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Патент USA US2403922

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July 16,1946;
I’
, 'w. P. HAWTHORNE '
2,403,922
CATALYTIC HYDROCARBON REACTIONS
Filed Nov. 22, 1944
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July 16, 1946.,
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2,403,922
CATALYTIC HYDROQ-ARBON REACTIONS
Filed Nov. 22, ,1944
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Patented July 16, 1946
2,403,922
UNITED STATES PATENT OFFICE
..2,403,922
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CATALYTIC HYDROCARBON REACTIONS
Wendell P. Hawthorne, Wenonah, N. J., assignor
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toSocony-Vacuum Oil Company, Incorporated,
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a corporation of New York
Application November 22, 1944, Serial No. 564,629.
4 Claims.
(Cl. 260-5834)
1
2
This invention relates to a method for con
the acid; forming an interface therewith at ll.
Immersed inv the liquid within tower Ii) are two
cooling’ coils l2 and it‘; of which coil [2 is adapted
to receive liquid phase feed from line H through
an expansion valve 15. The feed is expanded to
a pressure suitable to induce vaporization in coil
i2, thus taking up latent heat of vaporization
and cooling the liquids in tower Ill. The coil I3
ducting synthetic hydrocarbon reactions in the
presence of a liquid acid catalyst, and, is par
ticularly concerned with a preferred embodiment
involving alkylation of isopara?ins with ole?ns in
the presence of liquid hydrogen ?uoride.
The invention is directed to a method of con
ducting the processes disclosed and claimed in
applications Serial Nos. 481,430 and 490,487, filed
April 1, 1943, and June 11, 1943, respectively.
According to the earlier of the said applications,
reactions such as alkylation and polymerization
are conducted in the presence of such liquid acid
is connected to a suitable source of cooling medi
um, such as plant cooling water or a refrigera
tion system and serves to absorb the heat in
excess of that taken up by vaporization of feed
in coil l2.
catalysts as sulfuric acid, hydrogen ?uoride and
The vapor phase feed is conducted from the
phosphoric acid by injecting the feed hydrocar 15 outlet of coil, l2 to a, compressor I6, preferably by
bons in vapor phase to a liquid phase catalyst.
way of a heat exchanger IT. The heat of com
The later of said applications shows advantages
obtained by supplying the feed hydrocarbons, in
pression in compressor I6 serves to supply a con
siderable portion of the preheat normally desired
either vapor or liquid phase, at a temperature in
in operation of the system, but it is usually ad
excess of that at which the catalyst is main 20 visable to adjust the temperature in heat ex
tained. According to either of these processes,
changer IT. The preheated compressedfeed from
a rather heavy heat exchange load is imposed on
compressor l6, passes by line I8 to an atomizer,
the system for removal of heat of condensation or
such as the atomizing plate IS in the bottomof
sensible heat or both; in addition to the heat of
tower id. The atomized charge rises through the
reaction encountered in processes of this type.
It is a primary object of the present inven
tion to provide a method of contacting vapor
. 'liquid- hydrogen ?uoride, which is of su?icient
phase charge hydrocarbons; preferably heated to
should provide for a residence time of at least
about 5 seconds. Although the invention contem
a temperature above that of the catalyst; to a
body of liquid phase catalyst. The method pro
vides for simultaneously abstracting heat from
the contacting zone and supplying the desired
heat to charge hydrocarbons for vaporization, and
heating of vapors if desired, by indirect heat ex
change of liquid charge hydrocarbons with liquids
depth to provide a residence time suitable for sat
isfactory alkylation. In general, the system
plates longer residence times, such periods may
vary between about 5 and 90 seconds with good
results.
As the hydrocarbons, unr‘eacted feed com
ponents, and alkylate reach interface ll, they
merge into the layer of hydrocarbons above the
in the contacting zone under conditions to in
interface and further reaction is substantially
duce vaporization of the charge hydrocarbons.
inhibited. The liquid hydrocarbons are with
This expedient takes advantage of the high latent
drawn by line 20 under the control of liquid level
heat of vaporization to achieve high e?iciency
controller 21 and transferred to conventional
cooling and at the same time achieve the neces 4-0 equipment for recovery of product and separa
sary vaporization of the charge.
tion of unreacted hydrocarbons, acid catalyst
Further objects and advantages of the inven
and heavy ends in the usual manner.
tion will be apparent from the discussion below
The tower I0 is preferably operated under a
of preferred embodiments of the invention adapt
temperature and pressure such that a fairly large
ed for practice in apparatus shown in the annexed 45 proportion of unreacted hydrocarbons (princi
drawings, wherein:
pally isobutane in alkylation of isobutane with
Figure 1 is a diagrammatic view of a reactor for
butenes) and hydrogen ?uoride will pass from
alkylation in the presence of hydrogen fluoride
the hydrocarbon layer in Vapor phase. Any hy
according to the invention; and
drocarbons that can be removed without con
Figure 2 is a vertical section of a reactor struc 50 densation materially reduce the heat exchange
ture using a double coil heat exchanger.
load and evaporation of hydrogen ?uoride aids
Referring speci?cally to Figure 1, a body of
in heat control by requiring latent heat of vapor
liquid hydrogen ?uoride occupies the lower por
ization. These vapors, containing a small amount
tion of an alkylation tower indicated generally
of heavier hydrocarbons, pass from the top of
at ID. A layer of liquid hydrocarbons overlies
the tower by vapor line 22, through heat ex
2,403,922
3
changer 23 and compressor 24 to the charge feed
line 18, from which they are again admitted to
the tower [0. The vapors from line 22 may be
condensed in whole or ‘part, cooled and supplied
by way of feed line H! after separation of liquid
hydrogen ?uoride for separate return.
The embodiment of Figure 2 employs a double
coil heat exchanger in which the reaction mix
ture in an outer tube is cooled by heat exchange
4
maintaining a reaction zone containing said liq
uid hydrogen ?uoride under conditions favorable
to said reaction such that the products of said
reaction will be predominantly liquid and the re
actants will be predominantly vaporous, intro
ducing to said liquid hydrogen ?uoride a vapor
phase feed containing isopara?in and ole?n pre
pared as hereinafter described to thereby induce
said reaction with formation of a liquid product
while permitting unreacted material to remain
predominantly in the vapor phase, removing liq
with an inner tube in which the charge is va
porized and with a ‘bath of hydrogen ?uoride in
uid hydrocarbons from said reaction zone and
which the reaction coil is immersed. The reac
recovering the product therefrom, preparing a
tion is induced in a dispersion of acid catalyst
liquid phase fresh charge mixture containing iso
and reactants formed by injecting vaporous re
actants from line "5 through a nozzle 25 in the 15 para?fin and ole?n, vaporizing and expanding
said charge mixture in indirect heat exchange
open end of reaction tube 26. The stream of re
actants acts to draw catalyst from the liquid body
surrounding tube 26 and ef?ciently disperse the
relationship with said liquid hydrogen ?uoride to
thereby cool said reaction zone, withdrawing va
reactants in the ?owing stream so induced. The
porous unreacted hydrocarbons from said reac
liquid feed is admitted to inner coil 12 through
tion zone and mixing them with said vaporized
charge mixture to form said vapor phase feed
and introducing said vaporized feed to said liquid
expansion valve l5 from feed line 14 and is va
porized in coil l2 to cool the reaction mixture.
A cooling medium is also circulated in heat ex
change relationship with the body of catalyst, as
, hydrogen ?uoride as aforesaid.
2. The process of claim 1 wherein said isopar
by jacket 21, thus providing a cooling bath about ' ' arnn is isobutane and said ole?n is butene.
reaction coil 28. The feed vaporized in coil I2
and vapor recycle from line 22 are handled in
3. In a process for synthesizing valuable hydro
carbon products by exothermic reaction of an
much the same manner as in Figure 1.
isopara?n and an ole?n in the presence of liquid
In a typical run, the alkylation was conducted
at about 80° F. and 100‘ pounds per square inch
hydrogen ?uoride, the steps which comprise main
taining a reaction zone containing said liquid hy
drogen ?uoride under conditions favorable to
said reaction such that the products of said re
absolute by maintaining tower in at about those
conditions. The vaporous charge was admitted
action will be predominantly liquid and the re
to contact with the catalyst at 200° F. and 150
actants will be predominantly vaporous, intro
pounds per square inch absolute and comprised
90 weight per cent of isobutane and 10 weight 35 ducing to said liquid hydrogen ?uoride a vapor
phase feed containing isoparai?n and ole?n pre~
per cent of butene. The advantages of the in
pared as hereinafter described to thereby induce
vention are strikingly illustrated by these typical
said reaction with formation of a liquid product
conditions. Even if the system is operated to re
while Permitting unreacted material to remain
move all hydrocarbons, including unreacted ex
cess isobutane, in liquid phase; about half of the 40 predominantly in the vapor phase, removing liq
uid hydrocarbons from said reaction zone and
cooling required for cooling the reaction zone is
supplied by vaporization of charge. About 75%
of the heat required for vaporization and pre—
heating of charge is derived from heat exchange
with the reaction mass. Where a large propor
tion of unreacted isobutane is withdrawn from
recovering the product therefrom, ‘preparing a
liquid phase fresh charge mixture containing iso
paraffin and ole?n, vaporizing and expanding
said charge mixture in indirect heat exchange
relationship with said liquid hydrogen ?uoride to
thereby cool said reaction zone, withdrawing va
porous unreacted hydrocarbons from said reac
tion zone and mixing them with said vaporized
reduced, since condensation of vapors is the
greatest factor. Under these conditions, a cor 50 charge mixture to form said vapor phase feed and
introducing said vaporized feed to said liquid hy
respondingly larger share of the cooling e?ect is
drogen ?uoride as aforesaid; said vapor phase
obtained from vaporizing of the charge in heat
feed being adjusted to a temperature in excess
exchange relationship with the reaction mass.
of the temperature of said liquid hydrogen ?uo
I claim:
1. In a process for synthesizing valuable hy 55 ride before introduction thereto.
4. The process of claim 3 wherein said isopar
drocarbon products by exothermic reaction of an
a?in is isobutane and said ole?n is butene.
isopara?in and an ole?n in the presence of liquid
WENDELL P. HAWTHORNE.
hydrogen ?uoride, the steps which comprise
the reaction zone in vapor phase, in accordance
with preferred practice, the cooling load is greatly
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