
.
This invention relates to the catalytic isomer
ization of isomerizable saturated-hydrocarbons
and is more speci?cally concerned 'with' an 'im-,
proved‘process wherein these" hydrocarbons are
isomeri‘zed‘ under carefully selected conditions of
operation in the presence of certain polynuclear
aromatic hydrocarbons.
'
'7
' '
.
The ' isomerization’ of saturated hydrocarbons
has assumed considerable importance at the pres
ent time, particularly the isomerization of nor
mally liquid para?inic hydrocarbons such as pen
tane, hexanes, heptanes, etc, which upon isom;
erization produce compounds which have ' very
desirable antiknock properties when included in
aviation gasoline blends and other motor fuels,
Moreover,_ these isomerized, products, especially
the isomers having;at least one tertiaryncarbon
kylating agent such as ‘an, ole?n, alcohol, etc., to
produce‘higher molecular Weight alkyl derivatives
which have very desirableantiknocl; qualities and
which are useful intermediates in organic synthe
i,
i
,
,
,7
‘
l
2
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drogemf‘
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Broadly, thev invention comprises a. process for
isomeri‘zing a saturated hydrocarbon by contact
_
said hydrocarbon with an isomerizing cata--‘
lyst under isomerization conditions in the pres
ence of a‘ relatively minor amount oi‘a hydrocar
bon containingat least one polynuclear aromatic
group of the fused ring type.
'
‘ In one speci?c embodiment the present inven
' tion comprises a process for the ‘production of
isopentane by contacting normal pentane with an
aluminum chloride-hydrogen chloride catalyst
under isomerizing conditions in the presenceof a
15 relatively minor amount of naphthalene, ‘
I have discovered that the addition of these
aromatic hydrocarbons selectively suppresses the
decomposition reactions and permits‘ the isomer- '
atom per molecule, may be alkylated with an al
sis.
a
?culties which are inherent in the use of ‘hy
o
a It is well known that saturated hydrocarbons
ization of the saturated hydrocarbons with a high
20 degree of e?iciency and low catalyst consumption.
The exact mechanism by which the polynuclear
aromatics suppress decomposition reactions is not
thoroughly understood, but it will be evident from
the experimental‘data' hereinafter presented that
may be isomerized using catalysts of the Friedel 25 greatly improved results are'obtained when these
hydrocarbons are’ present.
Crafts typesuch as aluminum halides, zinc hal
ides,jzirconium halides, or mixtures thereof in the
presence of a hydrogen halide.‘ The primary, op
erating di?iculty accompanying these isomeriza
‘ "Th‘e‘polynucle‘ar aromatic hydrocarbons which
maybe employed to suppress decomposition re
actions during the ‘isomerization of saturated hy
tion operations is the tendency toward high cata 30 drocarbons comprise broadly those hydrocarbons
containing at least one polynuclear aromatic
lyst consumption due to theformation of metal
group of the fusedring type. The preferred com
halide ,- hydrocarbon complexes.‘ The catalyst
pounds are naphthalene and the alkyl naphtha;
complexes or sludges are formed ‘byzthe interac
lenes such as methyl naphthalene and ethyl naph
tion of the metal‘ halide with the products ofdee
‘Other compounds which may be em
composition reactions which occur simultaneously 35 ‘ thalene.
ployed within.‘ the scope of the invention are
phenyl naphthalene, ,anthracene, and dinaphthyl.
with
Various
the isomerization
methods havereaction.
been proposed
4., W ‘ to
, prevent
q
‘ The ‘various polynuclear aromatics are not nec
the decomposition of the saturated hydrocarbons
essarily equivalent in their effectiveness since ob
thereby preventing high Icatalyst consumptions.
viously different amounts of aromatic may be re-.
For example, it has been proposed to introduce 40 quired dependent upon the nature of the cata
hydrogen into the‘reaction zone tosuppress de
lyst and charging stock and also upon the oper
composition and presumably to hydrogenate fun
ating. conditions employed. The concentration of
saturated hydrocarbon fragments formed by de
the aromatic in the isomerization charging stock
composition of the charging stock. ‘ The use of hy 45 is generally from about 0.1% to about 5% by
drogen as a decomposition‘suppressorhas been
weight. The use of the above mentioned aromatic
found to be very expensive-‘and entailsthe use of
a ‘considerable amount of auxiliary ‘equipment
hydrocarbons to suppress decomposition reactions
is particularly applicable to the isomerization of
such as compressors, separators, etc., to provide a
normal pentane since normal pentane exhibits an
means for'recy‘cling the-hydrogen to the reaction 50 unusual tendency to undergo decomposition when
subjected to isomerizing conditions. The various
It is an object of the present invention to pro
polynuclear aromatics are separated from the
zone.
>
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‘
vide a‘method for suppressing‘ the decomposition
isomerization reaction products by fractionation
of the, isomeripzable hydrocarbons which ‘is eco
or other suitable means and may be recycled to
nomic‘aland practical‘ and which obviates the dif
the, isomerization step.
2,406,967
3
The operating conditions of the isomerization
A blank run was also made without the addition
of an aromatic to suppress decomposition reac
tions. The pertinent data from these tests are
tabulated as follows:
process such as temperature and pressure will
vary somewhat depending upon the aromatic and
catalyst employed.
Ordinarily, temperatures
within the range of about 50° F. to about 350° F. 5
and more preferably within the :range of from
about 120° F. to‘about 250° F. and pressures vary
ing from substantially atmospheric to about 500
{Run No.
l
2
3
pounds per square inch or more are desirable.
Any of the well-known Friedel-Crafts type-iso
merization catalysts may be employed. It isde
> Chargwgrams:
.
.Aluminum chloride _______________________ ._
Hydrogen chloride _______________________ ._
sirable that a hydrogen halide such as hydrogen
-
chloride and hydrogen bromide be used in :con- ' ‘
‘ ‘Naphthalene .... _.,-_.
‘ ‘2-methyl‘naphth8lene...
junction with these catalyticmateria'ls. ‘The‘
ordinary concentration of the hydrogen halide is 15
15
2. 8 I
2.8 |
3.1
.n-Pentane ___________ -i __________________________ _ .85 _____ _ ..
'ii‘emperaturawown.
.
.-
Maximum pressure, p. s. i. gage_ _
0
0
I
2.0
0
0
2.0
_____ . -75..... _ _
__ 110
|
63
|
70
{llinie,.liours.c_v ........ ._- ____________________________ _-6 ______ -_
within the range of about 1 to about-*Hlv-mol'
per cent of the charge and preferably from about
5 to about 20 mol per cent. The preferred cat
alysts comprise the chlorides and bromides of alu
.A'nalysisoi product; 'm’ol percent:
‘
1-i-Butune _________________________________ __
n-Butane.-.
8. 5
6. 7
8. 1
l. 0
0. 4
56. 1
37. 1
n-Pentane ________________________________ _- ll. 8
30. 7
52. 3
3. 7
4. 6
Hexane and higher ______________________ _.
minum, zinc, zirconium, ‘and iron, either alone 20
54. 1
19. 2
. i-iPonmna
6. 8
o'r'in admixture with one ‘another. “These cata
lysts may be employed in the solid granula‘r'state
or ‘upon inert supporting “materials ‘such ‘as ‘alu
‘In run *1‘, which ’Was' lthe‘blank "run, it will _"be
noted ‘that ‘although ‘19.2% Iisopentane was ob
mina, silica, thoria, crushed ?rebrick', quartz, ac
tainedthere 'was also-a totalbutane - production
of 622% which ‘represents-‘a relatively ‘low ' em
tivated clays, and ‘activated chars; "
It'is also'witl?nthe scope of ‘this inventionto
employ mixtures oi'tli'ese compounds and in par
ticular the aluminum halides with'thehalidesoi
antimony, bismuth, and'arsenic‘,'tofform catalyst
ciency'of'conversion o'f isopentane. ‘In~run' 2~em~
ploying naphthalene, 56.1% ~isopentane ‘WaS'U’b
tained with only 915% of butane thus indicating
the -marked; e?ect'of naphthalene ~insuppressing
decomposition reactions. v‘It will‘also'be 'noted 'in'
composites which are molten under the ‘condi 30
run 2 ~ that 30 31% ~ or unconverted normalipentane
tions of operation.
was recovered which ‘could be recycledi’or fur
‘The isomerization operation‘may be conducted
ther conversion in "a "continuous method of '01»
in various‘w'ays. v‘1*"orexam1?e‘, the heated ‘hydro
carbon charge containing‘the addedlpolynucl'ear
aromatic‘ may ‘be passed ‘eitherv in ‘the liquid,
vapor, or‘mixed phase “through a'reaction zone
containing .a'bed of solid‘ granular'catalyst either
‘supported or'unsupported, and'the reaction prod
uct maybe separated into ‘the desired ‘isomers
oration.
’
7
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"In ‘run :3, 2-methy1 naphthalene was employed.
Comparing ‘the ‘results of ~this ‘test ‘with the “re
suits obtained‘in'run ‘1 :it wi1l~be noted that the
presence of the aromatic hydrocarbonsuppressed
the " butane- ~production "to “a very marked extent
and unconverted material ‘the latter being re 40 and lre'sulted'in'a-high yield- of isopentane.
cycledto ‘the reaction zone.
I ‘claim as 1- my invention:
“Another method of operation consists of em
1.
isomerization process ‘which comprises
p‘loyin'g 'a catalyst supply ‘chamber containing’a
contacting a parai?n hydrocarbon under isomer
bed‘ of granular catalyst'throug'h'which a stream
izing "conditions with anv isomerizing catalyst
or the charge is passed ‘in liquid‘ phase‘ to dis
comprising ‘a ‘free ‘metal halideof " the iFriede'l
solve the required amountof'catalyst; ‘This cat
Crafts- type 'in1the~presence-'of a relatively minor
alyst-containing stream is ‘introduced ‘into "a re
amountwof ‘an ‘aromatic hydrocarbon containing
action 'z'onealong' with a regulatedamount or ‘the
at ‘least one ipol-yn-uclear aromatic group of the
hydrogen halide, and a substantial portion-of
fused ring type.
.
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the "hydrocarbonis isomerized ‘therein. ' ‘This're 50
42. An isomerization process which comprises
action zone‘may‘comprise a‘ large vessel which will
contacting :a normally liquid para?in hydrocar
provide sumci'ent time‘for'thereaotion’ to o‘ccur'or
bon with an isomerizing.‘catalystcomprisinga
vmay ' be j'?lled' with a ‘retaining ‘material such ' as
free .‘me'tal-hali'de' o'flthe FriedehCr-‘afts type under
molten salts, hydrocarbon-metal"halide com
isomerizing eondition‘sia‘nd in :thespresen'ce .ofian
plexes, or solid packing materials such as bauxite,
aromatic hydrocarbon .containing at .least :one
R‘aschig rings, berl saddles, granular quartz and
polynuclear aromatic igroup act :the "fused irin‘g
other materials “well ‘known'to "those ‘skilled in
type.
.
the art.
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.3. An isomerization ,process which :comprises
The following examples illustrate 'ina general
way ‘the effectiveness of the polynucle'ar aro
matic hydrocarbons disclosed herein insuppres's;
ing decomposition reactions during'th'e isomer
contactinga normally liquid para?in-hydrocarbon
60 with anz-isomerizing catalyst comprising -a free
metal halideof the Friedel-Crafts ‘type and -a
hydrogen'halide under .isomerizing conditions in
ization operation. It is not intended ‘that these
the [presence of an aromatic hydrocarbon con
examples'unduly limit'the generally ‘broad scope
taining atleast onepolynuclear aromatic group
of the .fusedring type.
4.~An isomerization ‘process which comprises
contacting a normally liquid .paraf?n with an
of this invention.
‘
A series of experiments was conducted ~to in
Ves'tigatethe eiTect of naphthalene and 2-methy1
naphthalene in the normal pentane isomeri'zation
reaction. An electrically ‘heated ‘autoclave
isomerizing catalyst comprising free aluminum
chloride and hydrogen chloride under isomeriz
equipped with a mechanical stirrer was charged 70 ing conditions and in the presence of an aro
with ‘85 grams of normal 'pentane and the desig
matic hydrocarbon containing at least one poly
nated amount of aromatic, and ‘anhydrous ‘alu
minum chloride and hydrogen chloride were
added; The autoclave was'sealedand'the reac
tion was carried out for a'period'of six hours.
nuclear aromatic group of'the ‘fused ring type.
'5. The process of claim .1 wherein said am
matic hydrocarbon comprises ‘naphthalene.
a
'6. The "process or claim "1 ‘wherein said’po'hh
2,406,967
nuclear aromatic hydrocarbon comprises an alkyl
naphthalene.
7. Thevprocess of claim 1 wherein said poly
nuclear aromatic hydrocarbon comprises methyl
naphthalene.
8. An isomerization process which comprises
contacting normal pentane with an isomerizing
catalyst comprising a free metal halide of the
Friedel-Crafts type under isomerizing conditions
in the presence of an aromatic ‘hydrocarbon con
taining at least one polynuclear aromatic group
of the fused ring types;
9. An isomerization process which comprises
contacting normal pentane with an isomerizing
catalyst comprising free aluminum chloride and
hydrogen chloride under isomerizing conditions
in the presence of an aromatic hydrocarbon con
taining at least one polynuclear aromatic group
of the fused ring type.
t
10. The process of claim 9 wherein said aro
matic hydrocarbon comprises naphthalene.
11. The process of claim 9 wherein said aro
matic hydrocarbon comprises an alkyl naphtha
lene.
12. The process or claim 9 wherein said aro- ‘
matic hydrocarbon comprises methyl naphtha
lene.
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HERMAN PINES.
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