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Патент USA US2408727

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2,408,725
Patented Oct. 8, 1946
UNITED STATES PATENT oEElcE
,
2,408,725
HYDROCARBON CONVERSION
Arnold Belchetz, Kew Gardens, N. Y., assignor to
pany, Jersey City, N. J.,
The M. W. Kellogg Com
a corporation of Delaware
Application September 4, 1942, Serial No. 457,530
15 Claims.A (Cl. 2604683.15)
1
This invention relates to an improved method
for producing olefin polymers. More particularly,
the invention -relates to an improvement in the
method in which olefins are ñrst absorbed in a
liquid acid polymerizing catalyst, and the extract
is then heated to polymerize the absorbed olefms.
Olefm hydrocanbons may be absorbed at rela
tively low temperatures in a liquid acid polymer
iZirlg catalyst such as sulfuric acid or hydro-fluoric
acid, and the absorbed olefìns may then be poly
merized by heating the extract to a suitable poly
merizing temperature.
The conditions under which olefin hydrocarbons
are absorbed by the liquid acid pclymerizing cata
understood, however, that the invention is not
limited to the use of this specific catalytic agent
but includes the use of other liquid acid catalysts,
such as hydrofluoric acid, which are capable of
absorbing olefin hydrocarbons at temperatures
below polymerizing temperatures and promoting
polymerization of the absorbed olefins when the
extract is heated to a suitable temperature,
In the selective »absorption of isobutylene in
sulfuric acid a mixture of gases containing iso
butylene, normal butenes and any accompanying
parañin hydrocarbons is contacted with the sul
furie acid under conditions eiiective to produce
the desired absorption of isobutylene by the acid.
These conditions are selected, with respect to the
lyst depend upon the molecular weight of the 15 use to which the polymers and the remaining
normal butenes lare to be put, to produce a greater
olefin hydrocarbon and also upon the molecular
or lesser degree of absorption of normal butylenes
structure thereof. For example, in the absorp
along with the isobutylene. When the principal
tion or" butylenes in sulfuric acid it is found that
kpurpose of the process is to obtain di-isobutylene
isobutylene is absorbed to a substantial degree at
temperatures which are too 10W to effect substan 20 for hydrogenaticn to iso-,octane a greater degree
of absorption of normal butylenes is tolerable
tial absorption of the normal butylenes. The
than in an operation carried out for the primary
selectivity of the absorption of isobutylene is ef
purpose of producing normal butylenes, substan-_
iected also by the strength of the acid, the ratio
tially free oi isobutylene, as a source material for
of acid to butylenes and the time of contact.
the production of butadiene. In operating the
The selective absorption of isobutylene from a
process as a preliminary step for the production
mixture including normal butylenes is theL
of butadiene it is desirable to effect as complete
acid”V process which has been used extensively for
as practicable a removal of isobutylene from the
the manufacture of tertiary butyl alcohol or in
mixture by absorption while keeping the a= sorp
the preparation of di-isobutylene for hydrogena
tion of normal butylenes at a practical minimum.
tion to iso-octane.
The isobutylene-acid extract is separated from `
» The invention will be described further by
speciiic reference to a modification of the “cold
the unabsorbed hydrocarbons, and the latter are .
then transferred elsewhere for further use, such
acid” process, although it will be readily under
as in the production of butadiene. The extract
stood that the invention is not limited to such
is then treated to regenerate the acid. This may
specific application -but includes within its scope
hydrocarbon by
be done by heating the extract to a temperature
, the polymerization of any oleñn
suiiìciently high to polymerize the absorbed ole
successive absorption of the olefin hydrocarbon in
ñns or .by diluting the extract to a lower acid
the liquid acid catalyst and polymerization of the
strength and heating the dilute extract to evolve
absorbed olefin by heating the extract. The “cold
acid” polymerization of isobutylene is selected as 40 the isobutylene or by diluting the extract to a
still lower acid strength and heating the dilute
the speciiic example of the application of the in
extract to evolve tertiary butyl alcohol. In the
vention for the reason that it is an important
methods involving dilution the acid necessarily
step in the production of isooctane and is a valu
able method for separating isobutylene from nor
must be reconcentrated for further use in the
-mal butylenes prior to subjecting the latter to 45 absorption step. Preferably, therefore, the ex
’for the production of butadiene.
tract is treated Without dilution to polymerize the
, dehydrogenation
oleñns and regenerate the acid at the strength
It will be understood, however, that the invention
required for the absorption step. Relatively con
is applicable also to the polymerization of olefins
having a greater or less number of carbon, atoms
having a strength between
centrated sulfuric acid
than isobutylene and is applicable 50 63 and 67 per cent is preferred for selective ab
sorption of isobutylene. At lower concentrations
also to the polymerization of oleñn hydrocarbons
other than iso-oleiins such as normal olefins and ' the rate of absorption decreases, and the rate oi
corrosion of steel equipment increases. At higher
dioleiins. For example, the process is applicable
t0 the polymerization of normal butenes or buta 55 acid strengths the rate of absorption of normal
dienes although these applications of the inven
butylenes increases.
The polymerization of the isobutylene absorbed
tion are at present less important than the poly
in the extract presents serious diiñculties in com
merization of isobutylene.
~
mercial operations because the corrosive eiîect of
In the further description of the Ainvention ref
erence will be made to the use of sulfuric acid as 60 the acid is greatly intensified when the extract
the liquid acid polymerizing catalyst. Itis to be
2,408,7'25
Ii
is heated to the temperatures necessary to effect
polymerization of the absorbed isobutylene.
Previous practice in the commercial “cold acid”
polymerization of _isobutylene involves heating
the extract by passage thereof through exter
those having three, four or five carbon atoms per
moleculeare preferred because ci the relation
ship of their boiling characteristics to the boil
ing characteristics of the isobutylene and be
cause they are readily separable from the re
nally heated coils consisting of copper or steel
sulting polymers by fractionation. While the
or lead. Heating coils made of steel or copper
use of lower boiling or higher boiling materials
have a relatively short life due to the corrosive
is Within the scope of the invention, these are
effect of the extract and require frequent re
placement. -By using thick. Walled lead coils a 10 practical ordinarily for use in the polymeriza
tion of isobutylene only Iwhen the sensible heat
somewhat longer useful life is attained, but the‘s
of the heating iiuid is sufficient te heat the ex
also require replacement at a frequency-which, in
vievv of the expense of the tubes, is undesirable.
In accordance with the present invention the
isobutylene-acid extract is heated to the poly
plication of an excessively high pressure to main
merizing temperature, without contact at the
extract with the above-mentioned metal coil-s at
Whereas higher boiling materials require heating
tract to the polymerizing temperature. Rela
tively low-boiling heating ñuids require the ap
tain liquid phase conditions in the reaction zone,
the polymerizing temperature, by contacting the
the heating iluid to an excessively high tempera»
extract with a hot fluid whereby the extract is
heated to a temperature sufficiently high to poly
ture to vaporize it at the pressure necessary in
the reaction zone.
In the selection of a heating fluid those ma"
terials should be avoided which will produce un
merize the absorbed isobutylene.
Preferably,
heating of the extract is effected by cont-acting
the extract with a vaporized fluid which is con
densed by contact with the extract, the sensible
heat and heat of vaporization of the huid being
suilicient to impart to the resulting mixture a
temperature sufficiently high to polymerize the
isobutylene. Preferably also polymerization of
the isobutylene is eflected by contacting the ex
desirable ‘by-products either by reaction with
themselves or'with the isobutylene polymers or
which react with the acid catalyst to deactivate
it. Low-boiling saturated paraiiin hydrocarbons
suoli as propane, the butanes and pentaries are
tract with a vaporized fluid which is similar in
advantageous heating fluids because of their rel
ative inertness `in the reaction zone. However,
the use of other low-boiling hydrocarbons which
boiling characteristics to isobutylene. For ex
ample, the polymerization of the absorbed iso
For example, vaporized propylene, butylene-p,I and
butylene is effected advantageously 'by mixing
the extract with vaporized butane, either iso
butane or normal butane, the temperature of the
butane and the proportions of the butane and
extract being regulated to produce a liquid mix
ture of the but-ane and extract at the desired
polymerizin'g temperature.
The use of normal butane or isobutane is es
are more reactive is not necessarily precluded.
pentenes may lbe usedto supply the necessary
heat to the mixture as they undergo polymeriza
tion in the reaction zone
increase the yield of
olefin polymers and amplify the supply of heat
by the release of heat of their reaction. Iso
butylene obviously is satisfactory since it forms
a product indistinguishable from that formed by
polymerizing the absorbed isobutylene. Normal
pecially advantageous because oi’ the relation 40 butylenes and propylene are satisfactory if the
products of their polymerization can be tolerat
ship of the boiling points of these materials to
ed in the polymer product of the process.
the’boiling point of isobutylene. Since it is pref
When the process of this invention is employed
erable to effect polymerization of the isobutylene
while maintaining the extract in a liquid con 45 to separate isobutylene from the fresh feed to a
process for making butadiene the succeeding
dition, it is desirab e rto maintain the polymer
stages of the latter process may furnisii a hy
ization reaction zone at a pressure suñ‘iciently
high to prevent vaporization of isobutylene.
the
drocarbon
heatingmixture
fluid. After
Iwhichthe
is treatment
suitable for
of use
a gas
When using normal butane vas the heating iiuid
the> pressure which‘is maintained on the reac 50 ecus hydrocarbon mixture, consisting essentially
of C4 hydrocarbons-and including iso-olei'ins and
tion zone to prevent vaporizaticn oi isobutylene
normal oleñns, in accordance with this process,
is sufficient to insure condensation of the vapor`to effect substantial removal of iso-oleñns the re
ized normal butano lwhen it is mixed with the
maining unabsorbed hydrocarbon mixture or
extract. When using vaporized-i-sobutane as the
dinarily is then subjected to a further extraction
heating íluid it is necessary only lto apply a
slightly higher pressure on the reaction’z-one to 55 treatment, for example with acetone, to separate
oleñns from paraflins. The unabsorbed parai
insure condensation of the isobutane and the
fins from such a treatment ordinarily consist of
release of the heat of vaporization thereof.
a mixture of butanes
proportions of isobutane
Normal butano and isobutane Vare preferred
and norm-al butane which depend upon the char
agents as heating ñui'ds for polymerizing iso
butylene because oi their relative inertness in the 60 acter of the process in which the gas mixture is
formed. If the original feed is obtained by a
reaction and because of their relationship to the
thermal cracking treatment of hydro-carbon oils
Iboiling characteristics of the isobutylene. It is
the butano mixture is found to predominate in
evident, howeverythat if the sensible heat of the
normal butane, whereas ir" a catalytic hydrocar
heating fluid is sufficient alone to produce the
desired polymerizing temperature, any gas or va 65 bon oil cracking process is the source of the gas
mixture the butane,; predominate in isobutane.
por may be used which does not condense on be
ing mixed with the extract, or any unvaporized
liquid may be employed. It is evident, also, that
for the polymerization of oleiîn hydrocarbons
other than isobutylene by means of a condensible
heating
tanes having
fluid different
other heating
boiling fluids
characteristics
than the may
be employed.
Ordinarily, low-boiling hydrocarbons vsuch as
In either case this mixture constitutes a useful
heating fluid for use in the present process.
Ordinarily, the mixture of normal butano and
isobutane remaining after the extraction of ole
ñns contains a trace of isobut'ylene and a few per
cent of normal butylenes. The presence of these
oleñns in the heating fluid is not objectionable,
however, since they are polymerized along with
thefisobutylene absorbed inthe acid polymerizing
2,408,725>
nozzle >2 by means of line 8 which connects ac
cumulator -I with mixing nozzle 2. Line 8 is pro
vided with a pump 9 for introducingthe'heating
fluid" into mixing nozzle 2 against the reaction
pressure. Heating meansv I0 is provided in line
8 to heat the heating fluid to the desired tem
perature. Preferably, the heating fluid is heated
catalyst. The presence of the polymers of such
olefins in the polymer product is unobjectionable
if the polymer product is to be supplied as fresh
feed _to an alkylation process. If the polymeris
to be hydrogenated to iso-octane the presence of
a small proportion of normal butenes in the heat
ing fluid is not objectionable for the reason that
the high proportion of isobutylene in the reac
tion zone will result in cross polymerization yof’
the normal butylene with isobutylene, resulting
inthe production of an. iso-octene which can be
hydrogenated to an octane of high octane ,num
at I0 yto a temperature sufficiently high to vapor
ize it under the pressure maintained in line 8 and
reactor I.
-
'As stated above, preferred heating fluids for
the polymerization of isobutylene in accordance
with the present invention are isobutane and
ber.- Theuse of a gas mixture from this sourceas
the heating fluid in this process is particularly
advantageous if 'the gases are obtained originally
normal butano. The use of normal butane per
mits the maintenance of a- slightly lower pressure
in reactor I but, on the other hand, the use of
fromga catalytic cracking process and if the poly
isobutane requires only a slightly higher pres
mer product is to be employed as fresh feed to
an alkylation process since, as pointed out above,
sure and does not require heating to as high a
temperature at I0 to vaporize it. Furthermore,
if it is desired to employ the isobutylene polymer
such a mixture predominates in isobutane.
While inthe above discussion of suitable heat 20 product as charging stock to an alkylation op
ing fluids specific reference is made only to hy
eration for the production of iso-octane, the use
of isobutane as the heating fluid is advantageous
drocarbons, it is to be understood that the inven
tion is not limited to the use of hydrocarbons as
since 'its presence in the polymer product does
heating iiuids. Any suitable ñuid may be used
not require fractionation prior to charging the
which does not form undesired reaction products.
polymer to» the alkyation process. In this
Consequently, fluids other than hydrocarbons
specific example, therefore, isobutane is accumu
which meet this necessary requirement may be
lated at 1 and charged into mixing nozzle 2 at the
used, particularly those which may be mixed
desired rate after having been vaporized at I0.
The amount of isobutane required for poly
with the olefin-acid extract in a vaporized con
merizing each unit of isobutylene charged to the
dition and which are condensed by contact» with
the extract at the reaction temperature and pres
system in the` extract through line 3 increases
sure. For examples of suitable »heating fluids
as the concentration> of isobutylene in the ex
other than hydrocarbons reference lmay be made
tract decreases. The molar ratio of HzSO‘i to
to the ethers, such as dimethyl ether and diethyl`
(74H3 inthe extract may vary from 0.5:1'.0 to
ether, alkyl chlorides such as methyl chloride
4.0:l.0. It is preferable when extracting iso
and ethyl chloride. The ethers are preferable
butylene in preparation for the polymerization
because of their relative inertness under the poly
step to maintain the concentration of isobutylene
in the extract supplied through line 3 such that
merization reaction conditions.
nection with the specific application thereof to
molar ratio of H2SO'4 to Cil-Is is within the
40 Ythe
range of 0.7:1 to 1.2:1.0. Higher molar ratio-s of
the polymerization Vof isobutyene. Inconnection
acid to isobutylene increase the heat requirement
The invention will be described further in con
with such further description reference will be
made to the accompanying drawing which illus
trates diagrammatically an assemblage of appa
ratus for carrying out the specific application of
the invention to the polymerization of iso
butylene. It is to be understood, however, that
the invention is not limited by such specific refer
ence to the polymerization of isobutylene or by
the reference to a specific assemblage of appa 50
ratus 'since the 'principles of operation illustrated
of the polymerization step substantially and
lower the selectivity of the extraction operation.
It is preferred ordinarily to maintain the poly
merization zone at a temperature Within the range
of 150° .to 230° F. Lower temperatures may result
in incomplete regeneration of the acid. The use ,
of higher temperatures involves the danger of de
composing the acid. Within the range of tem
peratures given above the preferred range is
170° F. to 210° F. Within this preferred range the
are applicable to the polymerization of other ole
iins, including normal oleñns and diolefins, by
means of other combinations of apparatus and
operating steps and by means of liquid polymer
izing catalysts and operating conditions other
higher temperatures apparently favor rapid poly
than those referred to speciñcally. .
merization reactor suii‘ìcient to prevent vaporiza
tion of isobutane at the reaction temperature.
`
merization with the formation of a high propor
tion of isobutylene dimers.
'
`‘The use of isobutane as the heating fluid re
quires the application of pressure on the poly
l
` Referring to the drawing, the polymerization
reaction is carried out in reactor I which is an
The vapor pressure of isobutane at 170° F. is 170
} elongated lead lined, acid-brick lined cylindrical 60 pounds per square inch (gauge) ,whereas at
vessel adapted to withstand the application of
substantial pressure. Preferably, reactor I is
filled with some suitable acid resistant packing
210° F. it is 275 pounds per square inch (gauge).
When using isobutane _as the heating fluid the
vapor pressure of this material at »the reaction
such as ceramic Raschig rings. The interior'of
reactor I communicates at one end thereof with
a lead lined mixing nozzle 2.
temperature selected represents the minimum
.
'The acid-isobutylene Vextract is supplied to the
operation through line 3 which connects with
mixing nozzle 2. Line 3‘ is provided with a pump
pressure `at which it is advisable to> operate the
polymerizing reactor. When employing normalv
butane as the heating fluid somewhat lower pres
sures may be employed, these being governed by
.the vapor pressure of isobutylene at the reaction
temperature. The vapor pressure of isobutylene
at 170° F. is 160 pounds per square inch (gauge)
whereas at 210° F. itis 255 pounds per square
4 for introducing the extract into nozzle 2 against
the pressure maintained in reactor I.
The heating fluid is introduced in the system
through line 5 which is provided with a pump 6.
inch (gauge). The vapor pressure of isobutylene
Line 5` connects with an accumulator 1 from. 75 at the selectedY reaction v,terilpereiilre is the
which .the heating fluid is transferred to .mixing
2,4osg725
mum pressure at which it is. advisable to operate
polymers-from the tertiary butylaloohol and ter
tiary butyl esters, -which are the forms in which
the isobutylene is retained in the extract, occurs
.the reactor when employing as .theheating fluid
nor-mal butane or `.any other material-havinga
Vapor pressure lower than that of isobutylene.
through reactions which are endothermic.
The vapor pressure of the isobutane, »or isobutyl
It
would beexpected, therefore, that the occurrence
ene, at the reaction temperature >is higher than
the Vapor-pressure of the reaction mixture, be
of such reactions :in the mixture as the latter
flows through the elongated reaction ‘zone would
lower the temperature of the reaction `mixture
progressively along the path of iiow of the re
actants. However, the initial heating ofthe ex
cause of .the presence therein of lower boiling ma
terials, such as polymers and normal butane.
However, the vapor pressure of the isobutane-or
isobutylene may be taken as a satisfactory mini
tract by admixture thereof with the Vaporized
mumfor thepressure in the reactor. Preferably,
isobutylene results in the regeneration of isobu
tylene as such from the extract. The reactions by
which such regeneration-occurs also are endo
thermic, so that a portionof the heat supplied at
the point `of mixing of rthe isobutylene and ex
the pressure on the reactor should be maintained
somewhat above the indicated minimum. For
example, when using isobutane as Ythe heating
lluid the operating pressure at 170° F. should be
about 200 pounds per square inch (gauge), where
.tract is absorbed bythe endothermic ‘reactions
resulting in the release of isobutylene. However,
isobutylene thus released polymerizes to di-iso
As pointed out above, the heat required to poly
merize a given quantity of isobutylene is greater 20 butylene during the passage #of-.the reaction mix
fas at 210° l-T'. it should be about 300 pounds per
square inch (gauge) .
ture through the reaction zone. This reaction-is
when the concentration of isobutylene in the ex
highly exothermic and serveswto supply the >heat
tract is relativelylow. The amount of isobutane,
which is absorbed by the reactions by which di
or other heating fluid, which must be injected
into mixing nozzle 2 is aiïected also by the tem 25 isobutylene is produced directly from the tertiary
butyl alcohol and tertiary butyl esters contained
perature of the extract flowing through line 3,
in the extract. Consequently, once the reaction
.the polymerizing `temperature selected and the
mixture is heated to the desired reaction temper
temperature of the vap-orized heating íiuid intro
duced into mixing nozzle 2.
ature by the cooling> and »condensation of the
vaporized isobutane the reactions resulting in the
The latent heat of condensation of isobutane ,
formation of nii-isobutylene `apparently do not
Varies from 112 B. t. u. per pound of »isobutane »at
absorb or generate sufûcient heat to affect ma
`a pressure of 200 pounds per square inch (gauge)
to 118 B. t. u. per pound of-isobutane at a pressure
terially the temperature of the reaction mixture.
In the preparation ofv cli-.isobutylene for hydro
of 300 pounds per square inch (gauge). Addi
tional heat may be made available to the reac 35 genation to iso-octane it is desirable, for obvious
reasons, to operate under conditions which pro
tion zone from the isobutane by superheating the
mote the >formation of dimers and minimize the
isobutane vapors or by cooling the liquid isobu
formation of trimers. It is found also -that
tane from its boiling point to the reaction tem
dimers are preferable to trimers in a polymer
perature. The vari-ation in the quantity of iso
butane required for various operating conditions 40 feed for an alkylation operation process `since the
consumption of acid `in the alkylation process is
and various-concentrations of isobutylene in the
lower when alkylating dimers than when alkyl
extract When the extract ñowing through line 3 is
supplied to mixing nozzle V2 at 95° F. »and when
ating trimers. It is desirable, therefore, to heat
the reaction mixture rapidly `to a relatively high
the Vaporized isobutane is supplied to the `mixing
nozzle 2 through line 8 at a temperature of 300° F. ,
polymer-ming temperature, limit the holding time
may be summarized in the following'table:
at the polymerizing temperature to that neces
sary to effect maximum formation of Vdi-isobu
Mol ratio of H2S042C4H8 in extract
0.75:l.0
tylene, and then'quickly lower the temperature
1.0:l.0
of the reaction mixtureto the point `at which
Polymerization temperature, ° F ____________ ., `17‘5
210 175
Polymerization pressure, pounds per square
inch (gauge) _______________________________ _, 200
300 200
300
Heat available per pound isobutane, B . t. u_„_ 185
Pounds of isobutane required to polymerizo
150 185
`
150
polymerization -is substantially inhibited.
210
'
50
each pound oi isobutylene to cli-isobutylene. 1.23 1.89 1.45 2. 28
E
The Vaporized isobutane and extract are inti
mately mixed by suitable contact means in mix
`When operating in this manner it is'desirable
that the reaction mixture emergingY from reactor
l be cooled rapidly to a temperatureV at which
polymerization is substantially inhibited. Slow
cooling maintains the mixture for an vexcessive
55 period of time in the relatively low range of
polymerizing temperatures at which formation
ing `nozzle 2 whereby the isobutane is condensed
of trimers is favored. Such rapid 'cooling of the
and the resulting mixture is brought to the pre
reaction mixtureY may be acc‘omplished'by‘any
selected reaction temperature. The reaction mix
suitable means. It is preferred, however, in this
ture then flows through the elongated reactor l 60 process
to eifect'such rapid cooling by 'quenching
at va rate which providesthe holding time neces
with a 'cooling iiuid the 'reaction' mixture emerg
sary to effect substantially complete polymeriza
ing from reactor I to a temperature ’suiii'ciently
tion of .the isobutylene. Necessarily, the holding
low
to minimize corrosion in “equipment through
time in reactor I will be governed by vthe poly
which
the mixture passes subsequently. Any
merizing temperature since this reaction pro 65
suitable'i‘luid may be used for this purpose, the
ceeds at higher rates, the higher the'temperature.
requirements of such a fiui'dib‘e'ing substantially
Within the range of »conditions set forth above a
the
same as those set forth 'above for the heating
holding time of 15 minutes ordinarily will be the
iiuid except that materials which would be less
maximum time required, and a holding time of 3
desirable Aas heating Yiîuids because of their 're
to 5 minutes ordinarily is found to be preferable.
70
activity
at the-highertemperatures-may be> used
The temperature of the reaction mixture ñow
to quench the reaction mixture. Conveniently,
ing through the reactor varies but little‘from the
the same fluid employed "for heating 4purposes
initial temperature assumed bythe reaction mix
.ture formed by the rapid and-intimate mixing
ofthe isobutane and extract. -The form-ation of
also may be employed as the quench. -In the
specific example illustrated -i'n the ¿drawing Ya
portion of the Visr’ib'utane supplied through line 8
2,408,725
The polymer product of the process is with
drawn from the lower portion of fractionator 28
through line 36 for further handling. This ma
terial may be used directly as an ingredient of
is diverted therefrom through line II. Cooling
means I2 may be provided in line II if desired
to chill the isobutane to a still lower temper
`ature prior to the use thereof as the quench.
motor fuel but preferably is hydrogenated prior
>For rapidand intimate mixing of the reaction
mixture and the quench iiuid a mixing nozzle I3,
which is preferably lead lined and may bev sim
to such use.
This material also may be em
ployed as feed stock for an alkylation process.
If the polymer product is to be employed in an
alkylation process and if isobutane is employed
ilar in construction to mixing nozzle 2, is pro
vided at the exit of reactor I. Line II connects 10 as the heating and quenching fluid in the poly
with mixing nozzle I3 in order to supply the
merization process it may be desirable to elimi
liquid isobutane for quenching the hot reaction
nate the fractionation step carried out at 28.
mixture as it emerges from reactor I.
All or a portion of the material flowing through
A suin
cient quantity of the cooling fluid is preferably
line 21 may be diverted therefrom throughline
31 for passage directly to an alkylation reactor.
supplied through line II so that the resulting
15
Cooling means 38 may be provided in line 31 to
mixture thereof with the reaction products will
have a temperature of from 120° to 150° F.
reduce the temperature of this material to that of
The quenched mixture in mixing nozzle I3 is
withdrawn therefrom through line I4 which con
the alkylation reactor. When operating in this
manner the isobutane required for heating and
quenching in the polymerization process may be
nects with a cooler I5 for cooling the mixture
to a still lower temperature. Cooler I5 conven 20 recovered from the alkylation process as a portion
of the isobutane normally recycled in that process.
Aiently takes the form of a coil I6 maintained in
indirect heat exchange with cooling water.
The mixture passing through coil I6 is cooled
preferably to a temperature of about 100° F.
`and emerges therefrom into line I1 which con
nects coil I6 with a settler I8.
1. In the method of converting olefin hydro
carbone in which olefin hydrocarbons are ab
25 sorbed in an acid polymerizing catalyst at tem
Settler `I8 may
be operated at the same pressure as cooler I5
and reactor I, but if a lower pressure is desired
peratures below polymerizing temperatures and
the extract thus obtained is heated under pres
sure to a temperature sufficiently high to poly
merize the absorbed ole'ñns in the liquid phase,
a valve I9 may be provided in line I1 for the
30 the improvement which comprises mixing said
necessary release of pressure.
In settler I8 the mixture of polymer and acid
is permitted to separate into a lower acid layer
extract while at a temperature below polymeriz
ing temperatures and at the polymerizing pres
hydrocarbon layer. The regen
sure with hydrocarbon vapors comprising at least
erated acid constituting the acid layer is with 35 a substantial proportion of an isoparaffin hydro
carbon boiling above the polymerizing tempera
drawn from settler I8 through line 20 for return
- and an upper
ture at the polymerizing pressure in proportions
to the olefin extraction operation. The hydro
which produce a resulting> mixture of extract and
carbon layer including polymers and isobutane is
condensed vapors which is at the desired polymer
withdrawn from settler I8 through line ZI which
izing temperature, separating from the resulting
connects with neutralizer 22.
40
polymerized product regenerated acid catalyst
` In order to neutralize the acid content of the
hydrocarbon mixturev flowing through line 2l
and a hydrocarbon mixture comprising the poly
mers and the isoparafñn hydrocarbon, recycling
alkali is introduced into the mixture through line
said regenerated acid catalyst to said absorption
23 which connects with line 2|. The hydro
_ carbons and alkali are intimately mixed by pas 45 step, and subjecting said hydrocarbon mixture
comprising olefin polymers andthe iso-paraffin
sage thereof through mixing nozzle 24, and the
resulting mixture is then permitted to separate
hydrocarbon to alkylation reaction conditions.
separa-tes as a lower phase and is withdrawn
2. In the method of converting relatively low
boiling oleiin hydrocarbons in which such low
'
The alkali
through line -25. If desir d a portion of this 50 boiling oleñns are absorbed in an acid polymer- .f
izing catalyst at temperatures below polymerizing
material may be recirculated through line 2E
temperatures and the extract thus obtained i is
which connects line 25 with line 23. Theneu
heated under pressure to a temperature suñi
tralized hydrocarbon mixture which separates in
ciently highV to polymerize the absorbed oleiins
therefrom through line 21 which connects with 55 in the liquid phase, the improvement which com
prises mixing said extract while at a temperature
fractionator 28.
neutralizer 22 as an upper layer is withdrawn
The hydrocarbon mixture may be preheated
below polymerizing temperatures with hydrocar
as desired by heating means 29 located in line
bon vapors comprising at least a substantial pro
portion of an isoparaflin hydrocarbon boiling not
21 prior to its introduction thereof into frac
tionator 28. In fractionator 28 the hydrocarbon
mixture is subjected to fractionating conditions
adapted to separate overhead the isobutane em
ployed as the heating and quenching fluids as
ywell as accompanying materials of similar boiling
60
Ysubstantially lower than saidabsorbed olefinsin
proportions which produce a resulting mixture of
extract and condensed vapors which is at the
desired polymerizing temperature, maintaining
the pressure on the mixture undergoing polymer
ization sufliciently high to maintain said oleiins
characteristics such as unconverted isobutylene. 65
and condensed vapors substantially Kcompletely in
This material passes overhead from fractionator
a liquid condition, separating from the resulting
28 through line 30 which is provided with con
densing means 3| and which connects with ac
cumulator 32. From accumulator 32 the con
polymerized product regenerated acid catalyst
lator 1 whereby material flowing therethrough 'is
sorption step, and subjecting said hydrocarbon
and a hydrocarbon mixture comprising olefin
densate is withdrawn through line 33 provided 70 polymers and said isoparaflin hydrocarbon, re
cycling said regenerated acid catalyst to said'ab
with pump 34. Line 33 connects with accumu
mixture comprising oleiin polymers and said iso
paraflin hydrocarbon to alkylation reaction con
33 may be diverted to line 35 and returnedy to
7,5 ditions..
returned forreuse as heating or quenching fluid.
Av portion of thek condensate-flowing through line
the ,upper portion of >fractionator .28 as reiiux.
2,40857252
12
3.' In the method of converting butene in which
butene is absorbed in an acid. polymerizing cata
sorbed oleiins in the liquid phase, the-improve
ment> which comprises mixing said-extractv while
lyst at'temperatures below polymerizing tempera
at a temperature below polymerizing temperatures and the extract thus obtained is heated
tures and at the polymerizing pressure with >vapors
under pressure to a temperature suinciently'high
to `polymerize the absorbed butene in the liquid Cu of an isoparafñn hydrocarbon boiling above the
polymerizing temperature at the polymerizing`
phase, the improvement which comprises mixing
pressure in proportionsl which produce a resulting
saiotextract> while at a temperature below poly
mixture of extract and condensed isoparafñn hy'
pressure with hydrocarbon> vapors comprising at li) drocarbons which is at the desired polymerizing
temperature, permitting the mixture to remainat
least a substantial proportion of isobutane in pro
the polymerizing temperature-for a-time sufncient
portions which. produce` a resulting; mixture of
to effect the desired polymerization' and regenextract and condensed hydrocarbons which is at
mer-izing temperatures and at the polymerizing
theadesired` polymerizing temperature, separating
from the-resulting, polymerized product regener
ated acid catalyst and a hydrocarbon mixture
comprising butene polymers and isobutane, re
cycling said regenerated acid catalyst to said ab
sorption step, and subjecting said hydrocarbon
mixture comprising isobutane and butene poly
15
erate the polymerizing catalyst, thereafter sepa
rating the resulting mixture of isoparañin» hydro.
carbons and olefin'polymers from the accompany
ing acid catalyst, recycling acid catalyst thus sep
arated to said absorption step, and subjecting' the
said hydrocarbon mixture- of isoparamn hydro
carbons andoleñn polymers to alkylation reaction
conditions.
20,
mers to alkylation reaction conditions.
7. The method of treating a hydrocarbonmix
42 In the methodof converting butenein which
ture comprising normal olei’ins- and iso-oleñns
butene is absorbed in an acid polymerizing cata
which` comprises contacting said mixture with an
lystat temperaturesxbelow polymerizing tempera
acid polymerizing catalyst at temperatures below
tures and the extract thus obtained is heated
polymerizing` temperatures and sufficiently low to
under pressure to a. temperature sufficiently high
absorb a portion only- of said oleñn hydrocarbons
to polymerize the absorbedv :butenel in the liquid
phase, the improvement which comprises mixing
said'extract while at a temperature below poly
predominating in iso-oleñns, separating the re
sulting extract from unabsorbed hydrocarbons,
mixing with said extract whileat a temperature
pressure with isobutane vapors in proportions 30 «below polymerizing temperatures and at the poly
merizing pressure with vapors of an isoparaiiin
which produce aresulting mixture of extract and
merizing temperatures and at the polymerizing
condensediisobutanewhich is at‘the desired poly
merizing temperature, separating> from the result
hydrocarbon boiling above the polymerizing tem
lyst and a mixture of butene polymers and iso
perature atV the polymerizing pressure in propor
tions which produce a resulting mixture-of extract
and condensed isoparañ‘ln vapors- which is at the
butane, recycling> said'l regenerated acid` catalyst
to said absorptionv step, and subjecting said‘mix
the mixture at the polymerizing temperature-for
ing polymerized product., regenerated acid cata
desired polymerizing temperature, maintaining
a time sufdcient to effect polymerization of the
ture of 'butene polymers and isobutane to alkyla
olefin hydrocarbons and regeneration of the acid
tion reaction conditions.
40 catalyst, thereafter separating from the acid cat
5. In the method of converting butene in which
alyst a mixture of olefin-polymers and isoparaf?in
butene is absorbed Vin an acid polymerizing cata
hydrocarbons, recyclingv said separated acid cata
lyst-at temperaturesY below polymerizing tempera
lyst to said absorption step, and subjecting said
tures and the extract> thus obtained is heated
mixture of oleñnD polymers and- isoparaiïdnr hydro
under pressure to a temperature sufficiently high
carbons to‘alky-lation reaction conditions.
to polymerize the absorbed butene in the liquid
8. A method'for treating a-low` boiling hydro
phase, the improvement which comprises mixing
carbon mixture comprising normal butylenes and
said extractV while at a temperature belowpoly
isobutylene which comprises contacting saidmix
merizing temperatures and at the polymerizing
ture with an acid polymerizing catalyst at tem
pressure with hydrocarbon vapors comprising at
least a substantial proportion of isobutane in pro 5 O peratures suñiciently low to avoid polymerization
portions which produce a resultingmixtureof
extract and' condensed hydrocarbons which is at
the desired polymerizing temperature, permitting
the mixture to remain at thel polymerizing tem
perature for a time suñî'cient to effect the desired
polymerization of butene, then admixing the re
action mixture with a suñicient quantity of rela
tively cold liquid hydrocarbons comprising at least
and eiîect absorptionv of aV portion only of said
butylenes predominatingy in isobutylene, sepa
rating the extract thusv obtained from` unab
sorbed hydrocarbons, mixing the extract while
at a temperature below polymerizing tempera
ture andkv at the polymerizing pressure with bu
tane vapors comprisingr atk least a substantial
proportion of isobutane in proportions which
produce a resulting mixture of extract and con
a substantial proportion-of`isobutane to reduce
the temperature of the mixture from the poly 6 O densed vapors which is at the desired polymeriz
ing temperature, separating from the resulting
merizing temperature to a non-polymerizing tem
perature, separating from the resulting polymer'
ized product regenerated acid rcatalyst and a hy
drocarbon mixture comprising butene polymers
andV isobutane, recycling said regenerated acid
catalyst to said absorption step, and subjecting
said hydrocarbon mixture of isobutane and bu
tene polymers to alkylation reaction conditions.
6. Inthe method of converting olefin hydro
carbonel in which oleñn hydcarbons are absorbed
inan >acid-polymerizing catalyst at temperatures
below polymerizing temperatures and the extract
thus obtained is heated under pressure to a tem
perature sumciently high to polymerize the ab
polymerized product amixture of butylene poly
mers and isobutane and regenerated acid cat
alyst, recycling said regenerated acid> catalyst to
said absorption step, and subjecting saidv mixture
comprising butylene polymers and isobutane to
alkylation reaction conditions.
9. A method for treating a low boiling hydro
carbon mixture comprising normal butylenes and
isobutylene which comprises contacting said mix'
ture with an acid polymerizing catalyst at tem
peratures suiîiciently low to avoid polymerization
and eiïect absorption of a portion only of> said
butylenes predominating in isobutylene, sepa
rating> the extract thusobtained from unabsorbed
2,408,725
13
.
hydrocarbons, mixing the extract while ata
temperature below polymerizing temperature and
at the polymerizing pressure with butane vapors
comprising at least a substantial proportion of
isobutane in proportions which produce a, result
ing mixture of extract and condensed vapors
which is at the desired polymerizing tempera
ture, maintaining the mixture at the polymeriz
ing temperature for a time su?licient to eiîect
substantially complete polymerization of the ab
sorbed butylene and regeneration of the acid
catalyst, then admixing with the reaction mix
14
lyst to said absorption step, subjecting said mix
ture of butene polymers and isobutane to alkyla
tion reaction conditions, recovering unreacted
isobutane from the alkylation reaction, and re
cycling said unreacted isobutane to said poly
5
merization step.
.
12. A method for processing a hydrocarbon gas
produced by cracking treatment of hydrocarbon
oil and containing isobutylene, normal butylene,
10 and isobutane, which comprises absorb-ing the
isobutylene content of said gas in an acid poly
merizing catalyst at temperature below polymer
izing temperature, treating unabsorbed gas to
ture a sufûcient quantity of cold liquid butane
separate normal butene therefrom whereby a rel
comprising at least a substantial proportion of
atively paraflinic residual fraction containing iso
isobutane to reduce the temperature of the mix 15 butane is produced, vaporizing at least a portion
ture to a non-polymerizing temperature, separat
of said residual isobutane fraction at a pressure
ing a hydrocarbon mixture comprising isobu
effective for polymerizing said isobutylene, mix
tane and butylene polymers and regenerated acid
catalyst, recycling said regenerated acid catalyst
to said absorption step, and subjecting said hy
drocarbon mixture comprising isobutane and
butylene polymers to alkylation reaction condi
tions.
20
»
10. A method for treating a low boiling hy
drocarbon mixture comprising normal butylenes
and isobutylene which comprises contacting said
mixture with a sulphuric acid polymerizing cat
alyst at 'temperatures sufñciently low to avoid
polymerization and effect absorption of a por
tion only of said butylenes predominating in iso
butylene, separating the extract thus obtained
from unabsorbed- hydrocarbons, mixing the ex
tract while at a temperature below polymerizing
temperature and at the polymerizing pressure
with butane vapors comprising at least a sub
stantial proportion of isobutane in proportions
which produce a resulting mixture of extract
and condensed vapors which is at the desired
polymerizing temperature, maintaining the mix
ture at the polymerizing temperature for a time
suiìcient to effect substantially complete poly
ing the isobutylene extract while at a tempera
ture below polymerizing temperatures and at
the polymerizing pressure with said vaporized
isobutane fraction in proportions which produce
a resulting liquid mixture which is at the desired
polymerizing temperature, separating from the
resulting polymerized product regenerated acid
catalyst and a mixture of butene polymers and
isobutane, recycling said regenerated acid cata
lyst to said absorption step, and subjecting said
mixture lof butene polymers and isobutane to
alkylation reaction conditions.
.
13. .In a process of producing higher boilin
hydrocarbons vfrom isobutane and isobutylene
wherein an absorption product of isobutylene in
sulfuric acid is heated to polymerize at least a
part of said isobutylene and polymers thus
formed are reacted with isobutane in the pres
ence of an alkylation catalyst, the improvement
which comprises adding isobutane in the vapor
phase under a pressure high enough to condense
isobutane and supply heat for said polymeriza-v
tion and to produce substantially dry isobutane
and feeding resulting polymer and substantially
meri'zation of the absorbed butylene and regen
dry isobutane to the alkylation unit. y
eration of the sulphuric acid catalyst, then ad
14. A process of producing higher boiling hy
mixing with the reaction mixture `a suftìcient
drocarbons
from isobutane'and an ’oleñn which
45
quantity of cold liquid butane comprising atcomprises adding isobutane in the vapor phase to
least a substantial proportion of isobutane to re
an absorption product of said oleñn in sulfuric
duce the temperature of the mixture to a non
acid under a pressure between about the vapor
polymerizing temperature, separating a hydro
pressure of isobutane at 150° F. and about 300
carbon mixture comprising isobutane and butyl
pounds per square inch at which isobutane'con
50
ene polymers and regenerated sulphuric acid cat
denses and supplies heat for polymerization of
alyst, recycling said regenerated sulphuric acid
said absorbed oleiin and substantially dry isobu
catalyst to said absorption step, and subjecting
tane isproduced and contacting resulting poly
said hydrocarbon mixture comprising isobutane
mer and substantially dry isobutane with an al
and .butylene polymers to alkylation reaction
kylation catalyst under alkylating conditions.
conditions.
`
k
l1. In the method of converting butene in
which butene is absorbed in an acid polymerizing
15. In a, process of producing higher boiling ì
hydrocarbons from isobutane and an oleñn
wherein an absorption product of said olefin in
catalyst at temperatures below polymerizing tem
an inorganic acid of polymerization strength is
peratures and the extract thus obtained is heated
heated to polymerize at least a_ part of the oleñn
60
under pressure to a temperature sufficiently high
content and polymersY thus formed are reacted
to polymerize the absorbed butene in the liquid
with isobutane in the presence of an alkylation
phase, the improvement which comprises mixing
said extractv while at a temperature below poly
catalyst, the improvement which comprisesvadd
ing. isobutane in the vapor phase under a pres
merizing temperatures and at the polymerizing
sure high enough to condense isobutane and sup
(i5
pressure with isobutane vapors in proportions
ply heatfor said polymerization andk to produce
which produce a resulting mixture of extract and
condensed isobutane whichis at the desired poly
merizing temperature, separating. from the re
sulting polymerized product regenerated acid
catalyst and a mixture of butene polymers and
isobutane, recycling'said regenerated acid cata
substantially dry isobutane and feeding resulting
polymer and'substantially dry isobutane to the
aikyiaucn unit.
'
’
ARNOLD BELCHETZ.
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