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Патент USA US2406954

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Patented Sept. 3, 1946
2,406,954
UNITED STATESEPATENT orrlclaiv
ALKYLATION 0F ISOPIARAFFINIC
HYDRO CARBONS
‘Carl B. Linn, Riverside, Ill., assignor to Universal
Oil Products Company, Chicago, 111., a corpo
ration of Delaware >
No Drawing. Application September 20, 1943,
Serial No. 503,105
8 Claims.
1
(Cl.
260-6834)
“
v
,
2
,
V
‘This application is a continuation-in-part of
my co-pending application Serial No. 424,783,
?led December 29, 1941.
the so-called primary reaction product is accom
panied by many side reactions among which ‘are
decomposition or cracking reactions and isomeri-<
This invention relates to a process involving
zation which under certain conditions can change
the treatment of isoparaf?nic hydrocarbons, both
gaseous and liquid, ‘to; produce therefrom
branched chain parafiinic hydrocarbons of higher
such as iso-octanes into‘ a mixture of isomers of
lower and higher boiling hydrocarbons frequently
molecular weight. In a more speci?c sense this
invention is concerned with a novel process for
of lower antiknock value. Accordingly, the pres
ent invention deals with the modi?cation of a
alkylating isoparaf?nic hydrocarbons comprising
isobutane and relatively low-boiling normally liq
uid is‘opara?ins with gaseous‘ or liquid ole?ns to
produce normally‘liquid saturated hydrocarbons
hydrogen ?uoride alkylation catalyst by the ad
dition thereto of certain inorganic compounds
which have substantial solubilities therein and
which moderate the action of this catalyst in
which may be utilized as components of gaso
such‘ a way as to improve the‘yield and quality
a substantial‘proportion of the primary product
line suitable for use in airplane and automobile 15: of the hydrocarbon alkylation product.v
engines.
‘
‘
According to the process of the present inven
tion, isopara?ins are. contacted with ole?ns in
These isopara?lnic and ole?nic hydrocarbons
the‘presence of a catalyst consisting of a major
have been utilized in alkylation reactions in the
proportion by weight of liquid hydrogen ?uoride;
presence of hydrogen fluoride alone or of hydro
gen ?uoride diluted with relatively small quanti 20 and a relatively minor proportion by weight of a
low boiling ?uoride or oxyfluoride which is solu
ties of water. The present type of catalyst is
ble in said hydrogen ?uoride. The term iso
a marked improvement over previous catalysts
paraf?n is herein used broadly to include all
containing hydrogen ?uoride in that the activity
alkylatable branched chain para?ins. The reac
of the catalytic material may be controlled more
accurately by proper dilution with non-aqueous 25 tion of the presentprocess is effected under con
trolled conditions of temperature and pressure
substances which are relatively inert catalytically
until the ole?ns have been substantially consumed
but which have substantial solubilities in liquid
and a substantially saturated hydrocarbon prod
hydrogen ?uoride.
‘
uct is formed which boils within the boiling range
Bro'adly,‘the invention relates to the use of
a hydrogen ?uoride alkylation catalyst which con 30 of gasoline.
Isobutane is the isopara?in commonly ' sub-'
tains dissolved therein at least one ?uoride or
jected to alkylation although higher molecular
oxy?uoride having a boiling point below about
weight isopara?ins may also be reacted with ole
300° C.
‘
'
" In one speci?c embodiment the present inven
?ns under similar or modi?ed conditions of oper
tion comprises the alkylation of'isoparaf?nic hy 35 ations to produce branched chain para?ins of
higher boiling point than the isoparaf?ns charged
drocarbons with ole?nic hydrocarbons in the
presence of a catalyst comprising essentially a
to the process. However, as the higher molecular
weight isoparafflns such as isopentane, isohexane,
major proportion of hydrogen ?uoride and a_
relatively minor ‘proportion of an inorganic com
pound which is soluble in said hydrogen ?uoride
and which has a boiling point below 300° C., said
inorganic compound being selected from the
group consisting of the ?uorides and oxy?uorides
of sulfur, selenium, nitrogen, phosphorus, molyb
denum, titanium, tungsten, vanadium, and silicon.
etc., are themselves valuable constituents of gaso
40 line, they are consequently used less commonly as
charging stocks for the alkylation process than is
Mono-ole?ns, and particularly those
containing from 3 to about 16 carbon atoms per
‘ isobutane.
' molecule, are utilizable for alkylating isoparaf?ns
“ in the presence of a mixture of hydrogen ?uoride
and a diluent o1_‘__spac_ing agent as herein de
scribed, although the common ole?n-containing
charging stocks are often limited to hydrocarbon‘
ride with a non-aqueous diluent so that the ordi
fractions containing propene and butenes and
narily vigorous reaction of anhydrous hydrogen
?uoride on catalytic condensation reactions 50 certain amounts of ethylene. Normal para?ins
among hydrocarbons is moderated to the extent
frequently present in hydrocarbon fractions con
A feature of the present invention is the dilu
tion of substantially anhydrous hydrogen ?uo
that reactions of alkylation occur in preference
to other less desirable reactions. Alkylation is
essentially a complex reaction since the simple
taining propene and butenes dilute the reacting "
hydrocarbons but are separable from the ‘alkyl
ation products by distillation. Thus, propane and
union‘ of paraffinic andole?nic molecules to give 55 normal butane may ‘beiremoved from the alkyl»
2,406,954
3
4
ation product, while an isoparaf?n such as iso
butane, which is also separated from the reaction
peratures and pressures. A tabulation of the
principal inorganic compounds of this class and
their physical properties is presented as follows:
product, is recycled to further alkylation treat
ment.
In order to favor the alkylation reaction rather
Compound
than ole?n polymerization, the hydrocarbon
charging stock including the isoparai?n and add;
ed ole?n-containing fraction may be commingled
with recycled isopara?in so that the ratio of iso
paraf?n to ole?n in the total hydrocarbon mix
ture charged to the alkylation zone is approxi
Boiling
point, DC‘
—63. 5
—99
—-30
—52
100
—34. 5
mately 5:1. In some cases this ratio may be as.
124
low as about 1:1 or as high as 10:1, or more, the
—56
—63. 5
exact ratio being somewhat dependent upon the
particular isopara?in and ole?n or ole?n-contain
-—95
—75
—40
ing mixture charged.
The amount of hydrogen ?uoride-containing
catalyst employed is preferably from about 10
to about 100 parts by weight of catalyst per 100
parts by weight of hydrocarbons undergoing
treatment at any one time, although in some
operations other ratios of catalyst to hydrocar
bons may be used. The concentrations of hydro
gen ?uoride in the composite catalysts which I
have found desirable are limited by the solubilities
in liquid hydrogen ?uoride of the compound or
compounds chosen as catalyst diluents or spacing
agents. Depending uponthe reactivity of the hy
drocarbon components in a given alkylation re
action, hydrogen ?uoride of different concentra
tions and different proportions of hydrogen ?u
oride and diluents may be employed to form active
1 Under pressure.
1 65 mm. pressure.
From the statements hereinabove set forth con
cerning the types of inorganic compounds which
may be employed as diluting or spacing materials
for hydrogen ?uoride, it will be evident that a
large number of catalyst composites of varying
compositions may be made according to the
30
needs of different alkylationreactions. However,
the di?erent diluents or spacing agents are not
necessarily equivalent inv their action.
While in most cases the activity of‘ the alkylat
Alkylation reaction temperatures between about
0° and about 50° C. are preferred, although satis 35 ing composite employed is due principally to the
hydrogen ?uoride, it is recognized that the inor
factory results may be obtained at temperatures
ga-m'c compounds added thereto may at times
as low as about —30° and as‘high-as about +100°
exert a de?nite‘ chemical in?uence upon the re-'
.0‘. when reacting isopara?ins with ole?ns in the
alkylating catalysts.
presence of a mixture of hydrogen ?uoride and
a spacing agent as herein described. As addi
tional means of regulation of the upper limits of
temperature, the proportions of hydrogen ?uoride
and diluent may be varied to produce good re
sults provided they are co-ordinated properly‘
with the reaction temperature and rate of charge
of' the isopara?ln and ole?n hydrocarbons. For
instance, the reaction of' isobutane with propenev
may- require more severe conditions such as a
somewhat higher temperature, a longer time of‘
contact, or a catalyst containing a higher pro- "
portion of hydrogen ?uoride to diluent than. thatv
used for catalyzing the reaction of isobutane with
the more reactive isobutene. Superatmospheric
pressure, generally not in excess’ of about 20 at
mospheres, is employed to assist the reaction and‘
to prevent undue loss of the reactants and cat
' actions other than merely moderating the effect
of the hydrogen’ ?uoride. It is also evident that
the selection of any particular compound or mix
ture of compounds for use with hydrogen ?uoride
is determined by solubility relations, the moderat
ing effect of said compound‘ on the activity of this
catalyst utilizedin thev alkylation of the isoparaf
?nic hydrocarbons involved, the general operat
ing conditions‘, and the matter of economy in the‘
cost of the reagents.
The process of the'present invention is carried
out in either batch or continuous types» of opera~
tion. In asimple'batch type process, an isoparaf
?n to- be alkylated such as isobutane, is brought
to the alkylating temperature within the approxi
mate range speci?ed and in the presence of the
alyst‘ by vaporization and, when desirable, to
necessary amount‘of catalyst mixture comprising‘
liquid-hydrogen?uoride and spacing agent, and
alkylation is e?ected by the gradual introduc
maintain the hydrocarbons and catalyst in sub
stantially liquid state or to effect liquefaction of
tion of an ole?n, or preferably of an ole?n-iso
. para?in mixture, under the surface of the liquid‘
a portion of the reaction mixture.
The spacing agents or diluents which are em
ployed in the present invention are inorganic ?u_
oridesv and oxy?uorides which are soluble to a
substantial extent in liquid hydrogen ?uoride and
which boil below about 300° C. The preferred
compounds are the low boiling ?uorides and oxy
?uorides of sulfur, selenium, nitrogen, phospho
rus, molybdenum, titanium, tungsten, vanadium,
and silicon. Of' the last named compounds the
?uorides and oxy?uorides of silicon are most
catalyst which. is stirred‘ mechanically to e?ect
intimate» contact between the catalyst and the
reacting hydrocarbons and to delay the settling
out and separation of the catalyst which is heavier
than‘ the liquid hydrocarbon mixture. Alkyla
tion may be allowed to progress to different stages
of reaction. In the case of the alkylation of iso
butane by propene or butenes, good products from
the standpoint of high antiknock gasoline are
produced usually by maintaining at all times in
readily obtained, particularly silicon tetra?uoride.
the reaction zone‘ a molar'excess of isopara?in
to ole?n. The presence of such an excess‘ of iso
Most‘ of these ?uorides and oxy?uorides are nor
mally gaseous compounds but are soluble to a
para?ins, generally at least 2 molecular propor
tionsv of isopara?in per molecular proportion of
useful extent in hydrogen ?uoride. A few of the
compounds are liquids or solids at ordinary tem
ole?n, tends'to minimize undesirable polymer
ization reactions. The mixture of‘ alkylation
2,406,954
‘5
,6
‘
products-and catalyst composite is removed pe
uctI-isreturned to further contactwith normal
riodicallyfrom the batch'type process and sep
butenes anda-mixture of fresh and used cat
alyst to produce a further quantity of alkylation
arated into a hydrocarbon‘layer‘ and a catalyst '
layer, the latter being returned to the reaction
zone “for further use while the hydrocarbon layer
is fractionallydistilled to separate therefrom the
gasoline fraction and‘the excess of the isoparaf»
‘ ?n originally charged to the process. rll‘he excess
product.
.
.
From 3000 c. c.‘ (approximately 1700 grams)
of the isobutane-normal butene mixture treated
there is obtained approximately 850 grams of
water-white, normally liquid, saturated hy'dro
carbons containing less than 0.001% by weight
isopara?in may be’ reacted further with an‘ ole?n
in a subsequent alkylation treatment in the 10 oforganically combined ?uorine and having an
end-boiling point of 450° F. The resulting nor
alkylation zone of the process.
mally liquid hydrocarbons are equivalent to ap
It is usually preferable to carry out the alkyla
proximately 200% by weight of the‘ butenes
tion reaction on a continuous basis by withdraw
charged to the process. 90% of the liquid hy
ing from the alkylation reactor a mixture ‘of
excess unreacted isoparai?ns and admixed nor 15 drocarbon products boil below 300° F. and are
thus in the boiling range of aviation gasoline.
mal para?ins, an alkylate of gasoline boiling
The aviation gasoline ‘fraction has an A. S. T. M.
range, higher boiling hydrocarbons, and catalyst
octane number of 93.
composite, said mixture being withdrawn at sub
stantially the same rate as that at which the
fresh hydrocarbon charging stock and catalyst 20
are supplied to the alkylation reactor. In order
to keep low the competing ole?n polymerization
reaction, the molar ratio of isoparaf?ns to ole
I claim as my invention:
1. An alkylation process which comprises re
acting an isopara?in with an ole?n in the pres
ence of a liquid hydrogen fluoride catalyst hav
ing dissolved therein a minor proportion of an
inorganic compound soluble in liquid ‘hydrogen
?ns in the alkylating zone is kept relatively high
throughout the entire reaction. The ratio of 25 ?uoride and boiling below about 300° C., said in
organic compound being selected from the group
isoparaf?n to ole?n is subject to some variation
consisting of the ?uorides and oxy?uorides of
and is a?ected considerably by the method of
sulfur, selenium, nitrogen, phosphorus, molyb
introducing the ole?n-containing fraction and by
denum, titanium, tungsten, vanadium, and sili
the efficiency of mixing. As the process is usually
_
operated, su?icient pressure is maintained upon 30 con.
2. An alkylation process which comprises re
the reaction mixture to keep a substantial pro
acting an isoparaf?n with an ole?n in the pres
portion thereof in liquid state. The exact pres
ence of a liquid hydrogen ?uoride catalyst hav
sure necessary depends both upon the composi
ing dissolved therein a minor proportion of sili
tion of the reaction mixture and the tempera
ture employed. The alkylation reactor used in 35 con tetra?uoride.
3. A process for the synthesis of saturated
the process consists quite often of a coil or tower
gasoline boiling range hydrocarbons which com
provided with ba?les, ori?ce plates, or other mix
prises reacting an isoparaf?n with an ole?n un
ing'devices, or a vessel provided with a stirrer or
der alkylating conditions in the presence of a
other mechanical means of agitation although >
catalyst comprising essentially a major propor
any method may be employed that satisfactorily
tion by weight of liquid hydrogen ?uoride and a
e?ects intimate contact of the reacting hydrocar
relatively minor proportion of an inorganic com
bons and mixture of catalyst and spacing agent
pound soluble in liquid hydrogen ?uoride and
employed.
.
boiling below about 300° C., said inorganic com
The following example is given to indicate re
sults obtainable by the use of the present proc 45 pound being selected from the group consisting
of the ?uorides and oxy?uorides of sulfur, seleni
ess, although it is not intended to limit the scope
um, nitrogen, phosphorus, molybdenum, titanium,
of the invention in exact correspondence with the
tungsten, vanadium, and silicon.
example.
4. An alkylation process which comprises re
A mixture of 392 grams of anhydrous liquid
acting
an isopara?inic hydrocarbon with an ole
50
hydrogen ?uoride and 8 grams of silicon tetra
?nic hydrocarbon at a temperature of from about
?uoride is charged to a steel autoclave of ap
-30° C. to about 100° C. in the presence of a cat
proximately 5000 c. c. capacity equipped with a
alyst comprising essentially a major proportion
pressure-sealed stirring device. The autoclave is
by weight of liquid hydrogen ?uoride ‘and a rela
maintained at approximately 38° C. by immer
sion in a cooling bath of appropriate temperature 55 tively minor proportion by weight of an inorganic
compound soluble in liquid hydrogen ?uoride and
and 3000 c. c. of a liquid mixture, consisting of
boiling
below about 300° C., said inorganic com
isobutane and normal butene in the ratio of 3
molecular proportions of isobutane and 1 molecu
lar proportion of normal butene, is introduced
continuously to the autoclave over a period of
two hours while the reaction mixture in the auto
clave is stirred mechanically. After'complet
ing the addition to the autoclave of .the mixture
of isobutane and normal butene, the stirring is
stopped, the hydrocarbon layer is separated from
the hydrogen ?uoride-containing catalyst layer,
the latter being returned to further use in an
other run. The hydrocarbon layer is debutan
ized, washed with water and caustic soda solu
tion to remove dissolved hydrogen ?uoride, dried,
and distilled to separate therefrom a substantial
ly saturated fraction of gasoline boiling range
containing a relatively high proportion of
branched chain octanes.
The isobutane recov
ered in the debutanization of the alkylation prod
pound being selected from the group consist
ing of the ?uorides and oxy?uorides of sulfur,
selenium, nitrogen, phosphorus, molybdenum,
titanium, tungsten, vanadium, and silicon.
5. An alkylation process which comprises re
acting an isoparaflinic hydrocarbon with an ole
?nic hydrocarbon at a temperature of from about
—30° C. to about 100° C. in the presence of a
catalyst comprising essentially a major propor
tion by weight of liquid hydrogen ?uoride and
a relatively minor proportion by weight of an
' inorganic compound which is soluble in said hy
drogen ?uoride and boils below about 300° C.,
said inorganic compound being selected from the
group consisting of the ?uorides and oxy?uorides
of sulfur, selenium, nitrogen, phosphorus, molyb
denum, titanium, tungsten, vanadium, and sili
con and the pressure in the alkylation zone be
7
2,406,954
ing sufficient to maintain the reacting .hydro
carbons .and catalyst in substantially the liquid
phase.
8
'alkylation zone being sufficient to maintain the
reacting hydrocarbons and catalyst in substan
tially the liquid phase.
6. An alkylation process which comprises con
tacting a molar excess of an isopara'i?nic hydro
carbon with an ole?ni-c hydrocarbon at a tem
perature of from about -30° C. ‘to about 100° C.
7. An alkylation process which comprises .re-*
acting isobutane with a mono-ole?n in the pres
ence of a liquid hydrogen ?uoride catalyst hav
in the presence .of .a catalyst comprising essen
drogen ?uoride and a relatively minor propor
tion by weight ‘of an inorganic compound soluble
inorganic compound soluble in liquid hydrogen
?uoride and boiling below about 300° C., said in
organic compound beingselected from the group
consisting of the ?uorides and oxy?uorides of
in liquid hydrogen ?uoride and boiling below
aboutf300° C., said inorganic compound beingse
num, titanium, tungsten, vanadium, and silicon.
tially a major vproportion by weight of liquid hy
lected from the group consisting of the ?uorides
ing dissolved therein a minor proportion of ‘an
sulfur, selenium, nitrogen, phosphorus, molybde
8. The process of claim 7 wherein said inor
and oxy?uorides of sulfur, selenium, nitrogen, 15 ganic compound comprises silicon tetra?uoride.
phosphorus, molybdenum, titanium, tungsten,
vanadium, and silicon and the pressure .in the
CARL B. LINN.
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