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Патент USA US2105467

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Jan. 18, 1938.
Filed Feb. 20, 1935
Patented Jan. 18, 1938
Pascal McDonald Biddison, Dallas, Tex., and Max
R. Ryan and Charles R. Burke, Tulsa, Okla.,
assignors to Danciger Oil & Refineries, Inc.,
Tulsa, Okla.
Application February 20, 1935, Serial No. 7,438
1 Claim. (Cl. 196-48)
Our invention consists in new and useful im
combine with this gas injection feature an eñi
provements in the method of producing low boil
ing point hydrocarbon products such as gasoline,
cient system of refluxing, heat exchange, cleans
ing, quenching and mixing at various steps of the
naphtha and benzol, suitable for use as motor
operation to produce a motor fuel of the desired
quality, with a minimum loss and maximum effi
fuels, from high boiling point hydrocarbons, and
is in the nature of an improvement on the in
vention disclosed in U. S. Letters Patent to Pas
cal McDonald Biddison and Hugh T. Boyd,
will appear as the description proceeds, our in
#1,345,740, issued July 6, 192,0.
The primary object of the invention is to great
vention consists in the novel features hereini set
forth, illustrated in the accompanying drawing 10
' ly increase the productionof low boiling point
hydrocarbon products suitable for use as motor
fuels and to improve their quality, and also to
eliminate many of the difñculties of operation
heretofore experienced in conversion processes.
Another object of our invention is to provide
means for carefully regulating and controlling
the operation in order that low boiling point hy
drocarbons may be simultaneously produced from
several higher boiling point hydrocarbons as de
0 sired by the operator. This we accomplish
among other means, by the injection of a suit
able gas which is mingled with the high boiling
point hydrocarbon oil to be converted into low
_ boiling point hydrocarbon products suitable for
motor fuel, while both are being heated to a tem
perature sufficiently high to accomplish the de
sired conversion.
'I‘he use of a gaseous medium in a process of
this character as described in the U. S. Patent
30 No. 1,345,740, above referred to, involves the law
of partial pressures, and is of -great value in pro
ducing the desired results, and We have found
that a further reason for the advantages of such
process is that under a temperature and pressure
relationship peculiar to each grade and class of
oil, prior to the occurrence of the vaporization
of the hydrocarbon oil, a condition of molecular
instability of several of the constituents of the
oil is produced and therefore certain constitu
ents of the gas combine with those of the hydro
carbon oil.
In our process, the mixture of hydrocarbon
oils and gas in the cracking zone is raised to such
a pressure and temperature that on at least a
portion of the oils, a state of molecular insta
bility is produced with the result that conversion
of some of the oil into lower boiling point hy
drocarbons occurs, and simultaneously there may
50 be molecular readjustment between oil constit
uents and gas constituents whereby certain gas
constituents become components of some of the
lower boiling point liquid hydrocarbon compo
nents resulting from the process.
A still further object of our invention is to
With the above and other objects in view which
and more particularly pointed out in the ap
pended claim.
In the accompanying drawing, we have shown
a flow diagram which illustrates one form of
apparatus by means of which our invention may 15
be carried out.
Referring to the drawing, I represents a line
leading from a suitable source of raw charging
stock (not shown) to the inlet end of a vapor
heat exchanger 2 located in the upper end of a
vapor separator 3. The outlet end of the heat
exchanger 2 is connected to a line 4 provided with
a valve 5 and terminating in communication
with line 6 leading into the lower portion of the
separator 3.
. 1 and 8 represent cracking zones preferably
of the type comprising a bank or banks of tubes
which also discharge into line 6, the former
through line 9 and valve l0, and the latter being
directly connected to line 6 through valved con 30
nectìon Il.
The lower extremity of the vapor separator 3 is
provided with a liquid draw-olf connected into
line l2 provided with a valve I3 and terminating
in communication with a stripping tower lli, the
latter being provided with a vapor discharge line
l5 leading to condenser I6, and a liquid draw
off at its lower extremity connected into line Il.
The discharge end of the condenser I5 is con
nected by line i8 to line I9 which leads in one 40
direction to a suitable storage tank (not shown)
and is provided with a valve 2D and pump 2l,
While in the opposite direction the line I9 leads
to substantially the central portion of a fraction
ating column 22, a suitable pump 23 and valve
24 being provided between the pipe I8 and the
fractionating column 22. Thus, by manipulation
of the valves 2D and 24, the condensate from l5
may pass to a storage receptacle or may be re
turned to the system through`the fractionating
column 22 as will hereinafter appear.
A second charging line 25 leads from a suit
able source of a lighter charging stock and has
interposed therein a pump 26, said line leading
to the inlet end of a second vapor heat exchanger 55
2'! arranged adjacent heat exchanger 2 in the
through Which the separated gases leave the
upper end of the vapor separator1 3. The outlet
end of this heat exchanger 2'! is connected into
a line 28 which leads to the inlet pipe 29 of the
cracking zone '!.
The bottom of the fractionating column 22 is
provided with a liquid draw-01T in communica
tion With line 30, having a suitable pump 3| in
terposed therein and terminating in communica
tion with the inlet pipe 32 of the cracking zone 8.
The top of the vapor separator 3 is provided
with a vapor outlet connected into vapor line 33
which terminates in communication with the
lower portion of the Íractionating column 22.
At a suitable point in the upper portion of the
vapor separator 3 below the heat exchangers 2
and 2'!, We provide a condensate accumulator 34
which may be of any suitable type, that shown
in the drawing consisting of an annular tray ex
tending entirely across the separator shell. and
having a central opening bounded by a vertically
extending circular wall 35, and an overiiow pipe
34’ equipped with a liquid seal at its lower end.
The side of the tray 34 opposite the liquid seal is
provided with an opening leading into line 36
which extends through the shell of the separator
and terminates at its opposite end in communi
cation with the fractionating column 22 at a point
preferably above the connection of the vapor line
33, said line 36 being provided with a Valve 3'!
at a point intermediate its ends.
38 represents a charging line leading from a
third source of charging stock such as gas oil
(not shown) and terminating in communication
35 with the line i9 leading to the fractionating
column 22, said line 38 having interposed there
in a pump 39. Thus, by manipulation of the
valve 24 in line I9, this gas oil charging stock
may be fed to the fractionating column 22 either
40 alone or combined with the condensate from
condenser i3.
At a suitable point in the upper portion oi the
fractionating column 22, we provide a line-4U
which leads to a point below the top of an ac
45 cumulator 4l, the lower end of the latter being
provided with a liquid draw-off connected into
line 42 provided with pump 43 and valve 44, and
terminating in communication with line 25 lead
ing to heat exchanger 2'! in the vapor separator 3.
The top of the accumulator è!! is arranged in
communication with a vapor line 45 which leads
into theupper portion of the fractionating column
22 at a point above the connection of line 4Q
just described. Thus the liquid in the accumu
55 lator 3l may be intermingled with the light dis
tillate ied through line 25, heat exchanger 2'! and
line 28 to the cracking .Zone l, and the vapors
from said accumulator carried back to the upper
portion of the fractionating column 2'2.
The top of the fractionating column 22 is
equipped with a vapor outlet arranged in com
munication with a line ¿i3 which terminates in
communication with a gas separator ë'! and has
interposed therein a suitable condenser 613. The
65 bottom of the gas separator 4'! has a liquid draw
off line e9 connected to a branch line 50 which
leads back to the upper portion of the fractionat
ing column 22, a pump 5I being provided at a
suitable point ingsaid branch line whereby a por
70 tion of the condensate kfrom the gas separator
4'! is returned to the top of the fractionating
column. The remainder of said condensate is
conveyed from the system through line 49 to a
suitable point not shown. 52 represents a- gas
75 line leading from the top- of the gasseparator 4'!
Adjacent the inlet ends of the cracking zones
'! and 8, We provide gas lines 53 and 5ft leading
into inlet lines` 29 and 32,- respectively, for the
purpose and in the manner hereinafter described
more in detail.
Having thus described one form of apparatus
by means of which our improved method ci'
treating high boiling point hydrocarbons may 10
be carried out, its operation is as follows:
Raw oil charging stock, which may comprise
any constituents of petroleum crude, is supplied
through line l, heat exchanger 2, line ë., valve 5
into line 6 Where it mingles with the gases, vapors 15
and liquids from the cracking Zones 'l and 8.
This mixture enters vapor separator 3 through
line E and substantial vaporization takes place in
said separator. The unvaporized portion of the
mixture has the general characteristics oi" fuel oil 20
and is withdrawn from the bottom of the vapor
separator through line l2, and if desired, this
residual oil may be further treated in the tar
stripper hi.
This tar stripper tower is maintained at a lower
pressure than the vapor separator 3 whereby
further vaporizatio-n occurs when the oil enters
this zone of lower pressure.
In some instances,
it may be desirable to increase the» stripping
action in the tower iii by the use of steam, cr
vacuum, or both. The vapors evolved in the
stripping tower lâ are discharged through line i5
and condensed in £3, and the condensate may
pass from line I8 through valve 23 and pump 2i
to a suitable storage receptacle not shown, or by
closing the valve 20, it may be conveyed in whole
or in part through line i9, valve 213 and pump 23
and discharged into the fractionating column 22.
The stripped residuum is withdrawn from the
stripping tower I3 by means of line H.
The gases and vapors formed in the vapor
separator 3 flow upwardly past the vapor. heat ex
changers 2 and 2'! where they are partially cooled
and the highest boiling point fractions arecon
densed, the condensate dropping back into the
accumulator 3d. From the accumulator Sil, this
condensate passes through line 36 and valve 3l
into the íractionating column 22. If desired, the
valve 3'! may be closed or regulated to permit the
condensate or a portion thereof to overilow `from
the accumulator 34 through the overflow pipe
34’ and drop back into the vapor separator, thus
acting as a cooling medium for the separator. .
The uncondensed portions` of the gases, and
vapors leave the separator 3 at its upper end
through line 33 and are introduced into the lower
portion of the fractionating column 22 at a point
below the connection of vline 36, and as they pass
upwardly through the fractionating column, they
come into contact with the cooler down-flowing 60
reflux which cools the gas vapor stream and con
denses the heaviest constituents of the vapors.
During this operation, a second stream of-cool
charging stock which preferably comprises 'a
clean oil such as gas oil, may be supplied through
line 38 and pumped by pump 39 and line i9 either
alone or admixed with the condensate from-NH3,
into the íractionating column 22 at a point above
the entrance of the vapor line 33. A portion of
this charging stock or mixture, as the case may
be,v is vaporized and passes upwardly with the
rising vapors in the fractionating column. The
remaining portion «of said charging stock will iiow
downwardly as reflux and together with the nor
mal condensate in the fractionating column», is 75
withdrawn from the bottom of the column
i through line 30 and pumped by pump 3l into the
inlet of cracking zone 8.
A stream of suitable~ hydrocarbon gas is contin
Ul uously introduced through line 54 into the inlet
gas furnace feeding to the cracking coils during
these periods averaged 1027° F. The average
pressure on the cracking coil was 438 lbs. during
the entire run.
line 32 of the cracking zone and comes into direct
contact with the oil fed from the fractionating
column 22, thus producing a charging mixture for
the cracking zone 8 composed of hydrocarbon gas,
a portion of the charging stock fed through line
38, andthe reflux formed in the fractionating col
umn 22, which mixture is subjected to suitable
Ycracking conditions in zone 8 and discharged
through valve II and line 6 into the separator 3,
15 commingled with the preheated charge of raw
Fresh oil charged _______________ ._
36. 2
976. 64
100. 00
Pressure distillate ______________ __
57. 4
44. 24
89. 85
9. 20
Pentane and higher in residue gas. ________ __
of charge
Gasoline in recycle stock at nd
of run._____-_
Residuum ____ __
17. 6
143. 99
14. 74
27. 7
156. 05
Recycle stock after removal of
gasoline at cnd of run _________ __
l5. 98
14. 70
‘ oil fed through lines I and 4 as hereinbefore de
'I'he presence of this hydrocarbon gas admixed
with the materials entering the cracking zone 8
20 creates a partial pressure effect which is of great
Value in producing the desired results, and fur
thermore, under suitable temperature and pres
sure conditions, produces a condition of molecu
lar instability of several ofthe constituents of
the oil prior to the'occurrence of the vaporization
of such oil, whereby certain constituents of the
gas combine with those of the hydrocarbon oil.
A portion of the down-flowing reflux in the
fractionating column 22 having the general char
30 acteristics of naphtha, is removed from the frac
tionating column through line 40 and is conveyed
to the accumulator 4I _from whence it is pumped
by pump 43 through line 42, valve 44 and line 25,
through the heat exchanger 21 in the vapor sep
arator 3, through line 28 and into the inlet 29
of the cracking zone l. This material may be
joined by a stream of fresh charging stock which
consists of a light distillate such as naphtha,
'kerosene or a light gas oil fed through line 25
40 and pumped by pump 26 through the system.
As in the case of the material entering the
cracking zone 8, a stream of suitable hydrocarbon
gas is continuously introduced through line 53
into the inlet line 29 of the cracking zone ‘I and
comes into direct contact with the material fed
through line 28, thus producing a charging mix
ture for the cracking zone 'l composed of hydro
carbon gas, a portion of the reñux from the ac
cumulator 4I and a portion of the fresh charge
50 fed through line 25, which mixture is subjected
to cracking conditions in Zone 'I and discharged
through line 9, valve I0 and line 6 into the vapor
separator 3 commingled with the cracked mix
ture discharged from zone 8 and the preheated
55 charge of raw oil fed through lines I and 4. It
will be noted that this commingling may take
place either prior to or during the vaporization
of the mixtures.
As in the case of cracking zone 8, thepresence
60 of the hydrocarbon gas in zone 'I creates a par
tial pressure eñect and a condition of molecular
instability whereby certain constituents of the
gas combine with those of the oil. The temper
ature maintained in the cracking zone 1 is pref
erably sufficiently high to partially crack the in
termediate boiling point hydrocarbons, but lower
than the temperature in the cracking zone 8.
A typical example of the conditions of opera
tion in a run of our improved process is as fol
70 lows:
'I'he unit was operated ñfty hours and twenty
minutes at an average cracking coil temperature
of 924° F. The last twenty hours and forty
ñve minutes of operation Was at a temperature
75 of 928° F. The temperature in the outlet of the
Av. rate
per hn
Cu. ft.
0u. ft.
Volume of gas charged to unit _______________ __
l2, 958
Volume of gas from unit _____________________ ._
32, 520
Volume of gas from u_uit pcntano, free _______ __
30, 249
Oil rates (average for entire run)
Fresh oil charged per hour ____ __gallons_.. 4.55
Recycle oil charged per hour ..... __do____ 22.13
Combined feed charged per hour___do____ 26.68
Ratio recycle to fresh oil _______________ __
Soaking time average for entire
run _______________________ __seconds__ 25.5
'I‘he total gasoline produced was 54.58% of the
fresh oil charged to the unit. Of this, approx
imately '7.69% is attributable to the gas charged 35
to the unit. This was calculated by a compari
son of an identical run without the introduction
of gas, which resulted in a production of gasoline
at the rate of 46.89% of the total fresh oil
It is understood that the foregoing is merely
given as an example and that we do not intend
to limit ourselves in any way by these figures.
Any vapors contained in the reflux fed through
line 4D to accumulator 4| and any vapors evolved 45
in said accumulator are returned to the frac
tionator 22 through line 45 leading from the
top of the accumulator 4 I.
The uncondensed gases and vapors from the
fractionating column 22, which comprise the 50
motor fuel constituents, pass from the top of the
fractionator through line 4B and ñow through the
condenser 48 from whence the condensate and
nOn-condensable gases enter gas separator 41.
There, a separation takes place, the gases leav
ing the system through line 52 and the condensate
being withdrawn through line 49. If desired, a
portion of this condensate may be directed from
line 49 through line 50 where it is pumped' by
pump 5I into the top of the fractionating column 60
22 to act as a reflux and control the top tempera
ture of the fractionator.
It will thus be seen that we have provided a
highly improved method of producing low boiling
point hydrocarbon products suitable for use as
motor fuels from high :boiling point hydrocarbons,
which method is capable of a maximum flexibility
of operation and regulation to control from vari
ous points in the system the quantity and quality
of the desired products.
Naturally the temperature and pressure condi
tions under which this operation is conducted will
vary in accordance with the grade of oil employed
as charging stock and the quality of the desired
product. It has therefore seemed unnecessary to 75
-. specifically mention pressures and temperatures _
ing point liquid hydrocarbons and conducting the
in the foregoing description as we feel that any
same to a cracking zone admixed with a stream of
`one skilled in the art would, from this disclosure,
be enabled to carry out the process to the ends
hydrocarbon gas,> preheating a second stream of
oil by indirect contact with hot vapors in said
vaporizing zone, and passing the same through a
From the foregoing it is believed that the opera ` separate cracking zone admiXed with a stream of
tion and advantages of our improved method may hydrocarbon gas, preheating a third stream of oil
be readily understood by those skilled in the art by indirect contact with hot vapors in said va
without further description, it being borne in porizing zone and commingling the same with the
mind that numerous changes may be made in the streams flowing from said cracking zones, the tem 10
perature of said third stream of oil being substan
details of apparatus and the steps disclosed With
out departing from the spirit of the invention as tially lower than that of the streams from said
set out in the following claim. .
What we claim and desire to secure by' Letters
Patent isz--
cracking zones, conducting the commingled mix
ture to said vaporizing zoney where substantial
vaporization takes place, conducting the evolved
>A process of treating hydrocarbon oils which
vapors and gases Vfrom said vaporizing zone to
consists in passing a stream of oil through a re
Aiiuxing zone in direct contact with a stream of
previously heated hydrocarbon gases and >vapors
20 from a vaporizìng zone, vaporizing the lower boil
ing fractions of said stream of oil in said reñuxing
said reiiuxing zone, continuously removing the
vapors and gases from the refluxing zone, and
subjecting'the same to condensation and separa
tion to form‘the desired product,` and withdrawing
the liquid residuum1v from said separating zone.
Zone while heating the higher boiling fractions of
said stream, condensing in said reñuXing zone the
higher boiling fractions of vapors, withdrawing
from said refluxing zone a mixture of higher boil
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