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Patented Mari 2, 1948 v
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2,436,923
v‘ UNITED smes 'l‘ATENT OFFICE
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2,430.22:v
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DEMETHYLATION 0F HYDROCARBONS IN
PRESENCE OF WATER
Haensel, Clarendon Hills, 111., minor
to Universal Oil Products Company, Chicago,
Ill, a corporation of Delaware
Application April 8, 1946,
".0 Drawing.Serial
No. 660,433
I 8 Claims. - (0!. 260-666)
2
1
This invention relates to the treatment of a
normally liquid hydrocarbon with water in the
presence of a hydrogenation catalyst to produce
a hydrocarbon containing at least one carbon
atom less than those present in the hydrocarbon
charged to the process.
More speci?cally, this
with an atomic number ofat least 27 and of
the eighth group of the periodic table at a de
methylation temperature and recovering the re
sultant demethylated hydrocarbons.
A further embodiment of the present inven
' tion comprises a process for reacting water with
invention is concerned'with a catalytic process
for treating with water, particularly water vapor
or steam, a hydrocarbon containing more than 4
a para?lnic hydrocarbon containing more than
An object of this invention is the'demethyla
methylated by reaction with water in the pres
4 carbon atoms per molecule in the presence of
a nickel catalyst at a temperature of from about
carbon atoms per molecule, said process being 10 180° to about 350° C. to split from said hydro
carbon only one methyl group or several methyl
carried out at closely correlated conditions of.
groups and form a paraf?nic hydrocarbon of
' temperature and charging rate so that the prin
lower molecular weight.
cipal reaction of the process is the replacement
I have found that normally liquid hydrocar
with hydrogen and the scission of methyl groups
to decrease the number of carbon atoms of said 15 bons including parai?nic, ole?nic, alkyl naph- ~
thenic and alkyl aromatic hydrocarbons are de
hydrocarbon by at least one carbon atom.
tion of a normally liquid hydrocarbon selected
from the group consisting of a paraffin, an ole?n.
an alkyl aromatic, and a saturated alkyl hydro
aromatic to produce therefrom a hydrocarbon of
lower molecular weight,
Another object of this invention isthe treat
ment of a saturated aliphatic hydrocarbon con
taining more than 4 carbon‘ atoms per molecule
with water at a demethylation temperature and
in the presence of a hydrogenation catalyst to
produce a para?inic hydrocarbon of lower molec
' ular weight.
A further object of this invention is the pro
duction of a paraiilnic hydrocarbon of lower mo;
ence of an active hydrogenation catalyst at-a
‘relatively narrow range of operating tempera
tures much below the temperatures needed for
the interaction of hydrocarbons with steam to
substantially gasify the hydrocarbons and pro
duce only hydrogen and carbon oxides. My
process selectively removes methyl groups from
the different hydrocarbons charged thereto and
produces hydrocarbon products containingyone
carbon atom less per molecule than present in
the hydrocarbons charged to the process.
Hydrocarbons which are demethyiated by my
process have more than 4 carbon atoms per mole
lecular weight by treating a para?lnic hydrocar
cule and generally include an alkyl group pref
erably containing at least 2 carbon atoms and
hydrogenation catalyst of a cyclic hydrocarbon
and monoisopropylbenzene and other monoalkyl
comprising a ring of 6 ‘carbon atoms and an alkyl
side chain to decrease the number of carbon
benzenes having more than 3 carbon atoms in
the alkyl group as well as dialkyl and polyalkyl
comprise parailins, ole?ns, alkyl aromatics and
bon containing more than 4 carbon atoms per
saturated alkyl hydroaromatics, The para?lnic
molecule and water in the presence of an active
hydrogenation catalyst at a demetlurlation tem 85 hydrocarbons include both normal and branched
chain paramns. Alkyl aromatic hydrocarbons
perature.
which are demethylated by my process include
Another further object of this invention is the
toluene, monoethylbenzene, monopropylbenzene
treatment with water in the presence of an active
tive hydrogenation catalyst of an alkyl aromatic
benzenes. Besides the alkyl benzene hydrocar
bons, other alkyl polycyclic aromatic hydrocar
bons may also be demethylated. The saturated
hydroaromatic hydrocarbons which are demeth
ylated by my process include methylcyclohexane,
ethylcyclohexane and other alkyl cyclohexanes
of higher molecular weight containing at least
hydrocarbon to remove one methyl group or
one alkyl group.
atoms in said alkyl side chain of said hydrocar
bon by at least one carbon atom by removing
only one methyl group or several methyl groups
from said alkyl side chain,
A still further object of this invention is the
treatment with water in the presence or an ac
several methyl groups from the alkyl side chain
of said aromatic hydrocarbon.‘
-
One speci?c embodiment of the present inven
The paraihnic hydrocarbons treated by the
process of this invention comprise the normally
liquid para?ins and particularly those containing
at least 6 carbon atoms per molecule. The process
tion comprises a process for reacting water with
is applicable to both normal and branched chain
a hydrocarbon containing more than 4 carbon
atoms per molecule in the presence of a metal 55 para?inic hydrocarbons. when producing trip
3
9,486,998
solution and diatomaoeous earth was agitated
tane, the octane, 2,2,3-trimethylpentane, is a pre
ferred charging stock, but this octane is not the
only aliphatic hydrocarbon convertible into trip
tane. Similarly, 2,3,3-trimethylpentane may also
was introduced thereto to form a precipitate
which was removed by ?ltration, and was then
vigorously while the sodium carbonate solution
be demethylated into triptane as is true with cer
washed, dried, heated, and reduced with hydro
tain highly branched nonanes, decanes and other
gen.
triptyl group _I mean an alkyl group containing a ’
The resultant nlckel-diatomaceous earth cata
lyst is employed in powder form when demethyla
hydrocarbons containing a triptyl‘ group. By a
quaternary carbon atom adjacent to a .tertiary
tion is eifected in batch type treatment or in the
carbon atom. Thus, a triptyl group contains 10 ?uidized or ?uidized fixed bed type of operation.
vicinal tertiary and quaternary carbon atoms.
When pelleted or formed catalyst particles are de
The demethylation reaction carried out ac
cording to my process may be represented by the
following Equation 1 as follows:
sired, the powdered mixture, preferably before be
- ing subjected to reduction with hydrogen or a re
ducing gas mixture, is mixed with graphite or
15 some other lubricant and formed into pellets by a
pilling machine. Other nickel-containing cata
lysts which may be employed similarly may be
group, an aryl group or a cyclopara?in group.
prepared to contain proportions of nickel dif-.
The alkenyl group is generally hydrogenated to
ferent from those aforementioned.
an alkyl group during the process. The aryl
Cobalt catalysts were prepared by essentially
group. is preferably a phenyl group and'the cyclo 20 the same series of steps as were used in produc
para?in group is preferably a cyclohexyl group.
ing 'nickel-diatomaceous earth catalyst com
. Although no hydrogen is charged to the process
posites. Diatomaceous earth and cobalt nitrate
represented by this equation. it may sometimes
so proportioned as to give essentially the same
wherein R represents an alkyl group, an alkenyl
I be desirable to recycle to the process a hydrogen
containing gas formed therein.
Analysis of the non-condensi-ble gases formed
in the process showed the presence of substantial
amounts of methane. This methane formation
‘was due to reaction of hydrogen formed in the
process with a portion of the liquid hydrocarbon
in the presence of the hydrogenation catalyst. Ac
ratio of cobalt to silica as of nickel to silica in the
above-described catalyst, were mixed with water
and then treated with an excess of a hot, satu
rated solution or sodium carbonate. The mixture
of cobalt nitrate solution and diatomaceous earth _
suspended therein was agitated vigorously while
the sodium carbonate solution was added thereto
to form a precipitate which was removed by ?ltra
cordingly more of the liquid hydrocarbon lost a
tion and was then washed, dried,'and reduced to
methyl group than that reacting with water. For
give an active cobalt-diatomaceous earth catalyst,
each molecule of hydrogen that reacted with the
utilizable in the form of powder or pellets in es
35
liquid hydrocarbon, one molecule of methane was
sentially the same manner as the nickel-diatoma
produced according to Equation 2:
ceous earth catalyst.
The process of this invention is carried out by
contacting water and a hydrocarbon with one or
Accordingly as Equation 1 represents the pri
more of the mentioned hydrogenation catalysts at
mary reaction of the liquid hydrocarbon with
a carefully selected operating temperature. The
water, the sum of the volumes of hydrogen and
temperatures generally used are from about 180°
methane formed in the process should be three
to about 350° C. and the operating pressures are
times the volume of the carbon dioxide produced.
from substantially atmospheric to a superatmos
These were approximately the proportions of the
carbon dioxide and the hydrogen-methane mix 45 pheric pressure, generally not more than about
200 atmospheres. The proportions of water to
tures formed in the runs obtained and referred to
hydrocarbon charged to the process are also con
in the examples.
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trolled so that generally from about 2 to about 12
Active hydrogeneration catalysts which are
molecular proportions of water are present per
used in the process contain one or more metals
molecular proportion of hydrocarbon charged to
of the eighth group of the periodic table with an
the process.
atomic number of at least 27. The active hydro
My demethylation process is carried out using
genation catalysts thus include cobalt, nickel,
either batch or continuous types of operation.
ruthenium, rhodium, palladium, osmium, iridium
In the continuous type of treatment which is pre
and platinum. Nickel and cobalt are preferred
catalysts for demethylation of hydrocarbons in 55 ferred, a hydrocarbon and water generally in the
form of steam are passed through a reactor con
the presence of water, particularly because of the
taining a catalyst of the type herein described and
general availability of these metals. The dif
the reaction products are discharged continuously
ferent demethylation catalysts comprising metals
from the reactor at substantially the same rate
or metal oxides of the mentioned eighth group
as that at which the reactants are charged there
metals having hydrogenating activities may be
to. The products of the demethylation treatment
used as such, but preferably they are supported
are fractionated by suitable means to separate the
by a carrier such as alumina, silica, diatomaceous
desired low boiling hydrocarbons from the un
earth, crushed porcelain or some other refractory
converted portion of the hydrocarbon material
material which has substantially no adverse in
65 charged to the process and said unconverted ma
?uence upon the demethylation.
terial is recycled to commingle with the hydro
A highly active nickel catalyst which is used
carbon material charged.
in the present process contains approximately
Demethylation of neohexane by my process
66% by weight of total nickel, 30% of diatoma
yielded a reaction product containing propane,
ceous earth, and 4% of oxygen, the latter present
in nickel oxide, This catalyst was made by the 70 isobutane, normal butane, neopentane, isopen
tane, normal pentane and some unreacted neo
general steps of suspending diatomaceous earth,
hexane. The presence of neopentane in the re
also known as kieselguhr, in a. dilute aqueous solu
action product indicated selectivity of demethyla
tion of nickel sulfate and then gradually adding
thereto an excess of a hot saturated solution of
tion. In other runs the demethylation‘of toluene
sodium carbonate. The mixture of nickel sulfate 75 in the presence of a nickel-kieselguhr catalyst
_ 9,486,928
liquid space velocity of 1.38. and water at an hour
ly liquid space velocity or 1.25 at a pressure of
yielded benzene as illustrated by the following
equation:
15.2 atmospheres to a steel reactor containing
nickel-kieselguhr catalyst maintained at a tem
perature of 285° to 303° C., the temperature be
ing lowest at the inlet and highest at the exit of
The following examples are given to illustrate
the process of this invention, although with no
intention of limiting unduly its generally broad
the reactor. The molar ratio of water to methyl
cyclohexane charged was thus 6.56. The treat
Example I
ment converted 35% of the methylcyclohexane
toluene and a smaller amount of the methyl
Neohexane and water were charged continu 10 into
cyclohexane
was converted into lower boiling hy
ously to a steel tube containing a layer of pre
drocarbons.
Non-condensible gases formed in
viously reduced nickel-kieselguhr catalyst in the
the treatment contained 1.5% carbon dioxide,
form of 3x3 mm. pellets maintained at a tem
91.7% hydrogen, 6.6% methane and 0.2% ole?ns.
perature of 263° C. and at atmospheric pressure.
Example V
The neohexane was charged at an hourly liquid 15
space velocity of 0.86 and the water was charged
Toluene was charged at an hourly liquid space
’ SCOPE.
at anhourly liquid space velocity of 0.94. The
‘velocity of 1.46 and water at an hourly liquid
molar ratio of water to neohexane charged was
. thus,7.75.
space velocity of 1.85 at atmospheric pressure to a,
The resultant reaction product con
steel tube containing nickel-kieselguhr catalyst
sisted of 20% by weight of non-condensible-gas 20 maintained at 263° to 266° C. The molar ratio of
and 80% by weight of a liquid mixture of hydro
carbons. The hydrocarbon mixture formed in
the process contained 3.5 mole % of propane, 1%
water to toluene charged was thus 8.1. The reac
tion product obtained wasfoun'd to contain 6%
of benzene, while the non-condensible gases ana
isobutane, 1.3% n-butane, 2.7%‘isopentane, 2.1%
lyzed 23.6% carbon dioxide, 0.8% carbon mon
normal pentane, 3.7% neopentane, 75% uncon 25 oxide, 75.4% hydrogen and 0.2% methane.
verted neohexane, 8.4% 2,3-dimethylbutane and
The character‘ of the present invention and
2.1% of dissolved carbon dioxide. The non-con
type of results obtained are evident from the pre
- densible gas content analyzed 21.0% carbon di
ceding speci?cation and examples, although they
oxide, 0.6% carbon monoxide, 38.3% hydrogen
and 40.1% methane.
Example II
are not to be construed as imposing undue limi
80 tations upon its broad scope.
I claim as my invention:
1. A process for producing a para?inic hydro
Following the procedure of Example 1, normal
carbon of lower molecular weight from a par
a?im'c hydrocarbon containing more than 4 car
heptane was charged at an hourly liquid space
velocity of 1.42 and water at an hourly liquid 35 bon atoms per molecule, which comprises com
space velocity of 1.07 to a reactor containing a
mingling water with said hydrocarbon in an
nickel-_kieselguhr catalyst at a temperature of
amount of from about 2 to about 12 molecular
from 300° to 310° C. at atmospheric pressure.
proportions of water per molecular proportion of
The mole ratio of water to heptane charged was
hydrocarbon, and subjecting thev resultant mix
6.13. By this treatment 21.3% of the normal 40 ture to reaction at a temperature of from about
heptane was converted into lower boiling hydro
' 180° to about 350° C. in the presence of an active
carbons. The product consisted of_ 80.6% liquid
hydrogenation catalyst comprising a metal of
hydrocarbons and 19.4% gas, the latter contain
group VIII of the periodic table with an atomic
ing 21.1% carbon dioxide, 26.5% hydrogen and '
52.4% methane.
45
Example Ill
number of at least. 27.~
2. A process for producing a para?inic hydro
carbon of lower molecular weight from a par
a?inic hydrocarbon containing more than 4 car
methylpentane mixture consisting of approxi
bon atoms per molecule, which comprises com
mately 35% of 2,2,3-trimethylpentane, 10% of 50 mingling water with said hydrocarbon in an
amount of from about 2 to about 12 molecular
2,3,3-trimethylpentane and 55% of 2,3,4-trimeth
ylpentane. This trimethylpentane mixture was
proportions of water per molecular proportion of
charged at an hourly liquid space velocity of 1.55
hydrocarbon, and subjecting the resultant mix
and water was charged simultaneously at an
ture to reaction at a temperature of from about
180° to about 350° C. to about 100 atmospheres
hourly liquid space velocity of 1.12 to a steel re
Another demethylation run was made on a. tri- I
actor containing a nickel-kieselguhr catalyst 55 in the presence of an active nickel hydrogenation . '
maintained at a temperature of 303° to 310° C.
catalyst.
3. A process for producing a para?inic hydro
and at a Pressure of 15 atmospheres. The mole
ratio of water to the trimethylpentane mixture
carbon of lower molecular weight from a par
a?inic hydrocarbon containing more than 4 car
was 6.43. _By this treatment 24.4% of the tri
methylpentane was converted into lower boiling 60 bon atoms per molecule, which comprises com
mingling water with said hydrocarbon in an
products consisting of 16% condensible gas and
84% of C5-C7 hydrocarbons. The C5-C1 hy
amount of from about 2' to about 12 molecular
proportions of water per molecular proportion of
drocarbons consisted of small amounts of pen
tanes, some neohexane, triptane and 2,3-di1'neth 65 hydrocarbon, and subjecting the resultant mix
ylpentane.
.
ture to reaction at a temperature of from about
The condenslble gas contained 12.8 mole %
180° to about 350° C. to about 100 atmospheres
propane, 34.4% isobutane, 20.6% normal butane,
in the presence of an active cobalt hydrogenation
5.8% isopentane, 3.1% normal pentane, 21.4%
neopentane and 1.9% of hexanes and higher hy
catalyst.
-
- 4'. A process for producing triptane from an
drocarbons. The non-condensible gas contained 70 aliphatic hydrocarbon containing at least 8 car
22.0% carbon dioxide, 0.2% carbon monoxide,
.bon atoms per molecule including vicinal qua-'
21.8%’ hydrogen and 55.6% methane.
ternary and tertiary carbon atoms. which com
Example IV
prises commingling water with said hydrocarbon
Methylcyclohexane was charged at an hourly 75 in an amount of trom about 2 to about 12 molecu
9,699,938 '
s
iar proportions oi.’ water per molecular proportion
of hydrocarbon, and subjecting the resultant mix
,
180° to about 350° C. to about 100 atmospheres
mingling water with said hydrocarbon in an
amount 01 from about 2 to about 12 molecular
proportions of water per molecularproportion
of hydrocarbon, and subjecting the resultant mix
in the presence of an active hydrogenation cat
ture to reaction at a temperature of from about
ture to reaction at a temperature of irom about -
aiyst comprising a metal of group
oi the
periodic table with an atomic number of at
180_.°,.-to about 350° C. and at a pressure of from
substantiallyatmospheric to about 1,00 atmos
least 27.
pheres in the presence of an active nickel hydro
>
5. A process for producing neonentane from ~ genation catalyst.
an aliphatic hydrocarbon containing at least 8 10 8. A process for the demethylation .oi ahydro
carbon atoms per molecule includinl a quaternary
carbon containing more than 4 carbon atoms
carbon atom, which comprises cm'mnimzlingv wa
ter with said hydrocarbon in an amount of from
about 2 to about 12 molecular proportions of wa
ter per molecular proportion of hydrocarbon; and
subjecting the resultant mixture to reaction at a
temperature of from about 180? to about 3511°
C. to about 100 atmospheres in the presence of an
per molecule and selected from the group con
si'sting of paramns, ole?ns, aikyl aromatics ‘and
saturated alkyl hydroaromatics, which comprises
commingling water with said hydrocarbon in an
- amount or from about 2 to about-12 molecular pro
_ portions of water per ‘molecular proportion or hy
droearbon, and'subjecti'ng the resultant mixture
active hydrogenation catalyst comprising a metal
to reaction at atemperature'oi.’ from about 180°
of group vm or the periodic table with an atomic‘
to about 350? Q. in ‘the presence of an active by
drogenation-catalyst comprising a metal of group
number of at least 27.
_
6. A process for producing triptane from an
aliphatic hydrocarbon containing at least 8 car
bon atoms per molecule including
oi the periodic table with an;i atomic num-I_
ber ‘of at least 27.
I VLADILHR HAENSEL.
qua
ternary and tertiary carbon atoms. which com
prises commingiing water with said hydrocarbon
in an amount or from about 2 to about 12 molecu
lar proportions vof water per molecular propor;_
tion of hydrocarbon, and subjecting the resultant
mixture to reaction at a‘ temperature ‘of from 30
about 180° to about 350° c. ‘and'at a pressure at
from substantially atmospheric to ‘about 100 at
mospheres in the presence or an active nickel;
hydrogenation catalyst.
'l. A process for producing neopentane from.
an aliphatic hydrocarbon containing ?-Lleast 6
carbon atoms per molecule including a dime
ternary carbon atom, which comprises, com‘
' The following
nnruanncas
references
are of {I record in the
tile of this patent:
_
UNITED STATES PATENTS .
Number
. 1,374,119
Name
'
Date
U Stevens ...._-.-_‘.-.__-.._ Apr. 5, 1921
41,599,629
“Anderson -__. ..... -- Sept. 24, ms
__$,Q28,795 j i McKee .... -_..----- Jan. 28, 193B
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Number
127,690
FOREIGN PATENTS
'7
Country
_
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Date
Switzerland ___'.>.--.. Sept. 1, 1928