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Патент USA US2403879

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Julyv 9, 1946;
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» w. A. scHuLzrz-- E_rAL
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2,403,379
PROCESS o_F MANUFAGTURE oF AVIATION GAsoLINE BLENDING sTocKs
Filed March 10, 1944
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Patented July 9, 1946
2,403,879
UNITED STATES PATENT OFFICE
2,403,879
PROCESS 0F MANUFACTURE 0F AVIATION
‘
GASOLINE BLENDING STOCKS
Walter A. Schulze and Carl J. Helmers, Bartles
ville, Okla., assignors to Phillips Petroleum
Company, a corporation of Delaware
l
Application March 10, 1944, Serial No. 525,922
13 Claims. (Cl. 260-671)
This invention relates to the production of
2
the yield and quality of blending stocks for avi
ation gasoline by means of combined catalytic al
kylation and treating steps.
Still another object of this invention is the
high octane hydrocarbon fuels by the catalytic
conversion of petroleum hydrocarbons. More
specifically the invention relates to the produc
tion of aromatic hydrocarbon concentrates suit 5 provision of an integrated process for the pro
able for inclusion in aviation gasolines through
duction of aromatic blending stocks of low sulfur
a novel sequence of catalytic operations.
and oleñn content through the catalytic treat
The production and recovery of aromatic hy
ment of selected fractions of the raw aromatic
drocarbons from petroleum sources are of par
product.
Other objects and advantages of the invention
will. be apparent from the following disclosure.
We have discovered that the production of
gasoline stocks rich in aromatic hydrocarbon
types may now be accomplished without recourse
ticular importance in supplying large quantities
of benzene, toluene, ethylbenzene, cumene and
other compounds needed as solvents, gasoline
blending agents and intermediates in organic
chemical industries. Recently, the demand for
high-quality aviation gasolines has greatly in
creased the demand for aromatic hydrocarbons
to multiple-pass catalytic cracking operations.
Subsequent to the relatively mild operating con
ditions employed in the catalytic aromatization
because of the extra power in rich-mixture per
formance derived from aromatics-containing gas
of the present process, -a substantial increase in
oline blends. In order to augment the supply of
the rich mixture rating of the aviation base stock
aromatic distillates, thermal and catalytic crack
is effected by a combination of two outstanding
ing of petroleum hydrocarbons have been em 20 novel features: (l) segregation of the benzene
ployed to produce aviation blending stocks with
fraction followed by alkylation with the oleñnic
the latter processes producing products superior
constituents from the primary catalytic reaction
to the straight thermal procedures. However, it
to produce alkyl benzenes greatly superior to ben
is well known that heretofore in order to produce
zene in rich mixture blending Value; (2) applica
high-quality aromatic distillates relatively severe 25 tion of a catalytic treating operation to the prod
conditions of catalytic cracking were required,
uct stream to remove deleterious impurities there
often involving multiple-pass catalytic cracking
by greatly improving the rich-mixture rating of
operations. Under such conditions the produc
the base stock.
tion of light gases may amount to 50 weight per
The beneficial results realized from the above
30
cent or more of the original charge stock. It is
features are such that the utility of catalytic
obvious then that the present catalytic cracking
processes are not entirely satisfactory in view of
the low yields realized and the plant equipment
required for multiple-pass catalytic operations.
The employment of aromatic concentrates in
aviation gasolines is contingent not only upon
a high aromatics concentration in the blending
stocks to impart desirable performance charac
teristics, but also on very low proportions of un
cracking oper-ations has been greatly extended.
Of inestimable value is the conservation of feed
stocks, since with our novel process it is now pos
35 sible to produce a high quality aromatic distil
late with less severe cracking conditions for a
given S-C rating. The aromatics content of the
finished»v blending- stock is increased by virtue of
40
desirable hydrocarbon types which impair the
blending 3-C octane values of the aromatics-rich
fractions. The quality of the aromatic blending
stœks as measured in flight tests and by the S-C
supercharged engine can often be greatly im pp. Ul
proved by the substantially complete removal of
non-hydrocarbon impurities such as sulfur com
pounds. It is also recognized that further quali
ty improvement can be eifected by conversion of
the benzene content of blending stocks to higher
homologs through alkylation with oleñns such as
ethylene, propylene and butylenes.
It is an object of this invention to accomplish
the conversion of selected hydrocarbon feed
stocks to gasoline of unusually high aromatic
content and relatively free of undesirable hydro
carbon and non-hydrocarbon impurities by
means of an interrelated sequence of controlled
catalytic operations.
the alkylation of the benzene fraction, since freez
ingv point consider-ations often preclude the inclu
sion of the total benzene fraction as such. An
other important advantage of the present process
is that the range of operable feed stocks has been
greatly extended in view of the quality increase
that can be realized from> the combined elîects
of the alkylation and the treating operations.
Considering only its broader aspects, the pres- `
ent process may be operated in the following man
ner to accomplish the objects and advantages
previously set forth. Ordinarily a petroleum dis
tillate having a high carbon -to hydrogen ratio is
catalytically cracked under cyclization conditions
with subsequent stabilization of the eliluent. The
light gas is processed to prepare an oleflnic al
kylation feed while the stabilized gasoline is clay
treated and separated by fractionation into a 200°
F. end-point benzene-containing stream and a
higher-boiling 350° F. end-point aviation blend
ing stock. The lower boiling fraction is treated
Another object of this invention is to increase 60
catalytically under polymerizing conditions to
2,403,879
3
remove sulfur and oleiinic material, both of which
are undesirable in the subsequent alkylation step.
A purified and refractionated benzene-concen
trate is catalytically alkylated with any one or
any combination of the light oleñns previously
produced in the primary conversion. The lean
flash vaporization tower 26.
Normally liquid
product hydrocarbons from the gas plant and
alkylation operations are conveniently added at
this point from line 25 and preheater 2S. The
overhead vapors of approximately 400 E. P. are
conducted through a line 30 to a clay-tower 3|
While the high boiling components are discharged
into a recycle line 68 through a line 29. The
clay-tower eiiiuent is discharged via a line 32
into a fractionator 33 where the product stream
tionated product stream where its valuable con 10 is divided for subsequent processing.
stituents are segregated in the 350° F. end-point
The overhead stream from 33 is comprised of
stock. This latter material is then catalytically
hydrocarbons boiling from C5 to 200° F. and is
treated under polymerizing conditions to produce
relatively rich in benzene and oleiins. This ma
a finished product of high rich-mixture blending
terial is passed through a line 34 to a heater 35
value. The secondary polymerization and alkyla 15 where
its temperature is raised to a suitable value
tion steps of this process not only coact to exert
of about 400° F. under sufñcient pressure to main
benzene effluent stream from the alkylation step
is recycled to the cracking step while the total
alkylate is fed directly into the main unfrac
a direct favorable effect on the volume and qual
tain substantially liquid-phase conditions, The
ity of finished product, but they also contribute
hot liquid is discharged directly into a catalyst
valuable recycle stock of high carbon to hydro
case 3S which is filled with the preferred silica
20
gen ratio to the primary conversion step thereby
alumina catalyst composition. The treated ef
further increasing the yield of aromatics as based
ñuent is partially vaporized in line 31 as the pres
on fresh feed.
sure is reduced and fractionation is effected in
The accompanying simplified drawing shows
a column 38. A fraction having an end-point of
one specific diagrammatic arrangement of appa
about 160° F. is taken overhead to motor fuel
ratus by which the present process may be car
storage through a line 39 while the kettle product
ried out. It should be understood, however, that
is taken Via a line 4i] -to a fractionator M where
>the invention is not limited to processing as here
in disclosed and that Various modifications of the
process and apparatus may be made without de
parting from the scope of the invention as de
fined in the appended claims.
Referring to the drawing, a thermally or cata
lytically cracked naphtha having a high carbon
to hydrogen ratio is transmitted from a charge
tank i into a line 2 that communicates with a
recycle stock line 'Il and a steam supply line 3.
The resulting mixture of naphtha, recycle stock
and steam constitutes a composite feed that is
preferably in a vaporous state and that is passed
into a heating coil il. The feed is preheated to
about 1100-1150° F. in heater ¿l prior to injection
into a catalyst case 5 which is filled with a solid
adsorbent-type catalyst such as bauxite and in
which conditions of temperature, pressure and
Contact time are selected so as to result in opti
mum aromatics formation. The efñuent from the
catalyst case is conducted through a line 6, a
vheat exchanger ‘l and a line 8 to a separator 9
where condensed steam is removed by means of
a line i0. Gaseous products are separated in this
i step and are conducted via a line l l, a compressor
l2 and a line I3 to a high-stage accumulator i4.
In this latter unit further condensation of water
along with small quantities of hydrocarbon is _ef fected and the condensate is drained through line
I5. The gaseous products then pass via a line I6
'to a column i'! where they are contacted with
absorbing liquid from a line 6I to remove C5 and
a benzene concentrate boiling between M50-180°
F. constitutes the overhead product and the ket
tle product containing oleñn polymer is removed
through a line 43 to the recycle line 68.
The benzene concentrate from column #il is
utilized as feed stock for the alkylation step along
with the olefins prepared in column 23. The
benzene stream from line »i2 is combined with the
oleiin-parañin gases from line 26 just ahead of
heating coil 45. The alkylation charge is pre
heated to alkylation conditions under a pressure
sufficient to maintain liquid or dense phase con
ditions and is discharged directly into the alkyla
tion reactor d5. The catalyst case may be filled
with a silica-alumina catalyst composition. The
reactor effluent is conducted through a line lll
with pressure reduction into a column 48 where
the product is stabilized with the light parafûns
and any unreacted olefms being removed through
a lineêâ to be employed as reñnery fuel or» in
other conversion operations. The kettle product
is suitably preheated and is transferred through
a line 50 to a fractionator 5| where the unreacted
benzene along with the naphthenic and paraf
finic constituents of the original benzene concen
trate are conducted through a line 53 to the re
cycle transfer line yESB: The kettle product from
'i column 5i which contains a mixture of mono
and di-alkylated benzene derivatives is passed
through lines 52 and 25 into heater 26 and thence
into line 2l, the main stabilized product stream
from the catalytic cracking operation. In this
heavier hydrocarbons. The rich absorbing liquid
manner alkylate boiling below about 400° F. is
is >then returned to the main product stream via (lil
passed on to further treatment and the high
lines i8 and 25. The C4 and lighter gases are
boiling alkylate finds its way into the recycle
conducted through a line i9 to a fractionator 20
line ES via line 29.
where hydrogen and methane are the .principal
After removal of the 200° F. end-point fraction
components of the overhead fraction that are re
in column 33, the main aviation base stock ma
moved through a line 2| while the kettle product
terial, which now includes aromatics recon
is transferred in a line 22 to a column 23 where
structed from the oleñns and benzene as well as
a gas fraction comprising C2, Cs, and C4 hydro
aromatics produced in the original cracking step,
carbons is prepared and charged to an alkylation
is passed through a line 513 into a fractionator 55.
unit 45 via a line 2e. The small quantity of Ct-ì
fraction boiling between 20G-350° F. is taken
hydrocarbons comprising the kettle product of 70 A
overhead in a line 51 while material distilling ,
column 23 is added to the main product stream
above 350° F. is discharged through line 5S into
_through line 25.
recycle line 6o. A portion of the overhead cut is
The stabilized product stream from separator
9 is withdrawn through a line 21, preheated in
diverted into a line 58, a condenser 59 and a re
heat exchanger 1 and finally discharged into a 75 flux tank _50. The condensed material not only
2,403,879
5
furnishes reflux for column 55 but also constitutes
absorbing liquid which is pumped through a line
El to column Il.
The product in line 5'." is heated in a coil ft2 to
a temperature of about 450° F. under pressure
adequate to maintain liquid-phase conditions
during the subsequent treatment in a catalyst
case G3. After further reduction of sulfur and
unsaturation over the preferred silica-alumina
catalyst, the product is transferred via a line 64
to a fractionator E5. High-boiling polymers and
sulfur compounds are removed through a line
06 and an overhead 20G-350° F. fraction is taken
to storage as finished base stock through a line
6l.
The recycle stock in line 63, which comprises
high-boiling hydrocarbons from columns 28, lil,
6
is transferred via lines 52, 25 and heater 26 to
the main product stream in line 21. The rich
mixture blending value of the final 20D-350° F.
fraction is greatly increased by the inclusion of
this cumene derived exclusively from the by
1products of the original catalytic cracking opera
ion.
Similar variations in the gas recovery system
may be effected in order to produce ethylbenzene
or mixed ethylene and propylene derivatives of
benzene.
The process of this invention can utilize a vari
ety of feed stocks including: straight run and
cracked gasoline, virgin and cracked naphthas
and gas oil. However, Where cracking and aro
matization are combined in one operation. a's in
the case of virgin naphtha feed, severe tempera
55 and 85 as Well as a light overhead fraction
ture conditions are required resulting in consid
from column 5 l, is passed through heat exchanger
erable formation of dry gas. The preferred feed
7 into a tar trap 69 Where partial vaporization 20 is a thermally or catalytically cracked gasoline of
occurs. High boiling refractory hydrocarbons
high carbon to hydrogen ratio and having an
and sulfur compounds are removed through a line
ASTM boiling range of about 150 to 400° F.
‘lil While the vapors are conducted through line
The catalytic steps of the present process in
'H to fresh-feed line 2.
the
order of o-ccurrence are: (1) aromatization,
The preceding description has broadly outlined
(2) polymerization and (3) alkylation.
the mode of operation 0f the present invention.
The catalyst for the primary conversion to aro
However, since the total C4 and lighter olefins are
matics is preferably an alumina base material
`produced. in a molar excess with respect to ben
which may be of natural or synthetic origin. A
zene, several alternative operations should be con
preferred catalyst is the naturally occurring
sidered with respect to the most economical uti 20
mineral bauxite although other catalysts of suit
lization of these by-product streams.
able activity and properties may be used such as
Thus, where it is desired to realize maximum
synthetic
alumina promoted with minor propor
conversion of light olefins to aromatic derivatives,
tions of other metal oxides.
the employment of benzene from some external
The process operations involving treatment of
source is necessary. Make-up- benzene in suffi
selected product streams under polymerizing and
cient quantity to equal or exceed the molar quan
alkylating conditions are carried out over silica
tity of light oleñns may be withdrawn from stor
alumina type catalysts. In general these cata
age through line ¿id and mixed with the 1GO-18()0
lysts are prepared by first forming a hydrous
F. fraction in line di?. Subsequent to alkylation
in 4S and fractionation in column 48, the excess 40 silica gel from an alkali silicate and an acid, ex
tracting soluble material With water, activating
benzene and inert parafñns and naphthenes are
the gel with an aqueous solution of a suitable
taken overhead in line 53 from column 5l. In
cases where benzene-olefin mol ratios of 2:1 to
4:1' have been employed, it is undesirable t0 re
metal salt, and subsequently washing and drying
the treated material. In this manner, a part of
cycle this material to the cracking reaction as 45 the metal presumably in the form of a hydrous
oxide, is selectively adsorbed by the hydrous silica
previously described. Instead a major portion
and is not removed by subsequent washing.
lof this stream is diverted from line 53 into 53a
More specifically, the preferred type of silica
and thence into line 52 from which it is returned
alumina catalyst is prepared by treating a Wet or
to the main product stream. In this Way the
excess benzene is recovered along With benzene 50 partially dried hydrous silica gel with an alu
minum salt solution, such as a solution of alu
derived from the cracking reaction Without ad
versely affecting the equilibrium in the cracking
step. However, a minor portion of the over
head from column 5i must be recycled via lines
minum chloride or sulfate, and finally washing
and drying the treated material. However, cata
lysts of a very similar nature but differing among
53, E58, heat exchanger ï, tar trap 69 and line 'Il 55 themselves as to one or more specific properties
may be prepared by using a hydrolyzable salt of
in order to prevent pyramiding of the parafûns
a metal selected from group IIIB or from group
and naphthenes in the benzene concentrate. This
IVA of the periodic system, and may be referred
mode of operation permits the inclusion of appre
to in general as “silica-alumina type” catalysts.
ciable quantities of high quality benzene homo
60 More particularly, salts of indium and thallium
logs in the 20G-350Q F. product fraction.
in addition to aluminum in group IIIB may be
used, and salts of titanium, zirconium and tho
rium in group IVA may be u'sedto treat silica gel
and to prepare catalysts of this general type.
valuabie benzene homolog, cumene. Fractiona
tor 20 in the gas recovery system is operated so as 65 Whether prepared by this method or by some
modification thereof, the catalysts will contain
to remove hydrogen, methane and ethylene. Col
a major portion of silica anda minor portion of
umn 23 is then employed to prepare a Ca fraction
metal oxide. This minor portion of metal oxide,
for the alkylation reactor While the C4 fraction is
such as alumina, will generally not be in excess
removed via line 25a for use as feed to codimer
of 10 per cent by Weight, and will more often be
operation or isobutane alkylation. In the ben
between about 0.1 and 1.5 to 2 per cent by weight.
zene-propylene alkylation, maximum conversion
The primary catalytic conversion or aromatiza
of benzene is sought, hence the overhead from
fractionator El may be recycled to the catalytic
tion stage 0f this proces-s is carried out over the
preferred bauxitecatalyst at temperatures rang~
cracking step via lines 53 and 68 as originally de
scribed. The cumene and di-isopropyl benzene 75 ing from about 1050 to about 1250° F. Moder
In those instances where employment of ex
cess b-enzene is not practical, it is usually desirable
to convert the available benzene to the most
2,403,879
".7
8
ately superatmospheric pressures are recom
mended for this reaction such as those extending
from atmospheric to about 200 pounds per square
inch gage. In many instances it may be desir
to reduce unsaturation and sulfur this material
was processed over a silica-alumina catalyst un
der a pressure of 1000 p. s. i. and at `an average
catalyst case temperature of 375° F., with a flow
rate of 2 to 3 liquid volumes per volume of cata
lyst per hour. The treated eiiiuent was frac
able to employ a diluent such as steam to aid in
temperature control.
tionally distilled to prepare a benzene concen
trate boiling from 160 to 180° F. To show the
value of the polymerizing treatment the same
One of the features of the present invention is
the second stage catalytic treatment of the prod
uct stream under polymerizing conditions over the
silica-alumina catalyst to elîect an ultimate re
duction of oleñn and sulfur content. This oper
ation is preferably conducted as a liquid-phase
operation. Pressure in the reactor may vary
from about 500 to 2000 pounds gage with a pre
ferred range of about 800 to 1500 pounds.
concentrate was prepared from a sample of un
treated stock.
`
160-180° F. fraction
Composition, Wt. percent
Untreated
Treated
Operating temperatures for the polymerizing
treatment may extend from atmospheric to about
700° F. depending on the characteristics of the
original feed 'stock and the extent of purification
required. Ordinarily it is preferred to carry out
this operation at temperatures of from 200 to
Benzene ___________________________________ _.
Oleûn _____________________________________ _.
Parañln ___________________________________ ._
Naphthene _______________________________ _ _
Sulfur _____________________________________ ._
60
17
13
68
6
10
l5
l1
0. 275
0.127
The treated benzene concentrate was subjected
to alkylation with a typical C2-C4 fraction of
light gas produced in the aromatization opera
ization reactor under the conditions of this dis
closure range from 0.5 to 10 liquid volumes per 25 tion. The gas contained approximately equi
molecular proportions of ethylene, propylene and
volume of catalyst per hour although the pre
butylenes admixed with the corresponding paraf
ferred rates are ordinarily those of 1 to 4 volumes
fins such that about 50 volume per cent of the
per hour.
gas was olefinic. The alkylation was carried out
A third stage catalytic alkylation treatment of
at a pressure of 1000 p. s. i. at a temperature of
the benzene-containing product stream is another
about 500° F. and with a feed rate of 2 volumes
novel feature of the present process. The feed
per hour per volume of catalyst. The mol ratio
to the alkylation reactor is comprised of the
of benzene to oleñn was maintained at 1:1 in or
160-180° F. fraction which has previously been
der to obtain maximum conversion of benzene.
treated for sulfur and olefin removal and a light
paraiñn-olefm cut derived from the gaseous pro 35 The effluent hydrocarbon was stabilized and
600°F.
.
Hydrocarbon iiow rates through the polymer
ducts produced in the aromatization operation.
A silica-alumina catalyst is employed at tempera
fractionated to yield the following data:
tures of from about 200 to 700° F. with the pre
Wt. per cent alkylate overhead at 350° F____ 73
ferred temperature being about 450° F.
Wt. per cent benzene reacted _____________ __ '71
Oper
ating pressures are chosen in accordance with 40 The weight of 350° F. end-point alkylate realized
is approximately the same as the weight of ben
reaction requirements and may vary from about
zene charged. However, the rich-mixture blend
ing value of the alkylate is about twice that of
100 to 1000 pounds. The aromatics-oleñn feed is
adjusted 'so that the benzene to olefin mol ratio
v
f the benzene, hence the alkylation procedure has
In order to further illustrate the specific uses
and advantages of the present invention, the fol
resulted in a blending stock equal to about twice
the weight of benzene originally produced. In
addition, 29 weight per cent of the benzene is now
available for recycle as such, while the kettle
product will contribute valuable aromatics on
further cracking treatment as recycle stock.
The crude aviation blending stock of 200-350°
lies between about l and 4.
.
lowing exemplary operation will be described.
However, since numerous other process modifica
tions will be obvious in the light of the foregoing
disclosure, no undue limitations are intended.
Eœample
F. boiling range was treated over the silica-alu
The operation as described herein was carried
out substantially as indicated in the drawing to
prepare an aviation base stock boiling between
mina catalyst under conditions identical with
those employed in treating the light fraction and
200-350° F. and containing the products derived
from the alkylation of the benzene stream with
F. blending stock. The improvement _in quality
a Cz-C4 olefin-parañin cut.
in the following tabulation:
'
the eiiluent was rerun to give a finished 200-350°
as a result of the polymerizing treatment is shown
The charge to the ñrst stage catalytic aromati
zation reaction was a polyform gasoline of 405° F. 60
2004350o F. Stock
end-point and 50.1° A. P. I. gravity. i The aver
age temperature of the bauxite catalyst bed was
maintained between 1100-l200° F. under a pres
sure of 85 p. s. i. and at a feed ñow-rate of about
6 barrels per ton of catalyst per hour. After
stabilization, the yield of butane-free gasoline`
amounted to 65 weight per cent based on the
charge. This stabilized material was clay-treated
and further fractionated into cuts having boiling
Untreated
Sulfur, wt. per cent _______________________ ._
Broniine number __________________________ ._
0. 279
10
Treated
0. 160
4. 0
37. 1
0. 95
36. 8
0.85
1. 20
2. 91
weight per cent of the charge and was found to
contain 21.5 per cent benzene, about 12 per cent
The yield of the ñnished blending stock was
46.4 weight per cent based on the original charge
to the aromatization step. Since the original
benzene yield was 4.0 per centon the same basis
and since the amount of alkylate produced was
olefin and 0.270 weight per cent sulfur. In order
approximately equal to the original benzene, the
ranges of 80-200° F. and 200-350° F., respec
tively.
The lower boiling fraction represented 18.6
9
2,403,879
overall yield of 20G-350° F. stock on addition of
the alkylate amounted to 50.4 per cent.
The addition of the high-quality alkylate which
amounts to about 8 per cent of the ñnal 20D-350°
F. stock increased the rich rating from 2.91 to 4.0
m1. of TEL in S-reference fuel, thus eiîective
1y transforming a moderately good blending stock
into a high quality product.
We claim:
10
catalyst to elîect removal of olefin and sulfur
content.
6. 1n a. process for the manufacture of aviation
gasoline blending stock having a high concentra
tion of aromatic hydrocarbons, the steps compris
ing aroinatizing a stream of a feed stock compris
ing hydrocarbons of relatively high carbon to
hydrogen ratio and boiling between about 150
1. In a hydrocarbon conversion process of the
class described, the steps comprising subjecting
a stream of a hydrocarbon feed stock comprising
a petroleum distillate having a relatively high
carbon to hydrogen ratio to cracking under _
cyclization conditions in the presence of an aro
matizing catalyst at a temperature of between
1050-1250o F.; separating eiiluent from the pre
ceding step into a first fraction comprising nor
mally gaseous oleñnic material, a, normally liquid
about 200° F. end-point second fraction, and a
400° F. in the presence of a catalyst; separating
e?iiuent from the preceding step to obtain a nor
mally gaseous fraction comprising Cl and lighter
cleîins and a normally liquid fraction comprising
about 350° F. end-point reacted eliluent, fraction
ating said liquid fraction to obtain a 200° F. end
point fraction and a fraction boiling between
20G-350° F.; polymerizing a stream of the 200° F.
end-point fraction in the presence of a catalyst to
effect substantial reduction of olefin and sulfur
content; fracticnating
stream of eiîluent from
the last named step to obtain a benzene fraction
third fraction boiling between about 20G-350° F.;
boiling between about i60-180° F.; alkylating said
the
polymerizing
presence of
a stream
a polymerization
of the second
catalyst
fraction
to ef
benzene fraction with said normali- gaseous frac
tion in the presence of a catalyst; recycling un
fect substantial reduction in oleñn and sulfur
content; recovering a benzene-concentrate from
effluent from the polymerization step; alkylating
reacted eiiiuent from the alkylation step to the
stream of feed stock; recycling total alkylate from
the eiiluent 0f the alkylation step to the 350° F.
a stream oi’ the benzene-concentrate with at least
end-point liquid fraction; polymerizing the final
Dart of said first fraction; recycling at least part
of the unreacted eiiluent from the alkylation step
to the stream of feed stock; and transmitting re
acted efñuent from the alkylation step to effluent
20G-350° F. boiling fraction in the presence of a
catalyst; and separating a substantially oleñn
and sulfur free product boiling between 20o-350°
F. from eiîiuent from the last mentioned step.
from the cracking step.
'7. The process in accordance with claim 6
2. The process in accordance with claim l
wherein a stream of the third fraction is treated
under polymerizing conditions and the so treated
third fraction is then fractionated to recover a
fraction boiling between about 20G-350° F. and
wherein the aromatizing step is carried out in the
presence of an aiumina base catalyst and the al
kylatin‘T and polymerizing steps are each carried
out in the presence of a corresponding silica
alumina catalyst.
substantially free of sulfur compounds.
8. The process in accordance with claim 6
wherein the aromatizing step is carried out at
wherein the indiivdual cracking and polymeriz 40 temperatures within the range of 1050--l250° F.
ing steps are each carried out in the presence of
and at pressures within the range of atmospheric
a corresponding suitable catalyst material.
to 200 pounds per square inch gauge; wherein
4. The process in accordance with claim l
the polyrnerizing steps are each carried out at
wherein the cracking step is carried out in the
temperatures within the range of 200-600° F. and
presence of a bauxite catalyst and the polymer 45 at pressures within the range of 80G-1500 pounds
izing steps are each carried out in the presence
per square inch gauge; and wherein the alkylating
of a silica-alumina catalyst.
stepl is carried out at temperatures within the
3. The process in accordance with claim l.
5. In a process for the manufacture of aviation
gasoline blending stock having a high concentra
tion of aromatic hydrocarbons, the steps compris
ing aromatizing a stream of a feed stock compris
ing hydrocarbons of relatively high carbon to
hydrogen ratio and boiling between about 150
400° F. in the presence of an aromatizing catalyst
at a temperature between 1050-l250° F.; recov
ering from efliuent from the preceding step a first
50
range of 20G-700° F, and at pressures within the
range of 1004.000 pounds per square inch gauge.
9. The process in accordance with claim 6
wherein the aromatizing step is carried out at
temperatures within the range of 1050-1250° F.
and at pressures within the range of atmospheric
to 200 pounds per square inch gauge in the pres
ence of an alumina base catalyst; wherein the
polymerizing steps are each carried out at tem
peratures within the range of 20D-600° F. and at
pressures within the range of 80G-1500 pounds per
fraction comprising normally gaseous olennic
material, a normally liquid about 200° F. enol
square inch gauge in the presence of a corre
point second fraction. and a third fraction boiling
between about 200-350o F.; polymerizing a stream 60 sponding silica-alumina catalyst; and wherein the
alkylating step is carried out at temperatures
of the second fraction in the presence of a catalyst
within the range of 20G-'700° F. and at pressures
to effect substantial reduction of olefin and sulfur
within the range of 10G-1000 pounds per square
content; fractionating a stream of eli‘luent from
inch gauge in the presence of a silica-alumina
the last named step to obtain a benzene fraction
boiling between about 160-180° F.; alkylating said 65 catalyst.
benzene fraction with said first fraction in the
presence of a catalyst; recycling unreacted effluent
from the alkylation step to the stream of feed
10. The process as in claim 6 characterized by
the alkylation of the benzene fraction with eth
ylene segregated from the normally gaseous frac
tion.
stock; transmitting total alkylate from the eii‘lu
l1. The process as in claim 6 characterized by
ent from the alkylation step to eli'luent from the 70
the alkylation of the benzene fraction with pro
aromatization step at such a point that said total
pylene segregated from the normally gaseous
alkylate may be further treated along with reacted
fraction.
products of said aromatizing step; and polymeriz
12. The process as in claim 6 characterized by
ing the final third fraction in the presence of a 75 the alkylation of the benzene fraction with butyl
2,403,879
1l
12
ene segregated from the normally gaseous frac-
350° F. and a higher-boiling fraction containing
tion.
polymers and sulfur compounds, and said higher
13. The process in accordance with claim 6
wherein effluent from the second polymerízìng
step is separated into a substantially olefin and
sulfur free product fraction boiling between 2.00- 5
boiling fraction is recycled to the feed stock
stream,?
‘
WALTER A. SCHULZE.
CARL J. HELMERS.
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