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Патент USA US2385484

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Patented Sept. 25, 1945
' ‘UNITED STATES PATENT orrlieE-i
PROCESS FOR THE PRODUCTION OF
’
DIOLEFINS
Kenneth A. Wright, 0akland, CaliL, assignor to
Shell Development Company, San Francisco,
Calih, a corporation of Delaware
‘ ~
:4 ~
No Drawing. Application January 14, 1944,
Serial No. 518,257
14 Claims. (Cl. 260-680)
above about 580° C. in the presencaof anexcess‘o‘f “ ,1
This invention relates to an improved process
steam with an alkalized' iron oxidecatalyst.
I
for the production of diole?ns by catalytic de
preferred alkali is an alkaline compound ‘of potas'
hydrogenation characterized by the use of spe
sium. In catalysts for dehydrogenation‘at.‘high,‘,
cial catalysts and special high temperature con
temperatures in the presence of‘ steam‘anauraam '
ditions affording exceptionally high conversion
metal promoter or its equivalent isRe'ssenti'aI sincejifj
and production capacity with excellent yield.
in its absence the catalyst loses itsinit'ial ,activit _ I,
Primary objects of the invention are to provide
an improved process for the production of diole
?ns, and particularly butadiene, by'catalytic de
in a few minutes of use.
1., _
'
'
It has now been found that the prornqtinge
fects of the various alkali metaliproiiioters" ‘inv
hydrogenation wherein (1) exceptionally high 10 ‘catalysts of this type, when usedun rlthjes'e“
conversions per passmay be realized, (2) sub
conditions, are by no means equival nt‘,
'that
stantially improved yields of butadiene may be
unexpected, different and greatly impfmveqrr ui‘
obtained", (3) the production capacity of a given
are obtained if the catalyst is ‘promoted, v.Wit ’
catalytic reactor is exceptionally high, (4) the de
rubidium. Thus, by the simple substitution,‘
hydrogenation is carried out in the presence of 15 rubidium for potassium the conversion per passjis ,
a large excess of steam and the use of vacuum or
approximately doubled; contrary‘ to ‘expectation, P:
; ?xed diluent gases is avoided, and (5) the dehy
the selectivity is increased and the active life'orj
drogenation may be carried out with inexpensive
the catalyst is increased. Thus, the production};
catalysts which retain their activity over longer
of a given diole?n in a given reactor, in a givenj
periods of time before requiring replacement.
20 time is greatly increased, the produc'iiop jperlvj;
The importance of diole?ns, particularly but-a
pound of reactant is increased, and the‘produc}; ,_
diene, and the desirability of having improved
methods for their production are well recognized.
tion
nitude
of the
perimportance
ofpound
the improvement
of catalyst
of the problem
isrealized,
increased.
andthethe
' In
present];
mag-f
View
Considerable attention has been given in the past
to the production of these valuable materials by 25 invention is considered “to be an importantxad
catalytic dehydrogenation processes. Catalytic , vancement in theart.
- dehydrogenation to produce diole?ns differs from
The process of the invention, since it requires“
most other dehydrogenation processes in requir
' the use of very large amounts of steamand-t‘em- ‘
ing a low partial pressure of reactantsin the re
peratures in the order of 600° C. or, above,i_s_‘ap- j ,,
action zone. Thus, it is necessary either to carry 80
out the dehydrogenation under a. substantial vac
plicable
tions
vantageously
areinrequired.
such
applied
casesThus,
for
where
thethe
production
these'drasticccndi
prqcesscan
ofstyreneff
be ad;
uum or to employ large quantities of a diluent. -
Operation under a vacuum is very costly. The use
from ethyl benzene and for theiproductiow
f _‘;
of inert diluents to decrease the partial pressure
is, however, particularly
from cyclopentanei",
advantageousl'fogth
The pros, ‘s“ "j
of the reactants usually makes the efficient sepa 35 cyclopentadiene
ration and recovery of the diolefln from the prod
production of dioleflns, and especially’conjug'ated if.
uct very difficult and is a serious disadvantage.
Steam is an ideal diluent but, unfortunately, many
of the most active dehydrogenation catalysts are
dioleflns, from such mono-ole?ns‘as"ar'e‘ca ablef",
of being vaporized and heated :with ste‘arri' ,to' ‘“‘
poisoned by water vapors and steam cannotbe .40
temperatures of at least 600° C. witho
'
employed as a diluent with them. Also, most of
the catalysts are not su?lciently selective in their
action and if steam is used as a diluent they cata
tial
Thus,
quaternary
decomposition
they process
carbonand
is
atomsv
particularly‘;
contain
in aatileast‘,
straight
advantag
'
lyze the oxidation of the reactant by the steam,
for
piperylene,
the production
isoprene,
of such
and the
diole?ris
héxadienes.
as butadi ,
thus giving low yields. ‘ Also, the known catalysts 45 ole?n to be dehydrogenated maybe] a‘, singl‘eg'hyéi ,
lose their effectiveness in a relatively short pe
drocarbon or, if desired, a mixtur'eiof ble?ns may j
riod, particularly when steam is employed, and
be dehydrogenated to produce a mixture 'jof ,diole'f ‘
must be frequently replaced.
fins. Also,‘ in some cases a single ,diole?n'mayjbc. ,
In order to produce dioleiins by catalytic de
hydrogenation using steam as a diluent it is nec
essary that temperatures above about 580° C. be
used and that the catalyst be properly promoted
with an alkali metal or its equivalent. Thus, as
produced from a mixture of isomeric ole?ns. ‘For
50 example, butadiene may be produced froni' either H
butene-l or butene-2 or a mixture‘ ofjthe "two?;
and isoprene may be produced from: methylfethyl if
ethylene, trimethyl ethylene, or isopropyl'ethyl
shown-in appending application Serial No. 520,534,
ene or a mixture of these ole?ns. ‘
filed January 31, 1944, diole?ns may be produced 55, In order to facilitate the recovery of the diole- '
by catalytic dehydrogenation at temperatures
2
2,885,484
?n and unconverted mono-ole?n from the product
and for various other practical reasons, itsis usu
ally desirable that the feed consist essentially of
the desired ole?n or mixture of olefins. This is,
however, not essential and excellent results may
be obtained using ole?n fractions containing ap
preciable amounts of relatively inert. materials.
Thus, for example, in the production- of butadiene
ing the preparation in the'iorm of various ru
bidium. compounds such. for instance, as the ni
trate, sulfate, carbonate, hydroxide, oxide and
the like. Very suitable and inexpensive rubidium
salts are the rubidium alums. These various
compounds; are preferably converted at least in
part to rubidium oxide during the preparation
and/or use of. the catalyst. Halides, when pres
a so-called. butane-lbutylene fraction containing
substantial amounts of butane maybe used‘. Un 10 ent in the catalyst, appear to exert a detrimen
tal' effect. Since traces oi’ residual halide anions
- der the. preferred conditions of operation the par
are di?lcult to remove from the catalyst, halide
a?in hydrocarbons are substantially unaffected
salts‘~ are. not recommended in the catalyst prepa~
and. therefore act as inertv diluents;
ration. The rubidium may be used alone as the
The catalysts which are applicable at high
promoter or it may be used‘ in conjunction with
temperatures‘ in the presence of large amounts of
one or more other alkali metal promoters such,
. steam and which are employed in .the process of
in particular, as potassium and/or caesium.
the- invention comprise as the primary active
Thus, the rubidium promoter may be advanta
component a d'ehydrogenating oxide of a transi
geously substituted in part "by a potassium pro
tion metal‘ of the ?rst transition series 01 the ele
ments (1.. e.
V, Cr, Mn, Fe, Co. and Ni), Of 20 moter. Very suitable mixtures of salts contain
ing potassium and caesium‘ as well as rubidium
these, iron oxide is particularly effective and suit
may be obtained from the working up of certain
able, and nickel‘ oxide is the least effective. These
minerals such as certain lepidolites, certain car
active dehydrogenating. metal oxides may be pres
nallites, and. certain porphyries containing ru
- ent singly,.in combination, or in combination with
minor amounts of known stabilizing and/or pro 25 bidium. A very suitable material‘ may be pre
pared, for example, from, the crude mixture of
moting substances such as oxides‘ of copper, zinc
salts of rubidium, caesiu'm‘and potassium ob
and silver, These metal‘ oxides as well as their
tained from the mother liquors in the produc
combinations are referred to. hereinafter as the
tion of potassium salts.
I
dehydrogenating metal oxide component of relati‘vely high- activity. The catalyst may consist 80 The amount of rubidium. required to produce
the desired promoting client is between about
ofv the dehydrogenating metal oxide of relatively
0.8% and 5% by weight of; the relatively active
high activity and the‘ rubidium promoter, or it
dehydrogenating metal oxide or mixture of metal
may contain minor or major amounts of a car
oxides in the catalyst. This corresponds to. be
rier,,support, diluent or extender of relatively low
tween about 0.9% and 5.5% by weight of rubid
catalytic activity. Thus, the dehydrogenating 35 ium
oxide. Thus, if the catalyst contains 50%
metal oxide of relatively high activity may be.
by weight 0! a relatively inert. diluent such as
employed in combination with a dimcultly reduc
alumina, magnesia. or the like, the concentration
of rubidium in the total catalyst is between about
zirconium or the like- These components may 40 0.4% and 2.5%. If'the rubidium is used in con
junction with potassium, the concentration may
be in the form of intimate mixtures, for, instance,
be decreased to about one-half these amounts.
mixed gels. In other cases the dehydrogenating
, The rubidium promoter may be incorporated
metal oxide of relatively high catalytic activity
into the catalyst at any suitable stage in the cat
may be- incorporated in. relatively minor amounts
in the surface of a major amount of a relatively 45 alyst preparation. In catalysts which are pelleted
or formed into pieces by extrudation or other
inactive support or‘ carrier such as gelsror mix
means, the rubidium is preferably incorporated
tures of gels o1 silica, alumina, chromi'a, zirconia,
prior to such forming operation since catalysts
etc.,, activated carbon, magnesia, diatomaceous
of somewhat higher activity and longer life are
earth, ki‘eselguhr, bauxite, and the like. Also,
ible oxide of relatively low catalytic activity such,
for instance, as an oxide of aluminum, silicon,
. these various materials of relatively low activity 50
may be combined in mass with the relatively
more active dehydrogenating metalv oxide to serve
as diluents or extenders. Preferred catalysts,
thus obtained.
a
»
In order to maintain the proper state of oxi
dation of thedehydrogenatliig metal oxide and to -
maintain the,catalytic activity, the process of
however, consist largely of the dehydrogenating
metal oxide of relatively high activity. Thus, a
the invention. is can'ied out‘in the presence of a
55 large. excess of steam. Thus, the mo] ratio 01'
preferred group of catalysts contain at‘ least 50%
steamv to hydrocarbon fed 'to the reaction zone
by weight and- preferably about 70% to 95% of.
is at least 2:1 and generally between about ‘7:1
iron oxide.
and 3011.
The preparation- of the catalysts with respect
In order; to obtain the desired results in the
to the preparation of‘ the d'ehydrogenating metal‘ 60 presence, or a large excess of steam, the dehydro
oxides and/or the combining oIv the. dehydrogen
genation is carried out at ‘relatively high tem
ating metal oxides with such diluent, extender,
peratures. Thus, the dehydrogenation is car
supporting or stabilizing materials may be eifect
ried out at a temperature at. least as high as 580°
ed in. any of the conventional manners. Thus, the
C. and generally between about 600°C. and 700°
catalysts may be prepared in they wet way by pre 65 C, Somewhat higher temperatures may be em
cipitation methods or by slurry methods, or they
ployed but are usually unnecessary. ‘A preferred
may be prepared by thermal decomposition of
method of operation affording high conversion
suitable salts, or they may be prepared by the
efficiencies consists of adjusting the temperature
conventional» impregnation methods.
initially to limit the conversion. to, say, 35% or
The active dehydrogenating metal oxide or 70 40% and then increasing the temperature as the
mixture of oxides, or mixture comprising one or
more diluent or carrier materials, is promoted
with the incorporation of a relatively small
amount 01' a compound of rubidium._ The rubid
process continues to maintain this conversion.
Thus, the process may be initiated with a fresh
catalyst at a temperature oi, say, 590° C. and the
temperature gradually increase; to, say, 670° C.
ium may be incorporated into the catalyst dur 75 during the life 01' the catalyst. By this method
3
2,885,“!
The steam and hydrocarbon were passed through
the bed 0! catalyst for periods of 90 to 105 min
conversioniei'?ciencies in,the order of 70% to- 0
90 %‘-may usually be maintained.
The" dehydrogenation may be carried out un
der ‘any-"pressurei'at which the steam and react
utes and thecatalvst was steamed tor about 15
minutes under the same conditions between each‘
process period. The following results were ob
ant exist in‘the're'action zone in the vapor state.
Thus, ‘either-‘vacuum or pressure may be used.
tainedi'
i
>
An important ‘advantage of the process, however, I
is that excellent results may be obtained at at
mosplieric pressure;
~
'
Cycle
‘
In ‘viewio't‘the"exceptional activity of the de
Butylene
->
'
reacted
Butylene
'
Conversion
'
cg?agsggo eiliclency
10
scribed rubidiumépr’omoted catalysts when used
Percent
underil‘the' described ‘conditions, the process of
1 ......................... ..
-
~
,
72
74
the invention; allows excellent conversion to be
obtained? ‘quite selectively over a‘ considerable
Percent
‘
lPercent ‘
43.4
40.9
i
vs
‘
soc
60.5
t4
range‘ of space'velo'cities. Suitable space veloci 15 _ A catalyst prepared in the. same manner using
ties are; for example, between about 300 and 3000,
the same materials except that 4.4% or ‘potas
volumes‘of' gaseous reactant (N. T. P.) per vol
sium nitrate wasused instead of 5.8% of. rubid
ume- of ‘catalyst per hour. Aicontact time afford
i'um carbonate, when used at a space velocity
ing the optimum results depends‘ upon the partic
of only 1000 (other conditions the same), gave
ular material being dehydrogenated and the par 20
ticular“ conditions chosen within the above given
the following results:
ranges and may best be determined for any given
case by trial starting with a very-short contact
Cycle
time .andigraduallyiincreasing the contact time
.
. _
_
'
Butylene
Butylene
‘
reacted
Maggie)?
Conversion
e?iciency ;
until‘the desireddegree of conversion is obtained. '
The-1 .contact time "in. the dehydrogenation of
butylenesf'and ‘butadienes by way of example is
preferably in the order of’, 0.02 to 0.5 second.
Percent“
2 ......................... ._
.
'Pcrcen't " ' Patent
73.5
‘, "r, 34.3
4 ......................... ..
The catalystjmayxbe usedv in any of the con-v >
35.1
'
,
7‘ ’
46.5
52
It will beobserved that by operating according to‘,
ven'tional ‘forms such. ‘as pills, spheres, saddles,
30 the process of the invention approximately 6%» ‘
greater conversion to butadiene was obtained at ,- ._
size adapted-tor the reaction system to be used. -
extrud-atcs' ‘oréirregular fragments ‘of a shape and
If desired, thelp'rocess may be carried out‘in a
so-called dust catalyst, ?uidized catalyst or mov
twice the space velocity.
ing bed system.) Excellent results may, however,
to about 230 % of the normal. - Y
conversion and production capacity afforded, the l
' present process has other important advantages.
actant vapors and-preheated steam through agre- ~
.
The. prior-known catalysts containing potassium - ’
40 become deactivated during use at a relatively fast~ ~
rate. Thus, prior-known catalysts are=presently
material. The ‘unconverted material may be sep
version
considered
to butadiene
to be goodunder
if theytheabove,
sustain a conditions
20% con; 3 ,
arated from ‘the product in conventional man
ners. and recycled.v .
~
Tl
>
Aside from the unexpectedlylarge increase ‘in :
be obtained. bysimply ‘ passing the preheated re
action chamber-?lled with the catalyst and main
tained ati1the. desired ‘temperature and pressure.
The steam in the product may beoeondensed and
separated from the ‘converted and, unconverted
‘This corresponds-to:
increasing the production capacity of the reactor. 7
except at a gaseous hourly space..-velocity of 500 -
‘
-
for 300 process hours. It has been determined‘ a‘
that one of the causes of, this deactivation is due ,
In ma'nyjcases it is most advantageous to carry 4.5
out the; dehydrogenation in'an intermittent man
to loss of potassium from the catalyst-byvolatiliz
ation. The rubidium in the catalysts used in the
‘process of the present invention is relatively non
ner, that; is, a to: carry vout the dehydrogenation in
relatively short periods of, for'instance, 1 to 8
hours with intermittent regeneration in the
known manner. In such cases the regeneration 50 volatile as compared to potassium and is volatil- _
ized from'the‘catalyst at a much slower rate.
This cause of decline in the activity of the cata
may be e?ectedby‘ simply treating the catalyst
with steam in the absence of the'reactantforpa .
short‘period at the reaction temperature.’ Cer
- lyst is ‘therefore substantiallyeliminated.
Any; ~
small amount of rubidium volatilized in the proct
tain of the catalysts, when employed under the
described ‘conditions, do not require‘ such periodic 55
ess of the invention may be recovered and re-, .
~ used. Also, rubidium may be recovered from the _
regeneration and when these catalysts are em
ployed the dehydrogenation mayxbe advanta- ‘ 1 spent catalyst bysimple leaching treatment and ~
geously carried‘ out in a substantially continuous
mannerr."
1.:
.
.
>.
Example
A catalyst was prepared asnfollowsrBaker’s
c- P. ie'rric oxide‘ was slurried ,‘with 5.8% by
reused in preparing fresh catalyst.
Thus, al
though rubidium saltsare relatively costly, the ,
60 catalyst costs in the operation of the process of
. the invention are not expected‘ to be increased
appreciably and may, in fact, be lower..
I claim as my invention:
_
.
.
..
_
y
weight of rubidium carbonate in aqueous solu-,_ 7
l. The process for- the productlonof butadiene
tion. ‘The, slurry was evaporated to dryness while i 65 which comprises contacting a normal butylene in
thepresence of at least 2,mols of steam per mol
stirring. Thefmass was heated at 700° C. for 1 ‘
of mono-ole?n at a temperature above '580". C.
hourlandithen broken up into_‘8-20 mesh par
ticles.
'‘
-
.
>
at a gaseous hourly space velocity between about ’
'
This catalyst wasused for the dehydrogenation ,
300 and 3000 with a catalyst comprising a de
of a butylenelfraction consisting of butene-l and \70 hydrogenating oxide of iron promoted with ru
butene-2 ‘under’. ‘the following conditions:
Temperaturmh“ ‘___;__'___'.. ____ .._‘»..._° C-..
630
Pressure_.“‘___.-...;_' 1 atm, at exit of'catalyst bed
Gaseous hourly space velocity_--__¢; _____ __ 2000
Mol ratio, steam to butylene _____ _; _____ .. 14:1
bidium in an amount equivalent to 0.9% and
5.5% by weight calculated as the oxidebased on
the dehydrogenating metal oxide of the catalyst.
2. The process for the production of .butadiene
which comprises contacting a normal butylene in
.
4
a,ses,4e4
the presence of at least 2 mols oi steam per mol
of mono-ole?n at a temperature above 580‘ C.
at a gaseous hourly space velocity between about
300 and 3000 with a. catalyst comprising iron ox
ide and magnesia promoted with rubidium in an
amount equivalent to 0.9% and 5.5% by weight
calculated as the oxide based on the dehydrogen
vating metal oxide of the catalyst.
'
3. The process for the production of butadiene
which comprises contacting a normal butylene in
the presence of at least 2 mols of steam per mol
of mono-ole?n at a temperature above 580° C.
adjusted to give a conversion to diole?n between
35% and 40% at a gaseous hourly space velocity
between about 300 and 3000 with a catalyst com
prising a dehydrogenating oxide of a metal of
_
series promoted with a mixture or alkali metal '
oxides comprising potassium oxide, rubidium ox
ide and caesium oxide in an, amount equivalent
to 0.9% and 5.5% by weight. calculated as the
oxide based on the dehydrogenating metal oxide
01' the catalyst, and separating the diole?n from
the reaction mixture.
i
_
.
p
9. A process for the production of a diole?n
- which comprises contacting a mono-ole?n hav
ing at least 4 and not more than 5 non-quater
nary carbon atoms in a straight'chain in the
presence of at least 2 ‘mols of steam per mol of
mono-ole?n at a. temperature above 580°C. ad
iusted to give a conversion to diole?n between
35% and 40% at a gaseous hourly space velocity
between about 300 and 3000 with a catalyst com
the ?rst transition series promoted with rubidium _ prising a dehydrogenating oxide of a' metal 01’
in an amount equivalent to 0.9% and 5.5% by
the ?rst transition series promoted with rubidi
weight calculated as the oxide based on the dehy
um in an amount equivalent to 0.9% and 5.5%
drogenating metal oxide of the catalyst.
by weight calculated as the oxide based on the
4. The process for the production of butadi 20 dehydrogenating metal oxide of the catalyst, and
ene which comprises contacting a normal butyl
separating the diole?n from the reaction mixture. ‘
ene in the presence of at least 2 mols of steam
10. A process for the production 0! a diole?n
per mol of mono-ole?n at a temperature above
which comprises contacting a mono-ole?n hav
580° C. at a gaseous hourly space velocity between
ing at least 4 and not more than 5 non-quater
about 300 and 3000 with a catalyst comprising 25 nary carbon atoms in a straight'chain ‘in the
a dehydrogenating oxide of a metal of the ?rst
presence 01' at least 2 mols of steam per mol of
transition series promoted with a mixture of
mono-ole?n at a temperature. above 580° C. at a
alkali metal oxides comprising potassium oxide,
gaseous hourly space velocity between about 300
rubidium oxide and caesium oxide in an amount
30 and 3000 with a catalyst comprising iron oxide
equivalent to 0.9% and 5.5% by weight calcu
and magnesia promoted with rubidium in an
lated as the oxide based on the dehydrogenating
amount equivalent to 0.9% and 5.5% by weight
metal ‘oxide of the catalyst.
calculated as the oxide based on the dehydro
5. The process for the production of butadi
genating metal oxide of the catalyst, and sepa
ene which comprises contacting a normal butyl 35 rating the diole?n from the'reaction mixture.
ene in the presence of at least 2 mols oi! steam
11. A process for the production of a diole?n
per mol of mono-olefin at a temperature above
which comprises contacting a mono-ole?n hav
580° C. at a gaseous hourly space velocity between
ing at least 4 and not more than 5 non-quater
I about 300 and 3000 with a catalyst comprising a
nary carbon atoms in a straight chain in the
dehydrogenating oxide of a metal of the ?rst
transition series promoted with rubidium and
potassium in an amount equivalent to 0.9% and
5.5% by weight calculated as the oxide based on
the dehydrogenatin'g metal oxide of the catalyst.
6. The process for the production of butadi 45
ene which comprises contacting a normal butyl
presence of at least 2 mols of‘ steam per mol oi’
mono-olefin at a temperature above 580° C. at a
gaseous hourly space velocity "between about 300
and 3000 with a catalyst comprising an oxide or
iron promoted with rubidium in an amount equiv
alent to 0.9% and 5.5% by weight calculated as
the oxide based on the dehydrogenating metal
oxide or the catalyst, and separating the diole?n
ene. in the presence of between about '1 and 14
mols of steam per mol of mono-ole?n at a tem
from the reaction mixture. ‘
>
'
perature above 580° C. at a gaseous hourly space
12. A process-for the production of a diole?n
velocity between about 300 and 3000 with a cata. 60 which comprises contacting a mono-ole?n hav
lyst comprising a dehydrogenating oxide of a
ing at least 4 and not more than 5 non-quater-~
metal of the first transition series promoted with
nary carbon atoms in a straight chain in the
rubidium in an amount equivalent to 0.9% and
presence of at least 2 mols of steam per mol of
5.5% by weight calculated as the oxide based on
mono-ole?n at a temperature above 580“ C, and
the dehydrogenating metal oxide of the catalyst. 65 at a gaseous hourly space velocity between about
7. The process for the production of butadiene
300 and 3000 with a catalyst comprising a dehy
which comprises contacting a normal butylene in
drogenating oxide oi’ as metal of the ?rst transi
the presence or at least 2 mols of steam per mol
tion series promoted with rubidium and potas
of mono-ole?n at a temperature above 580° C. at
sium in an amount equivalent to 0.9% and 5.5%
a gaseous hourly space velocity between about 00 by weight calculated as the oxide based on the
300 and 3000 with a catalyst comprising a dehy
dehydrogenating metal oxide of the catalyst, and
- drogenating oxide of a-metal of the ?rst transi
tion ‘series promoted with rubidium in an amount
equivalent to 0.9% and 5.5% by weight calcu
separating the diole?n from the reaction mix
ture.
13. A process for the production of a diole?n
lated as the oxide based on the dehydrogenating 65 which comprises contacting a mono-olefin hav
metal oxide of the catlayst.
ing at least 4 and not more than 5 non-quater
8. A process for the production of a diole?n
nary carbon atoms in a straight chain in the '
which comprises contacting a mono-ole?n hav
presence of between about '7 and l4‘mols of steam
ing at least 4 and not more than 5 non-quater
per mol of mono-olefin at a temperature above
nary carbon atoms in a straight chain in the 70 580° C. and at a gaseous hourly space velocity
presence of at least 2 mols of steam per mol of
between about 300 and 3000 with a catalyst com
mono-ole?n at a temperature above 580° C. at a
prising a dehydrogenating oxide of a metal of
gaseous hourly space velocity between about 300
the ?rst transition series promoted with rubidi~
and 3000 with a catalyst comprising a dehydro
um in an amount equivalent to 0.9% and 5.5%
genating oxide of a metal of the ?rst transition
by weight calculated as the oxide based on the
5
aaemae
space velocity between about 300 and 3000 with
a catalyst comprising a dehydrogenating oxide 01
a metal of the ?rst transition series promoted
ture.
‘
with rubidium in an amount equivalent to 0.9%
14. A process for the production of a diole?n
which comprises contacting a mono-ole?n hav Cl and 5.5 %- by weight calculated as the oxide based
on the dehydrogenating metal oxide of the cat
ing at least 4 non-quaternary carbon atoms in
alyst, and separating the dioleiin from the reac
a straight chain in the presence of at least 2
dehydrogenatinz metal oxide of the catalyst, and
separating-the diole?n from the reaction mix
mole oi steam per moi of mono-ole?n at a tem
perature above 580° C. and at a :aaeous hourly
tion mixture.
\
‘
KENNETH A. WRIGHT.
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