Note: Descriptions are shown in the official language in which they were submitted.
PROCESS FOR PRODUCING UNSA~URA'~ED
HYDROC~RBONS
'~he present i~vention relates to the production o~ un-
satura~ed hydrocarbons.
Said unsaturated hydroc~rb~s such as butylenes, iso-
amylenes, divinyl, isoprene, styr~ne, vinyltoluene are va-
luable mo~omers ~or tha ma~u~acture of various typ~s o~ sy~
thetic rubber, plastics, elastomers as w~ll as the starting
products ~or the industry o~ basic orga~ic synthesis.
Know~ in the art are various processes ~or tha produc-
tion o~ unsaturated hydrocarbons.
~ hus, known i.9 a process ~or the production of unsatu-
ratad hydrocarbons ~rom saturated ones at a ternperature
within the ranga o~ ~rom 400 to 800C in the presence of a
ga~eous oxyg0~ and a catalys-t containin~ molybdenum as well
as nickel or cobalt~ ~he yield of butadiene produced by this
process aoes ~at exc~ed 10.1% wit~ the selectivity relative
thereto of 31.0% and xelative to the total butylenes-buta-
diene of 46.~%.
~ l~o known i~ the art is a proce~s ~Dr produci~g mono-
a~d di~olef ines by way o~ a~ oxidizing dehydrogenation o~
paraI^~i~s at a temperature within the range o~ from 400 to
700C in the presence of gaseous ox~gen and a ¢atalyst csn- -
sisting o~ oxides 4~ molybd~um and/or tungste~ a~d at Least
one o~ the ~ollowin~ metals: chromium, man~anese, iron, ~ick-
el and ~admium. In accordance with thiQ process9 the yield of
., ~ ' .
- . ~. ., . . - . , . . , . : .
butadiene from n-butane does not exceed 21.6% wi~h sel~cti-
vity relative ther~to o~ 53.6% and r~lative to the total of
bu~ylenes-butadienq o:E 64-.8%.
A principal disadvantage of -the above-discussed prior
art processes resides in a low con~ersion o~ dehydrogenated
hydrocarbons and i~su~fici~nt selecti~ity relative to the
desired products.
~ he closest analogu~ o~ the process according -to the
present invention is a process ~or produc.i~g mo~o-- a~ di-
olefines by a~ oxidizing de~gdrogenation of, e.~. para~in
hydrocarbo~s, at a temperature within ~he ran~e of from ~00
to 700C and the molar ratio o~ oxygen to the paraffin h~d-
rocarbon of ~rom 0~1 to 3~0:1 i~ the presence o~ a~ inert
vehicle such as argo~, ~itrogen~ helium, steam or mixtures
thereof D
~ he process is conducted o~ a ca~alyst comprising o~ide
compou~ds of~ e.g., molybde~um and magnesium, with additives
o~ cobalt, iron, chromium~ vanadium~ nickel~ silicon3 ~i~7
boron, bismuth9 tita~ium, niobium~ gadoli~ium9 dysprosium9
gallium and zirconium. ~he yield o~ b~tadiene ~rom ~-bu~a~a
by this process is 36.6% with selectivit~ relative thereto o~
54.7~0 and relative to the total o~ but~le~es butadie~e of 64.3%~
For increasing the mechanical strength o~ the catalyst;
the active component is applied onto a carrier, such as alu-
mosilicate, aluminium oxide, silica gel. However, the use of
such catal~sts, e.g. with the applicatio~ o~ alumosilicate,
, ~
'
,
. . . . . . .
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in accorda~ce wi~h -the above cited meth.od9 leads to low~rin~
of th~ butadiene yield from n-butane dow~ ~o 4.7% with the
selectivity thereto o~ 140 3%~ '~hus, the method is characte-
rized by a low selectivity also, and~ in ~he case of usi~
a catalyst wi-th a carrier, by a low yield of` the desired
dehydro~enation products.
It is an object of the present invention to provide
such a process ~or pxoducing unsa-turated hydrocarbons which
would make it possible to increase -the yield o~ -th~ desir~d
products and increass selectivity o~ the proc~ss.
~ 'his and other objects o~ the prese~t i~vention are
accomplished by that in a process ~or produc~ng unsaturated
hydrocarbons by contac-ting para~i~, mono-ole~i~e a~d/or
aromatic compounds with a ca-talyst comprising a carxier with
a deposited thereo~to an oxids compound Q~ molybdenum i~ an
amount o~ ~rom 5 to 35% by weight o~ the catalyst in the
pr0sence o~ an inert gas a~d/or steam at a temperature with-
in the range o~ from 400 to 700C, i~ accordance with t~e
present i~ve~tio~, in ths catal~st as the carrier use is
made o~ a gra~ulated porous cr~stalli~e silica modi~ied by
mag~esia i~ an amount o~ ~rom 1 ~o 20% by weight of the cax-
rier, a gra~ulated magnesium-titanium carriar consisting o~
50 to 95% by weight 0~ ~gOs and 50 to 5~0 by weight o~ TiO29
or a granulated mag~2sium-alumi~ium carrier consisting o~
70 to 95% b~ weight o~ MgO and 5 to 30% by weight o~ A1203,
a~d at a temperatuxa wi~hin tho ran~e o~ ~rom 400 -to 700C
.... . . . ...
` , ~ , : ` ~ '
` . : ' ' ~ ' . :
.: .
.
~ 3
an oxyOcn-containing gas is passed through ~he spent cata-
lyst till regeneration o~ the ca-~alytic ac-tivity of the
catal~st.
As the starting material use may be made o~ various
organic compounds, namely ole~in~, paraf~in and alkylaroma-
tic hydrocarbons. In the oase o~ using paraf~i~s along wi~h
dienes there is ~ormed a certain amount o~ monoole~i~es
which togather with -the ~nreac-ting starting ma-terial are
recycled back into the xeaction æo~e to increase the yi~ld
of diene hydrocarbons.
Selectivity of the process is increased upon dilution
of the startin~ hydrocaxbons with inert dilue~ts; ~amely
nitrogen, argon, st~am and the li~e. Molar ratio between
the hydrocarbon a~d the diluent is varied within a Y~ide ra~-
g9 0~ from 1:3 to 1:30.
Vapours o~ the starting ~eed (butane 9 butyle~es, iso-
pentane, isoamylenes, othylbanzene, e~hyltoluene and the
like) in a mixture with a diluant are contacted with the
catalyst at a temperature within the range o~ ~rom 400 to
700C (preferably from 450 to 650C). ~s a result, a process
of dehydrogenatio~ o~ the starti~g orga~ic compounds occurs~
wherai~ hydxogen o~ said compounds is combi~ed with oxygen
of the catalyst with the :Eormation of the reaction wa-ter.
~ he content o~ oxy~sen i~ the catalyst is lowered., ~his re-
sul~s in decrease of val~llc~r o~ molybdez~um. Reduction of the
catal;srst is accompa~ied by a decr0ase o~ its activit~ and
' ~
, ~ . - . . -
.
' ' - : :
.. . . ~ , ...
. , . - . :. . , . .:, : ~ . . .. :
.. . . . . . . . ...
~ 3
substantial loss of activi-ty o~ the feecl conversionO ~'hera-
with, selectivity o~ the catalyst action is retained at the
i~itial level or even increased.
~ o maintain a hi~h activity o~ the catalyst 9 periodic
oxidizing regeneratio~ o~ the cata~yst is per~rmed by
means o~ a~ oxygen-containing gas such as air at a tempera-
ture within the range o~ ~rom 403 -to 700C~ ~pon the o~id-
izing rageneration there occurs elimination of carbonaceous
deposits ~rom the ca~aly~t sur~ace and oxidation of the ca-
talyst to its original s-tateO ~fter discontinuation o~ each
stage of the dehydro~enation a~d regeneration process9 the
catalyst is purged with a stream of an inert gas. 'l'here~ore,
in accordance with the present inve~-tion, there is no contact
o~ the hydrocarbon with oxyge~ in the gas phase which increa-
ses selecti~ity o~ the process and elevates ths yield o~ the
desired products du~ to the diminished role of the rsactio~s
of deep and partial oxidation and o~idizing crac~ing of ~yd-
rocarbons~
~ he cata}yst according to the pxese~t i~entio~, as it
has bee~ already me~tioned herei~before~ comprises a carrier
with deposited thereonto a~ oxide compound o~ mol~denum.
In the catalyst containing, as the carrier~ a granulated
crystalline silica modi~isd with mag~esia7 a high mecha~ical
strength o~ the ca~alyst is ensured at the acGou~t o~ a rigid
crystal lattice o~ silica~ whila the presence o~ magn~sia at
.
~ 3
--6
its surfaca results in ths formatiorl of an active ma~sesium
molybdate and a subst~ntial (by 10 to 40 tirsles) increas~ o~
a speci~ic sur~ace area of t-he catalyst~
The granulated small-size carrier used i~ tha process
according to tha presant inv3ntion co,~prises a mixture of
ma~nesia with titanium diDXide or alumina Increased content
of magnasia in the carriex cDmposition up to 50 to 95% by
weig~t cDntributes to an increased yield o~ the dasired
products and higher selectivity of tho dehydrogenation 2rocess~
The presence of titanium dioxide or alumina incrca~s r~c~-
nical stre~gth of the carrier and makes possible to lower
calcination temperature during its preparation.
The process of dehydrogenation o~ hydrDcarbons may be
also conducted on catalysts the active phase o~ which conta-
ins~ in addition to oxide compounds o~ molybdanum, oxide com-
pounds o~ cobalt, nickel, irDn or manganase in an amou~t
o~ from 3.7 to 15% by weight o~ the catalyst. ~uch catalysts
have di~ferent structural modi~icatio~s~ The catalyst type
a~fects selectivi~y o~ the process of dehydrogenation o~ par-
ticulax hydrocarbons~
~ he catal~st i9 employed in the shape o~ tables9 noodles,
rings a~d granul~s of various dimensions9 pre~arably of
~rom 0001 to 15.00 mmO
I~ order to prolo~g the sa~vica li~ of the catalyst
which is essential ~Dr dehydrogenation process performsd i~
~ ~ a statio~ary a~d liqui~iad bed of the catalystt into tha
,~ , .
- ~ . :~ ~ , : ,
dehydxogenation zone there is added a small arQoun-t of ox~gen
(up to 0~1 mole per mole o~ the starting hydrocarbon feed)~
This is o~ a grea-t importanceg since the opera-tion ti~e of
the catalyst (duration o~ dehy~o~enation) in apparatus wi-th
a stationar~ bed or in reactors with a fluidized bed usually
exceeds 3 to 5 minutes. '~he use o~ small amounts o~ oxygen
in the dehydr~genation zone doec; not substantiall~ a~ect
the ~ield o~ the desired product;s and selectivit~ o~ dehydro
genation.
In accorda~ce with the present i~entlon, the catalyst
employed in the pxocess ~or producing unsaturated hydrocar
bons is prepared by impregnation oX the a'oove-mentioned car-
riers with a~ a~ueous solution o~ ammoni~a molybdate to yield
a suspension. From the resultlng suspension water is removed
by evaporation, A~ter evaporation t~e thus-obtained mass is
subjected to calcination at a tempera-ture within the ran~e
of ~om 350 to 700C. ~he calcinatio~ is e~feGted in an inert
or oxidi~i~g medium.
During the impregnation of the carrier with an aqueous
solution o~ ammonium mslybdate there occurs ~illing o~ the
carrier pores with -this solution. I~ the subseque~ treat~ent
operations (evaporation, calcination) there occurs ~orming of
a catal~st as a result o~ the removal o~ water and decomposi-
tion of ammoni~ molybdate~
To intansi~y -the process o~ deh~dration o~ the suspen-
sion, it is advisable to carry out the evaporation under
; vacuum.
~ .
.. . . . . . .
.
.
. ~ , . . .
13L~lL9L9Lr~3
In some cases in the calcination proces~ sintering OL
particles is possible at a rapid growth of t~mperature Y~hich
results i~ varioations o~ the ~raction composition o~ the
catalyst and this, in -turn, necessitates inclusio~ of addi-
tional staOes such as crushing, separation. To avoid this,
calcination o~ the resulting mass should be pre~erably caxri~
ed out in a suspended bed.
In oxder to increase activity and selectivity of the
catalyst, it is advisable to include into its composition
oxide compounds o~ cobal-t, iron, ~ickel or manga~ese in an
amount o~ ~rom 3.7 to 15% by wei6rht o~ th~ catalyst. ~o this
end, p~ior to calcination the carrier is also impregnated
with an aqueous solution o~ cobalt ~itrate, or nitrate o~
nickel, iron or man~anese; -this impregnatio~ and said impreg
nation with an aqueous solution of ammo~ium molybdate i~ any
succession~ in doing so, inbe-tween two said impre~natio~s wa-
ter is removed from the resultin~ suspension by evaporatio~.
~In order to ~urther incr~ase activity and selectivity o~
;the catalyst, it is advisable to repeatedly a~d alternatively
(up to 3 -12 tLmes) per~orm impreg~ation o~ t~e carrier with
sol~tion o~ said salts including ammonium molybdate, ~ollowed
by evaporatio~ o~ water ~rom the suspension. Thereafter cal-
cinatio~ of the resulting mass is c ~ ried ~ut at a temperatu-
re of from 350 to 700C. ~his ensures a more un~or~ distribu-
tio~ of the active phase wi-thin the volume of the catalyst
granules and increase of ~i~e~ess of the active compone~t at
the sur~ace of t;he porous carrier.
1- - ~ , , : - -
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. . .. . . . . . . . .
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. - . - . . . . .. .. .
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~: . ~, . . ~ . . . . . .
:-. ' . . - -., : . : :,',.. . ' , , '
_ 9 ~ 44~3
Increased fineness o~ the active component is associa-
ted with the growth of its sur~ace area accessible ~or the
reagents which~ in turn~ make3 i.-t possible to per~orm the
dehydrogenation process at a higher rate at the sa~e char~e
of the catalyst. Unif ormity of distrib~tion o~ the ac-tive
component wi-thin the volume o~ the ca-lalys-t granules prev-
e~ts from a rapid loss o~ -the cat~lyst activity upon wear
thereo~ duri~g the opera-tion~
Further i~crease o~ the catalyst activit~ and simplifi-
cation o~ the technology o~ its preparation is ensured b~
that -the resulting maæs~ i.e~ carrier, impregnated with
aqueous solutions o~ ammonium molybda-te and a nitric acid
salt and dried, prior to the calci~ation is treated with an
aqueous solution o~ ammonia, amines or amin~alcohols ~ollow-
ed by the removal of wa~er by evaporation.
'rO this end, use may be made o~ methyl and triethyl-
amines, mono-, di- and triethanolamines and ~he like. '~he
-treatment therewith makes it possible to achi~ve a u~i~orm
distribution o~ acti~ components within the volume o~ the
catalyst granules and exclude repeated operations in the
preparation o~ a polycomponent catalyst.
'l'he use in -the process according -to -the present i~e~-
tion o~ the principle o~ alternative con~tacting o~ the hydro-
carbons ~ed -to .hydrogenation and oxygen supplied to regenera-
tion o~ the spent catalyst makes i-t po~sible to increase the
process svlectivLty as oompared to the prior art processss
,. ~ .
-
, .. . . . .. . .
.
. . . .
.
.'
- 10 - ~L~
(c~. US ~abent NoO 39~629256)~ ~hus7 uporL deh~droge~ation
o~ n-butane accordi~g -to the p~ocess o~ the ~rasent i~ven-
-tion~ salec-tivity relative to butadiene ls 75.1% as compared
to 5'~% in the prior art process7 while select:ivity relative
to the total o~ butylenes butadiene constitutes 85.4% as
compared with 64.3% in -the prior ar-t process9
~ his relatively low selec~tivi-ty in the production o~
unsatuxated hydrocarbons by the known method is appare~
due to in-tensive side reactions o~ a deep and partial o~ida-
tion o~' hydrocarbons in ~the prese~ce o~' gaseous oxygen supp-
lied i~to the dehydro~enation zone along with ~the starting
feed. A similar decrease in selectlvity relati~e to dehydlo-
genation products ~der the conditio~s o~ simultaneous supply
of hydrocarbo~s and air oxyge~ onto the catalyst has baen ob
served in our case too. ~hus9 when the process is carriad
out in the absence o~ gaseous oxygen in the reac-tion zone,
the yield o~ butadiene ~rom n-butane is 27%9 ths yield o~
combustio~ products (CO and C02) is 8~6%. Upon addition o~
oxygen into the starki~g ~eed composition at the stage o~
dehydrogenation only in~the amou~t o~ 0~5 mole per mole o~ ~
n-buta~e, the yield o~ butadie~e is reduced -to 22~2~o~ whila
the yield o~ combustio~ products is i~creased to 20~2~o~ whe-
reas total selecti~ity r~lative to the whole of the deh~dro-
genation products (C4H8 - C~,H6) is reduced ~rom 7500 -to
5401%. ~he yield o~ the products o~ partial oxydatio~ o~ hyd-
. . .. . . . . .
- : : . . .
- , . . . ~,
. - ..... . , ~ , . . .
.:: : ,' . , ' :,- . ~, ~': .,; ' ' ', .,. , .. ;:
.. : ~-. . : ~ .
" .
44~33
rocarbons, i.e. :~uran and o-the~ oxygen-co~-tainin~r compounds7
i~ this case is i~creased by a~out 5 times.
.~urthermore, carryln~ out the process in the absence o~
oxygen ~acili-tates the temperature control ln the reactio~
zo~e (owi~g bo lowered intellsity o~ highly exothermal combus-
tion reactio~s); there is totally avoided the possioility of
the ~ormation of a hazardous mixt;ure oP hydrocarbons with
oxygen; also substantially simpli.~ied is the problem o~ puri-
~icatio.~ o~ waste wa-terq due to a lowered yield o~ oxygen
-containing products o~ a partial oxidation o~ hydrocarbons,
Due to the ~act that the stock of` oxygen in the catalyst
is limited, -the period of` its eff`ective operatio~ under the
conditions of dehydrogena-tion is not long7 which is a subs-t-
antial obstacl6 to practical implementation o~ the process,
. . ~o avoid this, it is advisable to conduc-t deh~dro~enation
; ~ollowing the process according to the present inve~tio~
i.e. with continuous displacement o~ the spent ca-talyst from
the dehydroge~ation zone to the rege~eratio~ zone, with sub-
sequent recycle o~ tha catalyst bac~ to the dehydrogenation
zone after restoration o~. its activity. ~his displaceme~t o~
the catal~st and its operation in a suspe~ded bed imposes i~-
creased requirements o~ the mecha~ical strength a~d wear-resi-
sta~ce of the catalyst and makes practicall~ impossible the
use o~ catal~sts prepared b~ the p~ior art methods without a
carrier.
.:
.
.~ . ..... . ..
-
.. . . .
- ' .
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.
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- 12 -
At the same time, the use o~ catalys-ts prepared by the
prior art method with a carrier leads to a sharp reduction
of the yield of the desired products o~ dehydrogenatio~ of
hydrocarbons.
~ he catalyst as employed i.~ the proc~ss accordin~r to
the present iLven-tion, allows the desired produ~ to be
obtained in a high yield. Moreover~ -this catalyst, owing to
a mecha~ically durable porous carrier fea~ures a hi~h wear-
resistance a~d abili-ty o~ retai~i~g i~s ~ractional composi-
tion whic}l enables i-ts use in appaxatus with both s-ta-tionary
and mobile or li~ui~ied bed o~ the catalyst~
~ he porous crystalline silica as used as a carrier ~or
the catalyst in the process accoxding to -the present in~en-
~io~ nas a small sp~uifi~ sur~ace area (within th~ rangQ o~
~rom 0.15 to 2 m2/g) and a low absorptio~ power relative to
the active components of the catalyst~ ~odi~ication thereof
with magnesia ma~es it possiblQ to i~crease the speci~ic sur
Yace area o~ ~he carrier up to 10 - 12 m2/g. Magnesia, while
reactinæ during its application with the solutio~ o~ a~monium
molybdate, Iorms a magrnesium moly~aate which is c~talytically
active Ln the dehydrogenation reaction, a~d in the prepara-
tion o~, ~or.example, a cobalt-moly~denum catalyst, it stabi-
lizes the active a-pnase o~ cobal~ molyodate.
In the process according to the present inventio~ use
may be also ma~e o~ a catal~st having, as its carrie~, a
moulded ~nd calcined mi~ture o~ ~insly divi~ed ma~nesia a~d
.... :' '
.
:. . .. - . . ~ .. .
. ., . , - - , . .
~ : . . . . .. . . . . . . . .
~ 3
- 13 -
titania or alumina. In this case magnesia Lorr~s a ma-trIx o~
the carrier granule, while the incorporatad therein titania
or alumina substantially lowers the calcinatio~ temperature
o~ granules and makes it possible to obtain t~e carrier wi~h
a su~icientl~ developed specific sur~ace area~ since speci-
~`ic area o~ magnesia is conside:rably reduced with the gro~Jth
of calcination tempera~ture.
l'he catalysts used in the process according to the pre-
sent i~vention possess a high catalytic activity and sele-
ctivity, thermal stabili~y, impact resistance and ability to
withstand considerable te~nperature gradients~ ~hus; wear o~
a small-size cobalt molybdenum catalyst based o~ magnesiu~-
-titanium carrier constitutes 3- 4%~ while the sta~dard cru-
shed glass-like alumosilicate under the same co~ditions haS
a wear o~ l8- 20% b~ weight. ~till higher wear~resista~ce is
characteristic o~ catalysts based on a porous cr~stalline
silica (quartz). ~here~ore, the catalysts according to the
present inventio~ are highly e~fective in de~ydrogenation
process in reactors o~ all the above-me~tioned types~
~ he procass according to the E~esent i~vention is tech-
nologically simple and may be per~ormed in the ~ollowing
manner.
: According to the p~esent i~ention~ production o~ u~sa-
turated h~drocarbons by wa~ o~ dehydrogenation of para~in,
monoole~ine and/or alkylaromatic compounds is ef~ected by
con~acting the~ vapours ~ith the above-described catalyst
'
.. , ' ~,. ' .
- ~ :, . . - ,. . -
: . . . .. . .
. :
; : . ~ : . ., :
,
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a-t a temperature ~ithin the ran~e o~ ~rom 400 to 700C in
apparatus o~ di~erent design4 In order to increase selecti-
~ity of dehydrogenation~ the ~eed vapours are diluted wi-th
steam and/or an inert gas such as nitrogen3 argon, heliu~
In the periodic scheme o~ operation, into an app~ratus wi-th
a stationary bed o~ a granulated catalyst or with a liqui-
~ied bed o~ a small-size catalyst the s-tarting hydrocarbon
feed is supplied alon~ with t~e diluent at the above-mentio-
ned temperature and a contact time o~ the ~as stream and the
catalyst is varied within the range o~ ~rom 0.01 to 100 mi~0
~he reaction products are cooled and a~ter sepa*ation o~ -the
diluent are delivered to the fractionation system~ Duration
of passing the ~eed through the apparatus ranges from 15 sec
to 20 min. A~ter disco~ti~uation of the ~eed supply, the ap-
paratus is purged with an inert gas to xemove vapouls o~
h~drocarbons a~d then the spent catal~st is rege~erated at a
tempera-turs within the rang~ o~ ~rom 400 to 700C ~or a pe-
riod o~ ~rom ~5 seconds to 20 minutesD ~he re~neration is
effected in a current of a~ oxygen-cont~ining gas such as
air till restoratio~ o~ the cataly~t activity. ~o remove
oxyge~ ~rom the apparatus a~ter disco~tLnua-tion o~ the rege-
neration~ the catalyst is purged with steam or and iner~ gas
and ~eed is again admissed into the apparatus ~or the ~oll~w
i~g cycle.
: ~o prolong the service li~e o~ the catalyst under the
conditlons o~ dehydroge~atio~ it is possible to i~troduce,
.
,
~ ~ . - ' , ~ ., . . . . ' ,
- , . .
.. : - ~ .
:
~ 3
- 15 -
simultan~ously ~vith the feed9 a s~all amount of ~xygen (not
more -than 0.1 mole per o~e mole o~ the startin~r hydrocarbo~
feed).
Conti~uous opera-tion is obtained as a result of co~bi-
~atio~, in o~e pla~t, of -two or more reactors, wherein the
stages of dehydrogenation7 purging and regeneration are time-
-shi~tedO
It is most advisable to pex~orm the process according
-to the present in~ention in sys-tems with transportation o~
the catalyst, ~or example in a system of two ~`luidized-bed
apparatus wi-th a small-si~e catalyst~ In the first apparatus
dehydrogenation is effected under the above-described co~di-
tions. ~he sp~t catalyst via a tra~sportatio~ li~e is con-
tinuously ~ed to the oxidizing regeneration i~to the second
apparatus (re~enerator). The regenerated catalyst is recycled
back to the dehydroganatio~ zone. During transportation o~
the catalyst, it is subjected to pur~ing ~or the removal of
hydrocarbons and ox~ge~. Bppara-tus dimensions the catalyst
leYel thsrein, circulation ratio o~ the catalyst are determi-
ned by the plant capacity, composition of ths catalyst and
a~ optimal degree of the catal~st oxidation.
However, with the account o~ -the fact that irl many cas-
es the catalyst possesses the highest selectivity and acti-
vity only within ver~ short periods o~ tim~ and it is eco~o
mically efficient to use a catAlys-t with a lowered conte~t
of active componen~s capable o~ carrying sm~ll amounts o~
.
. . .. . . .
. - . ^ , , . . . -
- ~ ~ : . ~ . -- :
.. ;
' '
'
~3
~ 16 -
oxygen~ ~he mos~ suitable ~or ~omo!ercial implementation is
the ~ollowing technological embodi~ent o~ the pxocess accor-
ding to ~he present invention.
Eleated hydrocarbon ~eed ~apours along with said dilu-
e~ts are ~upplled i~to the bot-to~ section of a lift-reactor,
whereinto through a special means o~ the i~jector type a
smali-size catalyst is ~ed from the regenerator. ~he cata-
lyst is co~veyed by the stream o~ ~eed~ diluen-t and the
reaction products a~d sepaxated therefrom i~ a sepaxator
means. ~'he reaction products are ~urther puri~ied -to remove
the entrained catalys-t particles, whexeafter they are cooled,
separated Irom the diluen-t and ~r~her delivered to the se-
paration system, wherefrom the unreacted feed and intermedi
ate reaction products are recycled to the reactor.
The catalyst 9 af-ter purging~-o~ the hydrocarbons 3 iS
passed rro~ the separator, cyclones a~d fil~ers to the rege
nerator unit with a ~luidized bed o~ the catalyst~ whereinto
a~ oxygen-containing gas, e.g. air9 is ~d too. ~fter anoth-
er purging, the regenerated ca-talyst is recycled into the
bottom part o~ the reactor~ ~or pla~ts with a higher capaci-
ty, i-t is possible to combine in one sys-tem sevexal li~t-
-reactors with a comm~ regenerator and a commo~ system o~ ~
separatio~ of the reaction products~
llhe time o~ co~t~ct o~ the ~ed and the catalyst is
varied within the range o~ from 0.5 to 15 seco~ds; residence
time o~ the catalyst in the li~t-reactor and separatox does
not exceed 2 - 3 minutes.
-
,.
'~ , ' ~ ' ' ' ' '
~,: ' ' ' ;' . ,' ' ' , ~ .,
.
~ 3
- 17 ~
~ lhe proc~ss o~ d~hydroge~tion according to the present
inven-~ion undar the above-me~tioned conditions makes it
possible to provide for pla~ts with a higher unit output
~vith a high yield of the desirecl products and increased se-
lectivity relati~e thexeto. O~i~Lg to con-ti~uous scheme of
the process and constant composition o~ the r~action products9
separation -th~reo~ is facilitated along with reduc-tio~ of
losses of the products at this stage; temperature co~trol
and utilization of hea-t of the o~f-streams become more
simpleO
At the s~ne time, this mode of de~ydrogenatio~ imposes
Quite sever~ r~quir~ments on activity~ sele~tiviby a~d weax-
-resistance o~ the catalyst. Preparation o~ the catalyst em-
ployed in the process according to the present invention is
e~ected in the following ma~er.
At ~irst 9 the carrier is prepared. ~o this e~d, 96-99%
by weigrht o~ ~inely di~ided quartz sand are mixed with 1-~%
by weight o~ bicarbonate (carbonate) of sodium, potassium or
lithium, or 50-95% by weight o~ mag~ia are mI~ed with
5-50% b~ weight of ~itania, or 70 to 95~0 4y weight o~ magne-
sia are mixed with 5 to 30% by weight of alumi~a (alumi~ium
hydroxide)~ '~he resulting miæture is granulated to give pel-
lets o~ required dimensions a~d shape. ~ho granulation is
per~rrmed with the addition of water, aqueous sol~tions o~
poly~inyl alcohol, dextri~e, carboxymethylcelluloso using
tabletti~g machines~ extrusio~-type or adhesio~ granulators
of various des~g~s~ '~o pr~pare a small-size cRtalgst) a
" . . . . , : .
: ~, ~,' ~ :,
.
~3
spray drying is used alo~ with adhesion-type gra~ula-~ors~
~he resulting gra~ules are ~ried a-t a temperabure ~ithin the
range of ~rom 60 to 150C a~d calci~ation -thereof is e~ect-
ed at a temperature o~ ~rom 900 to 1,300C for a period o~
~rom 30 minutes to 6 hoursg ~he calcination duration and
temperatuxe are selected depending on the composi-tio~ o~ the
starting charged a~d rsquirements imposed o~ the resulting
carrier~
Duxing calcinatio~ o~ granules silicates o~ alkali me-
tals or tita~ates a~d alumi~a-tes o~ magnesium are formed
which ens~e a durable bondin~ o~ particles o~ silica or mag-
~sia in the caxriex granules. At a temperature o~ above
800C a phase transitio~ o~ ~ -quartæ to crystoballite is
observed.
~ he calcined granules of the porous quartæ carrier are
modi~ied by impregnation with a~ aqueous solution o~ mag~e-
siu~ ~itrate. ~he solution excess is removed by deca~ation
or evapoxation. Then the carrier is calci~e~ at a temperatu-
re within the range o~ ~rom 300 to 500C to decompose mag~e-
sium nitrate~
The thus-prepared carriers have a high mechanical
strength, increased heat~resistance. ~heir abrasion resist- -
ance is higher than ~hat o~ alumosilicate. Speci~ic surface
area o~ the carriers, depending on the composition and pre-
paration condition~ is varied withi~ the range o~ from 2
to 15 m2/g~ porosity is equal to 002 - 0.4 cm3/cm3.
.
,
~ . ,,, . , ,, ,, . :.
., - , "
. . . ' : -, : ' : . , , .:: : ~ .
:. : . .: . , .. : , , ,
~ 19 -
The -thus-prepared lot o~ the carrier o~ the re~uixed
~ractional compositio~ is poured with a concentxated solu~
tion of ammo~ium mol~bdate. To ensure a more uniform impre~-
nation o~ granules~ it is d~sirable to set the vessel Y~ith
the carrier under vacuum prior -to pouring the solutio~ the-
reinto Due to the interaction between a~mo~iu~ molybda-te
and magnesia ~he suspension is heated-up and ammonia is li
berated and evacuated ~rom the vessel. ~fter rasidence in
the reac-tor ~or 0.5 - 5 hours, water is evaporated from the
suspension at a temperature within the ran~e o~ Y`rom 60 to
180C. ~o avoid aggregation, the impregnatio~ and evapora-
-tion are carried out under continuous or periodic stirri~g
of the suspension. ~he ~aporizakion process can be intensi-
fied by setting the vessel under vacuum~ ~or this reason pre-
paration o~ the catal~st should be pre~erably e~ected in
hermetically sealed heated apparatus provided wi-th a low-
-speed stirrer ~or example in Z-shaped mixers. Completion o~
the process is determined by a rapid growth o~ temperatuxe
in the apparatus.
o prepare a polycomponent catalyst by this method, the
mass resulting ~rom o~aporatio~ is poured with an aqueous
solution o~ cobalt, nickel, iron or ma~ganese nitrate.
Impregnation and e~aporation are e~ected as described abo~e~
Impre~rna~ion with e~aporation makes i-t possible to p~e-
pare a catalyst o~ a prede-termined composition and lower con-
sumptio~ o~ the active componënts ~or the catalyst preparation~
.
;
. .
~ 20
To prep~re a polycomponent ca-talyst with a mox~ uni-
form distribution of -the active phase ~ithin the volu~e of
granules a~d with a better conlac-t among t~e compo~e~ts,
application .is effected Irom dllu-ted solutions o~ salts al
terrlatively~ i.e. repeatin~ operations o~ impregnation wi~h
each salt and a subse~uent evaporation ~or 3 to 12 timesO
Thus, in the preparation of a cobalt~molybdenum catalystl
the c~xrier is poured with a solution of c~monium molybda-te;
water is evaporated from the suspension ~nd then poured
with a solution o~ cobalt nitrate and -the susperlsio~ is
again evaporated, whereafter Impregnatiorl with a solution
of ammonium molybdate is ef~ec-ted and so on, th~ p~ocedure
is repeated ~or 3 to 12 times. As a result of a more u~i~orm
distribution o~ the acti~e phase within the volume of granu-
les and higher degree o~ eness thereof, the catalyst ac-
tivity is substantially increased, i.e. by 20 to 50%. l'he
same effect may be achieve ~ n the ~ollowing manneri After
impregnation of t~e carrier with a solution o~ ammonium
molybdate ? evaporation~ treatment with solukions o~ nitrates
of cobalt, nickel, iron or man~anese and a subsequent eYapo-
ration o~ water from the su~pension, the resulting mass is
treated with aqueous solutions of ammonia, amin~s or amino-
alcohols. ~hen evaporation of water is repeated with subse-
quent calcination of the mass under the above~me~tio~ed co~-
ditio~s. Upon treatment with ammo~ia, amines or aminoalcoho~s
, .
,
'.. ': '' '. ' . '' ' ' : '. . . ' .,:
.. . . . . .
., , . . : ., ~ . .
33
- 21 -
duri~g the prep~ration of polycomponent catal~st3) e.~. co
balt-~olybdeIlum ca~alyst, there occurs combina-tion of the
active components to complexes containing cations Co2~ ancl
Mo6~ as well as 1~I4 and OH groups which ensures a more uni-
~orm distxibution o~ t~e components o~ the active phase and
increases its finenes~ For this reason~ in suc~ catalysts
no ~ree o~ides of molybdenum ancl cobalt are ~ound (i-eO the
process o~ the preparation o~ the ca-talyst goes to its com-
pletion).
All o~her conditions being e~ualJ -the yield o~ divi~yl
and selectivity on a catalyst trea-ted~ durinO its prepara~
tion, with monoethanolami~e is about 2 -timss as ~igh as
those of a similar catalys-t prepared by a single-applica-tion
method.
In accordance with the process of the presen-t in~0~ion
after applicatio~ o~ the active components and e~aporatio~
o~ water, ~he clried mass is calcined for the ~inal ~ormation
o~ the catalyst ~or 0~5 to 25 hours (pre~erably from 2 to
6 hours) at a temperature within the ran~e of from 350 to
700C (preferably ~rom 450 to 600C). ~o avoid reduction of
the catalyst, calcination is conducted in an inert or oxidiz-
ing medium. ~o preven~ variations of the fractional composi-
tio~ of the small-siza catalyst due -to sintering of its par-
ticles, it is advisable to perfDrm calci~ation o~ said cata-
lyst in a fluiclized bed in a ciurrsnt of an inert o~ an oxygen-
-contiaining gaic;.
,
.. .. ~ . . . . .
- , , ,~ - . . .
~44f '~
- ~2 -
For a b~tter underst~nding o~ -the 1ires~-t inv~ntion
some specific e~amples illustratin~ -tha process ~or prodllc~
ing unsat-~a-ted hydrocarbons ~re given ~e~einbelow.
A carriqr is prepared in the followin~ ~a~ner. 95% by
weight of mag~esia are mi~ed with 5% by weib~ht o~` titania.
~he resulting mix~ure i5 plas-tl~ied b~J addin~ a 2~ solution
o~ polyvinyl alcohol and by -the rubbin~ method gra~ules o~`
a size o~ from 0.1 to 0~3 mm are prepared. ~he gxanules are
dried for two hours at a -temperature within -the ran~e of'
from 80 to 90C a~d calcined in a mu~fle ~ux~ace for one
hour at the temperat~re of 650C~
To prepare the catalystO -there are mi~ed a solution o~
24.3 g o~ ammonium mol~bdate in 100 ml o~ distilled water
and 70~0 g o~ the carrier prepared as above (~mpreg~ation).
As a result, there is obtained a suspension~ where~rom water
is remo~ed by evaporation with a progressive grow-th o~ -tem- -
perature up ~o 150C. ~he resulting mass is subjected to
calci~ation i~ a current o~ air at a temperature o~ ~ro~
590 to ~00C ~or the period of 25 ~ours. ~ catalyst is thus
produced having the following compositio~: ~oO3 22% by
weight9 MgO 74.1% b~ weight, TiO2 3~9% by weight~ Specific
sur~ace area of the catal~st is 65 m2~g~
I~to a r~ackor with a fluidized bed of the thus-prepar-
ed catalyst (fractio~ with a par-ticle s~ze of from O.l to
0.~ mm~ at -th~ temperature 590C there are alter~atively fed
, . . . . .
- ~ . . ' , .
' ; : ~ ,' ', ' . ~ '
. ~ . . .
. .
n-butane with argon, and air~ Molar ratj~o betwee~ ~-butane
and argon is equal to 1:10. Space velocit~ of the supply is
~50 hr 1 ~nd the supply duration is 0.5 minutes. ~he cotal
dura-tion o~ the process is 35 hoursO
Conversion of n-butane is 4892%, the yield o~ butadiene
is 36.2% wi-th selectivity relative thereto of 75~1~o and re-
lative to -the total o~ butylenes-butadiene 85~4%~
Example 2
~ o prepare a catalyst a solu-tio~ o~ 10.0 g o~ ammoniu~
molybdate i~ 20 ml of dis-tilled water is mixed with 16.0 g
of the carrier prepared in the foregoin~r E~arGple lo '~he re-
sultin~ suspension is subjected to evaporatio~ at a tempera-
ture wi-thin the range o~ from 80 to 130C. '~ha calcina~-ion
is ef~ected at a -temperature of ~rom 680 to 700C in the
atmosphere o~ nitrogen ~Qr 0~5 hourO A catalyst is thus pro-
duced and its composition is the ~ollowing~ MoO~ 35~0 b~
weight9 MgO 61.7% by weight, iO2 3.3% by weigh'c~ Speci~ic
surface area of che catalyst is 41~3 m2/g~
~ nto a reactor with a ~luidized bed of this catalyst
at -the temperature of 550C there are alter~atively ~ed n-
-butans in a mixture wi-th ar~on~ and air. Molar ratio betw~-
en n-butane and argon is 1:13. Space velocity o~ -the feed
supply is 105 hr 1, duratio~ of the supply is 0.5 mi~ ~pace
velocity of the air supply is 1,350 hr 1 and duration o~ the
supply is 0~5 mLn. ~he t~tal dura-tio~ o~ the process is
5 ~ours.
~: : ~ . . .
-- 2~L~ _
Conversion o~ n butane is 30.2%, the yield of bu-tadie~e
is 23~2,;~ with selectivity relative thereto o~ 764~ a~d re-
lative to the to-tal o~ butylenes-butadie~e o~ 85.8%.
~xample ~
'l'o prepare a ca~alyst a solution of 24.3 g o~ ~monium
molybda-te in 100 ml o~` distilled, wa-t~r is mixed with 70~0 g
of magnesium-aluminium carrier consistin~ o~ 70% by wei~h-t
of mag~esia and 30% by weight o~ alumi~a~ (Preparation o~
the carrier is e~ected in a ma~ner similar to that descri
bed in the ~ore~oi~g Exa~ple 1). ~he sta~es o~ evaporation
and calci~atio~ are conducted under the conditions o~ Ex~n-
ple 1.
A catalyst is prepared having -the .following composi-tion:
~oO3 2101% by wei~ht, ~gO 55.3% by weight, A1203 23.6% by
wei~ht. Speci~ic sur~ace area of the catalyst is 16~3 m2/g.
Into a reactor with a ~luidized bed o~ ~he catalyst
prepared as above at the tempera-ture o~ 595C there are al-
ternatively added ~-buta~e in a mixture with steam, a~d air.
Molar ra-tio be~wee~ n-buta~e and steam is 1:30. Space velo-
city o~ the mi~ture supply is 40 hr 1 a~d the supply duration
is 0.5 min. Space velocity of the air supply is 450 hr 1 a~d
the supply duration is 005 min. ~he total duration o~ ths
process is 4 ho~rsO
;~ Conversio~ of n-buta~e is 24.0~v~ the yield of butadiene
is 11.0% with sele¢tivity relative thereto o~ 45~9% and rela-
tive to the total o~ butyla~es-butadiene o~ 5103%.
~ ~ .
:
. ~ . . j . ~ ................ .
.
~: ~' .....
~ 25 ~
Use is made o~ -the catalyst described in the ~oregoi~g
Example 1~ ~he dehydrogenation process is per~ormed u~der
the conditions o~ Example 1. As -the starting ~eed use is
made o~ n-butylenes (the conten.t of n-bu-tylenes is 99~8% b~
volume), and o~ steam as a ~ehicle. ~he total duration of
tha pxocess is 38 hoursO
Conversion o~ butylene~ is 85.1%~ the -~ield o~ bu-tadie-
ne is 79.5% with selectivity rela-tive -to butadie~e o~ 9~.5%.
~ o prepare a catalyst, use is made o~ 100 g o~ a car-
rier with a particle size o~ Ool ~ O~ mm consisting of 75~O
by wei~h-t of magnesia and 25% by wei~rh-t of'-titania and cal-
cined at the temperature o~ l,000C~ a solution o~ 32.9 g o~
cobalt nitrate in 400 ml o~ distilled water (solutio~ ~) and
a solutio~ o~ 20.0 g o~ ammonium molybdate in 400 ml o~ di-
stilled water (solu-tion B).
Preparation o~ the catalys-t.is e~ected by alternative
t~o-s-tep application o~ the catalyst components (cobalt and
~ molybdenum) according to the ~ollowing scheme:
; l-st step: solution A is mixed with the carrier and
water is removed from the resulting suspension by evapora-
tion at a te~perature within the ra~ge o~ ~rom 80 to 120C;
2-nd s.~ep:.the mass obtained in the ~irst stage is
mixed with solutioll B and water is removed from th~ result-
ing suspensio~ by evaporation at a te~perature wi-thi~ the
range of from 80 to 150C.
.
. .: - .. . .
~Ll~L4~3
-- 26 --
The resul-ting mass is calcined a-t the temperature o~
550C in a suspended bed in the stream o~ air for 5 hours.
A catalyst o~ the ~ollowing composi-tion is obtained:
MgO 66.550 by weight, ~iO2 22.2% by wei~h-t, CoO ~.0~0 by
weigh-t, MoO3 7.3~ by weight.
Specific surface area o~ the catalyst is 12.3 m2/g.
~he dehydrogenation process on the thus-prepared catalyst
is co~ducted under the co~ditions described in the ~ore-
~oing Example 2.
Conversion o~ n-butane is 25.0%, the yield o~ buta-
diene is 6.1% with selectivity rela-tive thexeto o~ 24~2%
and relative to th~ total of butylenes-butadiene o~ 37.5%.
A catalyst is prepared ~ollow~ng the procedure descr-
ibed i~ -ths ~oregoing E~ample 5~ e~cept that ~pplication o~
the active componen-ts (cobalt and molybdenum) is e~ected
in 4 and 12 sta~es according to the following two schemes:
l-st scheme: ,
In the l-st stage 200 ml o~ solution A are mLxed with
the carrier a~d water is remo~ed ~rom the resulti~g suspen-
sion by evaporation at a tempsrature within the range o~
~rom 80 to 120C;
I~ the second stage the mass resulting ~rom the ~-st
stage is mi~ed with 200 ml of solution B a~d wa-ter is remo-
ved from the r~sulti~g suspensio;~L b~ evaporation o~ ~rom 80
to }50C;
'
,
- : . . :
': . .:
. . . . . ..
~:' - , , ,
1~144Q3
27 _
I:~ the 3-rd s tage the ~nass resulting ~rom th0 2-nd
s-tage is added vlith the remaining portion o~ solu-tion A
and water is evaporated at a tem~erature within th~ ran~e
o~ ~rom 80 to 120C7
In the 4~th stage the mass resulting from the 3-d
stage is added with the remai~ing portio~ o~ solution B a~d
water is removed by evapora-tion at a temperature of ~rom ~0
to 150C.
'~he mass obtai~ed in the ~ourth stage is calcined at
the t~mperature o~ 550C ~or 5 hour~ in a stream o~ air.
2-nd sch~me:
The numb~r o~ stages is 12; L~ each uneve~ stage there
are added 67 ml of solution ~, in each even stage there are
added 67 ml o~ solution B~ I~ each stage wa~er is removed
~rom the resulting suspension by way o~` evaporation and
a~ter the ~inal stage the resulting mass is subjected to
calcination at the temperature of 550C f~r 5 hours in a
stream o~ air.
~Characteristics o~ the catalysts prepared in the l-st
;and 2-nd schemes as well as the results o~ dehydroge~ation
processes carried out under the conditions o~ E~ample 2 o~
the catalysts prepared as described hereinbe~ore ~re shown
in t~e Pollowi~g Table 1.
. ~
4~3
~D ~ . ~ rJ
E-l ~ a),--¦ ~ ~ --~t
h, ~ ~ R ~ ~1)
, ,0 ~
C~ ~c
~1 ~ o ~
$ CQ ~rl ~ ~ C)
~ 0,~ ;1
rl C) O ~rl
d q-l h ~ .
o a~
~D ,1 ~,
h ~d
a) ~ a~
~ '~ ~ ~
F:l h ~
~ Ci~
o-,l I a) ~ ~
a~
u~ . ~ ,~
. , .
r~
~ ~ o C~
; ~ ~ O
~ . ~ r~ O~U
~ oo
~,1 E~l O ~i
4 ~ C) C' ~-1
i ~ o ~0
~ V ~ ~ ~D ~D
,~
~ ' .
; ~ O H H
.
~ ~7 :-
,:
, . - . , . . . . . - ., ~ , . .
, `'~ . . " ' ' .
.: ` . .. . .
:. : , - , ~ - :
,
-
- : ,~ .
, : . . . :, .
~44~3
-- 29 _
~Z
A catalyst is prepared ~ollowi~ the procedure descri-
bed in the ~oregoi~g ~xample 5~ except that z~ter applica-
tion o~ the active componen-ts the resulting ma~s prior to
calcination is treated with an a~u~ous solution o~ ~nonia,
an amin~ or aminoalcohol. From the resultin~r suspensio~
water is removed at a temperature withln the ra~e o~ ~rom
60 to 180C and the thus-obtai~ed mass is calci~ed at a
ternperature within the range of from 540 to 560C ~or 5
hours in the air atmosphere.
Charac-teristics o~ the thus-prepared catalyst~ as well
as the resul-ts o~ the dehydro~enation process p~r~ormed
under the condi-tio~s o~ Example 2 hereinbe~ore using the
catalyst prspared as above are given in '~able 2.
Preparation o~ a catalys-t is carried out following the
procedure described in the ~oregoing ~xample 6 (2-~d
scheme)~ e~cept that i~s~ead of the solu-tion of cobalt ni~
trate for the preparation o~ the catal~st use is made of
one o~ ths ~ollowi~g solutions:
(1) solution of 6302 g Of nickel nitrate in 400 ml of
distilled water;
(2) solution o~ 74.4 g o~ iron nitrate in 400 ml of
dis-tilled wal;er;
(3) sol~tjion of 62.4 g of ma~ganese nitrate in 400 ml
o~ distilled waterO
:: :
:
r-l V~ P~ ~rl ~H ~ Lr~ r~ a~
,D h ~ ~ J ~ r~ ~ N
~ .~ ,~ 1
h ,1 ,~
~ U~ ~ N
s:~ ,1~ ~7 O'~ \ ~ r~ r~
o , ~t ~t ~ u~ r~
~ ll
~
~ ,1~ ~,~ r ~ ;i
O . I q ~ ~ ~ . O oo O
o ~ ~ ~
~ ~ ~ co ~ 0 ~D
r~
P~ ~ ,I t~ ~ r~
u2 cq ~I r~ D r~
,~ s:l u2 E~ (U 0~ I r~
u~ c~ r~
h h O ;t~
P
co
o o C~ r-~ ~ ~ r~ ~
, O . cO cO r-~ cO
~Q ,~ .,1 ~ i ,
u~ E~ ~
O ~ o
~O ~0 ~ D
C~ C~ ~i ~ D
q~ ~ ~.
'~ u2 ~ ~~
~1 ~ ~ ~ o ~ ~ h
~Q O c~ O ~ O O ~ q:~ O E~0 4
,
h ~ o c~ o F ~ o ~ ~ o
a~ ~ ~ a5 tl~
~ ~, ~o ~, ~ 0 ~~ 0-~
a~ , . ~-~ O~ i
P:~ ~ ~ 01 ~
~ :. . ~ ,~ ~ r~ ~ Ll~
- ,
:
~ , ' ' ` . . ' `
-, . . ..
' ~ , ,
- : . , . ; ; ~ ,
::
~ 3
- 31
I~ all cases use is made of a solu-tion o~ 40~0 g o~
ammonium molybdate in 400 g distilled watex.
~ he dehydrogenation process is conduc-ted uader the con-
di-tio~s described Ln ~Xample 2 hereinbefore. Charac-terist-
ics of the catalysts and res~ ts o~ -the dehydrogenatio~
process are shown i~ the ~ollowing Table 3~
Preparation o~ the catalyst is effected ~ollowing the
procedure described in Example 6 hereinbe~ore (2-~d sche-
me)~ e~cept that the carrier employed for the preparation
of the catalyst is calcined at the temperature of 1,200C;
after impregnation and dryi~g the carrier is agai~ calci-
ned at the temperature of 350Co
~ he ~inal catalyst has the following compositio~: CoO4.8% by weight? MoO3 903% by weigh-t, ~gO 64.5% by ~Jei~ht~
i2 21,~% by weight~
Speci~ic sur~ace area o~ tha catalyst is 15.0 m2/g,
~ he process o~ dehydrogenation o~ n-butane i5 C onduct-
ed conti~uously ~or 1,000 hours~ ~he data are gi~en i~
~able ~ hereinbelow~
Upon addition of oxygen to -the starti~g feed in the
stage of dehydrogenation in the amount of 0~09 mol/mol of
n-butane under the conditions of the ~oregoi~g Example 1,
co~version o~ n-butan~ is e~ual to 40~8%~ the yield of bu-
tadiene is 26~4~o with the salectivity relative thereto o~
64.7% and r~latiYe to the total o~ butylenes-butadiene o~
73.0Yo. -
: ~::
: -i-: : , . . . , , ,; ,
. . . ~ . . , . , :
~ L~ 3
,dæ K~ O ~
~ .,~ ~ ~ ~D ~
~ r~7 r~ ~ ~ ~ ~D r~
F~ .
r~ P ~ ~ :
Pl Q " ~ . ~
g CQ r~
.,1 a~ o ,~
~ . ' s:l Fl~d .
~b311 ~ I
P~
q~ ,~ ;t C~
OJ o~ Oi
C~
.
,.
N~ N~ ~ ~
. O t~ O N (~1 N
:~ ~1 ~0 I I ~
q~ P O ~
4 ,j O I (U I
~ ~1 ~ ~
V r~ oN IS~ ,~ 0
~` ~ E-l ~
c~ ~ 2 ~ N N
,
~i
'
~ o
;~ ~3
~r~ r ~
~ ~
r-l r~ 1~ r3 a.~ u~ ~ ~0 ~\;:1~ r-l ci~
(D U:2 1:1 ~ ,C~ r~
r-l ~rl
~ I~
E-l ~ Lr~ OLS~ 1 O a~
G'~ P r~~ 3 ~D ~ ~ , L~
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O ~ ~ J ~ItU r-l(U rl r-lrI
h O
O rl I a) ~ 1 ~ N ~J
c~ u~ sl sl
rl a~ ~ O ~ U~ o O O o
~d ~rl ~rl ~ O O ~1 O C~ O t~
~::; h
10~ ~ ~ ~
G'~ ~ U2 h ~
~ ~ Lt~ ~ Lr\ u ~ u~ o! o o o
,s:¦ ~ ~ s l O O O O O O ~ I
h
4~ O OLr~ O 1~ O O O
~rl ~ -
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~ r~
~ ~ ~ g g P g P g O ~ s:l .. ..
H rc I ~ S ~ 3
Iq-1 .
(D O a~
P P~
~17 4 4 r l I O O C~ O O U~ O O U~
~ o~ ~ J CO O ;;i' ~
U2 -1 .q M
O~V : ' .
~-~1 h ~J O O O Ll~ O O O O
~1) ~ ~ CS~ O
s:l E3 3 1~ Lt~ C~
Q ~ . .
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, . . - .. .- -: ~ -
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~: ' ' ' ' " ' ' ' .' " -' ' .: . ; ., : ' : . ; : , ' : ' '
: ~ ~ . ....
-- 3'.~ ~
xclmple 10
'~`he d~hydrogenation process i.s carried out using the
catalys-t described in the ~oregoing Example 9~ ~s the s-tart-
ing ~eed use is ~ade o~ ethylbenzene. ~he data o~tained are
given in -the following ~able 59
Upon addition of oxygen to the st~rting ~eed in -the
s-tage o~ dehydrogenatio~ in -the amoun-t o~ 0.09 mol/mol o~
C6Elo undor the conditions described in ~x~nple 3 hereinbe-
~ore, conversion o~ ethylbenzene is equal to 97.~%, the
yield o~ styr~ne is 85~4% with the select.ivity relative
th~reto of 87.8%~
~xamp,~le 11
~ he dehydrogenation process is co~ducted usi~ -the ca-
talyst described in ~xample 9 hereinaboveO As the starti~g
feed use is made of ethyltoluene. ~he process i~ carried out
at the temperat~re o~ 5~0C 7 space velocity Qf the supply o~
ethyltoluene o~ 40 ~r 1~ molar xatio between eth~ltolue~e
and argo~ equal to 1:9, dehydrogenatio~ duration of 1 minute,
space velocity o~ air supply at th~ stage o~ regeneration o~
490 hr 1, re~a~eratio~ duratio~ of 1.0 minute~ Co~version o~
eth~ltoluene is 81~1%, the ~ield o~ vi~yltolue~e is 70.6%
with the selQctivit~ relative thereto o~ 87.3%.
~ '
The dehydroge~ation process is co~ducted using the ca-
talyst described in the ~oregoing Example 9~ ~s the starting
~eed use is made o~ iso-pentane with the purity o~ 98% by
~, .
.
, . :. ~
' ~ , '
~o 9~ IL ~3
rl
~ 0
~ ~1 ~ O O
c) ~ a~ c:) c~ ~ Lr~ ~
~ I ~ ~ co c~
a~ 0 ~
u~ h ~n
~ q~ ~
O Q~
o ~ r~ o
a) O ~ , . ,
~ Lr~ ~ ~ ~ o
r¦ ~ ) 1~l (u t
~Ul
h ~ ~ ~ ~I
s:~ o ~ ~ cr~
v ~n l',a ,1~ ~ ~o co
d g a~ ~
a~ ~rl ~1 O Is~ O O O
50~ rl ~ ~
~7 ~ ~1 0 ~ O ~
0 ~
Lr~ ~rlP~ OOOOO
~ c~ O O O O
~ ~ ~ ~ (U ~ ~ ~ .,
c~ o n h~
I ~
o o
~-,~
~ ~ ~ u~ o ~ O O
rc~ r O r--i r--l O
l l
~d ~
~ 0
~ h ,~ ~~ C~ a~ .
c~ P~ o - .0
r~ $ ~ ~r~r~ ~~¦ r~
13 0 N ~IS
I q~ q~ I r~
a~ o o ~1
~ hh~
a~
o rl ,QI h 0 o Lr~ o O ~
~ oO
u~ n
I ~ I
o o ~ ,~
~ a~ ~
,~,~0 oOOOO
5: ~ ~ h o u~ D O
. . . -
. .
. .
' . .,. ~ ' ' . . .'' '
: - : . . - : . . . .
: ~ :
~ 36
wei~h-t~ ~he process is conduc-ted at the -te~perature o~
550C3 space veloci~y of iso-p~ntane supply of 95 hr 19
molar ratio bet~Jeen iso-penta~e and argon equal to 1~13,
dehydrogenation duration o~ 0~5 minute; space ~elocit~ o~
the air supply o~ 50 hr 1 at -the stage o~ regeneratio~3
duration of the rege~era-tion is 0.5 ~i~uteO Con~ersion o~
iso-pen-tane is 28.9%, yield o~ isoprene is ~.2% with the
selectivity relative -t~ereto o~ 14.5% and relative to t~e
total o~ isoamylene-isopre~e o~ 22~5~o~
xa~n~le 1~
'l`he dehydro~enatio~ process is conducted usin~ the
catalyst described i~ ~xample 9 hereinbe~oreO ~s the start-
ing ~ead use is made o~ the isopen-tane-isoamylene fraction
ha~ing the ~ollowing compositio~, per ce~t by weight: 2-me-
thylbutene-l 1.56; 2-~ethylbutene 2 49.29; 2-meth~lbu-tene-3
30.35~ isopentane 8.28; ~-pentane 4000, ~-pe~-tenes 3~92;
; isopre~e 2060.
: ~he process is conducted at -the temperature o~ 545C
~ space rate o~ the ~eed supply o~ ~1 hr~1, molar ratio o~
i-C5 to steam e~ual to 1:7, dehydrogenation duration of
0.5 minute~ space velocity o~ the air su~ply in the regene
ration stage o~ 280 hr-19 re~enera-tion time ~f 0,5 minute.
Convarsion of the isopentane-isoam~lene fraction is 59~4%,
the yield of isoprene is 41~4~o with the selectivity relative
.~ thereto of 69.7%.
.
,~
''
.
.
- ~7 -
x~llple 14
Preparation of the catalyst is per~ormed ~ollo~Jing the
procedure described in the ~oregoing Ex~nple 6 (2-nd scheme).
~he carrier employed ~or the catalys-t preparation consis-ts
o~ 50% by weight of magnesia and 50~0 by weight o~ titania;
the catalys-t carrier is calcined at the temperatur~ of
1 400C
A catalyst is thus obtained with the ~ollowing compo~i-
-tion: MgO 4302~o by weight, ~iO2 43.1% by weight~ CoO 4.'7%
b~ weight, MoO3 9.0% by weight.
Specific sur~ace area of the catalyst is 1~9 m2/~.
~ he dehydrogenation process usi~g the resulting cata-
lyst is conducted under the conditions of ~xample 2 herein-
be~ore.
Conversion o~ n-butane is 1509%, the yield o~ butadie-
ne is 6.5% with -the selectivity relative to b~tadiene of
40.5% and rela-tive to the total o~ butyle~es butadiene o~
~4.7%0
Exam~
Preparatio~ o~ the catalyst is e~fected followi~g the
procedure described in Example 5 hereinbefore, except that
the carrier employed for the catalyst preparation consists
0~ 95YO by weight of magnesia and 5% by w~ight o~ alumina
a~d the removal of water ~rom the suspension is per~ormed
under vacuum at a tsmperature wlt~in the range o~ from 60
.~ .
.. .: , :
..... . ., ~. . . -
to 70PC. ~ ca-talyst is thus prepared whlch has the follow-
ing composition~ MgO 78.8% by wei~ht, A12O3 4.1% by ~^7eight,
CoO 6~2~ b~ wei~ht, MoO310.9% bv ~eight~
Spec.ific surface area of the catalyst is 17.6m2/g.
Dehydrogenation process ~ith the use of the resulting
catalyst is carried out under the conditions of the fore-
goina Example 2.
Conversion of n-butane is 24.3%, the yield of but-
adiene is 5.6% with the selectivity :relative thereto of 23.1%
and rela-tive -to the total of butylenes-butadiene of 29.7%.
Example 16
As a carrier for the prepara-tion of a catalyst use is
made of a porous crystalline silica (fraction with the par-
ticle size of O.l to 0.3 mm) calcined at 1100C, modified
with alumina. The modification of silica is conducted by
~: impregnation thereof with an a~ueous solution of magnesium
nitrate, followed by the removal of excess solution, drying
at a temperature within the range of from 110 to 120C and
calcination at a temperature of from 370 to 400C. The con-
tent of magnesia on silica is varied by appropriately adjust-
ing concentrations of the impregnating solution. The result-
ing carriers have the following characteristics depending
on the content of magnesia:
.
.. .. . . . ..
4~3
_ ~9 ~
Magnesia content as Specific Bulk vJei~ht,
No.calculated for the sur~ace 3
carrier7 wto% area, m~/g ~r/
1 1.0 0.6 0~80
2 1208 706 0.92
3 20.0 801 0.94
To prepare the catalyst7 a solution o~ 24.0 g a~monium
molybdate in 500 ml of distilled wa-ter i5 mixed with 100 g
of the carrier. From the resulting suspe~sion water is re-
moved by evaporation at a temperature within the ran$e o~
from 80 to 150Co ~he~ the resulting mass is mix~d with a
solutien of 39.5 g of cobalt nitra-te in 500 ml o~ distilled
water with 100 g of th~ carrier. From the resulti~g suspen-
sion water is removed by evapora-tio~ at a temperature of
f~om 80 to 120C and ~he thus-produced mass is calcined at
a temperatura of from 540 to 560C~ ~he resulting catalysts
have the follo~i~g characteristics depending on the starting
carrier employed
Conte~t of the active com~ Catal~st Catalyst
No po~e~ts as calculated ~or specific bul~ ~eight,
the catal~t, wt.% surface~ g/cm~
CoO ~0area9 m /g
:,
1 7.~ 8.8 1.~ 0O9
2 4.6 8.7 7.6 1~0
3 5.8 5~8 8~2 1~1
.
.:
~- , .- , ..... . .. ....
". .. ' "' ' ' '. ' ... ' ' ~. '.' ,., . , : , ,'
: - ... . ., : . -
. ~ - , . . . ,:
.. . ,; , ,. . : . ... ... . . ..
: , . . ;. .
-- ~o -
'~he process of dehydrogena-tion is carxied ou-t in a
reac~or similar to -tha~ described in -the foregoirlg ~xa~ple
1. Usi~g the catalyst No.l (see the above ~able), t~ough
the reactor at the temperature o~ 570C i-pe~ta~e i5 passed
at the space rate o~ 105 hr 1 a-t the molax ratio o~ i-pen-
tane to helium of 1:13. r~he duxation o~ i-pentane supply is
1.0 minute. Space velocity o~ the air supply in the re~ene-
ra-tion stag~e is 17350 hr 1 with the supply duratio~ o~ 1.0
mi~ute. '~he total process time is 5 ~ours.
Conversio~ o~ i-pe~tane is 7~7%9 the yield o~ isoprens
is 3.6% with the selectivit~ relat.ive -thereto o~ 46~8~o a~d
xelative to th~ sum o~ isoamylenes-isoprene of 58.6%.
Usin~ the catalyst No.2, through the reactor at the
temperatura o~ 550C n-butane is passed at the space veloci-
ty of 80 hr 1 at the molar ratio between ~-butane and the
diluent o~ 1:15. As the dilue~t use is made o~ a mixture o~
80% by weight of steam and 20% by weight o~ nitrogenO ~he
duration o~ n-butane supply is 1 sec. Space velocity o~ the
air supply is 19200 hr 1 with the supply duratio~ o~ 0.5 mi-
nute. ~he total duratio~ o~ the procsss is 0.5 hourO
Converqion o~ ~-bu~ane is 17.8%, the yield o~ butadie-
ne is 8.7% with the selec-tivity relative thereto o~ 48.9%
a~d relative to the total ol butylenes-butadiens o~ 54.3%.
Using the ca-talyst ~0-~7 through the react.ar at the
temperature o~ 560C with ~he space velocity of 90 hr 1 a
. .
. - , . , - - - . ,
. - : .- . ,
. . . ... .. ~. .
.
.
- L~ 3
mixture o~ hydrocarbons is paased consis-ting of 21~1~o by
weight o~ ~iethyltoluene, 6506% by weight o~ ethyltoluene7
ll~9~o by weigh-t of ethylbenzene and 1.4% by weight of tolue-
ne. ~he molar ratio be-tween the hydrocarbon.~eed and nitro-
gen is equal to 1:9. D~ration o~ the ~eed supply is 1 minu~
te. Space veloci-ty o~ tha air supply i~ the stage o~ rege-
neration is 900 hr 17 supply duration is 1 minute. r~he to-
tal duration o~ the process is one hour.
Conversion o~ ethyltoluene is 53.2%, the yield o~
vinyltoluene is 42.6% with the selectivity relative there-to
o~ 80.1%. ~he yield o~ divinyltoluene is 2~1~o~ the yield of
vinylethyltolue~e is 1~6%9 the yield o~ styre~e is 12.6% as
calculated ~or the total star~ing hydrocarbon ~eed.
'. ~
.,, ~ ~ ,. . . .
: . . : . . , : . :
