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Патент USA US2412675

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2,412,675
Patented Dec. 17, 1946
UNITED STATES PATENT OFFICE
2,412,67 5
IS ORIERIZATION 0F SATURATED
HYDROCARBONS
Joseph D. Danforth, Riverside, Ill., assignor to
Universal Oil Products Company, Chicago, Ill.,
a corporation of Delaware
Application February 11, 1943, Serial No. 475,515
8 Claims. (C1. 26o-683.5)
l
This application is a continuation-in-part of
my co-pending application Serial No. 370,323,
ñled December 16, 1940.
The present invention relates to the catalytic
2
in substantially liquid phase is passed through a
contact zone containing a metallic halide of the
isomerization of saturated hydrocarbons such as
Friedel-Crafts type under conditions of tempera
ture and pressure such that an amount of cat
alyst adequate to maintain the desired catalyst
butane, pentane, hexane, naphthenes such as
cyclohexane or hydrocarbon fractions boiling
dissolved in the liquid hydrocarbon.
the course of reaction due to depletion or con
packing materials.
concentration in a subsequent reaction zone is
The cat
alyst containing solution from said contact zone
Within the gasoline range containing substantial
is reacted in the presence of a hydrogen halide
quantities of these hydrocarbons. More specifi
cally it deals with an improved isomerization 10 in a reaction zone maintained under conditions
of temperature and pressure sufficient to convert
process wherein the catalyst in the reaction zone
a substantial portion of the saturated hydro
is constantly being renewed by the introduction
carbons to isomers thereof. The desired concen
of fresh catalyst to said zone in solution in at
tration is maintained in said reaction Zone by
least a portion of the hydrocarbon charge.
The previously proposed processes for the 15 continuously supplying thereto small increments
of fresh catalyst from a bulk supply in the first
isomerization of saturated hydrocarbons with
contact zone in solution in at least a portion of
catalysts of the Friedel-Crafts >type generally one
the saturated hydrocarbon charge.
Y
or more halides of aluminum, zirconium, zinc,
To obtain satisfactory results in the present
iron and the like, in the presence of‘hydrogen
halides consisted of passing the hydrocarbons 20 invention it is essential that some means be uti
lized to retain in the reaction zone at least a
and hydrogen halide through a fixed bed of gran
portion of the catalyst being introduced into said
ular catalysts either alone or deposited on solid
zone in solution in the hydrocarbon charge. Suit-A
supports under conditions of temperature and
able materials for this retention of the catalyst
pressure such that a portion of saturated hydro
may comprise granular particles or shaped bodies
carbons are converted to isomers thereof. One
of solid materials such as rachig rings, burl
of the most serious disadvantages in these proc
saddles, crushed fire brick and other Well known
esses is the decrease in catalyst activity during
During the initial period of the operation only
tamination of the active catalytic materials pres
ent. Due to the continual change in catalyst ac 30 a small portion of the catalyst entering the re
action zone is removed in the reaction products
tivity during the operation, it is necessary to
from said zone, the remaining portion adheres
vary the operating conditions to compensate for
to the surfaces of the packing materials disposed
losses in activity in order to maintain a suitable
within the zone. As the operation continues, the
conversion of the saturated hydrocarbons to
isomers thereof. This variation in operating con 35 packing material will become saturated and a
point will be reached Where the amount of cat
ditions introduces additional diñiculties and com
alyst being removed from the reaction zone either
plications in the operation and results in a de
in the reaction products as free catalyst or com
crease in the commercial applicability of the
bined with a portion 0f the hydrocarbons is sub
proposed isomerization processes. In spite of the
adjustment of operating conditions, the catalyst 40 stantially equivalent to the amount being intro
activity decreases to an extent Where it is no
longer commercially feasible to continue the op
eration which necessitates discontinuing the
isomerization and replenishing the catalyst in the
reaction zone. Various modiñcations of operat
ing procedure, such as the use of a plurality of
reaction zones have been proposed but these
duced into said zone in solution in the hydrocar
bon charge. After the establishment of this
equilibrium the catalyst concentration will be
maintained substantially constant throughout
45 the remainder of the operation. This catalyst
concentration will be in substantial excess of
that in the incoming catalyst containing solution
due primarily to the retention of a portion4 of the
catalyst by the packing materials in the reac
modifications, multiply to a considerable extent
the operating difûculties encountered.
The present invention provides an improved 50 tion zone.
In one speciñc embodiment, the present in
method wherein a more continuous and substan
vention relates to a process for isomerizing sat
tially more economical process than has been
urated hydrocarbons which comprises passing a
hitherto possible is obtained.
stream of said saturated hydrocarbon in substan~
In accordance with the present invention at
least a part of the saturated hydrocarbon charge 55 tially liquid phase through and in relative move
2,412,675
3
ment to a bulk supply of metallic halide catalyst
4
The catalyst disposed within tower I4 may
of the Friedel-Crafts type in a ñrst zone under
comprise aluminum chloride, zinc chloride, zir
conditions such that only a portion of said cat
alyst is issolved in said liquid hydrocarbon
stream, commingling the catalyst containing
conium chloride either alone or in admixture
effluent from said ñrst zone with a hydrogen hal
ide within a second ,- zone maintained under
isomerizing conditions and converting a substan
tial portion of said saturated hydrocarbons to
isomers thereof in said second zone in the pres
ence of the catalyst supplied thereto froml the.
ñrst zone.
I have discovered that by introducing the
catalyst into the reaction zonein _solution in, at _
with one another or any other well-know Friedel
Crafts type isomerizing catalyst which possesses
sufficient solubility in the hydrocarbons being
charged, under the particular conditionsof tern
perature and pressure maintained in tower I4 to
dissolve an adequate amount to maintain the
10 desired catalyst concentration in the subsequent
reactor.
For. a completely continuous operation, it is
desirable to have a second tower similar to tower
Mithrough which theA hydrocarbon stream may
least a portion of the hydrocarbon .charge the 15 lne-converted while tower I4 is being reñlled with
catalysts. The emuent solution in tower I4 is
desired amount of catalyst may be transferred
directed through line l5 containing valve I6 into
. from the bulk supply to the reaction chamberat
reactor VI wherein it is commingled with a hy
comparatively low temperatures. If, on the
drogen halide obtained as hereinafter set forth.
other hand, vapors of the hydrocarbon charge~
are used as a carrying medium, higher tempera
20 The temperatures and pressures maintained in
tures4 must,_be utilized-to carry an equivalent
amount- ofgcatalyst.` The `use of higher tem
peratures causes considerable,decomposition of
the charging stock in the catalyst supply zone
reactor I'I‘are dependent upon the hydrocarbon
and. Catalyst being utilized in the operation.
When utilizing aluminum. `chlorideas, the isom
erizing catalyst this temperature will be ordi
resulting ,in increased _catalyst consumption due
to thevformation of hydrocarboncatalyst com
plexes by the reaction of the catalyst with the
narily within the approximate range of 50 to 300°
F. With various other catalysts good conver
sions are obtained upto temperatures of about
decomposition products.
40095F. Thefpressure is dependent upon the hy
Utilization _of liquid phase transfer also pro
vides a simple method of regulating the rate of
catalyst introduction._ This rate will be pri
marilydependent upon _the _temperature in the
supply zone which _will control the solubility of
the catalyst in the hydrocarboncharge. With
vaporphase transfer, the rate of catalyst in
troduction willbe dependent not only on the
drocarbonV phase desired in reactor I‘I. I have
found that the isomerization reaction will pro
ceed-satisfactorily in the liquid, mixed or vapor
temperature but also on the pressure which con
siderably increases complexityvof vthe operation.
Furtherfeatures and advantages of the pres
ent ¿invention will be evident from a considera
tion of the follow-ingpdescription of the accom
panying _diagrammatic drawing of one type of
apparatus» in which the objects .of the invention
may> be, accomplished.
For- simplification such units as heat ex
phase».
In the preferred mode of operation, reactor Il
is packedv with any» of `the well-known» packing
materials such as rachig rings, berl saddles,
crushed fire-brick, etc. This packing provides a
surface -uponwhich a portion of the catalyst may
deposit so that vatv all» times during the opera
tion the amount of »catalyst present in` reactor I‘I
40 is> greater than that being introduced in the hy
drocarbon stream from-catalyst supply tower I4.
As a specific modification of the operation, a
portion of> the-butane leaving pump 3 may be
directedfto line 6 vcontaining lvalve -I into heat
ingv coil_v8-«disposed within furnace 9 wherein it
is >heated, -to the _desired temperature and trans
chgnrgers;` condensers, reboilers, etc., which are
not essential to the lunderstanding of the de
ferred through line _dI-containingvalve 42 into
scription have been eliminated.A
reactor I'I.~ Thisy method of operation increases
Referringto the drawing,_ a saturated hydro
to Ía considerable vextent the ,flexibility of the
regulationorthe temperature and catalyst con
carbon,v forexample, normal butane, is intro
duced through line I containing valve 2 into
centration within reactor; I l. The amount of
catalyst-'removed -from tower I4 is dependent pri
pump 3 which discharges _through line `¿l con
marily'upon the solubility of the catalyst in the
taining vvalve i_5 into heating coil I0 disposed with
hydrocarbon -»and the amount of hydrocarbon
in furnace I I_.¿ The heat absorbed by the butane
during its Ypassage through heating coil I0 is ¿3. Passed throughsaidtower perunit time. It is
obvious that by varying _the proportionsvof the
suiflcienttocompensate for any losses in heat
two streamsv entering furnaces 9 and II, respec
during the transfer Yof the heated butane streamv
through line I2 containing, valve I3 and still
tively, theamount of catalyst Vcarried into re
actor I'I may be _varied while maintaining a con
maintain ,the desired temperature in catalyst
stant charge of hydrocarbons to said zone. The
supply- tower I4.. The temperature within tower
hydrocarbon Vstream »passing through,> furnace 9
I4 is dependent îupon* the particular isomeriza
may be heatedY to a temperature substantially in
tion catalyst used >andthe solubility of the cata
lyst in the hydrocarbon. In the broader aspects
excess of that desired in catalyst »tower I4 and
can _be vutilized as a heat carrying medium to
of _the invention, this temperature is within the
range of about .100 to about 350° F. However, -» produce the desired ¿temperature when com
narrow rangesY areapplicable to the particular
isomerization catalyst utilized for example, a
mingled with; the.,cata1yst` containing _stream
fromtowerll! andthe added yhydrogen halide
temperature range of approximately 140 to 250°
F. is desirable when employing an aluminum
within reactorv I‘I.~ Further ¿advantages ,are` ob
tained in that this method of operating obviates
chloride while with other metallic halides, such
the, necessity bycontactinggthebulk-supply of
catalystgwith thegentire charging stock. This
is extremely important inthe event, that Vthe
as zirconium chloride Vand zinc chloride, a higher
temperature up to approximately 350° F.» may be
used.` The pressure in towenlftwill vary with
the temperaturehut.- itis essential that a liquid
phase. , be. maintained. within. said, tower._
charging stock containsgimpurities which may
poison orconsume the catalyst.
During~ thereactiona minor amount of the hy
"2,412,675
5
drocarbon reacts with the catalyst to form a com
plex commonly termed sludge which is withdrawn
from reactor l1 through line i8 containing valve
I9; The remaining reaction products are directed
through line 20 containing valve 2l into hydrogen
chloride separator 22 wherein the hydrogen chlo
reaction zone in an amount equivalent to about
11.7 mol per cent of the butane charge. Approxi
mately 40.3 per cent by volume of isobutane was
formed during the passage of the normal butane
through the reaction zone.
Eœample 2
~
Y
ride and light hydrocarbon gases, such as ethane
and propane formed during the reaction are sep
A normal pentane fraction heated to 170° F.
was introduced into a catalyst pickup chamber
arated from the isobutane and unconverted nor
containing a bed of granular aluminum chloride.
mal butane. The hydrogen chloride and a por '10 The chamber was maintained under a pressure
tion of the light hydrocarbon gases are recycled
of 260 pounds per square inch. Hydrogen was
through line 35 containing valve 40 into reactor
introduced
to the pickup chamber in an amount
I1. ' The original charge of hydrogen chloride and
equivalent to 10 mol per cent of the hydrocarbon
any additional make-up necessary during the op
charge. The eiiluent liquid having an aluminum
eration is introduced through line 38 containing
chloride concentration of about 1.1 pounds of
4valve 39 into recycle line 35. The concentration
aluminum chloride per barrel of charge was com
of hydrogen chloride in reactor l1 is dependent
mingled with hydrogen chloride in a packed re
upon the particular conversion temperature- and
action zone maintained at a temperature of 250°
hydrocarbon charge, but is ordinarily Within the
F. and under a pressure of 250 pounds per square
approximate range of 1 to 40 mol per cent of the
inch. The hydrogen chloride concentration in
hydrocarbon and preferably within the approxi
mate range of 5 to 25 mol per cent.
'
`
I have found that the addition of hydrogen
in some instances increases the eñiciency of the
operation. This hydrogen may be introduced
along with the hydrogen chloride through line 38
containing valve 39 into recycle line 35. The
amount of hydrogen introduced will usually be
less than approximately 30 mol per cent of the
the reaction zone was 10 mol per cent of the pen
tane charge. A conversion' of about 45.5 per cent
by volume of the charge to isopentane was ob
tained during the passage of the normal pentane
through the packed reaction zone.
Example 3
A 39 octane number acid-treated hexane frac
tion was introduced into a catalyst pickup cham
30
hydrocarbon charge. Further addition of hydro
ber containing a bed of granular aluminum chlo
-gen may be made through line 43 containing Valve
ride. The catalyst pickup chamber was main
44 into catalyst supply tower I4. To avoid a build
tained at a temperature of 170° F. and under a
up of light hydrocarbons, such as methane, ethane
pressure of 500 pounds per square inch. The eiilu
and propane in the system, a portion is period
ically withdrawn through line 36 containing valve 35 ent liquid from the pickup chamber having an alu
minum chloride concentration of about 1 pound
31 and the saturated gases'recovered as a prod
per barrel of hexane charge was commingled with
uct of the reaction after the removal of the hy
about 10 mol per cent of hydrogen chloride in a
drogen chloride therefrom.
packed reaction tower. The octane number of
The isobutane-normal butane stream is di
the product was about 72.3, an improvement of
rected from separator 22 through line 23 con
33.3 octane numbers over the charge.
taining valve 24 into fractionator 25 wherein the
I claim as my invention:
isobutane is separated from the unconverted nor
1. An isomerization process which comprises
mal butane. The separated isobutane is with
subjecting an isomerizable saturated hydrocarbon
drawn through line 23 containing valve 2l and
to catalytic isomerization in a reaction zone con
`recovered as a product of the reaction. Theun 45 taining a solid packing material and maintained
converted normal butane is directed through line
under isomerìzing conditions, maintaining in a
v28 containing valve 29 into pump 30 which dis
catalyst supply zone a bed of fresh Friedel-Crafts
charges through line 3| containing valve 32 into
metal halide catalyst not previously used in said
line I2. A portion of the recycle normal butane
may be directed through line 33 containing Valve 50 reaction zone, heating a liquid stream of said
isomerizable saturated hydrocarbon to a tem
34 into reactor l1 along with the heated butane
perature sufficient to dissolve a portion of said
stream from furnace 9.
`
catalyst, thereafter passing the heated stream
The following examples are presented as being
in substantially liquid phase through said bed in
characteristic of the results obtained when op
erating in accordance with the present inven 55 the supply zone and dissolving a portion of the
bed in the liquid stream, introducing the result
tion, although it is not intended to limit the gen
ant catalyst-hydrocarbon solution to the reaction
erally broad scope of the invention to the specific
zone and depositing catalyst from the solution
_conditions presented in the examples.
onto said solid packing material to maintain in
Eœample 1
the reaction zone a catalyst concentration sub
60 stantially greater than that of the solution be.
A stream of normal butane heated to a tem
ing introduced to the reaction zone, effecting said
perature of 180° F. was introduced into the bot
catalytic isomerization of the saturated hydro
tom of a catalyst tower containing granular
carbon in the presence of the catalyst thus re
>aluminum chloride. The tower was maintained 65 tained in the reaction zone, substantially all of
at ay pressure of 250 pounds per square inch to
the requisite quantity of fresh metal halide cat
insure the presence of a liquid phase of normal
alyst for effecting said catalytic isomerization
butane. The eilluent solution having an alu
being supplied to the reaction zone in said solu
minum _chloride concentration of 1.7 pounds per
tion, removing resultant reaction products from
barrel of charge was commingled with a second
the reaction zone and supplying the same to a
stream of heated butane and the resulting mix 70 fractionating zone without passage thereof
ture having a temperature of 220° F. introduced
through the catalyst supply zone, and fractionat
--into a packed reaction zone. The butane stream
ing the products in the fractionating zone to re
Acontaining aluminum chloride dissolved therein
cover the isomerized hydrocarbon therefrom.
amounted to about 47 per cent of the total mix
2. A process for isomerizing an isomerizabl'e
75
ture. Hydrogen chloride was introduced into the
«2,412,675
8
saturated hydrocarbon-which comprises heating
.dissolving a-'portion of the bed in the liquid
stream',fintroducing the resultantaluminum chlo~
a liquid stream comprising aiportionof ‘saidïhy
drocarbon and then passing the 4heated stream in
substantially liquid phase :through a bed of
fresh Friedel-Crafts metal v'halide catalyst at a
ride-hydrocarbon ksolution tothe' reaction zone
'and depositing aluminum chloride-catalyst from
the solution onto said solid packing `material rto
temperature su?licientto dissolve a portion of said
maintain in the reaction zonean aluminum chlo
bed, introducing the resultant catalyst-hydro
ride concentration substantially greater lthan
carbon solution to a reaction’zone containing a
that of the solution being introduced 4to the re
solid packing material, separately heatinga sec
.action zone, effecting said catalytic isomeriza
ond portion of said hydrocarbon to ya higher tem 410 »tion of' the saturated hydrocarbon in the lpres
perature than the nist-mentioned portion and
then introducing the same directly-¿to Ythe reac
tion zone, the amount and temperature 'ofi said
separately heated' second ‘portion being suiîlc'ient
to maintain an isomerizing temperature in ¿the
ence of the aluminum chloride catalyst Ithus re
tained in the reaction zone, substantially all of
the requisitequantity of fresh aluminum chlo
ride catalyst for eiîecting said catalytic isomeri
zation being supplied to the'reac'tion zone in -said
reaction zone, depositing catalyst ïf'rom said so
lution onto said solid packing material to main
tain in the reaction zone a catalystconcentra
solution, removing resultant reaction products
fromxthe reaction zone and supplying the same
to a fractionating zone Without passage thereof
tion substantially greater 'than that-of «said 'solu
through the catalyst supply zone, and fraction
tion, effecting substantial isomerization of said 20 ating the products in lthe fractionatingezone to
portions of the hydrocarbon> in `the presence of
recover the isomerized hydrocarbon therefrom.
the catalyst thus retained in 'the- reaction zone.
substantially all of the requisite-quantity of fresh
metal halide catalyst for eii‘ecting said catalytic
isomerization being supplied tothe reaction zone
in said solution, removing resultant reaction
products from said zone‘and recovering the isom
erized hydrocarbon therefrom.
3. An isomerization process »which comprises
subjecting an isomerizable saturatedhydrocarbon 30
to catalytic isomerization in the presence of a
hydrogen halide in a reaction zone containing
5. A process for isomerizing an isomeriz'able
saturated hydrocarbon which comprises .heating
a liquid stream comprising a portion of said hy
drocarbon and then 'passing the heatedv stream
in substantially ‘liquid phase .through .a `bed of
fresh .aluminum halide at altemperature. suffi
cient to dissolve afportion of said bed, 'introduc
ing the resultant aluminum halide-'hydrocarbon
solution and a hydrogen .halide toza reaction zone
containing a solid packing material, separately
heating a second portion of said hydrocarbon to
a solid packing material and maintained under
a higher temperature than thev first-mentioned
isomerizing conditions, maintaining in a catalyst
portion and -then introducing the same `.directly
supply zone a bed of fresh aluminum halide cat
to the reaction zone, the amount and .temperaalyst not previously used in said reaction zone,
ture of said separately heated second portion be
heating a liquid stream ofV said isomerirable` sat
ing suñicient to maintain an visomerizing tem
urated hydrocarbon to a Atemperature sufficient
perature in the reaction zona-.depositing .alumi
to dissolve a portion of-said aluminum halide,
num halide catalyst from 4said Asolution ontoï said
thereafter passing the heated stream in substan 40 solid packing material to'maintain in the re
tially liquid phase through said bed in the supply
action zone an aluminum halide~ concentration
zone and dissolving a portion of the bed in the
substantially greaterthan thatof said solution,
liquid stream, introducing the resultant alumi
effecting substantial isomerization of said por
num halide-hydrocarbon solution to rthe reaction
zone and depositing aluminum halide catalyst
from the solution onto said solid packing ma
reaction zone, substantially all. of v the‘requisite
terial to maintain in the'reaction zone an alu
quantity of fresh-aluminum halide catalyst for
tions of the hydrocarbon inthe presence -of the
aluminum halide-catalyst thus' retained in the
minum halide concentration substantially great
er than that of the solution being introduced to
the reaction zone, effecting said catalytic isomeri- ~
zation of the saturated hydrocarbon in the pres
ence of the aluminum halide catalyst thus re
tained in the reaction zone, substantially all of
the requisite quantity of fresh alurm'num halide
catalyst for effecting said catalytic isomeriaa
tion being supplied to the reaction zone in said
solution, removing resultant reaction pro-ducts
from the reaction zone and supplying the same
to a fractionating zone without passage thereof
through the catalyst supply zone, and fractionat
ing the products in the fractionating zone to re
cover the isomerized hydrocarbon therefrom.
4. An isomerization process which comprises
subjecting an isomerizable saturated hydrocar
bon to catalytic isomerization in the presence of
hydrogen chloride in a reaction zone containing
a solid packing material and maintained under
effecting ‘ said catalytic isomerization~ being sup
plied to the reactionA zone in said solution, re
movingfresult'ant reaction products from Isaid
zone> and recovering the isomerized hydrocarbon
therefrom.
6. A~process for isomerizing an -isom'erizable
saturated hydrocarbon which comprises heating
'a liquid stream comprising a'portion of said'hy
drocarbon to a temperature sufficient to dissolve
aluminum chloride therein and then passing the
heated stream in substantially liquid phase
through a bed of fresh aluminum chloride to dis
60 solve a portion of said' bed, introducing the re
sultant aluminum chloride-hydrocarbon solu
tion and hydrogen chloride to a reaction zone
containing a solid packing material, separately
heatingaJ second portion of said hydrocarbonv to
.a higher temperature than the ñrst-mentioned
portionV and then introducing the same directly
tothe reaction zone, the amount and tempera
isomerizing conditie-ns, maintaining in a catalyst
ture of, said separately heated second portion be
supply zone a bed of- fresh aluminum chloride
lng suñicient to maintain an. isomerizing tem
catalyst not previously used in said reaction zone, 70 perature in the reaction zone, depositing .alumi
heating a liquid stream of said isomerizable sat
num. chloride oatalystffrom said solution onto
urated hydrocarbon to a temperature'sufficient
said solid packing material to- maintain in the
to dissolve aluminum chloride therein, thereafter
reaction zone an aluminum- chloride concentra
passing the heated stream in substantially liquid
tion substantially greater thanv that :of said. so
phase through said bed in the supply zone and
lution, effecting substantial isomerization'of said
*2,412,675
. portions of the hydrocarbon ín the presence of
the aluminum chloride catalyst thus retained in
the reaction zone, substantially all of the requisite
quantity of fresh aluminum chloride catalyst for
effecting said catalytic isomerìzation being sup
plied to the reaction zone in said solution, re
moving resultant reaction products from said
zone and recovering the isomerized hydrocarbon
therefrom.
10
7. The process as defined in claim 3 further'
characterized in that said saturated hydrocarbon
is a normal paraffin.
8. The process as defined in claim 3 further
characterized in that said saturated hydrocarbon
is normal butane.
JOSEPH D. DANFORTH.
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