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. 17, 1946.
F. E. FREY
FLÚORINE REMOVAL PRocEss
2,412,726
Filed oct. 16, 1944-
44
'53 i
ATroRNEYs v
Patented Dec. 17, 1946
2,412,726
UNITED`- STATES Ara'rlzNr oFFlciE
Frederick É. Frey, Bartlesville, Okla., assignor to
Phillips Petroleum Company, a corporation of
Delaware
Application October 16, 1944, Serial No. 558,941
5 Claims.
( Cl.
This invention relates to the treatment o'f
organic materials to remove therefrom organic
not be greater than about 0.01 to about 0.05 per
cent by weight. Although the> exact natures and
compositions of these organic fluorine-containing
fluorine-containing compounds. In one general
embodiment it relates to the remo'val from hydro
carbon materials of ilumine-containing com
by-products have not been
definitely established, '
they are lbelieved to be predominantly alityl
pounds. In one of its specific embodiments this
invention relates to the removal of both hydro
gen fluoride and of organically vbound ñuorine
from hydrocarbon mixtures such as are produced
b_y alkylation.
26o-683.4)
and/or aryl ñuorides. They are not completely
removed by washing the hydrocarbon materials
with aqueous alkali solutions, such as ,aqueous-
'
solutions ‘of`sodium hydroxide or sodium carbon- In the presence of suitable catalysts, alkylatable 10 ate.- Some of them apparently are the alkyl
hydrocarbons react with unsaturated hydrocar
ñuorides which result from the addition of hydro- bons or other suitable alkylating reactants to pro
gen fluoride to the olefin used as the alkyla'ting
duce higher boiling hydrocarbons. The reaction, - ' reactant, o_r to replacement yof a hydroxyl group
which is known as alkylation..l is promoted
or of another halogen atom by >fluorine when
especially well by hydroñuoric acid. This catalyst 15
other akylatingreactants such as alcohols or chlo
rides are used in the alkylation reaction. These
have boiling points which are not substantially
higher than the corresponding oleflns. Other or
yields excellent results with isoparafûns or other
branched chain parañins and particularly paraf
ñns with at least one tertiary carbon atom per
molecule and with olefins having more-than two
ganic ilumine-containing compounds are’ higher
carbon atoms per molecule. However, under 20 boiling and are to be found in various fractions
especially favorable circumstances othervparaflìns
and/or olefìns may react. Besides paraflins, other
alkylatable hydrocarbons, such as aromatic hy
drocarbons, can vbe reacted with an alkylating 25
reactant in the presence of hydroiluoric acid to
produce higher boiling hydrocarbons. Suitable
alkylatin'g` reactants for the alkylation of either
parafiinsor aromatics include oleñns, relatively
polar nonprimary alkyl compounds, such as ter
tiary and secondary alkyl halides, advantageously
which have boiling points throughout the usually
accepted motor fuel boiling range, that is. up to `
about 400° F. The various organicñuorine-con
taining compounds tend to decompose at elevated
temperatures, especially the higher boiling ones,
and often decompose `during fractional distillation
of the hydrocarbon products, thereby contributing
to the problems of» commercial operation, par- _
30
ticularly problems relating to the combating and
control of corrosion in distillation equipment.
ñuorides andA chlorides, alcohols, and the like.` ,.Iikewise,
their presence in motor fuel products
The hydroñuoric acid preferably should be above -
decreases Vthe desirable
characteristics of such
about 80 per cent in strength and will generally
. products.
f
be used with a strength greater than 90 per cent; 35
InsomeA commercial operations wherein alkyla
it is most advantageous when it is substantially
tion is utilized to produce large quantities of hy
drocarbons in the motor fuel range it iscommon
. anhydrous, or about 99 t0 100 per cent in strength.
Because of its nonoxiding character, hydro
. practice iìrst to remove
catalysts as sulfuric acid. Furthermore, hydro
fluòric acid is relatively free from the tendency to
dissolved free hydrogen
fluoride from hydrocarbon eliluents of the alkyla
tion and subsequently toA treat the entire hydro
carbon mixture to remove all organic iluorine‘
when other catalysts are used.
In such alkylation processes smalll proportions
organic impurities. In other instances such a
fluoric acid does not produce the oxidation by
y products that are formed in alkylation with such
compounds therefrom. Since a large portion of
form complex tarry addition , products that are
these compounds correspond to the original a1ky1-..
formed in alkylation with certain other catalysts.
However, hydroiiuoric acid is appreciably soluble' 45 ating reactants and can be returned to the alkyla
tion step as a part of the charged alkylating re
in saturated hydrocarbons and itsI use as a catalyst
actant, such treatment often includes the removal
presents a problem of recovery that is not involved `
of ñuorine from unnecessary quantities of the
of organic fluorine-containing by-products are 50 hydrocarbon mixture, after the removal of free
hydrogen fluoride is subjected to fractional dis
tillation to separate various hydrocarbon fractions
mixture which can be separated from'eiiluents of
.and one' or more of the alkylate fractions are
such an alkylation will contain organically bound
treated to remove fiuorine compounds. When
fluorine in an amount not greater than about 1
also formed. Generally the entire hydrocarbon
per cent by weight, and often the amount /will
55
such treatment involves dehydroñuorination with
the "production of free hydrogen fluoride addi
'
" -
acier/ae
in
part to alkylation zone I I. Generally it is‘also
desirable to pass a portion of this used. catalyst
I >tional'tr'eating -equipment is necessary toeffect
removal of such free hydrogen fluoride.
»I I have now found that eflicient removal of high
er-boiling organic-fluorine-containing compounds
_. can be eiîected
by a dehydroiluorination and free
-to puriiìcation equipment, not shown, through
- pipe-IB.y The liquid hydrocarbon mixture which
is separated in separator I4 will comprise a sub
hydrogen fluoride so. produced can be removed
stantial amount of unreacted reactant, low-boil
«fing hydrocarbons such as isobutane, an appre
ciable but minor amount of normally liquid hy
emciently, together with removalof free hydro
gen ñuoride which-- is dissolved in liquid hydro- ' drocarbons produced by the .alkylation process,
carbon eiliuents of the alkylation step, by vaporiz .10, va small but dennite amount of dissolved hydrogen
such ' hydrocarbon
- ing» a substantial portion of
ñuoride and a stilll smaller amount of iluorine
eilluents so that most or all of the dissolved hydro
gen fluoride and a large portion of unreacted hy- .
dro'carbons, together with low-boiling alkyl' -.
fluorides, are removed as vapors, the unvaporized
I i residue is treated _to effect a removal of organically 15
present as organic fluorine compounds. i As an ex
ample, when isobutane is alkylated with butenes
in the presence of concentrated hydrofluoric acid
as the valkylation catalyst a total hydrocarbon
phase has been obtained which contains well over
- combined iiuorine, preferably in a dehydrofluorin
50 per cent' by volume. of unreacted isobutane,
ation step, eiïiuents of this treatment are passed to
about 10 to 20 per cent by volume of alkylate,
a fractional distillation, vaporsfrom the vaporiza
between about 0.3 and 2.0 per cent by weight of
tion step are cooled and condensed and passed to
dissolved hydrogen fluoride, and between about
’
and a hydrocar 20
. the same lfractional distillation,
0.01' and about 0.15 weight per cent of fluorine
bon material free from free hydrogen fluoride and
present as'organicall'y bound fluorine, of which
free from high-boiling organic ñuorine com
half to two-thirds is present as butyl-fluorides.
pounds is-recovered as a'high-boiling product of
Such a liquid mixture is passed through pipe I1
to
flash chamber 20 wherein a vaporization of a
said distillation.
l
`
- An object of this invention is to effect removal 25 large portion ofthe more volatile constituents is
oi iluorine from hydrocarbon materials contain
eiïected, including substantially al1 of the dis
ing-organic fluorine compounds as impurities.
solved free hydrogen fluoride. It is generally de
A further object of this invention is an im
for obtaining a substantially `
alkylate vfrom the alkylation of hy ‘3o
drocarbons in the presence of a catalyst compris
sirableto supply a substantial amount of heat to -
ing hydrogen fluoride.
coil I9 in the bottom of flash- chamber 20. Satis
factory operation is generally obtained by a sim
l
aid in .this vaporization. This may be obtained
by passing .the liquid hydrocarbon material
through heater I8 and/or by means of a. heating
-
Another object of my invention is to remove.
organic fluorine compounds from other organic
materials.
A further object of my invention is to effect a>
of higher-boiling iiuorlne com
selective removal
,
-ple vflashing with separation of vapors through
'
pipe 2I and of liquid through pipe 22. However, it may be found more desirable
‘ in some instances
pounds from eilluents of an alkylation process. _
Other objects and advantages of my invention
will become apparent to one skilled in theart
from the accompanying disclosure and discussion.
My invention will now be furtherdiscussed and .
to ald this flashing by including a small amount
of conventional packing, or a few bubble trays,
s0 as to insure substantially complete absence
of alkylate from the vapors passing through pipe
2I and to reduce the amount of low-boiling hy
drocarbons, such. as butane, present in the un
illustrated by a specific embodimentthereof, in
vaporized liquid passing through pipe,k 22. This
connection with the'accompanying drawing show-‘_
unvaporized liquid will contain substantially all
ing diagrammatically an arrangement of appa 45 of the alkylate, together with higher-boiling or
of a pre- _.
ratus which maybe used in the practice
ganic fluorine compounds which are deleterious
to the alkylate, This material is passed through
ferred modification of my process.'
'
- A suitable hydrocarbon charge, _such as an iso- '
dehydroñuorimator 23 wherein it is treated un-`
butane-butylene mixture containing a molar ex
der suitable dehydrofluorination conditions, such
to ’
cess of isobutane and generally also containing.
as will be morefully discussed hereinafteig'to de
appreciable amounts of normal butane and other
compose these organic fluorine compounds into '
inert . hydrocarbons, is passed
substantially
hydrocarbons and free hydrogen fluoride. Ef
through pipe i0 to alkylation zone II. A hydro
fluents of the dehydrofluorination are >passed J
gen fluoride catalyst is passed through pipe I2 to
through pipe-24 to fractionator 25, which may
alkylation zone II, wherein it 's mixed with the 55. be a, single fractional distillation column. In
hydrocarbon charge under alkylation condi-tions
such a case-these eflluents are preferablypassed
such as are well known to the art. Thus,_as an
example, the molar ratio of isobutane to butylenes
to an intermediate portion o_f the column.
Vapors from flash chamber 20 are passed
will be between about 3:1 and about 10:1, the
through pipe 2| and cooler and condenser` 26 to
of boron triiluoride may be added as a promoter,
phase often forms in accumulator -2.1. If such is
- generally in an amount between about 1 and about
10 per cent by weight of ‘the hydroiiuoric acid
the case this separates and can be removed
through pipe 30 and can be 'returned to separator
catalyst. Eiiluents of alkylatlon zone I I are passed
to separator Il wherein a sepa
accumulator 21 and containing dissolved'hydro
' liquid volume ratio of hydrocarbons to hydro 6o' an accumulator 21, which may serve as a simple
and these .
surge tank for the resulting condensate. How
‘ fluoric acid catalyst will be about 1:1 at
a tem
materials will bev intimately admixed
ever, since this material contains substantially all
115° F. for a reaction pe
of the hydrogen fluoride contained in the hydro
peraturejof about 80 5toand
about‘20
minutes.
If
carbons passing through pipe I1 vand has an
Iriad-»between about
desired, particularly when a normal paraflin is l appreciable smaller content of hydrocarbons in
`one of the alkylation reactants, a small yamount
most instances'a separate liquid hydroñuoric acid
. through pipe I3
ration is effected between hydrocarbon eii'luents,`
preferably as a liquid hydrocarbon mixture, and
liquid hydrofluoric acid.- The hydrofiuoric acid is -
I ‘ removed through pipe
Il. The liquid hydrocarbon material collected in
gen fluoride is- passed through pipe 3l to frac
When fractionator 25 is a single
tionator 25.column, as previously discussed,A this
I5 and is returned-'at least 75v rdistillation
` 9,419,720.
1
liquid hydrocarbon stream can be added near the
two molecules of isobutane unite to form 'an
- p of the column as a liquid redux. Heat for the
octane, a portion of this isobutane recycle stream
distillation may be furnished by a suitable heatlng means, illustrated by _heating coil 32. Any
may be diverted from pipe 45 through pipe 45 to
depropanizer 41. A low-boiling fraction com
uncondensed vapors, such as a propane-hydr - 5 prising propane is discarded from the system
gen ñuoride mixture, may be removed from acthrough pipe 48 and a puriiìed isobutane stream
cumulator 2l through pipe 28 and passed .to pipe
3 ,
is -returned to pipe 45 through pipe 49.
.
An alkylate fraction is removed from the bot
A low-boiling fraction comprising , all of the
tom of debutanizer 4I and may be passed through
free hydrogen fluoride which is present, both in 10 pipe 50 to rerun column 5I wherein a light alkyl
the stream passing through pipe 24 and in the
' ate fraction is separated from a heavier alkylate
stream passing through pipe 3|, is removed ‘ fraction. This light alkylate fraction may be re
through pipe 33 and may be passed through
covered for use as amotor fuel stock through pipe
cooler and condenser 34 and pipe 35 to pipe 4I3
52 and a heavy alkylate fraction is recovered.
and separator I4. ‘As more fully discussed in 15 through pipe 53.
my Patent 2,322,800, issued June 29, 1943, this
material will be accompanied by an appreciable
It will be readily appreciated by thos skilled
in the art that’the drawing illustrates th;;\u5e oi"
amount of low-boiling hydrocarbons. If desired,
conventional equipment which is not sho
in
a portion of this vapor stream may be diverted
detail, and that much conventional equipment
from pipe 33 through pipe 36 to heating coil i9 in 20 such as heaters, coolers, condensers, reflux equip~
order to supply heat to the vaporizing material
ment, ’ pumps, compressors, catalyst chambers,
in flash chamber 20 and the material, somewhat
and the like, will be necessary in the practice or
cooled by the vaporlzation taking place in iiash -
any >specific embodiment of my invention and
chamber 20, is returned to pipe 33 through pipe
can readily be adapted' by one skilled in the art
31. Also, if desired, a portion of the cooled and 25 in the light of the teachings vand discussion-pre
condensed overhead product trom fractionator 25
sented herein.
may be passed to accumulator 21 -through .pipe
38.A
«
.
‘
'
.
The iiashing of volatile constituents can be
ì
conducted most simply by heating the liquid ma
From the botto_m„of..1'ractionator 25 a hydroterial passing through pipe I'l, in heater I8, and
carbon mixture, which is substantially free from 30 passing the heated stream into a simple ilash
free hydrogen iiuoride and is also substantially
chamber. Thus, when isobutane present in a
free from higher-boiling organic iluorine com- l
pounds, is recovered and is treated to separate
butane mixture is reacted with butylenes present
in a refinery butane-butylene fraction, in the
various desired fractions.' Thus it may be passed
- presence of a hydroiiuoric acid alkylation cata
through pipe 40 to debutanizer "whereinnor- 35 lyst, the :liquid hydrocarbon effluent separated
mal butane and lighter hydrocarbons are sepa-
from the catalyst has a composition as _shown in
rated from heavier normally liquid hydrocarbons,
including' the alkylate produced in the alkylation
the ñrst column of the accompanying table, atea
lseparation temperature of about 88° F. and a
zone Il. The low-boiling fraction fro'm debupressure of about 35 pounds gage. When this
tanizer 4I is passed through pipe 42 to deisobu- ‘40 material is heated to about 100° F. and flashed, in
tanizer 43. From the bottom of deisobutanizer
a simple flash chamber, down to this same pres
43 normal butane is recovered through pipe 44
sure, the amount of material vaporized and re
for any subsequent. treatment as may b'e desired, « maining liquid, and the composition of the vapor
such as dehydrogenation to `oleñns for use in
. and liquid, will be as shown in the table under
alkylation zone Il and/or isomerization into iso- 45 the heading'corresponding to this temperature.
butane for use in alkylation zone Il. From the
top of deisobutanizer 43 an is"obutane fraction is
.
'
Similar data vare also shown for heating'. the
stream to 105° F.»and to 115° F. prior to ~ilashing. .
.
A
100° F.
Liquid
Mol per cent of emuent
100
.
105° F.
Vapor
Liquid
'
‘
Vapor Liquid
55
Composition:
115° F.
_
45
Liquid
68
32
_
Propane .... .__ ........... _.
_
Isobutan _ . , . _
.
. . ._--
N. butano...
Isopentene. .
‘..
'
iluorides ............... -_
_
'
Vapor
‘
5. 3
8.9
2. 7
7. 6
2. 4
6. 9-
l. 9
33. 3
40. 0
28. 5
29. 4
25. 8
38. 5
22. 1
46. 6
l. 5
» 46. 3
0. 9
46.8
l. 9
48. 7
0. 9
44.1
2. 2
50.0
l. 2
39. 2
2.. 2
1.0
18. 1
0.4
0. 2
1.1
23.2
0.7
0.0
0.7
10.5
0.2
0. 0
0.4
0.0
1.6
` 0.1
100.0
3.6
-
0. 1(-)
100.0
0.2
0. l(+)
100.0
2. 7
0.4
0.6
0.9._
0.2
0. l
0. l
100. 0
100. 0
1.3 l
31. 9
0.0
`
1.2
2.3
0. l(+)
100. 0
‘
0. 1
0.1(--)
100. 0 ,
removed through pipe 45 and may be recycled to , ‘_’
alkylation zone i . This fraction will comprise 00
Aan appreciable amount of butyl fiuorides present
in emuents oil the alkylation zone, since these will
A somewhatmore desirable separation is eilected
by supplying .a substantial portion of the heat of
vaporization to the bottom oi’ the flash chamber, \
as by means of a heating coil I9. By the use
have been vaporized in flash chamber 20 and will
-of only two‘or three bubble-trays the amount of'
not have been subjected to a dehydroiluorination. n butane and lighter (including hydrogen iluoride)
Since, incommercial processes, some propane will ‘U present in the liquid and of pentanes in the“
tend -to accumulate in the system, particularly if
`propylene or propyl fluoride ls present in thecharge to the alkylation step and if the reaction
vapors, particularly at the higher-temperatures,
can be decreased without adding greatly to the
expense of the operation. As will be appreci
conditions are such that this propylene or propyl
ated, such a vflashing operation can also be aided
fluoride takes up hydrogen to form propane as 75 by“ means of- a pump in pipe 22 and of a com
2,419,726
_. complete, dehydration of the oxide, which gen-
presser in pipe 2| , whereby ilash chamber 20 can
be operated at a lower pressure than subsequent
equipment. Although the amount of organic
iluorides in the vapor and in the liquid phases in
the preceding dashing operations are not
markedly different, the vaporized fluorides are
primarily volatile compounds which can be sat
'
erally will
be available in a more or less hydrous
the oxide may"
condition. After such dehydration
be treated directly with liquid‘concentrated hy
hours. Too
ldrofiuoric _acid for results
a periodinofseveral
a less active catalyst,
short a treatment
too long a. treatment often has the result that the
original granules disintegrate to the extent that
isfactorily recycled and the unvaporized'com
pounds are undesirable compounds normally 10
present in the alkylate.A
_
<
l
The dehydrofluorination step is conducted by '
the resulting material has too low a mechanical
strength for handling. It is often _more conven
ient to place the granular oxide in the catalyst
chamber and to pass through the granular mass
a stream of liquid concentrated hydrofluoric acid,
or a hydrocarbon stream containing tree hydro’
contact with a suitable dehydroñuorination cata 15 gen ñuoride. Bauxite or other granular oxide
material, which has been used in the manner dis
lyst under conditions such that most, or all, of
the organic fiuorine compounds are> decomposed
closed in my Patent 2,347,945, isslléd May 2, 1944, can also be employed as' a dehydroiluorination
to form iluorine-free compounds and free hydro
passing the hydrocarbon material' which con
tains organic ilumine-,containing impurities into
catalyst. However, it is 'generally desirable to
by passing the impure hydrocarbon material 20 give the used oxide material a further treatment ‘
with hydroduoric acid before employing it asa
either in the liquid or vapor phase, preferably in
gen fluoride. 'This can generally be accomplished
' dehydrofluorination catalyst.
the liquid phase, through the catalyst at a space
velocity of 1 to 10 volumes of liquid per volume
-The temperature in the
'of catalyst per hour.
Still another pre-y ,
ferred dehydrofluorination catalyst is produced
from yellowish ferrie oxide either in the form of
catalyst chamber is preferably between 150 and 25 limonite or in the form resulting from the oxida-é
tion with air of wet iron. Such a‘inaterial should
350° F., but temperatures asÁ low as 75° F. and as
then be treated with hydrogen fluoride as pre- »
high as 750° F. or higher may be used. The pres
sure is preferably sufñcient to maintain the hydrocarbon in the liquid phase. For treating any
ì
particular impure hydrocarbon material optimum
.
>conditions
can be readily determined by trial, in
the light of the discussion and disclosure pre
’
'
viously discussed.
_
It will be readily appreciated that various modi
.
l _fications, and embodiments of my invention may
skilled in the art, by follow
ing the teachings of the present disclosure with
out departing from the spirit thereof or from the
sented herein.
The dehydrofluorination catalyst
is - preferably
scope of the claims. .
contained in a suitable catalyst chamber as a 35
I claim:
»
,
l
,
_
"
1. `In a process for reacting. isobutane with a
butylene under alkylation conditions in the pres
ence of a- hydrofluoric acid alkylation catalyst,
mass of solid granular material, although other
' modifications of using vsolid catalysts which are
known in the oil cracking art or the like may be
employed if desired. As the dehydrofluorination `
the improvement which comprises passing 'efilu
catalyst various alkaline earth fiuorides, various 40 ents of suchan alkylation to a separating zone .
and separating as a liquid the hydrocarbon con
- metals such as aluminum, magnesium, iron or
tent thereofi from liquid hydrofluoric acid, pass-`
nickel or salts of such metals such as the fluorides
ing a resulting liquid hydrocarbon material con
or sulfates may be used. Catalysts which are par
ticularly active and useful in the practice of my
taining dissolved hydrogen fluoride to va flash L
vaporization zone under conditions that substan-> Y
process are the oxides of metals which have been
treated with hydrogen fluoride as has been more
fully disclosed and discussed byme in my co»-
tially all saiddi’ssolved hydrogen 'nuoride and a ,
substantial portionl of unreacted isobutane are
vaporized and such as to leave unvaporized sub
Y» pending` application Serial N0. 510,203, filed No
stantially all of the alkylate product,~subjecting
vember 13, 1943. These novel catalytic materials
are prepared by treating- various oxides> of metals 50 said unvaporized material to a dehydrofluorina
tion to decompose organic iluorine compounds
with hydrogen fluoride, or with a materialwhich
will release hydrogen vfluoride under the condi
contained therein as impurities forming free vhy
tions used for treating the metal oxide.
'
drogen ñuoride and hydrocarbons, passing efilu
entsv of ¿said dehydrofluorination‘to a fractional
distillation'zone, cooling and >condensing said "
An
especially desirable catalyst results from treating
a more or less hydrous oxide oí aluminum with
hydrogen fluoride .at a suitable temperature.
v
vaporizeddissolve'd hydrogen fluoride and unre
acted isobutane and passing a resulting isobu
tane-containing condensate to said4 fractional `
Other desirable catalysts -can be produced by
similar treatment of oxides of iron, chromium,
molybdenum, titanium,
nickel, cobalt, zirconium,
distillation zone, and recovering from said frac
60 tional distillation zone a low-boiling fraction com
vanadium. manganese, thorium, tungsten, ura
nium, hafnium, or the like, alone or in admixture.
prising free hydrogen fluoride together with at
synthetically produced or in natural occurring
forms, as in ores.
When u‘sing naturally occur-> '
ring oxides, Isuch as bauxite, limonite, manganite,
baddeleyite, brookite, brucite, diaspore, dysan
least a suiiicient-quantity of a normally gaseous
paraiiin hydrocarbon to form a minimum-boiling
'
therewith and as a high-boil
‘ azeotropicy mixture
ing fraction a hydrocarbon material free from
alite,'gibbsite, goethite, hausmannite, huebnerite,
ilmenite, lepidocrocite, rutile, spinel, valentinite,
hydrogen iluoride and comprising unreacted iso- `
etc. it‘is generally desirable to choose an ore
relatively free from substantial' amounts of silica.
although minor amounts are not deleterious, and
butane and alkylate.
.
.
2. In a process for the reaction of an alkylating
reactant with a low-boiling parailin hydrocarbon
in the presence of a hydrofluoric acid alkylation
often are advantageous, since a -more porous 70 catalyst,- the improvement which comprises pass
giranular material results -'from removal of the
ing etlluents of such an alkylation to a _separat
s lica.
-
>
‘
v This treatment is preferably carried out at a
temperature between about 50 and about 350° F.
One method is to effect a substantial, but not 7
ing zone and separating as a liquid a hydrocar
bon phase‘from liquid hydrofluoric acid, passing
a resulting liquid hydrocarbon material contain-
,
2,412,726
ing dissolved hydrogen iiuoride to a vaporization
zone and vaporizing same therein under condi
ride and a substantial portion of said unreacted
railin hydrocarbons are vaporized and substan
tially all ofy said alkylate together with high-boil
ing organic fiuorine compounds remain unva
.unvaporized material to a dehydroñuorination to
decompose organic ñuorine compounds contained
therein as impuritiesfor’ming hydrocarbons and 10
free hydrogen ñuoride, passing eiliuents of said
dehydroñuorination
to
a fractional
distilla- I
tion zone, cooling and condensing said vaporized
dissolved hydrogen fluoride and unreacted hydro
carbons and passing a resulting hydrocarbon- 15 ride phase, passing said liquid hydrocarbon phase
to said fractional distillation as a reflux stream,
containing condensate to said fractional distilla
and recovering from said fractional distillation a.
tion zone, and removing from said fractional dis
tilla'tion zone a low-boiling fraction comprising
free hydrogen ñuoride and as a high-boiling frac
tion a hydrocarbon material comprising unre- 20 from free hydrogen iluoride.
acted parafiins and alkylate.
3. A process for the removal of small amounts
' 5. In a. process for the reaction of an alkylat
of dissolved hydrogen _ñuoride and high-boiling
said dissolved vhydrogen Ii-uoride and a substan
tial portion of said low-boiling hydrocarbons are
vaporized and such as to leave unvaporized high
boiling hydrocarbons and high-boiling organic.
comprising hydrogen fluorideand a high-boiling
fraction comprising both low-boiling and high
boiling hydrocarbons and substantially free from
free hydrogen Iluoride and high-boiling organic
hydrogen ñuoridc- and
fluoride and unreacted isoparaiiln hydrocarbons
and passing a resulting hydrocarbon-containing
4. -In a process for alkylating a low-boiling par-\ 50 condensate to said fractional distillation zone, re
ailin‘hydrocarbon _in the presence of _a hydro- \‘ moving from said fractional distillation zone a
iiuorine compounds.
'
low-boiling fraction comprising free hydrogen
fluoride and as a high-boiling fraction a hydro
carbon material comprising unreacted isoparaf-4
porizing said material under conditions such that
substantially all of said dissolved hydrogen iluo- 60
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