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Патент USA US2412220

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Dec. 10, 1946.
G, A_ |BAcH ETAL
' 2,412,220
TREATMENT OF FLUORINE-CONTAINING HYDROCARBON MIXTURES
Filed Jan. >3, 1944
- u
HOLVNOLLOVt-id
r
X
HBMOJ. BdOBlOEIZV
INVENTORS
G. A. iBACH 8- C.C. TATE
stung”?ATTORNEYS
M In...‘
Patented Dec. 10, 1946
2,412,220 '
UNITED’ STATES PATENT. OFFICE ~
2,412,220 _
TREATMENT or FLUORINE-CONTAINING .
HYDROCARBON mxTunEs
-
Gerald A. Ibach, Borger, Tex., and Carmen C.
Tate, Okmuigee, 0kla., asslgnors to Phillips
Petroleum Company, a corporation of Delaware
Application January '3, 1944, Serial No. 516,868
5 Claims.
(Cl. 196-41)
The present invention relates to the treatment
of hydrocarbon materials and more particularly
to the removal from such materials of ?uorine
oontaining compounds, both organic and inor
game, which may be present therein as a result
of treatment with hydrogen ?uoride, concen
trated hydro?uoric acid or boron tri?uoride which
'
range of approximately 70° to 550° F. Superat
mospherio pressures, for example, such as are re
quired to maintain the material being treated in
the liquid phase, may be used, although the proc
ess may be conducted in the vapor phase at nor
mal pressures. Instead of bauxite, alumina gels,
chromium oxide, zirconium oxide, magnesium ox
ide and calcium oxide and oxides of metals of the
were used to facilitate polymerization, allryla
iron group, especially ?nely divided nickel de
tion or other reactions.
posited on an inert support,.may be used. The
The use 01 hydrogen ?uoride, hydro?uoric acid 10 reactions which occur with said metal oxide are
and boron tri?uoride and solutions of boron tri
not clearly understood but some of the organic
?uoride in water as catalysts for the polymeriza
?uorine-containing compounds are probably de
tion of unsaturated hydrocarbons‘ and for the .
alkylation oi hydrocarbons with unsaturated hy
composed to hydrogen ?uoride. Any hydrogen
?uoride present therein or formed in the treat-1
drocarbons has been widely adopted. Such proc» 15 ment reacts'with the bauxite'to form nonvolatile
esses are described, for example, in Frey Patents
compounds with the‘bauxite and some hydrogen
No, 2,322,800 and 2,317,901 and also in the arti
?uoride may react‘ with any silica that may vbe
cles by Frey‘ in Chemical and Metallurgical Engi
present in‘ the bauxite to produce silicon tetrafiu
neering, 1943, vol. 50, pages 126 to 128 (November,
oride or hydro?uosilicic acid, which remains in
1943) and Philnews, December, 1943, pages '1 to 20 the hydrocarbon material.
10. After treatment of hydrocarbon-containing
In conducting such a process as described in
mixtures therewith these catalysts must be re
said copending application of Frederick E. Frey
moved. The removal of the greater portion of
the bauxite. or other metal oxide may become
these catalytic materials from the treated prod
- vspent, either partially or completely, during the
ucts is a relatively simple matter but many un 25 operation, in which event the organic ?uorides
foreseen di?iculties arise in attempting to e?ect
will not be completely or will be but incompletely
the complete removal of these ?uorine-containing
removed. It channeling occurs in the bed of
catalysts and any ?uorine-containing compounds
metal oxide, the removal may also be incomplete.
which result from side reactions.
Furthermore, if any hydro?uoric acid or com
It is an object of the present invention to pro 30 pound which vis capable of liberating hydrogen
vide a process for the substantially complete re
?uoride or hydro?uoric acid is present in the ma
moval of small residual amounts of ?uorine-con
‘terial being treated, it may be unremoved or may
taining compounds from hydrocarbons and hy- '
be but partially removed in this manner.
drocarbon-containing mixtures that ‘have been
If the bauxite which is being used for the treat
treated with hydrogen ?uoride, hydro?uoric acid, 35 ment contains silica, as.most bauxite samples
boron tri?uoride or compositions containing
generally do, hydro?uoric acid or hydrogen ?uo-'
them.
'
ride, if present originally or if formed during the
It is a further object of the invention to provide~
treatment, may react with such silica and form
such a. process which is simple and economical.
silicon tetra?uoride or hydro?uosilicic acid which
40
Other objects of the invention, some of which
may be left in the hydrocarbon. Also, if the con
are more speci?cally referred to hereinafter, will
ditions of temperature, pressure and ?ow rate‘
be apparent to those skilled in the art to which
are not adjusted properly, the treatment with
the invention pertains.
bauxite or other of the speci?ed metal oxides may
In the copending application of Frederick E.
be only partially effective and may be accom
45
Frey, Serial No. 398,361, ?ied June 16, 1941 (Pat
panied by such reactions whereby organic fluo-_
ent No. 2,347,945 issued February 15, 1944) is dis
rides together with hydrogen ?uoride, silicon tat-,
closed a process of removing residual amounts of
ra?uoride or other inorganic ?uorides appear ‘or
organic ?uorine compounds from a mixture of
are formed and appear in the product of the
para?in hydrocarbons containing such organic
treatment. The process of the present invention
50
?uorine compounds, which comprises subjecting
is directed to the prevention or avoidance of any
said mixture to the action of a solid porous metal
of these di?lculties which may arise in the de
oxide such as bauxite, which is catalytically active
?uorination'of
hydrocarbon materials.
for hydrogenation and dehydrogenation reac
It has been observed during the course of con
tions, under suitable conditions. Such condi
tions include reaction temperatures within the 55 tinued operation of such a de?uorination process,
aeiaaao
4
in which the material after treatment with baux
ite is subjected to fractional distillation, that a
coating, cake or deposit of solid'matter accumu
lates in the fractional distillation apparatus and
azeotrope tower 2. This hydrocarbon charge may
_ be the hydrocarbon materials which are formed
in a polymerization or an alkylation process, for
example, it may be the alkylate resulting from
that the pipes orv conduits ‘through which the 5 the treatment of isobutane ‘with a butene-con
treated material circulates become clogged with
such deposits. The apparatus, which is usually
of iron or other metal also‘ becomes corroded.
. taining C4 hydrocarbon fraction or a pure butene
in the presence of liquid hydrogen ?uoride to pro
duce isooctane, orany reactions comprising hy
dro?uoricacid as catalyst. Besides the desired
10 ‘product, the hydrocarbon material will normally
contain unalkylated low boiling hydrocarbons and
dissolved or entrained liquid hydrogen ?uoride
The source of this deposit, which contains an ap
preciable quantity of silica, is evidently the sili
con tetraiviuoride, silicic and/or ?uosllicic acids in
the de?uorinator eiiluent, and which are probably
formed from siliceous matter present in the baux
or other catalytic material and organic ?uorine ite or other-naturally occurring metal oxides. Al
compounds.
_
though the amount of this deposit is negligible at 15
The hydrocarbon ‘charge is subjected to frac
the start of operations, it becomes greater as the
bauxite becomes spent and as the treatment pro
grasses.
-
tional distillation in azeotrope tower 2. The over- 4
head fraction of the distillation is discharged at '
’
3 and normally consists of a mixture of the low
Some of the aforesaid difficulties are partially
boiling hydrocarbons and liquid hydrogen ?uoride
obviated by using a series of bauxite chambers, 20 as an azeotropic mixture. This overhead frac
and so operating that the material leaving the
tion or distillate may be sent to an acid settler or
treaters or chambers comes into contact in the
similar device for separating the hydrocarbons
from the hydrogen ?uoride, which generally sep
arate when the distillate is'gcon'densed. These
last chamber of the series with fresh bauxite.
Such operation is costly, however, and uneconom
ical of bauxite, and, furthermore, requires care 26 separated materials may be returned or recycled
ful control and frequent observation.
,
to the reactor or alkylator and reused. The bot
v In accordance with our invention, the foregoing
tom fraction which is substantially devoid of free
di?lculties‘are entirely obviated, or obviated to a
or uncombined hydrogen ?uoride as a result of
great degree, by subjecting the hydrocarbon
material that has been treated with bauxite or
other metal oxide to treatment with sodium hy
droxide or other alkaline solution and then to ?l
tration through an essentially. non-siliceous.
granular ?ltering medium before being subjected
to distillation.
I
‘
. The ?ltering medium must, of course, be resist
ant to the action of alkaline solutions and be non
packing so that it is pervious to liquids and gases
the distillation is charged through conduit 4 to
bauxite treater 5. In the event that the hydro
carbon material is substantially free of hydrogen
?uoride or concentrated hydro?uoric acid, the
treatment or distillation in the azeotrope tower
may be omitted and the hydrocarbon material
35 charged directly to‘the bauxite treater.
The treatment with bauxite or other porous
metal oxide which is catalytically active for hy
drogenation and dehydrogenation reactions is
conducted in bauxite treater Ii substantially as
and may be readily wetted by aqueous liquids.
Suitable ?ltering media are anthracite coal, pe 40 described in the copendingapplic'ation of Fred
troleum coke, wood charcoal, and the like, which
erick E. Frey, Serial No. 398,361 (Patent No.
may contain small amounts of silica but which - 2,347,945 issued February 15, 1944),
Thus the
are essentially nonsiliceous. A metal ?lter, such
temperature of the treatment may be within the
as screenings or turnings of copper, silver, Monel
range of approximately 70° to approximately 550°
metal or other metals or metal alloys that are 46 F. and the pressure may be sufilcient ‘or greater
not aifectedby hydro?uoric acid, may also be
than that necessary to maintain the material in
used. The function of the ?ltering medium is to
liquid phase. Although one bauxite treater is
remove any droplets of aqueous alkaline solution
represented in the drawing, preferably two or
which may be entrained or carried over or be
more are used and they are generally of such.
present in the hydrocarbon being treated. when 60 capacity that su?lcient de?uorination is eil'ected.
siliceous ?ltering media are used, they may be
These treaters are also arranged so that the
come clogged by the action of the alkaline solu
material passes through that containing the most
' tion on the silica. When the sodium hydroxide
solution becomes spent or its circulation to the
- active or least spent treating agent last and pro
vision is preferably made for recharging the‘ '
washing unit is stopped, deposits of solids may 65 treaters sOythat operations will not
tinued while one is being recharged. be disconf
contact of the hydrocarbon material containing
The treated hydrocarbon material then passes
fluorine compounds with a siliceous ?ltering ma
‘through conduit 8 to tower 1 which is a washing
terial whereby silicon compounds are formed and
and'?lterin'g tower provided with baffles 8 and in
‘form in the fractionating unit as a result. of the
, are carried over with the hydrocarbon.
Aqueous solutions of sodium hydroxide are the
preferred treating solutions. Howevensolutions
of potassium-hydroxide, sodium carbonate, so-v
dium bicarbonate, potassium carbonate, borax or
similar alkaline substances or mixtures thereof,
in water or other solvents, may be used, although
their effectiveness for the purpose may be'some
what less than that of an aqueous solution of
which‘?ltering material 8 is disposed“ The wash
ing medium, which may be sodium hydroxide or
caustic soda solution or one of the other mate
rials hereinbefore referred to, is charged to tank
III through inlet II. After tank It) and the wash
ing system are ?lled, su?‘lclent material is added
at inlet I I to compensate for that withdrawn from
tank III through outlet valve I2. ‘The wash liquid
is pumped from tank III by means of pump I 3
through conduit I4 and into tower ‘I through a
The accompanying drawing is .a ?ow diagram
or spray IE or other suitable distributing
of a process that is a preferred embodiment of 70 nozzle
device.
Thede?uorinated hydrocarbon material
our invention. In this preferred process, the hy
- that has been treated with bauxite or other de
sodium hydroxide.
.
drocarbon layer remaining after the separation
of liquid hydrogen ?uoride or concentrated hy
?uorinating agent in treater I passes up through
'the tower ‘I where it is washed with the sodium
‘ dro?uoric acid is charged through inlet I to an 75 hydroxide solution and is then ?ltered through
'
9,412,220
which are capable of engendering silicon tetra
?uoride or hydro?uosilicic acid in contact with
materials used in earlier stages of the process.
Thus, the process of the invention is also applica
ble to- the'treatment of hydrocarbon materials
containing boron ?uoride,. which may be present
the bed of ?ltering material 9. It is then charged
through conduit 16 to fractionator IT. The ?lter
ing material is preferably granular > anthracite
coal or coke or other essentially nonsiliceous
granular filtering medium as hereinbefore de
scribed. The bed should be of a thickness suffi
as a result of the use of boron ?uoride or hydro
cient to remove substantially all entrained wash
?uoric acid containing boron ?uoride as catalysts,
ing solution.
‘
or the treatment of hydrocarbon materials con
In the event that the hydrocarbon material is
taining alkyl ?uorides or other organic ?uorides “
not contacted with the washing solution, any sili 10 that may be unstable to heat or to materials used
con tetra?uoride or hydro?uosilicle acid may be
in the de?uorination process.
>
,
condensed on the ?ltering material and thus will
The process of the invention has been described
not pass through to the fractionator. Further
particularly in connection with a hydrocarbon
more, if hydrogen ?uoride is left in the hydro
15 alkylation process, that is, a process in which one
carbon material after the washing treatment, no
silicon tetra?uoride which might be carried over
into the fractionator will be formed in the ?lter.
The presence of hydrogen ?uoride in the frac
tionator is less detrimental than the presence of
silicon tetra?uoride.
hydrocarbon is alkylated with another hydro
carbon and more speci?cally in which an all
phatic para?in hydrocarbon is alkylated with an ‘
ole?n hydrocarbon. .However, it is to be under- '
20 stood that it is applicable generally to ei?uents
of the treatment of any alkylatable hydrocarbon,
The concentration of the washing solution may
saturated or unsaturated, aliphatic, aromatic or '
be varied over a wide range, dependent upon the
amount of puri?cation required, and the capacity
cycloaliphatic, with an alkylating reagent, name
' . ly, unsaturated hydrocarbons, halides or alcohols,
of the washing tower ‘I, the degree of circulation
and that the term allnvlation includes polymeri
‘of the solution and the intimacyof the contact 25 zation. It can also be used to treat eiiluents of
between the hydrocarbon material and the solu
isomerization processes in which hydro?uoric
tion. Ordinarily an aqueous solution containing
from 1 to approximately 20% by weight or more
acid is used as a catalyst.
Generally the hydrocarbon material which will
of sodium hydroxide is used. The temperature
be subjected to treatment with alkaline solutions
of the washing treatment may also be varied‘over 30 according to the process of the invention will be
a wide range, being normally between approxi
in liquid phase but it is obvious that the process
mately 30° to approximately 200° F. and prefer
is capable of being used for the treatment of hy
ably between 60° and 100° F.
drocarbon materials in gaseous or vapor phase '
Fractionator I1 and subsequent’fractionators
not shown separate the total hydrocarbonsinto
in known manner.
Inasmuch as the foregoing speci?cation is
merely illustrative and comprises preferred em
. required recycle and e?luent products of the proc
ess. The overhead product leaves the fractiona
‘ bodiments of the‘ invention it is to be understood
‘tor ll through outlet l8 and the kettle product
- that the invention is not limited thereto and that ,
through outlet l9, and :these may be either ?nal
modi?cations maybe made therein and alterna
yield or recycle streams or intermediate streams 40 tives substituted for certain of the described pro
requiring further separation, as is evident to one
cedures without departing substantially from the
invention as de?ned in the appended claims.
‘ skilled in the art.
It is to be understood that the foregoing de
scription is merely illustrative, that the drawing
is merely a diagrammatic representation of the
We claim:
45
'
‘
-1. In a process for treating hydrocarbon ma
terials containing minor amounts of ?uorine
now of materials in the process, and that the ac
compounds as impurities by contact with a baux-'
tual apparatus which will be required may in
ite containing siliceous material under conditions
clude heaters, pumps, valves (some of which are
such that ?uorine is retained by said bauxite and
represented), pressure gauges,‘ ?ow meters, heat
tetra?uoride-is formed from such siliceous
exchangers, re?ux accumulators, surge tanks, 60 silicon
material,
the improvement which comprises,
and other conventional equipment whichwill be
passing
a
hydrocarbon material eilluent from
understood by those skilled in the art to whichv
such a treatment with such a bauxite, and con
the invention pertains.
taining said silicon tetra?uoride, into the bottom ‘
It is further contemplated that the apparatus
will be constructed of metals and other materials 55 of a puri?cation zone comprising a lower contact
ing zone and an upper ?ltration zone, passing an
which are inert or resistant to hydro?uoric acid
aqueous solution of sodium hydroxide to the top
and/or other substances which are used in con
of said contacting zone and contacting same
tact with the apparatus. Such materials of con
therein with said hydrocarbon material to dis
struction are described in the article by Charles
solve said silicon tetra?uoride therein, and pass
60
M. Fehr, “Materials of construction for anhy
ing said hydrocarbon material upwardlythrough
drous hydrofluoric acid" in Chem. Met. Eng,
said. contact zone and subsequently upwardly ,
1943, vol. 50, page 129 (November, 1943) and in
through said ?ltration zone to remove entrained
the articles of Frey referred to hereinbefore.
sodium hydroxide solution.
Although the foregoing process has been de-=
2. In a process for treating hydrocarbon mate
scribed particularly in connection with de?uori 65
rials containing minor amounts of ?uorine com
nation of hydrocarbon materials that have been
produced or treated with liquid hydrogen ?uoride
pounds as impurities by contact with a bauxite
or concentrated hydro?uoric acid catalysts, it is
containing siliceous material under conditions
applicable generally to the treatment of all hy
such that ?uorine is retained by said bauxite and
drocarbon materials which contain ?uorine-con 70 silicon tetra?uoride is formed from such siliceous
taining compounds capable of engendering hy
drogen ?uoride or hydrofluoric acid by hydrolysis
or by thermal decomposition or decomposition in
the presence of bauxite or other materials with
material, the improvement which comprises,
passing a hydrocarbon material eiliuent from
such a treatment with such a bauxite, and con
which the hydrocarbon material is contacted or 76 taining said silicon tetra?uoride, into contact
2,412,920,
with an aqueous solution of sodium hydroidde to
‘remove said silicon tetra?uoride by . solution
therein.
'
>
>
'
-
3. In a process for treating hydrocarbon ma
teriais containing minor amounts of ?uorine
taining said silicon‘ tetra?uoride, into contact
with‘ an aqueous alkaline solution. to remove said
silicon tetra?uoride by solution therein. ‘
_ 4. The process of claim 1 in which said ?ltra
tion zone contains a granular carbonaceous ma
compounds as impurities by contact with a baux
terial selected from the group consisting 01’ an
ite containing siliceous material under conditions
thracite coal, petroleum coke and wood charcoal.
5. The process ofv claim 1 in which said ?ltra
such that ?uorine is retained by said bauxite and
silicon tetra?uoride is formed from such siliceous
‘material, the improvement which comprises,
passing a hydrocarbon material é?iuent from
such a treatment- with such a bauxite, and con
'
10.
tion zone contains granular anthracite coal.
GERALD ‘A. mom
.7 CARMEN c.v 'rn'ra.
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