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Патент USA US3080321

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March 5, 1963
Filed Sept. 15, 1960
Straight Run
Gas Oil
Gas Oil
i‘ Fr ction
mma '0
Temperature //32
( Si lice ous
component )
(AlBr3 -HBr)
Hz Recycle
Distillation /
Above Gasoline
G7 Naphthene
‘ 05-67 Paraffins
Heavy Gasoline Fraction
United States Patent Q??ce
Thomas S. Mertes, Wilmington, DeL, assignor to Sun Oil
Company, Philadelphia, Pa., a corporation of New
, Phtented Mar. 5, 1963
Filed Sept. 15, 1960,.Ser. No. 56,198
ponent which is chromium sul?de derived by reduction of
chromium sulfate. Conditions of operation include tem
peratures in the range of 7 50-1050’ F., hydrogen input of
1000-10000 s.c.f. per barrel of feed and hydrogen pres
sures in the range of 500-5000 p.s.i.g.
In the present invention processes of the types men
tioned in the above-discussed patent application and pat
ents are utilized in a combination operation wherein both
straight run gas oil and catalytic gas oil are converted to
This invention relates to a combination process for pro
in the most e?icacious manner. According to
ducing high antiknock gasoline from both straight run and 10 gasoline
the invention the straight run gas oil stock is treated in a
catalytic gas oils by hydrocracking.
manner to separate essentially all of the aromatics from
In application Serial No. 25,509, ?led April 29*, 1960,
the saturate fraction. The aromatics are then blended
now abandoned, a process is described which is capable of
with the catalytic gas oil stock and the mixture is subjected
2 Claims. (Cl. 208-78)
converting high boiling saturate hydrocarbons, such as
catalytic hydrocra-cking conditions in the presence of
the staurate portion of gas oils, substantially completely 15 to
hydrogen and a siliceous cracking catalyst containing a
into saturate hydrocarbons boiling in the gasoline range.
hydrogenating component to produce catalytic gasoline.
These product hydrocarbons, which are mainly C4-C7 iso
The saturate fraction is blended with a ‘naphthene or mix
par-a?ins and C8 and higher naphthenes, have high anti
knock values and are suitable as components of high anti
knock gasolines. The process'involves hydrocracking at
relatively low temperature utilizing AlBr3~—HBr =as cata
ture of naphthenes having 7-9 carbon atoms to form a
‘blend containing 25~90% by Weight of the naphthene,
20 and AlBr3 is dissolved in the mixture- in amount of 25
100% by weight based on the total hydrocarbons. The
lyst, and the reaction must be carried out in the presence
of a substantial amount of one or more naphthenes of the
mixture is then contacted in the presence of HBr with
One drawback to the process described in said applica
saturate content to hydrocarbons boiling in the gasoline
range. In this reaction the C7-C9 naphthene remains
largely unconverted and can be separated from the reac
hydrogen under a partial pressure of 25-500 p.s.i. and at
C7-C9 range. The reaction system is homogeneous and
a temperature in the range of 0-1000 C. for a time sufii
the reaction proceeds cleanly without any sludge forma‘ 25 cient to convert at least a major portion of the charge
tion is that the charge stock must be essentially free of
aromatics, since these hydrocarbons form sludges with the
catalyst and prevent it from functioning in the manner
This circumstance necessitates the use of a feed
preparation step for removal of essentially all of the mo
matics from the gas oil feed stock. Since the resulting
aromatic product generally would have to be sold as
residual fuel oil at relatively low value compared to gas
oline, this procedure, in effect, results in a downgrading
tion product and recycled. Also the hydrocarbons boil
ing above the gasoline range can be totally recycled, so
that no material boiling above gasoline results from the
The invention is described more speci?cally in conjunc
tion with the accompanying drawing which is a schematic
illustration of the present process. Referring to the draw
ing, straight run and catalytic gas oils enter the system,
respectively, through lines 10 and 11. The straight run
of a portion of the gas oil stock.
The present invention involves a manner of utilizing
gas oil ?rst goes to an extraction zone 12 wherein the
the foregoing process advantageously in a combination
aromatics are substantially completely separated from the
system for converting both straight run gas oil and cata 40 saturates. While the extraction step could be carried out
lytic gas oil into high antiknock gasoline. Catalytic gas
by solvent extraction utilizing an aromatic-selective sol~
oils, which typically may have aromatic contents in the
vent, e.g. furfural, and sufficiently e?‘icient extraction con
vrange of 30—60% by volume, are not suitable charge
ditions to attain the necessary degree of separation, this
stocks for the above-discussed process in view of the cost
would be costly in view of'the fact that the saturate prod
of separating the relatively high proportion of aromatics 45 uct
needs to be essentially ‘aromatic-free. A distinctly
from the saturates and the low value of the aromatic por
better way of eiiecting the separation is by selective ad
tion. They are also not suitable charge stocks for con
sorption by means of silica gel. A particularly suitable
ventional catalytic cracking processes because of the re
selective adsorption process for this step is the “Arosorb
fractory character of the aromatics. However they can
Process” which is operated in cyclic manner as described
be cracked effectively into high octane gasoline by hydro 50 on pages 109-113 of Petroleum Re?ner, vol. 31, No. 5
cracking under conditions involving the use of a large
(May 1952 issue). In such process, the charge stock,
proportion of hydrogen and a siliceous cracking catalyst
preferably diluted with a low boiling saturate solvent such
containing a hydrogenating component.
as pentane, is passed through a bed of silica gel until the
A process of this type is described in Scott United States
capacity of the bed for adsorbing charge aromatics is
Patent No. 2,944,006‘. It involves the use of a catalyst
largely but not entirely depleted, after which a suf?cient
containing a hydrogenating component, which is either
quantity of desorbent to desorb the charge aromatics com
nickel sul?de or cobalt sul?de, supported on an active
pletely is passed through the bed. The desorbent, which
siliceous cracking catalyst such as silica-alumina, silica
preferably comprises a component of high adsorbability
rnagnesia, silica-zirconia and acid activated clays. The
such as benzene together with a component of low ad~
process is operated at temperatures between 350° and 60 sorbability such as pentane, is so selected that its boiling
700° F., with at least 1500 s.c.f. of H2 per barrel of con
range is sutiiciently below ‘the boiling range of the charge
Version product boiling below the charge and hydrogen
stock to enable easy separation of charge and desorbent
‘partial pressure generally in the range of 500-2000 p.s.ig.
components by distillation.
The antiknock value of the gasoline product increases as
The e?luent from the adsorbent case, during each cycle
the aromatic content of the charge increases. Normally 65 of operation, is collected in two or more portions, one of
the operation effects a conversion of 50-70% per pass and
which comprises charge saturates and desorbent, and an
the material which boils higher than the desired gasoline
other ofwhich comprises charge aromatics and desorbent.
product is totally recycled
These portions are then separately subjected to fractional
Another process for hydrocracking catalytic gas oils is
distillation in order to recover a charge saturate fraction,
described in Hansford United States Patent No. 2,885 ,349‘. 70 a charge aromatics fraction, and desorbent for recycle
This process utilizes an acidic oxide cracking catalyst,
.to the‘ process. For the present purpose the selective
such as silica-alumina, containing a hydrogenating com
adsorption step is most economically operated under con
the AlBra and further conversion of the hydrocarbons to
gasoline. The heavy gasoline fraction is composed essen
ditions such that the saturate fraction obtained is essen
tially aromatic-free while the aromatic fraction contains
a substantial proportion of saturates, e.g. 20% by vol
ume.- This allows the separation to be effected more read
tially entirely of naphthenes ‘boiling above the cut point
of the recycle naphthene fraction together with isoparaf
?ns, and it also has a high antiknock value.
iily than would be the case if a pure aroma-tic fraction also
were to be produced. The saturates in the aromatic frac
Referring back to the aromatic fraction which is ob
tained from extraction zone 12 via line 30, this material
tion are not reduced in value since they are readily
is blended with the catalytic gas oil from line it and with
recycle material from line 31 and the material is fed to
the aromatic fraction.
cracking zone 32 which operates at considerably higher
The aromatic-free saturate fraction obtained from 10 temperature than is used in cracking zone 14. The proper
extraction zone 12 is sent through line 13 to a low tem
temperature level in zone 32 depends to considerable ex
perature cracking zone 14. Prior to entering this zone
tent upon the particular catalyst being used but in any
the saturate fraction is admixed with a recycle stream
event falls within the general range of 350-1050“ F. The
cracked to gasoline in the subsequent hydrocracking of
from line 15 which stream contains one or more naph
thenes of the C7-C9 range (indicated in the drawing as O;
naphthene). A small amount of make-up C7 naphthene
can be added to the system through line 16. The propor
tion of the hydrocarbon streams should be such that the
C7-C9 naphthene content of the mixture is in the range
of 25-90% by weight, more preferably, 30-50%. Any 20
naphthene of the C7-C9 range can be used for this pur
pose. While it remains mainly unconverted in the sys—
tem, its presence in reaction zone 14 is important for ob
raining a clean reaction and avoiding sludge formation.
The catalyst used in reaction Zone 14 is AlBra in, 25
combination with HBr. The amount of AlBr3 present
should be 25-l00% based on the weight of total hydro
carbons in zone 14. The amount of HBr used is not par
ticularly important as long as at least a small amount is
catalyst is composed of a hydrogenating component de
posited on an active siliceous cracking catalyst support,
such as described in the aforementioned United States
Patent No. 2,944,006 and Patent No. 2,885,349 wherein
the hydrogenating components are nickel sul?de, cobalt
sul?de or chromium sul?de. Other hydrogenating com
ponents that can be used are the sul?des of iron, molyb
denum and tungsten, the oxides of iron, nickel, chromium,
molybdenum and tungsten, platinum, rubidium and rho
diurn. Hydrogen in amount of 1000-2500 s.c.f. per bar
rel of mixed hydrocarbon feed is introduced through line
33 into cracking zone 32 and a hydrogen partial pressure
in the range of 500-5000 p.s.i. is maintained therein. The
hydrogen stream is composed of recycle hydrogen from
line 34 together with make-up hydrogen admitted from
line 35.
present, for example, 025% by weight based on the 30 The e?luent which leaves cracking zone 32. via line 36
hydrocarbons. Hydrogen is fed into reaction zone 14
is passed through suitable separating means (not shown)
through line 17 and the amount so introduced should be
for recovering the excess hydrogen and then into distilla
su?icient to maintain a hydrogen partial pressure in the
tion zone 37. The hydrocarbons are fractionated to re
range of 25-500 psi. The reaction temperature should
C, and lighter hydrocarbons as indicated by line
be maintained in the range of 0-100° C., more preferably (0 Us move
33 and a debutanized gasoline as shown by line 39. The
25-75° C., and the reaction mixture should be agitated
residuum, composed of hydrocarbons ‘boiling above the
continuously to effect intimate contact with the hydro
gasoline range, can all be withdrawn through line 40 as a
gen. The reaction mixture is homogeneous, and under
fuel oil product but preferably is at least mainly recycled
the conditions speci?ed essentially no sludge formation
line 3-1 for further conversion to gasoline. The
occurs. A su?‘icient residence time in the reactor should
gasoline fraction from line 39 can be blended with the
be allowed to convert at least a major portion of the gas
C5-C7 parat?ns from line 22 and the heavy gasoline frac
oil saturates to hydrocarbons boiling in the gasoline
tion from lines 25 and 41 to yield a high quality gasoline
The reaction mixture from zone 14 passes through line
In order to illustrate advantages of the present process,
‘18 to a distillation zone indicated diagrammatically at 19.
the following comparison is made between a process op
I-lBr is ?rst stripped from the mixture and passes back to
erated according to the aforesaid application Serial No.
cracking zone 14 through line 20. Isobutane, which is
for the purpose of processing 10,000 bbls./ day of
invariably produced in substantial yield, is removed next
straight run gas oil and the present process operated to
hydrocrack a total of 10,000 1bbls./ day of gas oils com
as indicated by line 21 and can be utilized in another
process such as alkylation. The C5-C7 para?in products,
which are preponderantly isopara?ins of high antiknock
value, are removed as indicated by line 22. Then the C7
naphthene (or if desired a mixture of C7-C9 naphthenes)
prising 6,667 hbls/day of straight run gas oil and 3,333
bbls/day of catalytic gas oil. It is assumed that the
straight run and catalytic gas oils have aromatic contents
of 20% and 40% by volume, respectively.
The following data show the processing capacities re
quired for the two operations and the products obtained:
can be recovered as indicated by line 23 and a part or all
of this material is recycled through lines 24 and 15 to
cracking Zone 14 to maintain the necessary naphthene
content of the reaction mixture. Only a small amount of
the naphthene originally used is converted to other prod
Process of
8. N. 25,503
ucts in the reaction and hence in no event is any large
make-up of naphthene through line 16 required. In fact,
when only a C7 naphthene such as methylcyclohexane is
originally used, not only is the extent of disappearance of
Gas Oil Charge, bblslday:
the C7 naphthene small but C8 and C9 naphthenes gen
Unit Capacities, bbls/day:
erally are produced in substantial amounts from the gas
oil saturates. Hence su?icient C8-C9 naphthene can be 65
recycled to maintain the desired naphthene content in
zone 14 and no make-up whatever is required through
line 16.
A heavy gasoline fraction, which boils above the cut
point of the naphthene cut, is distilled and removed 70
through line 25, leaving as residue hydrocarbons boiling
above the gasoline range with AlBrs dissolved therein or
both dissolved and dispersed therein depending on AlBra
concentration and the temperature. of the stream. This
material is recycled through lines 24 and 15 for re-use of 75
Straight r1111 ............................. __
Extinction zone ......................... __
Low Temperature Cracker ____ __
10, 000
10, 000
7 500
High Temperature Cracker_.___
Total .............................. ._
Products, bbls./day:
6, 667
3, 333
6, 667
17, 500
16, 667
O; and lighter
1, 625
Gasoline. . _ -
7, 185
10, 090
Fuel OiL..-
Total .............................. ._
F-l Octane No. of Gasoline (@ 3 cc. T.E.L./
2. 500
__________ __
10, 907
11, 875
88. 9
89. 3
From the data presented it can be seen that the present
ing 25-100% by weight, based on the hydrocarbon con
process requires less total plant capacity and produces a
considerably larger volume of gasoline without any pro
duction of fuel oil. Also the gasoline produced has an
tent, of AlBr3, contacting the reaction mixture in the
presence of HBr with hydrogen under a partial pressure
of hydrogen at 25-500 p.s.i. at a temperature in the range
appreciably higher antiknock value.
major portion of said saturate fraction in the reaction
of 0—100° C. for a time su?icient to convert at least a
I claim:
mixture to hydrocarbons boiling in the gasoline range, and
1. A process for cracking straight run gas oil and
blending said catalytic gasoline and said hydrocarbons
catalytic gas oil which comprises contacting a straight run
in the gasoline range to yield a gasoline product
gas oil stock With silica gel to obtain an aromatic fraction
anti-knock value.
and a saturate fraction essentially free of aromatics, blend 10
2. A process according to claim 1 wherein said hydro
ing said aromatic fraction with a catalytic gas oil stock,
genating component is selected from the group consisting
subjecting the blend of aromatic fraction and catalytic
gas oil stock to catalytic hydrocracking conditions in the
presence of hydrogen and a siliceous cracking catalyst
containing a hydrogenating component at 35 0-105 0° F. to 15
form catalytic gasoline, forming a reaction mixture com
prising said saturate fraction and 25-90% by weight,
based on the total hydrocarbon content of the reaction
mixture, of monocyclic naphthene having 7-9 carbon
‘atoms yer molecule, said reaction mixture also contain
of nickel sul?de, cobalt sul?de, and chromium sul?de.
References Cited in the ?le of this patent
Eglo? et al ______________ Aug. 10, 1943
Lanning ______________ .. Feb. 3, 1953
Hansford _____________ __ May 5, 1959
Schneider et -al __________ _._i Oct. 13, 1959
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