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Патент USA US2131191

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Patented Sept. 27, 1938
~ 2,131,191
- UNITED STATESIIPAITENTA OFFICE‘
2,131,191
DISPERSION
OLEFINES IN’ ACID POLY
MERIZATION
I
Bruno E. Roetheli 'and- Eldon E. Stahly, Baton.
Rouge, La., assignors to Standard Oil Develop- .
ment Company, a corporation of Delaware '
Application October 24, 1936, Serial No. 107,322
7 Claims.‘ ‘(01. 196-10)
The present invention relates to an improved cient height to hold at' least 3 ft. of acid when
> process for producing polymers suitable for motor measured in the quiescent state, and it will be
fuels and motor fuel constituents from normally understood that the level will rise considerably
gaseous .ole?nes,‘ and more speci?cally to an im
5 proved method for effecting such polymeriza
tion with sulfuric acid. The method will be fully
understood from the following description and ~
the drawing.
thereafter when the ole?ne is‘passed into the ma
terial so that‘ the total height of the chamber
should be at least 5 ft. and. preferably about 12 ft.
A pipe 9 is provided at‘ the upper end of the .
chamber for the withdrawal of the mixture of acid
Referring to the drawing, Fig. 1 shows a sec
and ole?ne. Pipe 8 may be jacketed with an ele
10 tional elevation of an apparatus for effecting ,ment 2| in whicha cooling ?uid may be cir
polymerization or condensation of normally culated to maintain a uniform temperature of the 10
gaseous ole?nes by means of sulfuric acid and the exit materials or to cool the; same. ' Pipe 9 dis
?ow of material through the apparatus is in
charges into the settling drum 22, which drum is
dicated. Fig. 2 is a top cross-sectional view of the connected by means of line 23 to vent line l8.
15 ‘apparatus shown in Fig. 1 taken along the line A cooler in is provided to reduce the temperature
X-—X. Figs. 3 and 4 are larger scale drawings of the mixture as it flows from the settling drum ‘
of the jets which are used to force the ole?nic 22 to the'separation drum II. Settling drum 22
material to be polymerized into the reaction is also provided with a draw-off line 24.
chamber.
‘
In the separation drum theacid and the hydro)
2
The polymerizing action» of sulfuric acid has carbon materials are allowed to stratify; the acid
20,
been long known, and more recently it has been - being heavier is ‘found in the lower layer. This
employed to eifect the polymerization of lique?ed is removed by a pipe I2 and recirculated to pump
normally gaseous ole?nes, especially isobutylene,
to form dimers and trimers which are well suited,
2 especially after hydrogenation, for use as motor
‘fuels or for constituents of motor fuels. The
present invention is an improved method for
carrying out this reaction and related condensa
tions between various ole?nes.
-
‘
Turning to the drawing, in Fig. l the numeral I
3O
denotes a feed line by which the liquid ole?nes
such as isobutylene or mixtures of isobutylene
with propylene, normal butylenes, amylenes or
3.3 L!
other ole?nes are forced by means of the feed
pump 2. The feed passes through one or the
other of the two ?ne mesh screen ?lters 3 and 4
which are suitably ?tted with valved connections.
so that the one may be'cleaned while the other
is in, use. The material then passes by a pipe 5‘
into?" the lower portion of the polymerization
4° chamber 6, into which it is discharged at a high
iii to the bottom of the polymerization chamber.'
The upper layer, which consists of the polymer,
unpolymerized ole?ne and such saturated hydro 25
carbons as may be present, is taken off by a. pipe
l4 through a further cooler l5 to a collection vessel
i6. Gas binding of the equipment is prevented by
the vent lines I‘! and I8. If desired a part of the
product from vessel i6 may be recirculated by, 30
pipe l9 and pump 20.
.
-
- Figs. 3 and 4'illustrate the preferred type of the
jets ‘I mentioned in connection with Figs. 1 and 2.
These jets are preferably ‘replaceable as shown
and are in the form of wide tubes narrowed at the‘
end to provide a hole of small diameter, so as to
cause the liquid to attain an extremely high
velocity in passing into the acid bath. This type
of construction minimizes the pressure drop re
quired for the operation. In Fig. 3 thejet is di
4.0
velocity through a plurality of jets ‘I, which will be 1 rected upwardly, which is the preferred form,
while
in
Fig.
4
the
jet
is
directed
downwardly
'
described more fully below. The arrangement of
these jets is more clearly shown in Fig. 2, in against a plate la which may be the bottom of
which it may be seen that the various jets are reaction vessel v6, ‘or may be a separate member‘
4 approximately equally spaced from each other and so placed as to best receive the stream of hydro
from the side walls of the vessel.
, ‘
‘
vThe reaction chamber 6 is surrounded by a
jacket 8. for heating, but it will'be understood
that other heating means may be employed if de
carbon and reverse its ?ow, at the same time
breaking it up into tiny droplets.
From the above description of the apparatus,
the operation‘ will be generally understood, but“ 50 sired. The reaction chamber is adapted to main- ' the conditions for best operation vary consider 50
tain a relatively deep bath of sulfuric acid, and ably depending upon the particular ole?nes in the
therefore it should be constructed of materials . feed,'the. type of polymer desired, and other con~
capable of withstanding its corrosive action. The - 'ditions., The acid may be described generally as
diameter of the chamber is determined by the‘ being maintained at polymerizing strength and- '
56 number of’ jets required. It should be of sum
temperature. Withv more dilute acids, ‘somewhat
2
2,181,191
higher temperatures are preferred and vice versa.
There is also some variation depending on the
particular oieiines used. In general, it may be
stated that ‘sulfuric acid within the limits 50 to
80% by weight more or less is satisfactory for
the purpose. Where it is desired‘ to polymerize
merely the iso-ole?nes, for example isobutylene,
'10
in the feed, the temperature should be main
tained within the limits of approximately 70° F.
to 150° F. but in bringing about copolymeriza
The rate of ?ow of acid upwardly .through the
reaction chamber proper is relatively slow and
the hydrocarbon droplets rise quite rapidly
through the acid. The flow of the acid is rapidly
increased at. the top of the reaction vessel so
that the reaction is substantially stopped when
the mixture of acid and hydrocarbon leaves the
reaction chamber by the'exit pipe. This effect
may be enhanced by cooling the mixture as it is
withdrawn ‘and if desired the withdrawal pipe 10
tion of the isobutylene with another ole?ne of the - may be packed with acid-resistant shapes so as
straight chain type, such .as propylene or to assist the coalescence of the hydrocarbon. The
butylene, higher temperatures‘ of the order of actual separation occurs in the drum from which
the acid is withdrawn for recirculation and‘ the
200 to 300° F. are used. For non-selective poly
polymer withdrawn for recovery.
15 ‘merization of olefines or oleflne mixtures, tem
It has been found that by increasing the time
peratures from 300 to 500° F. are employed.
Super-atmospheric pressures should be employed of. contact by recirculation of a part of the poly
with elevated temperatures in order to maintain mer by means of line I 9 and pump 20, other con
'20
the normally gaseous hydrocarbons in the liquid
condition. Pressures of 300.—600 lbs. per square
inch are ordinarily ‘required at temperatures of
200-300° F.
'
The above conditions for‘ the. polymerization
are important, and are broadly known in the
25 prior art.
It is necessary, however, to combine
these conditions with the following speci?cations
in order to obtain the best results. It has been
ditions being the same, the yield of the codimer of
iso and normal butylene is increased. Without
such recirculation there is a substantial propor
tion of 2,2,4 trimethyl pentene formed, appar
ently by polymerization of isobutylene, but by
recirculation this can be reduced and 2,2,3 tri
methyl pentene substituted, apparently by the
copolymerization of iso with normal butylene.
At the same time such recirculation allows poly
merization of normal butylene to form appreciable
found that a single jet may be employed effec
tively, and in that case the reaction vessel is best percentages of 3,4 dimethyl hexene 2. Under
30 between 6 inches and 12 inches in diameter. For the optimum conditions 'of acid height, strength, 30
commercial operations it is more desirable to use temperature and rate of flow through the orifice,
a plurality of jets in a reaction vessel of larger this expedient is not absolutely necessary in order
diameter. The jet diameter may vary from about to reach the theoretical codimer, but recircula
0.010 to 0.15 inch and the velocity at the throat tion is desirable where optimum conditions are
35 of the jet should be of the order of at least 40
feet per second. If the velocity is below this
figure, or on the other hand, if the diameter of the
jet is larger, the hydrocarbon tends to issue in a
continuous stream and effective polymerization is
40 not obtained.
For example, the yield drops off
very rapidly because of the loss of interi'acialv
area and consequent time of contact.
When a
plurality of jets is employed they should be spaced
not employed.
35
.
.
Example 1
To illustrate the operation of the present in
vention, an oleiine mixture consisting mainly of
isobutylene and normal butylenes, the latter be 40
ing in excess, was forced through a jet into the
bottom of a bath of 60% sulfuric acid. The
temperature of the bath was maintained at 225°
F. and a total pressure of 400 lbs. per square inch
was employed to maintain the ole?ne in liquid
condition. These conditions are adapted to‘form
at least 6 inches apart, preferably 10-12 inches
45 apart, with a minimum distance of 4 to '6 inches
from the side wall of the vessel. These latter copolymers of the isobutylene with normal
dimensions are important because if the jets are . butylene, and the most effective operation would
placed too closely together 'or toonear the side be one in which a yield from 175 to-200%,
walls, there is too rapid coalescence of separately '
are produced ‘and the yield is effectively dimin
ished. If it is ‘attempted to make this up by‘
increasing the height of the acid, it is found that
an excessive amount of trimer results which is
55 likewise unde'irable. As indicated before, it‘ has
50 formed droplets, with the result that larger drops
been found that these conditions can' be so
balanced that an extremely effective polymeriza-*
tion may be obtained with an acid height of 3
to 10 feet for the higher temperatures. indicated ,
60 above, 200-500° FL, although it is preferred tov
provide from 5.to 11 feet and to use lower tem
' peratures. This acid height, it will be understood,
65
is measured while in the, quiescent state, and it
rises considerably during the‘ operation.
The acid may be maintained in the reaction
ve'sel'without any circulation or stirring, other
than is obtained by the introduction of the hy
drocarbon at high velocity. It has been found,
70 however, that while the acid itself appears to act
wholly as. a true catalyst, still itv is gradually
consumed through side reactions and should be
made up from time to time. It is also founththat
the most convenient method of carrying out} the
15 reaction is to circulate the acid as shown in Fig. 1.
based on the isobutylene entering, is obtained 50
together with a practically ‘complete absorption
of the isobutylene. The acid in the quiescentv
state stood at a height of 3 feet in a vessel of
5 feet over all heightr
Using a jet with a diameter of .018 inch, the
ole?ne was forced in at different feed rates. . In‘
the table below, the feed rate, velocity at the jet
orifice, the yield of polymer based on the iso‘
butylene originally present, are given together
with the time of contact in minutes, estimated 60
from the jet size, feed rate and the like. These?
times of contact were also checked against runs
in which naphtha or other like hydrocarbons
were dispersed through acid in a glass vessel in
which the operation could be ‘put under direct 65.
observation :
Yield based
Jet
N°' diameter Fm mm 0313?:
Liters/tour
1
.018
4
2
.018 -
8
3
. 018
14
_
_
'
Jet
velocity
-
Contact
time
Percent
FL/uc
, 120
22. 2
l. 11
160
44.4
Minute:
1. 7i
180
77. 7
l. 82'
70
2,131,191
The ?rst run produced under low feed rate
and consequently under a low velocity was such
3
inch in'diameter, 6 feet of acid appears to be
perfectly satisfactory.
as to produce a substantially continuous-stream
Runs 4 and '7 should be particularly noted as '
of the hydrocarbon which eventually broke into
relatively large globules of the liquid. It will be
they appear to employ the best combination of
conditions. The polymer yield is very close to
that theoretically obtained by copolymerization.
of isobutylene with normal butylene: moreover,
the isobutylene was substantially completely con
noted that the time of contact was only 1.1 min-'
utes and the yield about 129% based on the iso
butylene, which means either that the conversion
per pass- was low and that while some copolymer
verted to polymer.
.10 was produced, it failed by far to reach the theo-'
‘
. »
10
Example 3
retically possible quantity. Analysis of the exit
gas showed that 90% of the isobutylene in the
feed had been polymerized together with 19%
In order to further illustrate the e?ect of the
jet velocity, some further runs are included in
of the normal butylenes.
the following table, beyond the ranges illustrated
_
_
15
In the second run, twice as much of the ole?ne
‘ was fed through the jet as in the previous run.
above.
20 that the rate of flow had been increased twice
over the previous _run,-the time of contact was
also greatly increased due to the fact that very '
. coupled with the fact that a more effective poly;
30 'mer is obtained, that is to say, the polymerv is
‘.closer ‘to the theoretical copolymer. Analysis
showed that 92% of the isobutylene was absorbed
from the feed together with 33% of the normal
_ butylenes.
The increased throughput is very no
ticeable, for example, the overall amount of
polymer produced in the second run is about 2%
times as much as that produced in the ?rst run.
In the third run the rate is even higher and
thevelocity is well within the preferred range.
40 .It will be noted that the polymer is even more
effective because it approaches even more close- -
ly the theoretical copolymer. Analysis shows
that 94% of thu- isobutylene is converted along
with 40% of the normal butylenes. The total
45 polymer produced under these conditionsis about
?ve times as much per hour as is obtained under}
the slow rate of flow illustrated in Run No. 1.
.
'
‘‘
Jet diam
Feed rate
Inches
Liters/hr.
Yield on i-C4H;
Jet velocity
FtJsec.
0. 023
0. 02s
' 12
18 _
163
19s
0. 023
24
189
0.023
40
191
43
65
S5. 5
141
Example 4
25
To illustratethe polymerization of a normal
ole?ne by the above processes, thefollowing ex
periment was performed. The acid level was 3
feet in height at a temperature of 225° F.‘ 60%
vsulfuric acid was used ‘and the feed comprised a 30
lique?ed butylene and butane.
The feed con
tained about 18.1% of normal butylene with less 7
than 25% of isobutylene.
It was fed in liquid
state through the jets having a diameter of .018
inch at a rate of 15 liters per hour, which corre- . 35
sponds to a jet velocity of 53.7 feet per second.
The polymer produced amounted to 35.5% of the ‘
normal butylene contained in the feed and was
based on an analysis of feed and exit products.
The polymer consisted of about 86% dimer and
14% trimer, and began to boil at ‘79° F., 69%
distilled over at about 300° F. and in the distilla- _
tion a recovery of 74% was obtained.
The
hydrogenated material had excellent blending
value as an antidetonation agent.
-
Example 5
The following experiment was carried out to
Example 2
In the following experiments the same mix
illustrate the process of copolymerizing ole?nes
containing three and four ‘carbon atoms.v The 50
tures of iso and normal ole?nes were used as in
reactor was ?lled with 66% sulfuric acid at a _
the prior examples but a larger jet size was em
ployed and the acid height was raised. As .be-_
temperature of 200° F., under 600 pounds per
fore the temperature was 225° F., pressure 400
55 lbs. per square inch.
Table I
eter of .018 inch and the velocity of the lique?ed
hydrocarbon through the jet was 43.2 feet per
second. The analyses of the feed and the exit
Run '
.
No. Jet Glam‘
Acid
' height
Feed rate
15
Table II
The velocity here was therefore twice what it
was before, and rose above the critical velocity‘
of about 40 feet per second. In spite of the fact
much smaller droplets were produced. There
was substantially no continuous stream of they
25 hydrocarbon and consequently very little co
alescence. It will be noted that the' yield of
polymer rose to 160% based on the isobutylene.
This increase is quite remarkable in that it is
‘
Yield on
isobutylene
Jet veloc
_ ity
square inch of pressure.
The jet had a ‘diam
materials were as followsi
‘Fad
I 'Exitgas
(20
Inches -
Feet '
Liters/hr.
FL/uc.
1
0. 023
6. 5
12
163
43. 2
2
0.023
3. 0 v
12
134
43.2
3
0. 023‘
6. 5
4
5
O. 023
0. 023
11. 0
3. O
6
18
192
64. 8
18 .
24
201
156 .
64. 8
86. 4
0. 023
6. 5
24 '
187
86. 4 ‘
' 7
O. 023
11. 0
24
191
36. 4
8
O. 018
6. 5
12
188
67. 2
9
O. 018
3. 0
12
180
* 67. 2
Percent
65
, From these analyses it can be seen that 43%
These runs show ?rst that the '11 foot acid head
is preferable to the 3 foot or 6.5 foot head. This
is illustrated by comparison of Runs 1 to '7, al
though the improvement in the ‘use of the 11
foot head over that obtained with the 6.5 foot
75 head is not very large, With the smaller jet,’.018
of the propylene present in the feed is extracted
and converted to a polymer. 75% of the iso
butylene present is likewise converted with 30%
‘of normal butylene. The product has a gravity
of 55.0 A. P. I. and began boiling at 123° F.; 95%
at 335° F.; the aniline point was 34° F.; color
14% (R). 'From the distillation curve it appears ‘
15'
4
2,131,191 ‘
the ole?ne mixture in a lique?ed state into the
ent, showing a large number of combinations of lower part of the acid baththrough a minute di
ameter ori?ce having an ori?ce size within'the
the-propylene with butylene and isobutylene.
In subsequent experiments with various sized limits of 0.01 and 0.15 inchat a velocity in excess
jets, it is foundthat a minimum acid height of 3 - of 40 feet per ‘second, whereby the liquid ole?ne
to 5 feet and a maximum of about 10 to 12 feet is is dispersed in small droplets throughout the' acid,
permitting the droplets to rise through the acid,
preferable, especially for polymerization of iso
rbutylene or copolymerization of iso with normal the, height thereof being at from about 3 feet to 10
feet when measured in the quiescent state, then
butylene, the particular type of reaction depend
10 ing chie?y on the temperature used. With such separating hydrocarbons from the acid and re
‘
acid heights and a linear velocity of between v‘i0 covering the polymer.
' 4. In a process for the polymerization of a mix
and 150 feet per second at the jet, it is possible to
ture of iso- and normal ole?nes to produce poly
closely approximate theoretical yields of diiso
butylene or codimer of iso and normal butylene mers suitable for motor fuels, the improved steps
15 as the case may be, with nearly complete reaction which comprise maintaining'a bath of sulfuric
of the isobutylene. Under these conditions only a acid at polymerizing strength and temperature
‘trace of isobutylene escapes in the exit liquor and within the range of 50-80% and 200-300° F., re
the polymer itself contains less than 10% of spectively, forcing the ole?ne through a jet of
from 0.01 to 0.15 inch in diameter at a rate in ex
trimer.
The present invention is not to be limited to any 7 cess of >40 feet per second and providing a height 20
20
of acid from about 3-10 feet when measured in a
theory of the operation nor to the reactions in
volved therein, nor to any particular acid quiescent state, then separating the hydrocar
' strength, temperature, or the like, but only to the bon from the acid and recovering the polymer
following claims in which it is ‘desired to claim from the hydrocarbon.
5. A process according to claim 4 in which. the 25
25 the invention as broadly as the prior art permits.
' a great many individual hydrocarbons are prese
We claim:
, ‘
1. In a process for polymerizing lique?edrnor
mally gaseous ole?nes by means of sulfuric acid
to form polymers suitable for motor fuels, the
steps of maintaining a bath of sulfuric acid at pol
ymerizing strength and temperature, forcing the
sulfuric acid is passed at a slow rate upwardly
through the reaction zone, the mixture of acid
and hydrocarbon withdrawn rapidly from the re
action zone into a separation zone, and in which
the acid is recirculated from the separation zone 30
i to the reaction zone.
6. In a process for polymerizing lique?ed nor
mally gaseous ole?nes by means of sulfuric ‘acid to
form polymers suitable for motor fuels,,the step of
second, whereby the liquid ole?ne ‘is dispersed in ‘maintaining a ,bath of sulfuric acid at polymeriz
small ‘ droplets throughout the acid, permitting ing strength and temperatures, forcing the ole
the droplets to rise through the acid, the height ?ne mixture in a lique?ed state into the lower
ole?ne mixture in a lique?ed state into the low
er part of the acid bath through a minute diam
eter ori?ce at a velocity in excess of 40 feet ‘per
, thereof being adapted to provide time for a sub
part of the acid bath through a minute diameter
stantial reaction of the ole?nes, then separating, ori?ce at a velocity in the range from about 40 feet ‘
to 150 feet per second, whereby the liquid ole?ne,
40 hydrocarbons from the acid and recovering the is dispersed in small droplets throughout the acid,
polymer.
'
'
2. In a process for polymerizing lique?ed nor- ' permitting the droplets to rise through‘ the acid,
mally gaseous ole?nes by means of sulfuric acid the height thereof being adapted to provide time,
to form polymers suitable for motor fuels, the for a substantial reaction of the ole?nes, then
separating hydrocarbons from. the acid and re
45 steps of maintaining a bath of sulfuric acid at pol
ymerizing strength and temperature, forcing the
covering the polymer.
ole?ne mixture in a lique?ed state into the lower
part of the acid bath through a minute diameter
ori?ce having an ori?ce size within the limts of
50 0.01 and 0.15 inch at a velocity in excess of 40
feet per second, whereby the liquid ole?ne is dis
persed in small droplets throughout the acid, per
mitting the droplets to rise through the acid, the
height thereof being adapted to provide time for
55 a substantial reaction of the ole?nes, then sepa
rating hydrocarbons from the acid and recovering
the polymer.
'
3. In a process for polymerizing lique?ed nor
mally gaseous ole?nes by means of sulfuric acid
80 to form polymers suitable for motor fuels, the
steps,of maintaining a bath of sulfuric acid at
polymerizing strength and temperature, forcing
'
~
‘
_
i
'
_
7. In a process for the polymerization of a mix
ture of iso and normal ole?nes to produce poly
mers suitable for motor fuels, the improved steps
which comprise maintaining a bath of sulfuric
acid at polymerizing strength and temperature
within the range of 50 to 80% and 200 to 300° F.,
respectively, forcing the ole?ne through a jet of
from 0.01 to 0.15 inch at a ratein the ranged
from 40 feet per second to 150 feet per second and 55
providing an acid height of from 3 to 10 feet when
measured in a quiescent state, then separating the
hydrocarbon from the acid and recovering the _
polymer from the hydrocarbon.
> BRUNO E. ROETHELI.
ELDON E. STAHLY.
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