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Патент USA US2407136

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Sept. 3, 1,946. _
|__ A.' CLARKE
A_LKYLATION OFÁ HYDROCARBONS
Filed Deo. 24, 1942
_.OE
_.
2 Sheets-Sheet lA
Sept '3, 1946»
L. A. CLARKE
_ 2,407,136
ALKYLATIOÑ OF HYDROCÀRBONS
` Filed Deo-L 24, 1942
HG2
2 Sheets-Sheet 2
FIG. 3
Louls A. CLARKE
Rf.
2,407,136
l Patented Sept. 3, `1946
vUNITED STATES VPATENT OFFICE
2,407,136
ALKYLATION OF HYDROCARBONS
`Louis A. Clarke, Fishkill, N. Y., assignor to The
Texas Company, New York, N; Y., va corpora
tion of Delaware
# Application December 24, 1942, Serial No.'470,043 l
9 Claims.
(Cl. BSO-683.4)
1
is the so-called mixer of the turbo type which
utilizes internal recirculation of emulsion at very
high velocity. The power requirements for this
type of apparatus are substantial, and other
objections and difficulties with certain types of
This invention relates to alkylation for the
production of motor >fuel hydrocarbons of high
antiknock value, and more particularly to the
alkylation of paraiiin hydrocarbons with olefms
or other suitable alkylating agents in the pres
ence of a liquid alkylation catalyst.
catalysts, as noted above, are encountered.
A third type of apparatus which has been
used commercially for “this alkylation reaction is
the so-called -jet reactor wherein the hydrocar
bon and catalyst are pumped under high pressure
One of the principal objects of the invention
is to provide an improved method of carrying out
this alkylation reaction to obtain large yields of
high quality alkylate withgood catalyst life while
avoiding emulsion and settling difficulties, elimi
and introduced through a jet or thimble having a
plurality of ports into the catalyst-hydrocarbon
nating or minimizing corrosion difliculties and
effecting economy in power consumption.
Still another object of the invention is to pro
mixture so as to produce substantial agitation and
emulsiñcation of the contents of the reactor. In
this form, emulsion is withdrawn through an
vide novel and improved apparatus for carrying
overflow, a minor portion being passed to' a suit
able settler, and a major’ portion of the emulsion
`being recycled to the jet.` This type of equipment
simple in construction and of low initial and
retains all the disadvantagesnoted above.
maintenance cost.
'Other objects and advantages of the invention 20 The present invention provides a novel reactor
which is generally applicable‘to the varioustypes
will be Vapparent from the following description
oi liquid alkylation catalysts. The expression
when taken in conjunction with the accompany
“liquid >alkylation catalyst” is used throughout
ing drawings and appended claims.
the Vdescription and claims tomean a material
Heretofore, alkylation of an isoparafñn with
an olefin has been carried out commercially in 25 which is fluid and pumpable even though it may
contain dissolved or suspended solids or‘gases.
several diiierent types of equipment> or reactors.
This includes among others a pure liquid such as
One generally used type is the so-called pump
anhydrous hydrofluoric acid, a liquid containing
and time tank reactor wherein the feed hydro
out this alkylation reaction and accomplishing the
above noted advantages, the apparatus being
dissolved gas or other liquid such as hydrofluoric
carbons are introduced at the suction side of a
pump into an emulsion recycle stream of mixed 30 acid `containing 'dissolved boron iluoride, and `a
liquid containing iinely divided suspended matter
catalyst and hydrocarbon, the stream being forced
but which is fluid and pumpable, such as alumi
With turbulent flow through a suitable chiller
num halide-hydrocarbon complex containing sus
and then into a time tank which usually con
pended aluminum halide. Moreover, by means
tains suitable baiiies or other means for prevent
ing breaking of the emulsion. A substantial prc- « of the novel method of this invention, emulsion
and settling difficulties are avoided, corrosion and
portion of the stream Withdrawn from the time
erosion of parts, such as pumps and pump pack
tank is recycled to the recirculating pump while
ings, are effectively eliminated, and economy may
a minor proportion is withdrawn for recovery of
be effected in power consumption.
In accordance with the present invention, the
alkylate. ‘f While this type of equipment func
tions very satisfactorily with certain catalysts,
particularly sulfuric acid, difficulties are encoun
liquid alkylation catalyst is maintained as a rel
atively stationary body in the continuous phase
tered When it is attempted to adapt that equip
ment to a liquid catalyst containing suspended
in a vertical reactor of substantial height, such
as a tower, and a `mixed feed of paraffin hydro
carbon and oleiin or other alkylating agent in
solid material, such as an aluminum halide-hy
drocarbon‘complex containing added aluminum
halide, due to clogging of the lines and other
liquid phase, with the paraflin in substantial
molar excess of the alkylating agent, is intro
duced through a small orifice or a plurality of
orifices into the lower portion of the liquid cata-V
causes, Moreover, the power requirements for
operating the pump are material; and corrosion
diiiiculties of the moving parts of the pump, the
pump packing and other parts are experienced 50 lyst body. Asa matter of convenience, the in
vention is described hereinafter in connection
with certain-highly corrosive catalysts, such as
with the use of olefin as the alkylating agent, but
it is to be understood that other alkylating agents
Another type of equipment which has` been
hydrofluoricacid.
`
-
l
usedcommercially for alkylation and operates
-upon this generalprinciple of‘emulsion recycle
can berused in place of the olefin, as more par
55
ticularly pointed out‘hereinbelow.' The mixed
2,407,136
3
feed passes through the oriiice or orifices in such
a manner that the feed liquid is dispersed in fine
drops in the continuous catalyst phase.
The liquid alkylation catalyst has a higher
speciiic gravity than the mixed paraiiin hydro
carbon and olefin employed, whereby the dis
persed drops of hydrocarbon mixture rise up
wardly through the body of liquid catalyst due
to this diiference in gravity. While there is some
turbulence of the liquid catalyst body adjacent
the point or points of introduction of the hydro
carbon mixture, there is insuñicient agitation to
form an emulsion. By the expression “emulsion”
4
lyst body, they coalesce to form a superposed
hydrocarbon layer. A distinct interface between
the liquid catalyst body and the superposed hy
drocarbon layer is generally maintained in the
upper portion of the tower. A stream of this
hydrocarbon layer overñows through a discharge
line in accordance with the feed rate to the tower.
It is found with some catalysts that the dis
persed hydrocarbon drops may tend to entrap a
small amount of the catalyst liquid in this super
posed hydrocarbon layer. Since the rate of rise
of the dispersed drops of hydrocarbon through
the catalyst is relatively slow, a considerable vol
is meant the intimate mixture of subdivided par
urne of dispersed hydrocarbon is normally pres
ent at any one time in the catalyst liquid, so that
the interface -level in the tower during operation
character by mechanically driven stirrers, high
is substantially above the initial level of the cata
capacity pumps producing turbulent iiow, or agi
lyst alone, Moreover, accidental or deliberate
tating jets which produce eflìcient mixing and
iiuctuations in the throughput may cause the
movement of the catalyst along with the hydro 20 interface level to vary; and increase in through
carbon through the reaction zone.v Such an emul
put `may cause the level to reach the point of
sion resists breaking in the reaction zone or re
stream withdrawal. Further, the tower can be
actor and is passed from the reactor into a rel
satisfactorily operated with the interface level
atively quiescent zone >of a settler, where sufficient
at the stream withdrawal point so that the cata
ticles of both catalyst and hydrocarbon hereto
fore produced in alkylation reactions of this
settling time is allowed for separate catalyst and 25 lyst continuously overflows along with hydro
hydrocarbon phases to be formed. In the present
carbon. In order to `insure that catalyst thus
case, the hydrocarbon mix passes into the main
tained body of catalyst liquid in the form of dis
persed drops without emulsiiication. Even though
into the neutralizing »and fractionating sections
portion of the continuous catalyst phase due to
the higher velocity of the hydrocarbon adjacent
the locus of introduction, the liquid catalyst re
erably at about the level thereof. Since such
catalyst as is entrapped in the superposed hydro
carried over with hydrocarbon does not pass
of the unit, a separator or trap is provided ad
there may bea localized disturbance of the lower 30 jacent the point of stream withdrawal and pref
mains as ra continuous phase.
The dispersed
carbon layer or ‘overflows through the stream
withdrawal is not in the form of an emulsion with
-drops of hydrocarbon rise upwardly through the 35 the hydrocarbon, it immediately, or at least rap
tower without rcorresponding upward movement
idly, drops out in this separator, so that large
of the catalyst liquid. The net result is 'that the
.settling volume with substantial settling time is
hydrocarbon mix passes in dispersed form up
wardly through a relatively ‘stationary continuous
catalyst phase, and promptly forms a separate
and superposed hydrocarbon layer as it reaches
the top or upper surface of the catalyst liquid.
As distinguished from the prior practice in this
art, wherein highly eñicient agitation with the
formation of emulsion was considered a prime
requisite for the production of vhigh yields of
alkylate of good quality, it has now been 'dis
covered that such emulsion-forming agitation
can be avoided while 'still obtaining the desired
results .by utilizing the principles of the present
invention. .As :stated above, the liquid catalyst is
relatively unagitated except for Vsuch turbulence
and liquid ilow as results from the introduction
of the reactants, and the movement of the dis
persed drops of reactants upwardly through the
maintained body of catalyst liquid. There is sub
stantially*unidirectional flow -of the hydrocarbon
or `reactant phase upwardly through the rela
not required as in the case of an emulsion. How
ever, the trap or separator can be constructed -of
' substantial volume, when hydrocarbon recycle
is employed, to function as a reservoir for the cir
culating hydrocarbon. All or any portion of this
trapped-out catalyst is preferably returned to the
maintained catalyst body within the tower, to
gether with such make-up catalyst as may be re
quired. In continuous operation, a portion of
Athis catalyst may be intermittently or continu
ously discharged from the system to recovery, and
fresh catalyst introduced to make up for that
withdrawn
The recycle .of .settled hydrocarbon unmixed
with acid or other catalyst to the alkylation re
action zone has 'heretofore been proposed in con
nection with reactors operating with eiilcient agi
tation and th'e formation of emulsions. How
ever, this requires very extensive settling volume,
particularly where the recycle rate is many times
the Vfresh feed rate. Consequently, such hydro
tively stationary `continuous catalyst phase. Also,
carbon recycle has not proved commercially at
the orifice is of such small size, generally having a
60 tractive, and emulsion recycle has been univer
`diameter of about ,de vinch to ‘lé inch, and is so
sally employed. While a once-through operation
correlated with the through-put, that the hydro.
is feasible in the ‘present reactor, it is found that
carbon Vreactants are dispersed in >the form of
small drops of various sizes not ’exceed-ing about
1A; inch in diameter, and preferably' much smaller
so as .t0 have a large .surf/ace area to volume ratio.
This añords a :large Iarea vof contact between the
outer ñlm of each Ydrop and the surrounding cata
materially improved results can be .secured in
many cases by recycling hydrocarbon to the reac
tion Zone. Preferably a high recycle ratio of the
order of about 10 to öll'volumes or more of hydro
carbon recycle to 1 volume of fresh feed is em
ployed. This materially increases the ratio of
lyst liquid. This ‘operation has been found ‘to
promote the desired alkylation reaction between
the paraflin and the olelin present in the dispersed
drops as the latter »pass upwardly through the
substantial height of continuous catalyst phase.
As the drops of Ymixed alkylate and unreac'ted
paraffin `to olefin in the reaction zone and in
creases the eifective time of contact, as is well
known. Since the settling is quite rapid or a1
most instantaneous in the present-operation, it is
hydrocarbon reach the upper surface of the cata- ”
separated from an emulsion Aare effectively over'
apparent that the diiiiculties inherent in previ
ous proposalsl involving recycle of hydrocarbon
5
2,407,136
come. The recycled hydrocarbon is preferably
first- admixed with the fresh feed hydrocarbon,
mersV of isobutylene and normal butylene, mixed
or non-selective Ca-C4 polymers, and the like,
and various fractions of thermally or catalyti
cally cracked gasolines and of polymer naph
and themixture introduced through' the orifice
or oriñces into the reaction zone.
The trapped
out catalyst is preferably returned directly and
thas may be used.
by gravity to the maintained catalyst body, there
by avoiding the use of pumps in the handling of
the more corrosive catalyst liquid.
If desired, the reactor or tower of the present
invention may be supplied in the reaction zone 10
with one or more layers of solid contact or filling
In place of an olefin as-the alkylating agent,
various alcohols and ethers, such as isopropyl
alcohol, tertiary butyl alcohol, secondary butyl
alcohol, isopropyl ether and the like, may be em
ployed with suitable known alkylation catalysts
which' have tolerance for water liberated in the
material to thereby increase the length of the
reaction. Likewise, the corresponding alkyl
path of flow and th'e time of contact for each
esters, such as the alkyl halides, sulfates, phos
once-through flow- of the dispersed drops in the
phates, etc. of the oleñns, may be used as the
catalyst liquid. The packed tower can be oper
alkylating agent with an appropriate or compat
ated withonce-through flow or hydrocarbon re
ible alkylation catalyst, as- is well known.
cycle. Any suitable contact material, which is
vWherever the expression “alkylating agent” is
non-reactive with respect to the catalyst and the
used throughout the description and claims, it
reactants and which provides sufficient free space
will be understood that this refers to oleñns as
‘for the proper travel of the drops, may be em 20 well as alcohols, ethers and esters of th‘e charac
ployed. A very suitable type of material for
ter described above and which are capable of re
this purpose consists of‘small contact pieces, each
acting with a paraflin or other hydrocarbon hav
shaped to simulate a saddle, and known to the
ing a replaceable hydrogen atom to produce an
trade as “berl saddles”. There is some indica
alkylated hydrocarbon of higher molecular weight
tion that the use of a packing in the tower may
of the character set forth herein.
`
`
enable the use of somewhat larger size drops
Any ofthe well known conditions suitable for
and obtain as good results as with a higher degree
the various alkylation reactions can be used. In
of dispersion (i. e., smaller size drops) in an un
general, a substantial molar excess of paraffin
to olefin or other alkylating agent is employed,
4packed tower. Moreover, the combination of a
packed tower with a high degree of dispersion
such as a `feed ratio in excess of 1:1 and prefer
can be used. i However, very satisfactory results
ably about 4:1 to 8:1, which provides a sub
Vare secured with an unpacked tower operating
stantially higher contact ratio in the reaction
with either Yonce-through' flow or hydrocarbon
recycle, preferably the latter.
Any of the conventional catalytic alkylation
35
zone generally inl excess of about 50:1 when hy
drocarbon recycle is used. The reactor is main
-reactions can be carried out by the method and
tained under sufficient pressure to linsure- that
the hydrocarbons and alkylating agents are in
with the apparatus of ` the present invention.
the liquid phase. The temperature of the reac-V
Thus, the reaction of an isop'araf’fin with an ole
.ñn or other alkylating agent, as well as the alkyl
ation of a normal parafûn with an olefin or other
'alkylating agent, in ’the presence of suitable
alkylation catalysts can be accomplished. Th'e
'paraffin charge stock may be either normally
gaseous or normally liquid or a mixture thereof.
In isoparafiin alkylation, isobutane and isopen
tane are preferred, although it is to be under
`stood that any of the low boiling isoparañins may
be used and conventional catalysts effective for
such isoparaiiin alkylation can be employed.`
The present invention appears particularly effec- f
tion varies with the hydrocarbons or alkylating
agents employed and with the catalyst, as is well
understood, but generally ranges from about
_40° F. to about 150° F. A high ratio of catalyst
to hydrocarbon is inherently maintained in the
reaction zone due to the maintained body of cat
alyst liquid of substantial height through which
the» hydrocarbon phase is dispersed. As pointed
out above, the present invention departs radically
-from the previous practice in this art with respect
to agitation, since mechanical stirrers and high
capacity pumps with eincient agitation are avoid
ed, and introduction of dispersed hydrocarbon
vtive for isoparañîin alkylation with hydroiiuoric
acid or aluminum chloride-hydrocarbon complex
`without the formation of an emulsion and the
`containing suspended aluminum chloride as the
catalyst. Likewise normal paraflins can be alkyl
ated with olei'lns or other alkylating agents in
the Vpresence of suitable catalysts, such' as hy
tively stationary body of continuous catalystV
drogen ñuoride containing dissolved boron tri
iiuoride or aluminum chloride-hydrocarbon com
plex' containing suspended aluminum chloride.
Various normally gaseous or liquid normal paraf-`
ñns, such as normal butane, normal pentane and
-higher normal paraffins or mixtures thereof, may
be used for the charge stock. Likewise, mixtures
of visoparaffìns and normal paraffins may be em
ployed. 'I'he features of tower type alkylation of
the present character, as applied to isobutane
ethylene with an activated aluminum chloride
hydrocarbon complex catalyst, is disclosed land
claimed in the copending application of Louis A.
Clarke, Serial N0. 535,261, flled May 12, 1944.
The olefin charge stock may be any of the
normally gaseous or normally liquid olefins or
mixtures thereof. For‘example, ethylene, pro
pylene, butylenes, amylenes, C4 polymersI such
Vas di-isobutylene and tri-isobutylene, cross poly- l
risingof hydrocarbon drops through the» rela
' phase by the difference in gravity therebetween,
»are substituted.A
‘
‘
`
The invention is more particularly illustrated
in the attached drawings which disclose preferred
embodiments thereof. In the drawings:
Fig. 1 is a diagrammatic illustration of appa
'ratus’ suitable for carrying out the method of the
present invention;
Fig. 2 is a partial vertical sectional view on
an enlarged scale of the tower reactor of Fig. l.
Fig. 3 is a partial view similar to Fig. 2 of a
modification;
"
Fig. 4 is a plan view of the orifice plate of Fig.
3; and
‘
Fig. 5 is a partial View similar to Fig. 2 of a
second modification.
Referring to the drawings, particularly Fig. 1,
the hydrocarbon mix 'containing the paraffin and
' olefin in liquid phase is introduced by pump 9
through pipe I0 controlled by valve Il into the
bottom of tower `I2 beneath the orifice plate I3.
.The `tower may be equipped with an external
2,407,136
8
jacket I5 provided with inlet IB and outlet I1
for the supply of a suitable cooling or heating
medium to maintain the desired temperature
within the reaction zone. It is to be understood
that other conventional means for controlling the
temperature in the reaction zone can be used,
mentioned condition of operation, which is ob
jectionable and is to be avoided, can be readily
detected by the drop in interface level. While
satisfactory operation can be secured at the lower
throughputs described above, it is generally de
sirable to operate in. the upper portion of the
such as the fresh feed and recycle hydrocarbon
chiller hereinafter described, internal evapora
tive cooling, etc. As shown more particularly in
Fig. 2, the tower is partially filled with a suit
throughput range which produces greater disper
sion and a higher interface level approaching the
upper limit described above.
Referring again to Fig. 1, the tower I2 is
able liquid catalyst I8. The amount of catalyst
liquid is generally such that,l during operation
equipped with an overflow or outlet 26 through
which the hydrocarbon layer 20 is discharged in
with an appreciable volume of hydrocarbon liq
uid dispersed` in the Catalyst at any one time,
the interface I9 between the relatively stationary
a stream to a suitable separator or trap 21. AS
shown, this is preferably a cylindrical vessel
arranged with its longitudinal axis somewhat in
clined to the horizontal. Adjacent the lower end
body of liquid catalyst and the superposed hydro
of the separator, a bottom discharge line 28
carbon layer 20 is positioned adjacent the upper
is provided to conduct catalyst by gravity back
end ofthe tower.
to the lower portion of the tower. Pipe 28 opens
The oriñce plate I3 is provided with an open
ing or orifice 22 shown as positioned at the ver 20 into the tower at a locus 29 opposite the main
tained catalyst body I8, so that this catalyst is
tical axis of the tower, this orifice being of small
returned directly thereto.
size of the order previously indicated. The en
The upper end of separator 21' is also provided
tire tower is maintained under sufficient pressure
with an overflow 33 connected with branched
so that the hydrocarbon mix ysupplied by line I0
is in liquid phase, and this mix is under sufi-l 25 lines 3l and 32 controlled -by valves 3|’ and 32’
respectively. Hydrocarbon may be passed to the
cient additional pressure to counter-balance the
alkylate discharge line 3| or a portion of the
height of the liquid column within the tower and
alkylate passed to the discharge line 3| and the
to overcome the pressure drop through orifice 22
balance to the hydrocarbon recycle line 32 con
to obtain the desired dispersion. The space 23
in the tower beneath the orifice plate I3 remains 30 taining a suitable pum-p 33. Line 32 communi
Cates with the hydrocarbon mix feed lineV I0, a
filled with the hydrocarbon mix, and the catalyst
suitable surge drum 34 being preferably con
liquid is prevented from flowing down through
nected to line 32 by branch line 34' in advance of
the orifice. into this space and backing up into
pipe Ill to take care of fiuctuations in the pump
the- inlet pipe I0 by the maintained feed pres
sure. This causes the hydrocarbon to pass 35 ing rate and to maintain the regulated pressure
in the feed line Ill. Preferably, a'suitable chiller
through orifice 22 with the formation of a mul
or heat exchanger 35 is positioned within line
titude of small drops indicated at 24, which pass
Iii' in advance of the tower inlet to- precondition
up through the liquid catalyst body due to the
the temperature of the fresh feed hydrocarbon
difference in gravity between the catalyst and the
hydrocarbon. As the drops reach the interface 40 and the recycle hydrocarbon to maintain the
desired temperature withinv the reaction zone of
I9, they coalesce to form the superposed hydro
the tower. Any suitable control means can be
carbon layer 20.
used for regulating the pressure and rate of
While the orifice plate i3 can be equipped with
through-put of the fresh feed and hydrocarbon
a simple opening in some cases, it is preferably
recycle through the orifice to thereby control and
provided with an upstanding nozzle 25 of a known
regulate the degree of dispersion of the drops
type adapted to effect a spray dispersion of the
in the catalyst liquid, such as the proportion
hydrocarbon in the form of ñne drops. For any
ing pumps 9 and 33 and the surge tank 34 as
given nozzle of this character, at the lower
shown.
throughput or rate of supply of hydrocarbon,
As pointed out above, a major portion of the
fewer drops of a larger size will issue from the
hydrocarbon is preferably recycled through line
opening or discharge orifice of the nozzle. Theo
>3? and> re-introduced together with the fresh
retically, the throughput rate can be reduced to
feed through line I0 into the tower. A minor
proportion of the settled hydrocarbon is with
drawn in accordance with the fresh feed rate
through pipe 3| and passed by pump 36 together
drop is of a proper small size. As the through
with suitable neutralizing agent, such as caustic
put rate is increased from this given orifice, the
drops not only issue faster but are of smaller
soda solution, introduced by line 31, into a scrub
ber 33 where the hydrocarbon is neutralized.
size. This also causes the level of the inter
face I9 to rise, due to the larger number of dis 60 The neutralized materiall overñows by line 39
persed drops and the greater volume of hydro
into an intermediate portion of a settler 49 where
carbon present in the liquid catalyst body at any
the caustic soda solution settles out and is with
drawn through line 4I. The bulk of the solu
one time. As the throughput is further in
tion is recycled by line 42 to line 31 for reuse
creased, the drops become exceedingly fine and
in treating fresh quantities of hydrocarbon, while
the interface level reaches a maximum height.
a minor proportion may be withdrawn inter
Further increase of the throughput beyond this
mittently or continuously by a discharge line
limit causes an accumulation of hydrocarbon to
43, fresh make-up caustic soda solution being
be formed within the base of the tower surround
added by feed line 44.
ing the nozzle, from which globs o-f the hydro
The neutralized and settled hydrocarbon over
carbon break off and rise upwardly through the
flows from settler 4I] through line 43 and is in
tower. This latter condition results in a drop
troduced by pump 41 into a stabilizer 48 where
in the interface level, due to the fact that the
unreacted gases including excess paraffin are
degree of dispersion and the quantity of hydro
removed overhead by line 49. These lighter
carbon dispersed in the catalyst liquid at any one
time is then reduced. Consequently, this last 75 gases are forced by pump 50 into a suitable frac
the point where the drops issue one after the
other in relatively slow succession, provided the
orifice is sufficiently small so that each individual
2,497,136
10-Y
9 ..
tionator 5I where separation is made between
unreacted isoparaiiin, such as isobutane, which
is withdrawn by overhead line 52 for recycling
to the reaction tower I2, and any heavier hydro
carbons such as normal butane, which are with
drawn by bottom line 53. It will be understood
that >the fractionating system shown is that par
ticularly designed for isobutane alkylation
spaced as to-substantially encompass` the cross
section of the tower‘with the drops. This_ pro
wherein the charge, which may be a suitable
thetower 86 is provided with a packing 8l of solid
refinery C4 cut, also contains normal butane.
However, the fractionating system can
modi
While a nozzle or plurality of nozzles can be'used .
ned from that 4shown in accordance with the
charge stock being handled as is well understood
lysts such as an aluminum chloride-hydrocarbon
in the art.
'
duces a series of sprays of drops 'l5 into the lower ,
portion of the maintained liquid catalyst body,
while avoiding undueagitation, and avoiding un
due interference of the drops from one nozzle
with those from another.'
`
Figure 5 dis closes another modification wherein '
Contact material
above .. the orifice plate 82. ,
in this form, it is foundthat with certain cata
complex containing suspended aluminum chlo-`
.
ride a simple opening or oriñce 83 through lthe
The stabilized alkylate is removed from the
bottom of stabilizer 48 byline 55-and passed by
orifice plate functions satisfactorily to accom
by bottom discharge line 58‘.
of the contact zone containing the liquid catalyst,
or may extend above .the oriñce plate 82 through
out only a portion of the height of the tower
confining the catalyst, with an upper unpackedv
plish the desired dispersion and distribution of
pump 56 to a> suitab-le fractionator 51 which
the hydrocarbon drops throughout the catalyst
serves to take overhead a desired fraction, such
liquid, as aided by the contact material. This
as an aviation fraction boiling up to about 350
to 375° F. A heavier residue fraction is removed 20 packing may extend throughout substantially all
The o-verhead
vaporized fraction passes by line 59 through a
suitable condenser 60, and the condensed liquid
flows by line 6I into an accumulator 62. Any
light gases may :be bled off from accumulator 25 section "84. > As shown, the hydrocarbon issuing
from oriñce 83 in the form of the dispersed drops
62 by vapor drawoff 63 and the desired stabilized
85 is distributed within a short upward travel
fraction of the alkylate is removed by bottom
throughout the cross~section of the tower. The
line 64 to suitable blending tanks or storage (not
shown).
Y
yThe `reaction tower |'2 illustrated in Fig. 2
is of a relatively smaller capacity type having a
single orifice 22. This tower may be conven
dispersed drops rise through the catalyst liquid
Vthrough the free space provided by the packing,
‘the latter impeding the normal velocity of up
ward travel due to 4difference in gravity and in- '
creasing the length of the path of travel thereof.
iently constructed of an interior diameter of
While a nozzle, or a plurality of nozzles, adapt
about one inchto 12 inches or more, with an ori
‘ rice selected to give fine dispersion and a lateral 35. ed to direct the drops upwardly within the tower,
distribution to substantially extend throughout> ‘ has been shown in the drawings, it is to be under
stood that this arrangement is not essential.
the, >cross-section thereof. The tower may be
Thus, the nozzle may be directed in an inclined
from about 5 feet to 20 feet or more in height.`
or horizontal direction, so long as the hydrocar
It. will ‘be understood that this is merely repre
sentative of satisfactory tower reactors having a 40 bon is dispersed into the catalyst liquid in the
" form of fine drops as described above, which are
single orifice, and that the invention is not lim
then free to rise through the catalyst liquid, and
ited to -towers of these dimensions. However,
so long as undue agitation and emulsification are
for a single oriñce type, the height should be
avoided. Moreover, it is to be understood that
many times greater than the diameter. Such
towers have >,been successfully operated -with 45 other types of dispersing devices can be employed,
such as a cone adapted to introduce the hydro
heights of catalyst liquid varying from about 30
carbon from the periphery thereof and thus dis
inches up to> about 200 inches or more.
'
seminate the drops over a larger area of the
Where a plural number of oriiices are used,
cross-section of the tower.
`
the diameter >of the >tower maybe greatly in
The invention is further illustrated by the fol
creased without necessarily increasing the height.-
lowing specific examples; but it is to be under
stood that these are given by way of explanation
and the invention is not limitedthereto.
Ercample I
The latter dimension is regulated in accordance
with thecharge stocks and catalysts with a view
to insuring substantially complete disappearance
of the oleñn or other alkylating agent as such
in a once-through passage. objectionable side’ 55
The Afollowing example illustrates the applica?
reactions due to prolonged contact of hydrocar
tion of the invention to the alkylation of a mixbon or unreacted olefin with catalyst »in transfer
ture of isobutane with a C4 fraction from a crack
linesA and settlers are minimized or avoided. »It
ing operation, using anhydrous HF as the cata
is to be understood that two or more towers'canä
lyst. The mixed hydrocarbon charge had the
be used with series flow of hydrocarbon there 60
following analysis:
through, where the desired degree of conversion
‘
or `reaction cannot be accomplished in a single
tower of practical height. In this tower reactor,
-
v
`
i»
In Figures 3 and 4, there is shown a modifica-v
tion of the tower reactor particularly designed for
largerscale operation. In this form the tower»
10 is of relatively larger'diameter, such as from
Weight percent
1.4
Isobutane _____________________________ __ 68.6
the time of >contact for all portions of the react#
ing hydrocarbons is uniform.
‘
Propane ______________________________ __
65
Normal butane- ________________________ __ 14.7~
y Isobutylene
__ _________ _;__; ____________ _-
6.9>
Normal butylenes ______________________ __
8.0
Caïn. ________________________________ _.;
0,4
The apparatus employed in the following runs
A bottom oriñce plateV 12 70 included a `.tower constructed of one-inch steel
tubing about seven feet .long equipped with a
is ’provided with a plurality of upstanding nozzles
jacket through which cooling water was passed
1-3 arranged more or less uniformly over the cross
two to six feet or more.
section'of the plate. „ Eaohnozzle is constructed
for thepurpose of controlling the temperature.
The overflow from the tower was connected with
to provide effective dispersionin the manner pre
viQuÍSly, . descrieéd; 'the Several mzzl@ .heini S0.' 75 aninclined separator made of copper which was
1l
12
two inches in diameter by seven feet long. The
towerwas operated under two conditions, namely,
packed for about iive feet of its height with brass’
apparatus of the present invention avoided hy
drogen transfer reaction with the production of
n-butane in the above noted- C4 alkylation with
HF. An analysis ofthe oífgas from the run with
the unpacked tower listed above showedl the fol->
plated steel jack chain and utilizing once
through operation for one continuous run, and
unpacked with top separator recycle for a second
lowing:
continuous run. The volumetric characteristics
of the tower were as follows:
,
Weight per cent
Propane
cc.
Isobutane
1.3
_____________________________ __ '75.7'
Volume of tower unpacked _____________ __ 1340 10 Normal butane _________________________ __ 21.6
Free space in tower packed...v __________ __ 1050
Residue _______________________________ __
1.4
Free space in tower to top of‘ packing ____ __ 675
Calculating from the charge stocky employed
The tower was provided with an axially-arranged
and assuming no hydrogen transfer reaction„ the
theoretical 'weight percentage of normal- butane in
the oiigas should be 21.5%. It is; thusI seen that
alkylation took place in the- presence of HF under
these conditions without this objectionable side
reaction, thereby avoiding the formation of un
desired normal butane.
orifice et; inch in diameter.
In the run with the packed tower, the latter
Was charged with 605 grams (605 cc.) of anhy
drous liquid HF which nearlyl filled the packed
portion thereof. The remainder of the system
was then ñlled with isobutane, and the premixed
charge, composed of a primary debutanizer over
head and commercial isobutane which had the
above listed analysis, was charged into the bot
tom of the maintained catalyst body through the
oriñce ata charge rate varying from 0.4 to 1.6
pounds per hour. The hydrocarbon mixture
Example II
The following runs illustrate the alkylation of
a normal parañ‘ln, such as normal butane, with
' » an oleñn in the presence of a catalyst containing
a major proportion by weight of anhydrous liq
passed upwardly through the packed catalyst
uid HF and a minor proportion of BF: dissolved
layer, and a stream of the superposed hydrocar
therein, under the general conditions set forth
bon layer was continuously Withdrawn to the sep
in the copending application of Louis A. Clarke,
arator, from which a top eiiiuent hydrocarbon
stream was passed through a caustic scrubber, 510i Serial NO. 438,418, filed April 10, 1942. Briefly,
these conditions include a high normal parafñn
stabilized, distilled and tested.
to-oleñn mol ratio, a catalyst consisting of HFv
Inthe run withY the unpacked tower employ
containing less than 46% by weight of BF: based
ingï top separator recycle, the tower was- charged
on
the weight of the mixed catalyst and gener
with 415 grams (415 cc.) of the anhydrous liquid
' 'rally about 12-20%, a temperature within the
HF and' the free space iilled with isobutane. Hy
range of 0-l50° F. with about 'l0-130° F. being
drocarbon fresh feed of the' same composition
preferred, a pressure of about 100-250 pounds per
together with hydrocarbon recycle from the top
square inch, and a high catalyst to hydrocarbon
of the settler were passed through the oriiice into
ratio in the reaction zone. AS set forth in the
the catalyst body, the fresh feed charge rate being
0.4 pound per hour and the recycle rate being 1.7 40 said copending application noted immediately
above, this. reaction not only eiTects alkylation of
gallons perV hour. A stream from the hydrocar
normal
paraffin with oleñn but concomitantly ef
bon layer in the tower was passed to the sepa~
fects isomerization or the production of a sub
rator, from which a major portion of the hydro
stantial yield of isobutane.
carbon >was recycled to the fresh feed inlet while
A series of continuous runs utilizing the HF
the remainder ywas passed through a caustic
BFs catalyst for the alkylation of normal butane
scrubber, stabilized, distilled and tested.
with various oleñns to produce alkylate and con
Each of the runs was continued vfor a period
comitantly form isobutane were carried out in
in excess of about 50 hours. The conditions and
accordance with the present invention in a stain
results of thel runs were as follows:
50 less steel unpacked tower eight feet high and
one inch inside diameter. The catalyst is highly
Packed ~ Unpacked
corrosive to iron and ordinary steel; but copper,
tower
tower-top
Monel metalv and I8-8 stainless steel satisfac
single
separator
pass
recycle
torily resist corrosion. A convenient method of
maintaining the required amount of BFs in the
Charge rate, pounds per hour ____ ._
_.
0. 4-1. 6
0.4
catalyst liquid, which was used in these runs, in-Recycle rate, gallons per hou
_ i
None
1. 7
volves Isaturating normal butane at room tem
Temperature, ° F ......... ._
70
70
perature and about 160 pounds per square inch
Isobutane/oleiin mol ratio
5:1 '
5:1
Yield debutanized alkylate:
i
pressure with BFS; and introducing this normal
Weight per cent on olefin ........... .i
_184
182
Volume per cent 311° F. E. P. frac
butane saturated with BFa. together with a stream
tion on basis of total debutanized
of mixed normal butane and oleíin through the
alkylate ........................... _.
77
90
, Volume per cent 2,2,4 trimethylpen
orifice at the bottom of the tower into the. pre
tane on basis of total debutanized
<
alkylate ___________________________ __
20
viously supplied catalyst liquid. 'I‘he tower was
48»
provided with a 1/8" diameter orifice.
A brass
tube two inches in diameter and seven feet long
65 served as a separator.y
Octanenumber of 311° F.
E. nalkyme
Clear ____________________ ._
'
AFD 1C
90.6 _____________ ._
In starting up the` run, the system was ñlled to
CFRM
200- pounds pressure with catalyst and. normal
butane. Various heights of the maintained body
94.6.
of catalyst were employed in different. runs -, but
in the runs listed below, a height of about 108
109’ ’ was used with very satisfactory results. Topv
separator recycle was employed, and catalyst was
Plus l ce. TEL/ga1lon__... 97.1 ............. ._ Ist’ìIÄlëzItJane-l-l-.ZG cc.
Plus 3 cc. TEL/gallon_-_.. Iso - octane + 0.14
cc. TEL.
Plus 6 cc. TEL/gallon _______________________ __
Iso-octauc-|`-l_98 cc.
TEL.
f
' It was found in this work that the method and
75
returned to the tower by gravity flow. The por
tion of the hydrocarbon 'not recycled was caustic
neutralized, stabilized, fractionated and tested. -
25,407,136@1
13T
ethylene respectively: y
Y
‘
114i
catalystliquid may be continuously or intermit
"I'he‘ following are the conditions and results
on two continuous runs of extended duration on
normal butane-propylene and normal butane
tently withdrawn from a lowerV` or intermediate
portion of the tower, and fresh catalyst liquid
supplied to the maintained catalyst body con-`
.
tinuously or intermittently at an upper or inter-`
Olefin
109
70
0. 8
23. 3
7. 9
Bromine number _ _ _ _ _ _ _ _ _ _
108
70
0. 8
23. 3
_10. 5
257
394
95. _6
96. 1
_ _ _ _ _ _
Residuerper cent by volume of total alk ate_
4. 4
_
12. 2+
stantially higher velocity than the velocity of
movement of the catalyst. In such event, the dis
persed hydrocarbon drops are still appropriately
described as rising upwardly through a “relatively
stationary” body of the catalyst liquid, and this
3. 9
' expression is used as a matter of convenience
2
throughout the description and claims to include
0r
Bromine number _________________ ..-_____ i __________ __
Volumes’of alkylate per volume of catalyst.
hydrocarbon, the latter of course moving at a sub
83. 9
0
Octane number CFRM _________ ._` _-_` ___________ __
Isobutane:
mediate portion of the tower. Thus, there may
be relatively slow and progressive movement of
the catalyst liquid downwardly through the tower
countercurrent to the upwardly rising drops of.
Propylene Ethylene
_ 29. 2+’
these various operations as above described.
.
Weight per cent yield basis normalbu~
tane..v ...... __ __________________ __’__-._
27.1
Weight per cent yield basis olefin _ _ _`. _ _ _
29
Weight per cent yield basis catalyslr.-.
974
It is therefore seen that, in accordance with
40. 4
420
l, 958 20
` In the, series of runs mentioned above, it was
found _that by increasing the height of the cata
lyst from 31’ ’ to 109’ ’ in normal butane-propylene
alkylation employing hydrocarbon recycle, there
was an increase in the yield off alkylate basis
the present invention, the necessity for handling`
and recycling catalyst, oran emulsion contain
ing catalyst, by high capacity pumps or other
moving parts is avoided. The recycle of hydro
carbonvunmixed with catalyst can be accom-_
vplislied without corrosion or erosion difficulties.
' The tower itself and other parts such as the sep
arator and lines which contact the catalyst can
olefin, the percent of alkylate boiling below 311°
readily be constructed of corrosion-resistant ma
F., the 4conversion of normal butane to isobu-tane
terial; and the `more highly corrosive catalystY
and the catalyst life. Also, byV increasing the ratio
does not come in contact with movingv parts,`
of top settler recycle to fresh feed from `11.7 to 30' pump packings and the like. _
y
.
23.3, the yields and catalyst life were improved.
It has heretofore been proposed to effect ab,
Higher yields of alkylate and isobutane base-d on
sorption or polymerization of oleñns by dispers
the olefin charged were obtained from normal
ing the oleíins >in liquid phase through nozzles
butano-ethylene _alkylation than from normal
35 into aA body of sulfuric acid. However, it is well
butane-propylene alkylation.
__ _
.
q
‘
recognized that such reactions take place read
_ While the invention has been described above
ily without efficient agitation. It has also been
in connection with the alkylation of paraffins with
proposed to apply this operation to a refinery C4
olefins or other lalkylating agents, it is alsocon
cut from which isobutylene had been removed,
templated that Vthe method and apparatus of the
and which contained both isobutane and n-bu--.
present invention can be employed for thealkyla
tylenes with the latter in molar excess, in the
tion of other hydrocarbons having afreplac'eable
presence of strong H2SO4 of at least 87%, for the
hydrogen atom, such as aromatic and naphthene
absorption of n-butylenes in the acid and the
hydrocarbons, with olefins or other alkylating
concomitant production of a small yield of gas
agents, 4such as alcohols’ethers and esters. For _ oline hydrocarbons of an unsaturated character.
example, the alkylation of benzene with propylene
It has not been heretofore recognized and taught
for the production of isopropyl benzene, the-al
kylation of benzene with ethylene for the produc
tion of ethyl benzene, _etc.,in the presence oflsuit
ì that, in accordance with the method of the pres-Í
ent invention, and by avoiding eiiicient agitation
producing an emulsion, alkylation of a hydro
able well known liquid catalysts which are im 50 carbon or paraflin with an olefin or other alkylat
miscible with >the hydrocarbon reactants, can be
ing agent could be accomplished as the principal
carried ,out in the manner and with the> tower
reaction of the process, with minimum oleñn ab
sorption and/or polymerization, whereby a sub
`While in certain cases, the same liquid cata
stantially saturated alkylate of good quality is'ob
lyst body as originally supplied tothe tower may
tained with minimum catalyst deterioration and
be maintained _therein for the entire reaction, thus
resultant long catalyst life. This was unexpected
providing continuous feed of hydrocarbon with
and directly contrary to the previous knowledge
batch feed of catalyst, it is to be understood that
and experience in »this alkylation art. As pointed
a portion of the liquid catalyst may be continu
out above, this invention is particularly advanta
ously or intermittently withdrawn and replaced
geous for those alkylation catalysts which are
with fresh catalyst during continuance of the 60 morecorrosive to pump parts and packings than
process. . By the expression “relatively stationary”
sulfuric acid, such as I-IF, vlilik-Bib., BFanI-IZO,
as applied tov the'liqui‘d catalyst body, it will be
etc., as well as for those alkylation catalysts which
apparent that this signifies that the hydrocarbon
tend to clog emulsion recycle lines, such as the
moves relatively to the catalyst body and at a
65 aluminum chloride-hydrocarbon complex con
reactor vas described above.
_ Y `
_
substantially greater rate or velocity, irrespective
of such localized movement or turbulence which
taining suspended aluminum chloride.
Obviously many modiñcations and variations
of the invention. as hereinbefore set forth, may
be made Without departing from the spirit and
be understood that this expression includes op
scope thereof, and therefore only such limitations
erations in which a small portion of the catalyst 70
should be imposed as are indicated in the ap
liquid may continuously or intermittently over
pended
claims.
flow to the separator and be returned through
I claim:
f
‘
.
the gravity line or in other suitable manner to
1. The method of continuously alkylating a
the liquid catalyst confined within the tower, as
Well as an operation in which a portion of the 75 hydrocarbon having a replaceable hydrogen at
may exist within the catalyst liquid, particularly
at the lower portion thereof. Moreover, itis to
15`
2,407,136
om with an alkylating agent in the presence of
an alkylation catalyst of greater specific gravity
than the hydrocarbon and alkylating agent, which
comprises maintaining an undispersedl liquid
body ofv the alkylation catalyst of substantial»
height as the continuous phase in a reaction
16
5.> The method according to claim 1, wherein
at least a portion of the settled catalyst is re
turned directly to the maintained catalyst body
without previous mixing with the fresh feed and
recycled hydrocarbon dispersed into the lower
portion of the catalyst body.
6. The method according to claim 1, wherein
the hydrocarbon is a paraiiin, and the alkylating
zone, continuously dispersing a fresh feed> of
mixed hydrocarbon and alkylating agent sub
stantially free from alkylation catalyst and with
agent is an oleñn.
the hydrocarbon in liquid phase i-nto a lower por-V 10
'7. The method according to claim 1,. wherein:
tion of the liquid catalyst body Without dispersion
the movement of the dispersed liquid> drops ris
of the latter to form-a multitude of ñne liquid
ing through the liquid catalyst body in the reac
drops of mixed hydrocarbon and alkylating agent
tion zone is modified and increased in length by
which rise in dispersed form through a substan
contact with packing material submerged within
tial height of the continuous catalyst phase- due
the liquid catalyst body.
tol difference in gravity therebetween, whereby
8. The method of continuously alkylating a
alkylation of the hydrocarbon with the alkylat»
hydrocarbon having a replaceable hydrogen atom
ing agent> to form normal-ly liquid alkylate takes
with an alkylating agent in the presence of an
place as the principal reaction of the process, the
`alkylation catalyst of greater specific gravity than
dispersed drops coalescing to form a hydrocar-v 20 the hydrocarbon and alkylatingv agent, which
bon phase upon reaching the upper surface of'
comprises maintaining an undispersed liquid body
the liquid catalyst body, continuously removing
of the alkylation catalyst of substantial height
a stream containing the coalesced hydrocarbon
as the continuous phase in a reaction zone, con
phase, settling any entrained catalyst from thev
tinuously dispersing a fresh feed of> mixed- hy
removed stream to provide a hydrocarbon layer
substantially free from catalyst, recycling a ma
drocarbon and alkylating agent substantially free
from alkylation catalyst and with the hydrocar
jor portion of the hydrocarbon layer containing
bon in liquid phase into a lower portion of the
alkylate and substantially free from catalyst and
liquid catalyst body without dispersion of the
mixing the same with the fresh feed for redis
latter to form a multitude of ñne liquid drops
persion unmixed with alkylation catalyst into 30 ofi mixed hydrocarbon and alkylating agent which
the lower portion of the catalyst body, recovering
rise in dispersed form through a substantial
a substantially saturated hydrocarbon alkylate
height of the continuous catalyst phase due to
from- a minor portion of said hydrocarbon layer,
difference in gravity therebetween, whereby al
and adding _fresh alkylation catalyst directly to
kylation of the hydrocarbon with the alkylating
the maintained body without premixing with said 35 agent to form normally liquid> alkylate takes place
fresh feed as the operation proceeds to preserve
the alkylating- activity thereof.
2. The method according to claim 1-J wherein
the said hydrocarbon is a low-boiling isoparail‘in
as the principa1 reaction of the process, the dis
persed drops coalescingV to form a hydrocarbon
phase upon reaching the upper surface of the
liquid catalyst body, continuously removing from
and the alkylating agent is- an olefin, and the» 40 substantially at the level of the interface be
liquid catalyst comprises hydroiluoric acid.
tween the upper surface of the continuous cata
3. The method according to claim l, wherein
the said hydrocarbon is a normal parañìn and
lyst body and the lower surface of the coalesced
hydrocarbon phase a stream containing coalesced
the al-kylating agent is an olefin, and the liquid
hydrocarbons along with some overflow catalyst
catalyst consists essentially of a major propor 45 liquid, rapidly separating catalyst liquid from the
tion of- substantially- anhydrous hydrofluoric acid
removed stream to provide a hydrocarbon layer
containing a minor proportion of boron fluoride.
substantially free from catalyst, removing a
4. The method according tov claim l, whereinl
stream of the hydrocarbon layer and recovering
the rate of throughput of fresh feed and. recycled
a substantially saturated hydrocarbon alkylate
hydrocarbon produces- a dispersion of a large 50 therefrom, and adding alkyl'ation catalyst direct
number of drops- each of less tha-n 1A; inch in
ly to the.- maintained catalyst body without pre
diameter throughout the liquid* catalyst body giv
ing
the
the
tial
mixing with said fresh feed as the operation pro
a substantial rise in the operating levelY of
ceeds to maintain the volume and alkylating ac
interface between the catalyst liquidi and
tivity of the said catalyst body.
superposed hydrocarbon layer above the ini 55
9. The method according to claim 8, wherein
level of the catalyst body alone, the said.
rate being below that: which causes an accumu-y
lation of the fresh feed and' recycle liquid imme
diatel'y about the region» of dispersion inthe lower
portion of the reaction zone` resulting in a. re
duction in the degree. of dispersion of the dropsi
anda lowering of theinterface level.
atleast a portion of the settled catalyst together
with fresh make-up catalyst is returned' directly
to the maintained catalyst body without previous
mixing with the fresh feed at a level near the
60 lower portionY of the maintained catalyst body.
LOUIS A. CLARKE.
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