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Патент USA US2404280

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July 16, 1946.
_ H. A. DUTCHER
PRODUCTION OF“ UNSATURATED NITRILES
2,404,280
Filed Dec. 9, 17943
UNSATURATEd
NITRILE
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ALIPHATIC
ALDQXIME
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CATALYTIC
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INVENTOR
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H. A‘ DUTCHER
. AT ORNEYS(
2,404,280
Patented July 16, 1946
., j . UNITED "STATES PATENT OFFICE
2,404,280
.
' PRODUCTION OF UN SATURATED NITRILES
Harris vA. Dutcher, Bartlesville, 0kla., assignor to
. Phillips Petroleum Company, a corporation of
Delaware‘ ,
Application December 9, 1943, ‘Serial No. 513,568
'
9 Claims.
(Cl. 260-464)
This.v invention relates to the production of un» ‘ ‘
saturated nitriles, More speci?cally it is con
cerned with the formation of acrylonitrile and its
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dehydrogenation or polymerization, ‘ A contact
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time ranging from 1 to 5 seconds isgenerallysat-v
The ‘dehydration of aldehyde oximes to form
isfactory. Irisu?iciently dehydrogenated prod
saturated nitriles is a Well-known chemical reac
tion, usually accomplished, by treating the ox~
imes with acetic anhydride' of acetyl chloride.
The ‘formation of saturated nitriles among other.
products, by passing ketoximes over, thoria or
alumina at 350-380“ 0., has been reported.
(Mailhe and de, Godon, Bull. soc. chim. 23,‘ 18-30
the catalyst. chamber is preferably maintainedat
a rate such that an ‘economical conversion per
pass is obtained without an excessive amount ‘of
homologs by the simultaneous dehydration and
dehydrogenation of aldehyde oximes.
"
ucts, such .as propionitrile, may be readily sepa
rated from the ei?uents and recycled, thereby in- _
10
(1918)) .. so far as I am aware, however, the for
creasing the, ultimate yield of acrylonitrile. .Too
severe-conditions may lead to the formation of
‘the nitrile of propiolic acid, CHEC——CN.
Rapid. cooling of the reaction products is desir
able, and in a preferred method of accomplishing
mation- of unsaturated nitriles by the simultane 15 this resultthe; e?‘luents are subjected to a direct
Water quench, after, which the acrylonitrile and
ous dehydration anddehydrogenation of Valde
other vproducts; .are: recovered by fractional dis
hyde oximes. has notbeen accomplished hereto
fore.
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The ‘aldehyde oximes to .be employed in my
7 The object of my invention is toprovide a proc
process mayv be prepared: by any convenient
ess for the production of unsaturated‘ nitriles
tillation,
from. saturated aliphatic'aldehyde oximesb‘
39
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,A, further object of myinvention is to provide
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method, such as the reaction ‘of the aldehyde
with hydroxylamine hydrochloride. The method
of preparing the oximesis not a part of my in- ,
aprl'ocess for the production} of acrylonitrile from
propionaldehyde oxime, or a-fmethyl acrylonitrile
from isobutyraldehyde oxime.
vention.
25
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1
. The accompanying,‘ drawing showsin schematic
The process of my invention is carried out by
passing the vapors of an. aliphatic saturated al
dehyde oxime, for example, propionaldehyde 0X
ime, over a catalyst of‘the type which promotes
.form one speci?c embodiment. of my invention.
sure in the catalyst zone may be varied over a ,
rather wide range, typically from slightly below
atmospheric to 50 pounds per sq. inugauge, but
accomplished by fractional distillation of the
stream from quenching means 3. It is preferred
to carry out. the dehydration-dehydrogenation
it is more convenient to operate at substantially
under conditions such that excessive ,dehydrogeng
An-‘aldehyde oxime, preferablyin admixture with
asuitable diluentgas, is fed via line I into catae
lytic converter Zwhere itcontacts a dehydrating
both dehydration and dehydrogenation reactions, 3.0 dehydrogenating catalyst at a temperaturergf [j
from 700‘ to 900° F.‘ The e?‘luents fromcatalytic
at a temperature in the dehydrogenation range.
converter 2 are conducted to quenching-means'ii
Catalysts‘ comprising a major proportion of A0
where theyare quickly cooled preferably by wa
tivated Alumina or bauxite and a minor propor
terto the temperature, desired at the entrance ‘to
tion of the lower oxides of chromium, molybde
separating means. 4, to which they arev carriedby
num, vanadium, or tungsten, are employed in my
line‘ 5.‘ The aforementioned temperature-‘is, of’
process. The preferred catalyst is composed of
course, sufficiently below the reaction tempera
the mineral bauxite impregnated with a small
ture that no further reactions take place. Sepa;
per cent, say from 5 to 30%, of chromium sesqui
ration of the unsaturated nitrile from any satu
oxide, CmOs. Such catalysts are readily prepared
rated nitriles and other products may be readily
in various ways well known to the art. The pres
atmospheric pressure.
It is preferable to use a 45 ation is avoided, even though this may‘ result in
pressure just sufficiently above atmospheric. to
maintain the desired ?ow rate. Low partial pres
the presence of some of the saturated nitrile inv
the e?iuent from the catalyst chamber. This ma
sures of the reactants are advantageous. This
may be attained by using an inert diluent gas
terial may be readily recycled to the dehydration- v
such as steam or nitrogen.
The desired dehydration-dehydrogenation re
action may be carried out at temperatures with
in the range 700 to 1100° F. or even higher, how
ever, a range of from 700 to 900° F. is generally
preferred. The ?ow of reactant vapors through
dehydrogenation zone, via line 6, if it is desired
50 to increase the yield of unsaturated nitrile, The
unsaturated nitrile is removed via line ‘I, and any
high boiling polymers or other by-products are
withdrawn through line 8. Hydrogen‘ gas is vent
ed from the system through line 9 in the top of
quenching means 3.
I
7 2,404,280
4
3
,
which comprises passing the vapors of the cor
, responding aliphatic saturated aldehyde oxime at
Example
a temperature within the range of 7700 to 900° F.
over a catalyst composed of chromium sesquioxide
supported on bauxite eiiecting simultaneous de
hydration and dehydrogenation of said oxime to
Propionaldehyde oxime, B. P. 130-132’ C. was
ivaporized and passed continuously over a cata
Zlyst comprising principally bauxite with a minor
§prop0rtion of chromium sesquioxide, at’ a tem
perature of 800° F. The products were cooled by
av direct waterjl quench, acrylonitrile and pro;
jpionitrile being ‘subsequently ‘recovered and sep
the
corresponding nitrile.
v
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I 6. The process of making, an aliphatic unsat
urated nitrile of 3 to 4 ‘carbon atoms per molecule
which comprises passing the vapors of the corre
1 arated by fractional distillation. Propionitrile .10 sponding aliphatic saturated aldehyde oxime at
1 was recycled to the catalyst chamber for further
dehydrogenation. Acrylonitrile was obtained in
5 good yield.
l ' a temperature within the range of ‘700 to 900° F.
. ‘contact
and at substantially
with a catalyst
atmospheric
composed pres/sure
of chromium
into
I claim:
l. The process of making acrylonitrile/ which" 15 ‘sesquioxide' supported on bauxite effecting simul
taneous dehydration and dehydrogenation of the
‘ comprises passing the vapors of propionaldehyde
‘ oxime over a dehydrating-dehydrogenating cat- 0' -
‘ alyst composed of chromium sesquioxide sup- ,
aliphatic saturated aldehyde oxime to the corre
sponding aliphatic unsaturated nitrile.
7. The process of making an aliphatic unsat
vported on bauxite at a temperature of from 700 '
20 urated nitrile of 3 to _4 carbon atoms per molecule
_: to 900° F;
> ~
which comprises contacting the vaporsof the cor
2.‘ The process of making a-methyl acrylonitrile
responding aliphatic saturated‘ aldehyde voxime
‘ which comprises passing the vapors of isobu
. at a temperature within the range‘ of '700 to ‘900?
3 tyraldehyde oxime over a dehydrating-dehydro
1 genating" catalyst composed of chromium ses- ‘ F. and at a pressure within the range of ' substanr /,
j quioxide supported on bauxite at a temperature 25 tially atmospheric pressure ‘to about ‘50' pounds
per square inch gage into contact with a catalyst
1
of from 700 to 900°, F.
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composed of chromium ‘sesquioxide supported on
3; The process of, making an aliphatic unsat
1 uratednitrileof 3 ‘to 4 carbon atoms per molecule
‘alumina for a period of time within the range'of
1 to '5 seconds such as to simultaneously dehy
4 which comprises passingthe vapors of the corre- ‘
> sponding aliphatic saturated aldehyde oxime over 30
‘ a‘ dehydrating-dehydrogenating" catalyst ‘com-f
drate and dehydrogenate the aliphatic saturated
aldehyde oxime to “the corresponding aliphatic
‘ posed of’ chromium sesquioxide supported on '
unsaturated nitrile.
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,8. The process of making an'aliphaticiunsaté
alumina at a temperature in the dehydrogenation
urated nitrile of 3 to 4 carbon atoms per‘molecule
3 range, treating the reaction e?luents- to sepa-‘
rately recover the unsaturated nitrile as the prod 35 which comprises contacting the vapors of 'th'efco‘r
responding saturated aliphatic aldehydel'oxime
‘ ' uct ofthe process and the saturated nitrilecon
with a dehydratingedehydrogenating ' catalyst
comprising aluminum oxide and a minor propor
tained in said e?luents, and recycling’ said sat
urated nitrile to the catalytic conversion zone. '
I ' 4.‘ The process of making an aliphatic unsat
urated-nitrile of 3 to 4 carbon atoms per molecule
tion of a material selected from the group‘consi'ste
a ing of the oxides of chromium; molybdenum;
‘vanadium and tungsten at a temperature within
which comprises passing the vapors’ of the corre
sponding aliphatic saturated aldehyde oxime ‘over
a dehydrating-dehydrogenating catalyst com-‘t
posed of v chromium sesquioxide supported ' on,
the‘ range of 700 to‘900f’vF. therebye?e'cting con
\ version of the aliphatic saturated aldehyde oxime
'to j the corresponding aliphatic unsaturated
alumina at a temperature in theldehydrogenation1 45
9. The process of making an unsaturated nitrile
If range, quenching the reaction e?luentswith water:
which comprises contacting the vapors "of an
to quickly cool same to a temperature at which
aliphatic saturated aldehyde‘oxime over a dehy
any further reactions are prevented, and'frac
drating-dehydrogenating catalyst ‘composed of’
tionally distilling the resulting mixture to sepa
rately'recover the unsaturated nitrile as the prod so aluminum oxide and a minor proportionjo'i a male. _
nitrile.
uct of the process and the saturated nitrile con
tained in said e?luents, and recycling said sat
g
' terial selected from the group ‘consistingofpthee
‘ ‘ urated nitrile to the catalytic‘ conversionvstep.
5. The process of making analiphatic unsat- 7
V.
urated nitrile of 3 to 4 carbon atoms per molecule 55
oxides of chromium,amolybdenum, vanadiumjand
tungsten’ at a temperature within the range of
'700to 171O0°F.'
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HARRIS ‘A, DUTCIjl‘ER.
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