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Патент USA US2408934

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Patented Oct. 8, ‘19:46Í
20,408,033
UNITED STATES PATENT OFFICE
2,408,933
HYDROGEN FLUORIDE ALKYLATION
PROCESS
John 0. Iverson, Chicago, Ill., assignor to Uni
versal Oil Products Company, Chicago, Ill., a
corporation of Delaware
Application March 27, 1944, Serial No. 528,206
9 Claims.
(Cl. .2M-683.4)
l
This application is a continuation-in-part of my
co-pending application Serial #444,939, ñled May
29, 1942 which in turn is a continuation-in-part
of my co-pending application Serial #404,607,
iìled July 30, 1941, Patent No. 2,388,918, granted
November 13, 1945.
This invention relates to an improved process
for the reaction of isoparai’?ns with olefìns in the
presence of a hydrogen fluoride catalyst and more
particularly to a method of regenerating the used 10
2
head, condensing and returning the hydrogen
fluoride to the reaction Zone, subjecting the re
maining hydrocarbon reaction products to frac
tionation for the separation of an unconverted
isobutane fraction and a motor fuel product, re
turning said isobutane fraction to the alkylating
zone, continuously withdrawing from the alkylat
ing zone a, stream of used hydrogen fluoride cat
alyst, heating at least a portion of said stream of
used hydrogen fluoride catalyst to a temperature
catalyst.
suflicient to decompose a substantial portion of
The reaction of isoparafñns with olefins in the
the organic fluorides contained therein and fiash
presence of a hydrogen fluoride catalyst is an im
vaporizing said heated stream of used hydrogen
portant method of producing saturated branched
iluoride catalyst in the presence of heated isobu
chain hydrocarbons having high antiknock values 15 tane vapors to recover purified hydrogen fluoride
and suitable for use in aviation fuels. In the usual
vapors from heavier organic materials comprising
manner of conducting this process, a liquid mix
essentially polymers, returning a portion of said
ture of isoparafüns and oleñns is agitated together
puriñed hydrogen fluoride to the alkylating zone,
with a liquid hydrogen ñuoride-containing cata
subjecting another portion of the puriñed hydro
lyst until the reaction is complete, and the result 20 gen fluoride to fractionation whereby to separate
ant mixture is then allowed to settle in order to
relatively dry hydrogen fluoride from a mixture
separate the hydrocarbon reaction products from
of water and hydrogen fluoride and condensing
the catalyst. In this invention, steps have been
and returning the puriñed and dried hydrogen
included for recovering and regenerating the used
ñuoride to the alkylating zone.
hydrogen fluoride catalyst which will materially 25 Hydrogen ñuoride is slightly soluble in hydro
reduce the cost of the catalyst for the process and
carbons. Therefore, the'products from the re
are therefore highly desirable from a commercial
viewpoint.
action zone will contain a small amount of the
order of 1% of dissolved hydrogen iluoride. The
Broadly, the present invention comprises a
fractionation step following the reaction zone
process for alkylating isoparañins with oleñns 30 may be operated so as to remove propane, butane,
which includes the steps of contacting said iso
or other light hydrocarbons and also the dissolved
paraflins and oleñns with a hydrogen fluoride cat
hydrogen fluoride. Upon condensation of the
alyst under alkylating conditions, separating the
overhead stream, the hydrogen fluoride forms a
hydrocarbon reaction products from the used cat
separate layer which may be returned to the al
alyst, returning at least` a portion of said used 35 kylation zone, and the condensed hydrocarbons
catalyst to the alkylating zone, recovering puri--A
are returned to the fractionation step. In order
ned hydrogen ñuoride from another portion of
to remove the hydrogen fluoride which has a
said used catalyst, separately recovering dissolved
higher boiling point than either butane or pro
pane, it is necessary to vaporize a relatively large
hydrogen fluoride from the hydrocarbon reaction
products, and returning the hydrogen ñuoride re .40 quantity of hydrocarbons. If no propane is to be
removed from the reaction products, the hydrogen
covered in each of- said last two steps to the alkyl
ating zone.
fluoride may be removed by vaporizing, condens
In one speciñc embodiment the invention com
prises a process for reacting isobutane with nor
ing, and refluxing higher boiling hydrocarbons.
This step of removing and recovering the dis
mally gaseous oleiìns which includes contacting 45 solved hydrogen fluoride from the product is im
portant because its presence -in the finished prod
said isobutane and oleñns with a hydrogen ñuo
uct would present a serious corrosion problem and
ride catalyst under alkylating conditions, intro
possible health hazard and would increase the
ducing the reaction mixture into a settling zone
amount of catalyst that would have to be added
wherein a substantial proportion of the used hy
to the process.
drogen fluoride catalyst is separated from the hy
drocarbon reaction products, returning at least a
The hydrogen fluoride catalyst tends to lose a
portion of said used hydrogen fluoride catalyst to
substantial proportion of its activity after a pe
the alkylating zone, subjecting the separated hy
riod of use. This decrease in activity is mainly
drocarbon reaction products to fractionation for
due to two factors, namely, the contamination of
the removal of dissolved hydrogen fluoride over 55 the hydrogen fluoride with organic material and
afroaées'
3
the dilution with water. Although it is not known
whether the nature of the contamination is a so
lution eifect or a loose chemical combination, it
has been discovered that this contaminating or
d
troduction of heat into the fractionation zone
and more important, the decomposition of the
organic fluorides to polymers and hydrogen fluo
ride, thereby permitting the separation of the
ganic material can be removed and the activity 5 hydrogen iluoride in the subsequent flash dis
tillation zone. This decomposition can be ob
of the catalyst restored by heating and distilling
tained at temperatures within the range of about
oif the active hydrogen fluoride. An organic ma
terial containing hydrocarbon polymers remains
after the distillation.
Hydrogen iiuoride has a great afûnity for water
and it is very diflicult to remove water from the
catalyst by ordinary dehydrating methods. A1
though the incoming charge may be very nearly
dry, nevertheless, the catalyst will gradually ac
cumulate water. This water not only reduces
the catalyst activity, but also makes the hydro
200 to about 800° F., depending primarily upon
the residence time of the organic fluorides in
the heating Zone. The maximum temperature
to which this mixture may be heated is con
trolled somewhat by the type of materials em
' ployed in the construction of the preheating zoneIt is understood, of course, that any corrosion
of this material is greatly accelerated by in
creased temperatures. This, therefore, is a pri
gen fluoride more corrosive to the apparatus in
which it is handled. It is desirable to maintain
mary consideration in determining a maximum
, In the process of this invention, the water is
atures of the order of 200 to 550° F. are satis
temperature to be employed to accomplish the
decomposition reaction. I have found that with
the concentration of water in the hydrogen ñuo- ~
20 the usual type of construction materials, temper
ride below about 10%.
removed from the catalyst in a fractionation
step in which substantially dry hydrogen fluoride '
factory.
As previously stated, the decomposition re
action obtained in the preheater is dependent
is distilled off and a mixture of hydrogen fluo
ride and water is withdrawn as reflux conden 25 upon the temperature and residence time of the
organic material in said zone. Therefore, in
sate. This mixture may be a constant boiling
designing preheaters, the size of the preheating
mixture containing about 35 to 40% of hydrogen
zone is dependent to some extent upon the tem
fluoride or some other mixture of higher hydro
perature to be employed therein.
gen fluoride content.
The addition of heated isobutane to the bot
Any suitable apparatus or reactor may be em 30
toms permits the use of a direct heating medium
plowed to contact the hydrocarbon reactants
instead of the conventional reboiler. Various
with the liquid catalyst in the reaction Zone. It
difliculties have been encountered when employ
is only essential that very intimate contact be
ing indirect heat exchangers as a source of heat
tween the two liquids be maintained for a period
of time suiiicient for the reaction. In general, 35 for the distillation. These diiiiculties are mainly
attributable to the presence of the high boiling
some forni of agitation such as mixing, stirring,
polymers in the spent acid upon constant reboil
etc., obtained in various types of apparatus such
ing in the bottom of the column. These high
as Stratford contactors or turbo mixers is used
boiling polymers tend to form heavy carbona
thereby forming an intimate mixture or emul
ceous materials which deposit upon the outer
sion of the hydrocarbon and hydrogen fluoride.
surfaces of the reboiler forming a ñlm and pre
In one particular form of apparatus illustrated
Venting effective heat transfer from the heating
in the drawing, this agitation is obtained by con
medium to the liquid bottoms. Eventually, the
tinuously recycling a large portion of the reac
heat transfer becomes so inefficient that it is
tants in the time tank through an external cooler
and causing this emulsion to pass through rather 45 necessary to discontinue the regeneration and
remove the deposition from the surfaces of the
small openings in a series of horizontal plates
reboiler. The addition of these light vapors de
placed in the time tank whereby intimate con
tact is maintained between the hydrogen fluoride
and hydrocarbon phases.
A stream of fresh re
actants is continuously added to the recirculat
ing emulsion and a portion of the reaction prod
ucts is continuously withdrawn from the recir
culating emulsion. A settling section is pro.
vided in the time tank above the outlet to the
recirculation line where most of the hydrogen
iiuoride in the portion of the withdrawn reaction
products can settle back into the recirculating
stream, This settling section may eliminate the
necessity for an outside settler as it is possible
to remove all of the residual hydrogen iiuoride
carried over with the reaction products in the
first fractionatin-g column as hereinafter de
scribed.
-A feature of the present invention is the flash
vaporization system employed for the regenera
tion o-f the used catalyst. The most important
factors which must be taken into consideration
for the successful regeneration of the catalyst
are the temperature at which the spent catalyst
is preheated prior to the introduction of said
material into the regeneration zone and the in
troduction of isobutane stripping medium into
the lower section of the regeneration zone, The
preheating of the spent catalyst performs a two
fold function in the operation, namely, the' in
creases the viscosity of the bottoms and permits
more effective stripping so that a bottoms prod
50 uct substantially free of hydrogen fluoride may
be obtained.
By operating the regeneration zone by a con
trolled reduction of pressure, a partial vapcriza
tion or flashing is accomplished which permits
55 the separation of the hydrogen fluoride and water
from the heavier hydrocarbons and by main
taining the hydrogen fluoride and water in a
vaporous state, the undesirable effects of corro
sive liquid hydrogcn fluoride-water mixtures are
eliminated in the regeneration zone. The va
porous hydrogen iiuoride and water are removed
overhead and further treated in suitable equip
ment to separate a relatively dry hydrogen fluo
ride from the constant boiling hydrogen fluoride
'65 water mixture.
'I'he accompanying diagrammatic drawing i1
lustrates one specific form of apparatus employ
ing the features of the invention and in which
the process of the invention may be conducted.
‘70 . Referring to the drawing, ‘a normally gaseous
charge consisting essentially of isobutane, butyl
enes, and butane is passed as a liquid under pres
sure Vthrough line I, valve 2, and charge pump 3
to line 4. The charge is combined in line 4
l75 with a recycled isobutane fraction from line
5
2,408,939
6
5|. The combined feed from line 4 is then
admitted to line I3 containing a recirculating
disposed in preheater |94. This preheater may be
emulsion of hydrogen fluoride and hydrocarbons.- ,
type which provides suñ‘icient temperature and
a fired heater or a heat exchanger of any desired *e
The resultant commingled mixture is then passed
time to decompose the organic fluo'rides-present
through pump 6, line 1 and valve 8 to time 5 in the used hydrogen iiuoride catalyst, The
tank 9, in which the interaction of oleflnic and
heated used hydrogen fluoride catalyst passes
isoparañinic hydrocarbons is substantially com~
through line |05 and pressure reducing valve I B5.
pleted. A large portion of the emulsion of hydro
carbons and hydrogen fluoride from time tank
to flashing stripper 60, the function ofwhich is
to separate the lighter hydrogen fluoride and
water from the heavier organic materials. By
9 is withdrawn through line I0 and valve vII,
through cooler I2, wherein a portion of the heat
hashing the hydrogen fluoride and water to va
of reaction is removed and thence lthrough line
vapor, the undesirable effects of corrosive liquid
i3 and valve Ill intorecirculating pump 6. The
hydrogen fluoride-water mixtures are eliminated. ‘
combination of time tank 9 with the emulsion
The purified hydrogen fluoride is taken overhead,
recirculating system comprises the reaction zone. 15 through line 5| and pressure control valve E52,
A small portion of the emulsion of hydrom
condenser 63 and valve 64 to receiver 65 equipped
carbon andhydrogen fluoride from time tank 9 ì
with conventional gas release line 66 andvalve
passes through line I5 and valve IS to alkylation
51. The heavier materials consisting essentially-_
settler I1 wherein hydrogen iiuoride is settled
of organic polymers is withdrawn from the bot
out into a lower layer and withdrawn through line 2O tom of flash stripper 55 through line ñßgand
I 8 and valvel I9 as shown later. The hydrocarbon
valve 59. A small amount of light hydrocarbons
from alkylation settler I1 passes through line `'23,
may also be carried overhead with the hydrogen
valve 2|, pump 22 and line 23 to fractionator Y2li.
fluoride. The purified liquid hydrogen ñuoridev
ri"he vapors from fractionator 24 pass through
in receiver 65 is withdrawn through line ,1Q andV
line 25 and valve 26, condenser 21, and valve El!
valve 1| and is then divided into'two streams, one
to receiver 29. This fractionation column removes
passing through line 10 to fractionator 12 and->
the propane and dissolved hydrogen fluoride from
the other passing through line 13 and valve 14.
the product. However, it is necessary to reflux a
to be recycled to the alkylation stage ofthe
iarge amount of hydrocarbon in order to remove
process, as will be described later.
all of the dissolved hydrogen iluoride. This reflux 30 In fractio-nator 12, any water that is presentl
is returned from receiver 29 through line 39, valve
in the hydrogen fluoride is removed in the reflux.
3|, pump 3_2, and valve 33 tothe upper portion
condensate as a constant boiling> mixture ci Wateri!
of fractionator 24. Any gaseous propane that
and hydrogen iiuoride, or some mixture of higher
may be present is removed through line 34 and
hydrogen fluoride content, through line 15 and
valve 35. The hydrogen fluoride which separates
valve 1S. Relatively dry , hydrogen íìuoride is
as a heavy lower layer in the bottom of receiver
Iwithdrawn overhead from fractionator 12 through
29 will be withdrawn through line 3S and valve
line 11, valve 18, condenser 19 and valve 89 to re»
31 to be returned to the process as shown later.
ceiver 8|.
Provision is made for the removal Vof
The reñux condensate from fractionator 24 is
any non-condensable gases from this receiver
withdrawn through line 38 and valve 39 and 40 through line 82 and valve 83. The purified and
directed to a second fractionation step in frac
dried liquid hydrogen fluoride passes through line
tionator 40.
From this fractionation the over
‘ 84, valve 85, pump 85 and valve S1 to be returnedv
head product, consisting mainly of isobutane, is
to the reaction zone. The combined streams. of ,
withdrawn through line 4|, valve 42, rcondenser
hydrogen fluoride from lines 84, 36,18 and 13
¿i3 and valve 44 to'receiver 45. Any nonconden 45 are returned through line 88 and line 55 tc line.'
sable gases present will be removed throughmline
¿it and valve 41. The liquid isobutane passes
I3 and the reaction Zone. Fresh hydrogen fluo
ride catalyst may be added when necessary-
through line 48, valve 49, pump 59, line 5|, and
through line 89 and valve 9U.
valve 52 to the beginning of the process where
Flash stripper Bü is supplied with heat by the
it is combined with the charge inline 4. f A prod 50 introduction of preheated isobutane or other~ light.
uct consisting of n-butane and alkylate is with»
hydrocarbons by means of line lßï'controlledby
drawn through line 9| and valve S2.
valve IUS in order to assist in the flash vaporiza
The above described catalyst regeneration
tion of the hydrogen fluoride and water. This iso-,l
process eliminates the accumulation of a corro
butane may come from line 5I or any other suitm
sive constant boiling mixture of hydrogen fluoride 55 able source. In cases where the heavy fractionV
in any part of the apparatus where it would be
from the ñash stripper |59 contains more hydro
harmful. To minimize the danger of vaccumula
gen fluoride than desired, a portion ci' it may be
tion of constant boiling mixture, the top tempera
recycled by means of line | |19, valve lill, pump
ture of the fractionator is maintained sufficiently
IML-line |9I, valve |02 and line 58 to coil |93 Yor .
high to insure that the water isV carried overhead. 60 in certain cases, the heavy material may be with
drawn through line 68 and valve 59 and subjected
In order to maintain the catalyst activity in
to additional treatment in equipment not shown.
the reaction system, a small portion of the cata
lyst is continuously regenerated and recycled to
The addition of the heated isobutane not only ;
the system. This regeneration is accomplished
provides a source of heat for the bottoms in the ,
in the following manner:
65 fractionation zone, but also decreases the partial
A stream of hydrocarbon and hydrogen fluoride `
pressure of the hydrogen iluoridein the vapors in
equilibrium with the bottoms, thereby permitting
emulsion is withdrawn from circulating line 'I
the removal of a greater amount of hydrogen
through line 53 and valve 54 to an emulsion set
tler 55 wherein the hydrogen ñuoride settles out.`
fluoride from the bottoms product at the same
The hydrocarbon layer substantially freed from 70 conditions of temperature and pressure than
hydrogen ñuoride is returned to the reaction
would be removed if the isobutane were not
zone through line 56 and valve 51. Hydrogen
present.
.
fluoride catalyst containing organic contaminat
It will, of course, be understood that the invene v
ing materials is passedv from emulsion settler 55 e
tion is not limited to the specificform of appara,-`
through line 58 and valve 59~to heating coil,` |93 75 tus illustrated and 1 above described, since; other?
¿4.0483933
7
forms of apparatus may be utilized to accomplish
8
tane and high-boiling alkylate and the desired
fraction may then be blended with isopentane and
substantially the same results.
leaded or otherwise treated to produce a finished
'I'he fractionator shown for the removal of sub
aviation gasoline.
stantially anhydrous hydrogen fluoride will or
For the regeneration of the used hydrogen fluo
dinarily be quite small and can be built of mate CII
ride
catalyst, which contains about 80% free hy
rials that will withstand the corrosive hydrogen
drogen fluoride, the ratio of the volume of cata
fluoride-water mixture which accumulates and
lyst regenerated to alkylate produced may be ap
is Withdrawn as reflux condensate. Fractlonating
proximately 1 to 15. The difference in pressure
columns which are copper or silver lined have
10 between the suction and discharge of the recir
been found to be satisfactory.
culating pump 8 is about 40 pounds per square
The preferred range of operating conditions
inch and is suflicient to recirculate the emulsion
which may be employed in an apparatus such as
illustrated and above described for conducting the
processes of the invention may be approximately
as follows:
The pressure at the outlet of the charge pump
3 and in the reaction zone may be from 125 to 200
pounds per square inch. It is only necessary to
use enough pressure to maintain both catalyst
and hydrocarbon substantially in the liquid phase.
The preferred temperature in the reaction zone
may be in the neighborhood of 100 to l25° li,
although the reaction will occur at higher tem
peratures and even at temperatures below 0') F.
The time of contact between the hydrogen fluc
ride catalyst and the hydrocarbon charge, defined
as the Volume of _catalyst in the reaction zone
divided by the volume per minute of hydrocarbon
feed to the reaction zone may be from about 5
to about 80 minutes. Although the ratio of hy
drocarbon to hydrogen fluoride in the reaction
zone may vary considerably, a suitable ratio will
be in the range of 0.5 to 20 parts of hydrocarbon
through the emulsion settler. II‘he flow through
the emulsion settler is normally controlled by
valve 51. The hydrogen fluoride layer is re
moved from emulsion settler through line 58 and
passed through preheating c_oil |03 to flash strip
per 60. Preheating coil ID3 is operated at a
pressure of about 150 pounds per square inch and
the iiash stripper is operated at a pressure of
about 85 pounds per square inch and a tempera
ture of 375° F. Only small amounts of heavy
polymers are withdrawn from the bottom of flash
stripper 60 through line 58, and an overhead
fraction containing about 90% free hydrogen
ñuoride and the balance light organic materials
and water passes through line 6I. The amount
of purified hydrogen iiuoride being sent to irac
tionator 12 to remove the water present, depends
upon the amount of water present in the charge.
Although the example given describes a process
for alkylating isobutane with butylenes, the ln
vention is not limited to this process but may
to 1 part of hydrogen fluoride catalyst. The ratio
also be applied to the alkylation of isobutane with
suiiicient pres-sure to be a liquid as supplied to line
I and is discharged from pump S at a pressure
of 150 pounds per square inch, combined with an
catalyst to produce saturated branched chain hy
of isoparaflin to olefin in the combined feed to 35 other oleñns and the alkylation of other isoparaf
ñns such as isopentane with other olefins such as
the reaction zone may also vary considerably de
propylene or pentenes.
pending upon other conditions, but will ordinarily
It is also within the scope of the invention to
be in the range of from 1.5 to 15 molecular pro
incorporate î additional catalytic substances or
portions of isoparaliin per one molecular propor
40 substances promoting the catalytic eiîect of hy
tion of olefin.
drogen fluoride, such as boron trifluoride, al
A specific example of an operation of the proc
though hydrogen fluoride is the essential com
ess as it may be conducted in an apparatus such
ponent of the catalyst. Commercial “anhy
as illustrated and described is as follows: The
drous” hydrogen fluoride is usually employed.
charging stock ßis a refinery gas containing 35%
'
isobutane, 31% of butylenes, and the rest essen 45 I claim as my invention:
1. In a process for alkylating lsoparailins with
tially normal butane and propane. It is under
oleñns in the presence of a hydrogen fluoride
drocarbons wherein with continued use said hy
isobutane recycle fraction through line 5I and 50 drogen fluoride catalyst becomes contaminated
with accumulated heavy organic material and
then an emulsion of hydrocarbons and hydrogen
water, the improvement which comprises sepa
fluoride through line I3, and the total material
rating from the alkylating zone a stream of used
is then passed through pump 5, after which the
hydrogen fluoride catalyst, heating said used
pressure is 190 pounds per square inch. There
fore, the pressure drop in the emulsion recircula 55 catalyst to a temperature sufficient to decompose
a substantial portion of the organic iluorides con
tion system is about 40 pounds per square inch.
tained therein, introducing the heated catalyst
The reacted material withdrawn through line
into a flash vaporization zone, effecting therein
I5 and valve I6 is separated into a hydrogen iluo
controlled partial vaporization of said catalyst,
ride layer and a hydrocarbon layer and the hy
drocarbon layer is pumped through line 23> to 60 removing purified hydrogen fluoride vapors and
water vapors overhead from said flash vaporiza
fractionator 24. In this fractionator, small
tion zone, withdrawing unvaporlzed heavy or
amounts of propane and dissolved hydrogen liuc
ganic material from the bottom of said ñash
ride are removed. The reflux condensate is again
vaporization zone, and separately introducing
fractionated in fractionator di) to remove the un
reacted isobutane which is recycled through line 65 into the bottom of said fiash vaporization Zone
preheated vapors of a relatively low boiling hy
5I and valve 52 to the beginning of the process.
drocarbon to liberate and separate hydrogen fluo
The ratio of isobutane to oleiins in the charge' is
ride from said organic material by the stripping
approximately 1.1 to 1. However,~ when the re
action of said vapors.
cycled isobutane is combined with the charge, the
ratio of isobutane to oleiirrs becomes approxi 70 2. In a process for alkylating isoparaliins with
olefins to produce saturated branched chain hy
mately 5 to 1. From the bottom of fractionator
drocarbons including the steps of contacting said
40, a product is Withdrawn which contains 53%
isoparaliins and olefins with a hydrogen fluoride
normal butane and 47% alkylated hydrocarbon.
This material maybe fractionated further by
Ricans ?otï'shown in? theïdrawing, tdre'rriove‘bli-y
catalyst under alkylating conditions, separating
735 the
hydrocarbonl conversion products' from the
2,408,933
10
used hydrogen ñuoride catalyst, returning at least
reaction zone, subjecting another portion of the
a portion of said used catalyst to the alkylating
zone whereby with continued use said hydrogen
fluoride catalyst becomes contaminated with ac
hydrogen iluoride- and Water to fractional dis
tillation whereby to separate a mixture of Water
and hydrogen fluoride as reflux condensate from
cumulated heavy organic material and water,
subjecting said conversion products to fractional
substantially water-free hydrogen fluoride, and
returning said substantially Water-free hydrogen
distillation to remove dissolved hydrogen ñuoride
from a reflux condensate, condensing and re
fluoride to the alkylation reaction Zone.
4. In a process for alkylating isoparañins with
turning the hydrogen fluoride from said frac
tional distillation to the alkylating zone, sub
jecting said reflux condensate to a second frac
tional distillation whereby to separate an uncon
verted isoparafün fraction from a second refluX
condensate, withdrawing said second reflux con
densate as an alkylate product, and returning
said unconverted isoparail'in fraction to the al
kylating zone, the improvement which comprises
preheating a portion of said used catalyst to de
olefins to produce saturated branched chain hy
drocarbons in the presence of a hydrogen fluoride
catalyst wherein with continued use said hydro
gen fluoride catalyst becomes contaminated With
accumulated heavy organic material and Water,
the improvement which comprises separating a
stream of used hydrogen fluoride catalyst from
the alkylation zone, heating at least a portion of
said stream under superatmospheric pressure to
a temperature suilicient to decompose a substan
compose organic fluorine compounds contained
tial portion of the organic fluorides contained
therein, introducing `the heated catalyst to a 20 therein, passing said heated stream into a flash
flash distillation Zone, removing hydrogen fluo
vaporization zone maintained at a lower pressure
than said superatmospheric pressure, separately
ride and water vapors overhead from said ñash
distillation zone, withdrawing unvaporized heavy
introducing into the bottom of said flash va
organic material from the bottom of said flash
porization Zone preheated isobutane vapors, re
distillation zone, separately introducing into the 25 moving overhead from said ila-sh vaporization
bottom of said flash distillation Zone preheated
zone vapors of puriñed hydrogen fluoride, Iwater
vapors of a relatively low boiling hydrocarbon to
and isobutane, and withdrawing from the bottom
liberate and strip from said organic material
of said flash vaporization Zone a liquid stream of
heavy organic material substantially freed of hy
substantially all of its hydrogen fluoride content,
condensing and returning a portion of the hydro 30 drogen fluoride by the stripping action of said
gen fluoride and Water to the alkylating Zone,
isobutane vapors.
subjecting another portion of the hydrogen fluo
5. A process for the regeneration of contami
nated hydrogen fluoride catalyst containing ac
ride and Water to fractional distillation whereby
to separate a mixture of water and hydrogen
cumulated organic material and water which
comprises heating said catalyst under superat
fluoride as reflux condensate from substantially
anhydrous hydrogen fluoride as a vapor, and
mospheric pressure to decompose organic fluorine
condensing and returning the substantially an
~ compounds contained in said catalyst, introduc
hydrous hydrogen fluoride to the alkylating Zone.
ing the heated catalyst into a flash vaporization
zone and therein vaporizing hydrogen fluoride
3. In a process for reacting isobutane with ole
fins to produce saturated branched chain hydro 40 and Water, removing hydrogen ñuoride and Water
vapors overhead from said zone, withdrawing un~
carbons in which a hydrocarbon mixture contain
vaporized organic material from the bottom of
ing substantial proportions of isobutane and ole
said~zone, introducing preheated isobutane vapors
lins is subjected to alkylation conditions in the
into the ybottom of said zone to eilect the re
presence of a hydrogen fluoride catalyst wherein
moval of hydrogen iluoride from said organic
with continued use said hydrogen fluoride cata
material by the stripping action of said vapors,
lyst becomes contaminated with accumulated
and removing said isobutane vapors overhead
heavy organic material and water, the improve
along with said hydrogen fluoride and water va
ment which comprises separating a stream of Used
hydrogen fluoride catalyst from the alkylation
pors.
6. The process of claim 5 further characterized
reaction zone, heating said stream of used cat- I
alyst to decompose organic fluorine compounds
in that said catalyst is heated in said heating
step to a temperature of from about 200° F. to
contained therein, introducing the heated catalyst
to a flash distillation zone, removing' hydrogen
about 550° F.
7. The process of claim 1 wherein said rela
fluoride and water vapors overhead from said
tively loW boiling hydrocarbon is isobutane.
flash distillation zone, withdrawing unvaporized
8. The process of claim 1 wherein the heating
heavy organic material from the bottom of said
flash distillation zone, separately introducing into
of said used catalyst is effected at superatmos
the bottom of said flash distillation zone pre
pheric pressure.
heated isobutane vapors to substantially com
9. The process of claim l wherein said used
catalyst is heated to a temperature of from about
pletely remove hydrogen fluoride from said heavy
200° F. to about 550° F. prior to its introduction
organic material by the stripping action of said
into said flash vaporization zone.
vapors, returning a portion of the thus separated
JOHN O. IVERSON.
hydrogen fluoride and water to said alkylation
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