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De;- 17, 1946;
'
H. G, M. FISCHER
2,412,819
CHEMICAL PROCESS
Filed May 31, 1941
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Patented Dec. 17, 1946
2,412,879
UNITED STATES PATENT'OFFICE
Herbert G. M.
Fischer, West?eld, N. J., assignor to
Standard Oil Development Company, a corpo
ration of Delaware
Application May 31, 1941, Serial No. 395,920
7 Claims. (0]. 196—55)
The present invention relates to the art of
treating hydrocarbon oils to obtain desired prod
and more particularly it relates to the ther
heated oil into a chamber where the oil is main
tained at the temperatures indicated and under
atmospheric or superatmospheric pressure for a
suf?cient period of time to e?ect the desired con
version. As the process of coking proceeds in
move constituents boiling up to about 700°—850° F.
In processing a crude petroleum oil, the modern
re?ner must deal with the crude material in a
the chamber, the coke formed in the process
accumulates progressively until ?nally a time is
reached when the coking operation with respect
manner to provide maximum quantities of de
sired products, and from time to time the coin 10 to a particular chamber must be discontinued in
order to remove the coke. The decoking is a
mercial demand for certain petroleum products
time-consuming and'laborious operation since'the
may vary widely. _For example, in the northern
part of the United States during the winter
coke forms aistrong‘, tough mass which to com
pletely' ‘remove, as stated, involves a great deal
of labor.
15
readily obtainable from crude petro
leum oil by simple distillation and, as a result, it
is often necessary during the winter season to
process topped crudes to recover additional quan
tities of hydrocarbon oils which are suitable for
domestic heating fuel On the other
hand, during the summer months the commercial
demand for gasoline and motor fuels may be such
as to require an entirely di?erent treatment of
petroleum crude oils in order
to obtain the maxi
mum production quantities of gasoline; Ordi
‘Usually after a coking chamber has been taken
‘0d the onstream‘ operation, it is ?rst permitted
to cool, whereupon the operators remove the coke.
The coke removal in the ordinary intermittent
coking process is an operation which consumes
considerable time and labor and, consequently,
any method which will eliminate a substantial
portion of the time and cost necessary to decoke
a chamber would effect a material advantage.
The main object of the present invention is to
carry out the coking of heavy petroleum oils con’
tinuously by forming the coke in such a manner
narily when a crude oil is received in a modern
re?nery it is the practice to subject it to a '
that it is" highly frangible, relatively soft, and
adapted to be continuously removed from the
coking zone.
‘
A more speci?c object of my invention is to
carry out a, coking operation in the presence of
added cellulose linters, threads, sawdust, wood
?our or other cellulosic‘ material in divided form,
under conditions such that the charcoal resulting
from the added cellulosic material intermixes,
with the formed coke and greatly reduces the
When, however, the commercial demand is‘
such that increased quantities of gasoline are
desirable, the reduced crude may be subjected to
a thermal treatment whereby a
tensile strength of the latter so that it maybe
easily removed from the coking zone.
40
verted to vaporizable hydrocarbons and a ‘solid 45
coke.
The coking operation, as ordinarily practiced
in a modern re?nery, entails a. number of prac
" Other and further objects of my invention will
appear from the ensuing more detailed descrip
tion'of my present invention.
The present'invention will be best understood
by reference to the accompanying drawing which
shows diagrammatically a form and arrangement
of apparatus elements in which my process may
be carried into practical effect. I shall describe
the process in terms of the coking of a speci?c
reduced crude, but it is to be clearly understood
Probably the most troublesome aspect of a coking 50 that the specific example I have chosen is ptu'ely
illustrative and does not constitute a limitation
operation is the removal of the coke from the
of'my invention. ‘
'
coking zone. The coking operation is generally
Referring in detail to the drawing, a reduced
performed by heating the reduced crude to ‘a
East Texas crude petroleum oil having an A. P‘. I.
temperature within the range of from 800°-1000°
F'., usually in a coil, and then discharging ‘the 55 gravity ‘of 18° is introduced into the system
tical operating dii?culties and disadvantages.
through line I. Sawdust’ of the‘ordin'ary' com‘
2,412,879
it
carbons, together with light and heavy naphtha,
mercial grade is withdrawn from hopper l4
through star feeder i5 and conduit l1 and dis
charged into the oil in line i and thereafter a
and light and heavy gas o‘l. These fractions may
be recovered in any known manner and usually
a heavy fraction is recycled to the line I! for fur
slurry of sawdust and oil is discharged by pump
ther treatment in the process. A light fraction
3 into a coil 6; disposed in a suitable furnace set
ting 5. In coil 4 the oil is heated to a temperature
of from about 800° F. to ll00° F., and during the
In
may be taken off from the top of column 42 by
line 43 and a heavy fraction by line 50.
In order to point out the advantages of my
presentinvention I may direct attention to a run
which I made on an East Texas reduced crude
having an A. P. I. gravity of l3°, under the con
ditions hereinbefore speci?ed, in which I em
order to assist in the vaporization of the oil,
ployed‘ 2% by weight of sawdust and found that
steam at a temperature within the range of from
about 825° F. to 1100° F. is discharged into the.
7 upper part of drum 25 through line 23. Instead
8% by‘ weight of a friable, porous coke, based on
the original feed, was formed. This coke was of
such form and condition that it could be easily
removed from a coking drum. I made a similar
run with the same feed stock but omitted the
heating operation the sawdust/is at least partially
converted to charcoal. The heated oil is with
drawn from the coil through line 5 and discharged
into the top of coking drum 25 as shown.
of introducing the sawdust into the liquid oil in
line I, the sawdust may be introduced into the
vapors in line 9, employing for the mixing of the
oil vapors into the sawdust any suitable device, 20
such as an injection means. This may be accom
plished by means of the by-pass 5i. Valves 52
and 53 are arranged respectively in lines ii and
5! to control the flow of the ?nely divided solid
either to the heating coil or to line 9. In either
sawdust, and I found that I obtained 15% by
weight of coke and that the said coke was dense
and hard and was difficult to remove from a
coking drum.
Therefore, there are two advan
tages in my present process, as follows: First, the
amount of coke produced from a given stock is
25 less and this means, of course, that more vapor~
event the amount of sawdust mixed with the oil
izable‘ hydrocarbons are produced, which is a
may be from 1% to 10% by weight of sawdust
known desideratum; and, second, the coke which
I produced was easily crushable and porous in
and 90% to 99% oil. vaporized at least in part
the case where I employed sawdust, while the
The oil, ordinarily
in line 9,
was true when sawdust was omitted.
containing sawdust and/or charcoal
is then discharged 2-‘ reverse
To review brie?y, the present invention relates
however introduced therein,
as indicated into the top of coking drum 25. The
to a; continuous coking operation carried out in
oil passes downwardly through the drum 25 and
the presence of a friable cellulosic material, such
as sawdust, the sawdust serving to form an ad
during this passage it is converted to vaporizable
hydrocarbons and non-vaporizable hydrocarbons.
sorbent charcoal during the heating, which char
coal is intermixed with the formed coke and ren
conditions stated, particularly in the upper sec
ders the latter readily disintegratable or crush
tion of the drum represented by A. The tarry
able' so- that it may be substantially continuously
material thereafter continues its downwardly
removed from the coking zone. A relatively small
progress through the drum and the conversion 40 amount of sawdust present in the oil during
coking is suf?cient to accomplish the desired
continues.
The heavy oil and the tar formed in the region
result. I have found, for instance, that 2% by
generally‘ indicated by A are converted to a
weight-of sawdust based on the oil fed is sufficient
frangible coke in. the region generally indicated
to produce a soft coke. The sawdust which I may
by B. This coke: contains the charcoal resulting
from the car-bomzation of the sawdust,_ and it is 45 add may be either green wood sawdust or dry
A heavy oil or tar is formed in’ drum 25 under the
35
this charcoal which forms a weak link in the
structure of the coke so that the same may be
readily broken into lumps and thus readily re
sawdust. From a commercial standpoint, as well
as from a technical standpoint, sawdust is a very
desirable material‘ since it is relatively inexpen
sive, constitutingto a large‘ extent a waste product
moved from the coking drum. If desired, grind
from saw-mills, and the like. I may of course
ing or crushing means Zii may be positioned in 50 use divided cellulosic material, such as in‘ the form
the lower portion of drum 25 to disintegrate and
of wood flour, wood chips, wood meal, cotton
reduce the coke into readily removable lumps.
linters, cottonseed hulls, etc.
Additional steam, say at a temperature of 825° F.
The operation previously described is carried
to 1100° F., mayinbeorder
discharged
intothethecoke
drum
to purge
of 55 out under normal atmospheric pressure, but it
is to be understoodv that my process is broad
through line 30
volatile constituents.
enough to be carried out under superatmosp'heric
,
The coke is withdrawn from the drum through
pressure; for instance, pressures as high as 100
a star feeder 3! and conduit 32. Since the. coke
500 lbs/square inch in the coking zone. The
issuing from the drum 25 is at anthe
elevated
tem .60 amount of steam, if used, may be from 5-10 mol
withdrawn
perature, it is desirable to force
per cent and this quantity is fed into the drum
7 coke through a suitable. cooling means 35 to re
25 through lines 28 and 38' as indicated. A- tem
duce its temperature. This cooling; meansv may
perature of‘ about l100° F. in coking drum 25 gives
consist of water, or any other cooling ?uid which
excellent results.
.
may be circulated in a jacket surrounding con
Many modifications of my invention will be
be
sprayed
directly
on
the
65
apparent to those who are familiar with this
duit 32, or which: may
not coke. The cooled coke is then discharged
particular art.
into a receiving" bin is at a temperature such
What I claim is:
r
that it will not ignite upon exposure to the air.
1. A continuous method of. producing coke
Ordinarily a safe temperature would beone below 70 which is frangible and easily disintegrated, com
300° F. to 325°v F.
>
The vapors formed in the coking drum 25 are
prising the coil preheating of a heavy petroleum
oil to coking temperature but without substantial
coke formation, commingling a cellulosic mate
rial with the preheated oil, passing the com
withdrawn overhead through line 41 and deliv
ered to a fractionating column 112. Ordinarily
the coking operation results in the production of ‘75 mingled» preheated oil and cellulosic material into
5-25% of gasoline and. normally gaseous hydro
2,412,879
r
a zone wherein coke is formed, continuously dis1% to 10% of cellulosic6material with
a reduced
integrating the coke, adjacent a point of withcrude petroleum oil and heating the mixture to
drawal from said zone, and continuously remova temperature within the range of from about
ing coke therefrom.
1"
800° F. to 1100° F., thereafter discharging the oil
2. A continuous method of producing coke‘ u and cellulosic material into a coking zone, per
which is frangible and easily disintegrated, committing the oil and cellulosic material to remain
tinuously disintegrating the admixed coke and
charcoal adlacent a point of withdrawal from said
Zone, and Continuously removing the admixed
4 The process set fOl th in claim 3 in which the
cellulosic material is sawdus
5. The process set forth in claim 3 in which the
coke and charcoal therefrom.
cellulosic material is wood ?our.
‘
3. A continuous method for converting ther- 20
6. The method set forth in claim 3 in which the
mally a relatively heavy petroleum oil residual
into vaporizable hydrocarbons containing subStantial quantities of gas 01'1 and coke-forming
constituents, Whlch process is characterized by
coke and charcoal mass are ground and then
recovered from the coking Zone.
7. The process set forth in claim 3 in which the
cellulosic material is sawdust and in which the
the feature that the coke produced is frangible 25 amount of sawdust is 2% by Weight of the oil.
and readily crushable, which comprises mixing
HERBERT G. M. FISCHER.
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