Патент USA US2369181

Patented Feb. 13, 1945
v ‘2,369,181
UNlTED . , STATES PATENT IOFFlCE
2,369,181
CONTROLLED OXIDATION OF ALICYCLIC
HYDROCARBONS AND OF THEIR DERIVA
TIVES
Frederick F. Rust and William E. Vaughan,‘
Berkeley, Calif., assignors to Shell Development _
Company, San Francisco, Calif., a corporation
6! Delaware
No Drawing. Application January so, 1943,
Serial No. 474,222
12 Claims. (Cl. t>..‘60----586)v
very di?lcult, it not commercially impossible, or
at least greatly increase the cost‘ oi’ the ?nal
- product or products. It is also freuqently de
sirable to obtain predominantly carboxylic acids,
organic peroxides, and/or ketones rather than
mixtures containing them and large amounts of
other oxygenated compounds, e. g. carbon mon
oxide, carbon dioxide, aldehydes, alcohols, lac
tones, and the like. Furthermore, it is frequent
10v ly important or at least desirable to obtain oxyg
genated compounds having at least the same
This invention relates to the controlled, non-, .
explosive oxidation of alicyclic hydrocarbons and
of their halogenated derivatives containing a re
placeable hydrogen atom, and more particularly
- pertains to the catalytic controlled oxidation of
saturated alicyclic hydrocarbons. ‘In one 01' its
more speci?c embodiments, the present invention
is directed to the treatment of‘saturated alicy
clic hydrocarbons which may or may not con
tain saturated acyclic side chains attached there
to, to produce high yields of predetermined car
boxylic acids, organic peroxides and/or ketones
,_
(including diketories) having the same number
number of carbon atoms per molecule as the
starting organic material. In all such cases the
of carbon atoms per molecule as the starting or
previously known methods of partial oxidation
15 of hydrocarbons, whether they be catalytic or
The oxidation of various hydrocarbons has been
non-catalytic, are impractical because of the par
e?'ected for a number of years both non-cata
tial or complete decomposition of the starting
lytically and in the presenceof various catalysts.
organic materials to form carbon and compounds
As a general rule, most if not all of these oxida
containing fewer carbon atoms per molecule, as
tions resulted in considerable decomposition of
well as due to the above-mentioned formation of
the hydrocarbons, i. e. cleavage of carbon-to
mixtures of compounds which are oxygenated to
carbon bonds of the organic starting material.
a greater or lesser degree.
Also, the products of reaction of such oxidations
It is therefore the main object of the present
contained various percentages of hydrocarbons
invention to avoid the above and other defects,
which have been oxidized to a greater or lesser 25 and to provide a novel process whereby high
extent. For instance, the catalytic oxidation of
yields of predetermined oxygenated organic com
para?lnic, hydrocarbons in accordance with the
pounds may be obtained. A further object of.
teachings of the prior art, formed mixtures con
the invention is to provide a process for the pro--v
taining various percentages of carbon monoxide,
duction of high yields of carboxylic acids, ke
ganic material treated.
'
carbon dioxide, ole?ns, water as well as some al
dehydes, alcohols, acetals, esters, ketones ‘and
other oxygenated compounds. Similarly, the
catalytic oxidation of aromatic hydrocarbons,
' e. g. toluene, in accordance with the teachings of
30 tones, alcohols, and/or organic peroxides to the
substantial exclusion of other less desirable oxy
genated organic compounds. A still further ob
ject is to provide a'process whereby predeter
mined carboxylic acids, ketones, alcohols, and/or
the prior art frequently formed mixtures contain_ 85 organic peroxides having the same number of
ing various percentages‘ of saturated and unsat_
carbon atoms per molecule as the starting ma- '
urated hydrocarbons, saturated and unsaturated
terial may be produced in economical yields to
aliphatic and aromatic aldehydes, ketones, lac
the substantial exclusion of other products of
tones, alcohols and other oxygenated compounds,
oxidation which are normally formed when hy
such as carbon dioxide. Furthermore, these var‘ (0 drocarbons are subjected to partial oxidation in
ious oxygenated compounds formed during the
accordance with the processes of the prior art.
oxidation‘ of various hydrocarbons according to
Another object is to provide a novel process for
the teachings of the prior art usually contained
the catalytic oxidation of alicyclic hydrocarbons
varied numbers of carbon atoms per molecule due
(including those having acyclic substituents)
‘to the carbon-to-carbon bond scission, as well as 45 and/or of their partially halogenated derivatives,
to other side reactions such as polymerization,
to produce high yields of alicyclic carboxylic
condensation, and the like.
acids, ketones, alcohols and/or organic peroxides,
Although most of the oxygenated'organic com
to the substantial exclusion of oxygenated com
pounds formed as a result of the partial oxida
pounds having a lesser number of carbon atoms
tions of hydrocarbons according to the known 60 per molecule than present in the alicyclic comprocesses are generally more valuable than the
pound subjected to treatment. Still other ob
primary materials subjected to- the oxidation re- I
jects of the present invention will become appar
action, the subsequent fractionations of the re
ent from the following description. The term
action mixtures and the separate recovery of the
“ketone” as employed herein and in the appended
individual compounds therefrom are frequently 55 claims refers to organic compounds'containing
2,869,181
one or more ketonic carbonyl groups, and there
fore includes diketones.
It has now been discovered that the above and
other objects may be attained by effecting the
partial and ‘controlled oxidation in the presence
of hydrogen bromide employed as a catalyst.
taneous combustion or substantial decomposition
of the carbon structure occurs. This upper tem
perature limit will at least in part depend on the
speci?c organic substance treated, as well as on
the proportions thereof and of the oxygen and
hydrogen bromide present in the vaporous mix
ture subjected to the elevated temperatures. Gen
More speci?cally stated, the invention resides in
erally speaking, this upper temperature limit is
the‘ controlled, non-explosive oxidation of alicy
in the neighborhood of about 200° C. to 225° C.
ciic hydrocarbons, particularly of saturated ali
cyclic hydrocarbons, and of vtheir partially halo 10 However, some of the more ‘stable organic com
pounds of the de?ned class may be heated to
genated derivatives, in the presence of a catalyst
gether with oxygen and hydrogen bromide to
consisting of or comprising hydrogen bromide, '
or of a compound capable of yielding hydrogen
bromide under the operating conditions. In one
of its more speci?c embodiments the invention
resides in the production of alicyclic carboxylic
acids, ketones, alcohols and/or peroxides by the
controlled oxidation of alicyclic hydrocarbons, es
pecially saturated alicyclic hydrocarbons, or of
products of their partial halo-substitution, this
oxidation being effected by subjecting. the above
higher temperatures, e. g. about 250° C., and
‘higher, particularly in the presence of inert dilu
i5 ents, ‘without causing the mixture to decompose
with the concurrent formation of high yields of
carbon. In this connection it is to be noted that
excessively high temperatures, even though they
are below the explosive region, should be avoided
20 because of certain undesirable side reactions such
ing material, in the presence of hydrogen bro
as excessive conversion of hydrogen bromide to
organic bromides. This in, itself is not detrimen
tal because as stated, the organic bromides them
selves may be treated in accordance with the
25 present invention to form bromide-free oxygen
mide or a substance capable of yielding hydro
ated organic compounds and the corresponding
gen bromide under the operating conditions, and
at temperatures and pressures which are below
those capable of causing spontaneous combustion,
portion of the hydrogen bromide is regenerated
mentioned and hereinbelow more fully described
class of alicyclic compounds to the action of oxy
gen or of an oxygen-containing or oxygen-yield
hydrogen bromide (so that in e?ect at least a
and may be re-used). The excessive formation of
and, therefore, resultant decomposition of the 30 organic bromides during the controlled oxidation
carbon structure of the startingiorganic mate
ofia given alicyclic hydrocarbon (or of its halo
rial.
genated‘derivative), however, is undesirable be
The above-outlined invention is predicated on
cause this decreases the catalyst concentration
the discovery that the presence of hydrogen bro
and may a?ect the yield or output of the desired
mide during the oxidation of the de?ned class of 85 oxygenated product or products. As stated, the
organic compounds controls the oxidation reac
upper temperature limit is generally in the neigh
tion so that oxidation occurs on the carbon atom
borhood of about 200° C. to 225° C. However,
or atoms to which a halogen atom would normally
with shorter contact periods this temperature
attach itself if the starting organic material were
may be raised above the mentioned limit. Some
subjected to a halo-substitution reaction. Fur 40 of the more readily oxidizable alicyclic compounds
thermore, it has been found that the presence
may be economically oxidized according to the
of hydrogen bromide, besides retarding the ex
present process at lower temperatures, e. g. be
plosion or complete combustion of the organic
.tween' about 150° C. and about 175° C. With a
starting material, has the e?ect of inhiibting de
further decrease in the operating temperature,
composition of the carbon structure of such or
the output of product per unit time will decrease,
ganic starting materials, so that the resultant ‘ so that at temperatures of below about 100° C.
oxygenated compounds contain the same num
the controlled oxidation in the presence of the
ber of carbon atoms per molecule as the starting
hydrogen bromide, or substances capable of yield
organic material. a
ing it under the operating conditions, may be
The following is a representative list of ali 50 come uneconomical.
cyclic hydrocarbons (which term includes the al- -
kylated derivatives thereof) which may be oxi
dized'in accordance with the process of the pres
ent invention: cyclopropane, cyclobutane, cyclo
pentane.cyclohexane, methyl cyclopentane, meth
yl cyciohexane, 1,2,4-trimethyl cyclohexane, 1,3,5
trimethyl cyclohexane, thujane, sabinene, carane,
The reaction may be e?ected in the liquid or
Vapor phase, or in a two-phase liquid-vapor sys
tem. Since it is dif?cult to maintain a desirable
relatively high oxygen concentration when the re
action is conducted in the liquid phase, it is gen
erally preferable to e?ect the oxidation accord
ing to the present process in the vapor phase.
Since some of the relatively higher boiling ali
pinane, camphane, and the like and their homo
logues. Also, the products of partial halo-substi
tution of such alicyclic hydrocarbons, whether 60 cyclic hydrocarbons, which may or may not con
tain halogenated substituents, cannot be effec
such halo-substitution be in the ring or in ‘the
tively maintained in the vapor phase and in
alkyl chain or chains attached thereto, may be
contact with sui?c‘ent concentrations of oxygen
employed as the starting material. The process
and of hydrogen bromide without causing spon
of the present invention, however, is particular
ly suitable for the controlled oxidation of the 65 taneous combustion, the oxidation of such com
pounds may be readily e?ected in the presence
lower homologues, and especially of the lower
of inert diluents such as steam, nitrogen, carbon
saturated homolo-gues, of these alicyclic com
dioxide, and even methane, which latter is rela
pounds. Obviously, mixtures of these and like
tively stable at temperatures at which other men
organic compounds may also be employed as the
organic starting material.
70 tioned hydrocarbons, and their corresponding
halogenated derivatives, may be oxidized ‘accord
It was stated above that the slow (i. e. non
ing to the invention. Of the above diluents, the
explosive) controlled oxidation of the above-out
use of steam is believed to be most advantageous
lined class of organic compounds is effected in
because the hydrogen bromide may then be re
accordance with the present invention at tem
peratures which are below those at which spon 75 moved from the reaction mixture as an overhead
,
r 3
2,869,181
rial subjected to oxidation, at various interme
mix
fraction in the form of its constant boiling
ture of hydrogen bromide and water.
Although the volumetric ratios of the organic
starting material to the oxygen may vary within
diate points along the reaction zone. Such op
erationlmay be frequently desirable to control
‘ the operating conditions in the reaction zone.
Generally, the contact time may vary within
relatively wide limits and is at least in part de
pendent on the other operating conditions such
as speci?c starting material, the ratios thereof
to the oxygen and/or the catalyst, the presence
or absence of inert diluents, the operating tem
peratures and pressures, etc. In a continuous
relatively wide limits, it may be stated that satis- '
factory yields of the 'desired oxygenated prod
uct or products can be obtained by using equi
volumetric quantities thereof. An increase in the _
ratio of oxygen to the organic material in the
treated mixture may increase the yield of the
desired alicyclic carboxylic acids, organic per
.
systemit has'been found that satisfactory yields
oxides and/or ketones. However, any undue in
crease in this ratio is generally dangerous be
of the desired alicyclic carboxylic acids, alcohols, :
organic peroxides and/or ketones may be ob
other hand, the use of oxygen-to-hydrocarbon 15 tained with contact periodsof between about one
ratios which are considerably below equivolumet
and about three minutes. ‘Nevertheless, shorter
ric will lower the output of the desired product
or longer contact times may also be employed.
cause of excessive explosion hazards.
On the‘
Instead of using pure or substantially pure
oxygen per unit of space. This renders the proc-,
oxygen for the oxidation in accordance with the
ess less economical. Nevertheless, the process is 20 process of , the present invention it is also pos
per unit of time because of the presence of less .
still operable, and, in fact it must be noted that
sible to employ oxygen-containing mixtures such
a lowering of the oxygen-to-hydrocarbon or oxy-'
gen-to-organic halide ratio may cause a faster
consumption of oxygen per unit of time. It was
as air, or even substances capable of yielding
molecular oxygen under the operating condi
tions.
Also, although the examples presented
stated above that satisfactory yields of the desired 25 hereinbelow are directed speci?cally to the use
oxygenated products may be obtained when equi
of hydrogen bromide .as the catalyst, the process
volumetric mixtures of oxygen and of the speci
of the present invention may also be realized
?ed organic starting vmaterial are subjected to
by using substances capable of yielding hydrogen .
the action of hydrogen bromide at the speci?ed
bromide under the operating conditions em
operating temperatures. Such mixtures usually 30
present no hazards in so far as explosions are
The‘inventlon is illustrated by the following,
concerned, the hydrogenbromide apparently act
examples which are presented herein for the
ing as an explosion retardant?or inhibitor.
purpose of clarifying the, process of the present
ployed.
The amount of hydrogen bromide employed as '
.
.
'
,.
invention as well as the results and advantages
the catalyst may also vary within relatively wide 35 derived therefrom. It is to be understood, how
limits, although optimum amounts or percent
_ ever, that these examples are merely illustrative
ages may be readily determined for each indi-
of the invention and should not be considered
vidual starting material treated and for the
as limiting the invention in any sense.
‘
speci?c operating conditions employed. - Gen
Example I
erally speaking, the' percentage of oxygen which 49
will react to form the-oxygenated products (other
The reactor consisted of a, coil of glass tubing
conditions being equal) will vary with the change
having an internal diameter of about 15 mm,
in the hydrogen bromide concentration in the
and a volume of about 450 cc. This coil was im
mixture subjected to treatment. When the hy
mersed in an oil bath which permitted accurate‘ I
drogen bromide concentration is varied from zero
control of the reaction temperature. A preheated
to about 20 per cent there is a proportional and
vaporous mixture of cyclopentane, oxygen, ni
noticeablechange in the percentage of. oxygen
trogen and hydrogen bromide (which substances
which reacts with the organic starting material.
were employed in a volumetric ratio of 2:2:2:1,
Increases in the volumetric or mol concentration
of the hydrogen bromide above about 20%, how
ever, do not have such a marked effect on the
percentage of oxygenwhich will react.
Nev
ertheless, very high hydrogen bromide concen-
trations will cause ‘excessive dilution and thus
decrease the output of the desired product'or
products. Such high concentrations should
' respectively) was then conveyed at substantially
5.0 atmospheric pressure through the above coil re
‘actor at such a rate that the residence'time was
equal to about 3 minutes. The nitrogen was
.
employed for the purpose of maintaining the
cyclopentane in the vapor state. The tempera
55
ture in the reactor was maintained at about 185°
C. The e?luent reaction mixture was conveyed
therefore be avoided for economic reasons.
into an aqueous sodium bicarbonate solution to
The oxidation in accordance with the present
neutralize the hydrogen bromide.‘ The liquid
process may be effected at atmospheric pressures,
reaction product contained a major amount of
although higher or lower pressures may also be 60 cyclopentanone, and it was found that between
employed. In fact, it is generally preferable to
employ super-atmospheric pressures because
about 60% and about 70% of the introduced
oiwgen reacted to produce oxygenated products.
It' was also found that no reaction occurred when
cyclopentane and oxygen were subjected, under
more of the mixture subjected to treatment may
be present in or conveyed through a given unit
65
of reaction space per unit time.
the above-mentioned operating conditions, to a
The invention may be executed in a batch,
temperature of‘ 185° C. in the absence of hy
intermittent or continuous manner.
When op
drogen bromide.
'
erating in a continuous system, all of the react
Example If
ants, as well as the diluents, if diluents are used,
A vaporous mixture consisting of 2 parts by
and the catalyst may be ?rst mixed together 70
and the mixture may then be conveyed through
volume of vcyclohexane, 2 parts by volume of
oxygen, 2 parts by volume'of nitrogen and 1
the whole length of the reaction zone. In the
part by volume of hydrogen bromide was con
alternative, it is possible to introduce at least
a portion of the catalyst and/or of one or both of
veyed through the same reactor as that used in
the reactants, i. e. oxygen and the organic mate 75 Example I. The residence time was equal to
4
2,869,181
about 6 minutes, but the reaction temperature
was raised to about 222° C. The e?‘luent product
was passed through and collected in water, and
the liquid organic product thus produced was
found to contain an appreciable amount of
cyclohexanone. Also, diketones were found to be
present in this reaction product. About 45% of
the introduced oxygen reacted.
6. A process for the production of ketones
which comprises subjecting a vaporous mixture
of cyclohexane and oxygen to the action of hy
drogen bromide, at a temperature of between
about 100° C. and the temperature at which
spontaneous combustion occurs, e?ecting the re
action for a period of time su?icient to cause
the controlled catalytic oxidation of the cyclo
The reason for the relatively high temperature , hexane, and recovering the ‘ketones from the
employed in the above run is because cyclo 10 reaction mixture thus formed.
'
hexane is quite resistant to oxidation. For in
7. A process for the production of oxygenated '
stance, when the above reaction was repeated
organic products which comprises subjecting a
at a temperature of about 180° C. and with a
mixture of cyclohexane, oxygen and hydrogen
residence time of about '3 minutes, substantially
bromide to the action of an elevated tempera
no oxygen was consumed.
In fact, even at a 15 ture of between‘ about 100° C. and the tempera
temperature of about 196° C. and a residence time
ture at which spontaneous combustion occurs,
of about 3 minutes, the reaction was only 25% . and e?ecting the reaction for a period of time
complete. On the other hand, at a temperature
of about 227° C. there was considerable decom
su?icient to cause the controlled catalytic oxida
tion of the cyclohexane.
’
position of the carbon structure of the cyclo 20
8. In a process for the controlled oxidation of
hexane, and large amounts of carbon dioxide,
alicyclic hydrocarbons, the steps of subjecting
carbon monoxide and lower hydrocarbons were
found in the reaction product.
vapors of a saturated alicyclic hydrocarbon to ‘
the action of oxygen in the presence of hydrogen
As in the case with cyclopentane, no oxidation
bromide and effecting the reaction at a tempera
of cyclohexane was noticed when the reaction 25 ture of between about 100° C. and the tempera
was attempted in the absence of hydrogen
bromide even at temperatures considerably high
er than those employed above for the oxidation
in the presence of this catalyst.
We claim as our invention:
_
.
' tu‘re at which spontaneous combustion and the
resultant decomposition of the organic com- _
pound will occur.
.
9. The process according to claim 8 wherein
30 the saturated alicyclic hydrocarbon and oxygen
are employed in substantially equivolumetric‘
1. A process for the production of cyclopen
tanone which comprises subjecting a vaporous
proportions.
mixture containing cyclopentane and oxygen at
10. In a process for the controlled oxidation
substantially atmospheric pressure and at a tem
of alicyclic hydrocarbons, the steps of subject
perature of above about 100° C. but below the 35 ing vapors of saturated alicyclic hydrocarbon to
temperature at which spontaneous combustion
occurs, to the action of hydrogen bromide em
ployed in an amount in excess of about 20 mol
the'action of oxygen in the presence of hydrogen
bromide and at a temperature of between about
100° C. and the temperature at which spontane
percent, e?ecting the reaction for a period of
ous combustion and the resultant decomposition
time su?icient to cause the controlled catalytic 40 of the organic compound to carbon will occur.
oxidation of the cyclopentane, and recovering
and continuing said reaction for a period of time
cyclopentanone from the- reaction mixture thus
su?‘icient to effect a substantial reaction between
formed.
said saturated alicyclic hydrocarbon and the
2. The process according to claim 1, wherein
oxygen.
an inert diluent is employed to maintain the 45
11. In a process for the controlled oxidation
cyclopentane in the vaporous state.
of organic compounds, the step of subjecting va
3. A process for the production of cyclopen
pors of an organic compound selected from the
tanone which comprises subjecting a vaporous
group consisting of alicyclic hydrocarbons and
mixture containing cyclopentane and oxygen to
of their products of partial halogenation to the
50
the action of hydrogen bromide at an elevated
action of oxygen in the presence of hydrogen
temperature which is below the spontaneous . bromide and at a temperature of between about
combustion temperature of the mixture, effect
100° C. and the temperature at which spontane
ing said reaction for a period of time su?icient
ous combustion and the resultant decomposition
to cause the controlled catalytic oxidation of the
of the organic compound to carbon will occur.
cyclopentane, and recovering cyclopentanone 55 12. In a process for the controlled oxidation of
from the reaction mixture thus formed.
organic compounds, the step of subjecting an
4. A process for the production of cyclohex
organic compound selected from the group con
' anone which comprises subjecting a substantially
sisting 'of alicyclic hydrocarbons and of their
equivolumetric gaseous mixture of cyclohexane
products of partial halogenation to the action
and oxygen at substantially atmospheric pressure 60 of oxygen and of hydrogen bromide at a temper
and at an elevated temperature of below about
ature of between about 100° C. and the tempera
200° C. to the action of hydrogen bromide cata
ture at which spontaneous combustion and the
_ lyst for a period of time su?icient to effect the
resultant decomposition of the carbon structure
controlled catalytic oxidation of the cyclohexane,
of the starting organic compound occurs.
and recovering cyclohexanone from the reaction 65
mixture thus formed.
FREDERICK F. RUST.
5. The process according to claim 4 wherein
WILLIAM E. VAUGHAN.
hydrogen bromide is employed in an [amount
which is in excess of about 20 mol percent.