close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2115794

код для вставки
May 3, 1938-
'
K. swAR'rwooD
2,115,794
CONVERSION OF' HYDROCARBON OILS
Filed Aug. l0, 1936
Z8
Frac z ¿o rra
2]
J9
45
gf:
25
24
„525
Patented May 3, 1938
2,115,794
UNITED STATES PATENT OFFICE
2,115,794
CONVERSION OF HYDROC‘ARBON OILS
Kenneth Swartwcod, Chicago, Ill., assigner to
Universal Oil Products Company, Chicago, Ill.,
a corporation of Delaware
Application August 10, 1936, Serial No. 95,167
2 Claims. (Cl. 1964-48)
This invention particularly refers »to an im
somewhat higher boiling selective fractions of
provedfprocem for the fractional distillation of the charging stock, including anyvhigh-boiling
hydrocarbon oils of relatively wide boiling range
accompanied by the selective pyrolytic conversion
of selected relatively low-boiling and higher boil
ing fractions thereof as well as intermediate liq
uid conversion products of the process. The in
vention contemplates the production of high
yields of high antiknock gasoline ywith minor
10 yields of either liquid residue or relatively dry
coke and fixed gases.
One specific embodiment of the invention corn
prises heating charging stock, comprising an oil
gasoline fractions of unsatisfactory antiknock
value, are separately recovered from the distilling
Zone and subjected to the desired cracking or 5
reforming conditions.
On the other hand, when the charging stock
does not contain any appreciable quantity of de«
sirable low-boiling fractions, such as gasoline of
satisfactory antiknock value, its total selected
low~boiling components, comprising any gasoline
or gasoline fractions of the charging stock as well
as, when desired, higher boiling distillates such as
which contains a substantial quantity of mate
naphtha, kerosene, and the like, may be subjected
' rials within the boiling range of gasoline, naphtha to the desired cracking or reforming conditions
or the like and higher boiling fractions, to a suf- ` separate from the selected high-boiling frac
fìciently high temperatui‘e to effect vaporization tions of the charging stock.
of selected low-boiling fractions thereof, includ
A special feature of the invention is the advan
ing the gasoline, by means of heat recovered from tageous manner in which the charging stock is
Within the system as later described, subjecting subjected to fractional distillation by means of
the heated charging stock to fractional distilla
heat recovered from within the system, which is
tion, subjecting selected low-boiling fractions of ordinarily Wasted in a conventional cracking op
the charging stock recovered from the distilling eration. This is accomplished in two stages, the
step to conditions of cracking temperature, sub
first of which comprises passing the charging
stantial superatmospheric pressure and conver
stock> in indirect heat exchange withl Ythe
sion time regulated to effect the production there
hot vaporous conversion products, prior to their 25
from of high yields of high antiknock gasoline, fractionation for the formation of reflux con
introducing the resulting products into an en
densate, while in the second stage the components
larged chamber wherein separation of vapors and of the charging stock which remain unvaporized
non-vaporous residue is accomplished, passing in the distilling zone following the first heating
said vapors in indirect heat exchange with the of the charging stock are directly commingled
charging stock whereby to heat the latter to the with the hot vaporous conversion products, prior
desired temperature, as previously described, re
to their fractionation for the formation of lre
moving selected higher boiling fractions of the flux condensate, whereby said remaining non-va
5 charging stock from the distilling step and com
porous components of the charging stock are sub
mingling the same with said vapors, returning jected to further vaporization. These two stages
non-vaporous components of the commingled of heat exchange between the charging stock and
materials directly to said enlarged chamber, sub
jecting vaporous components of the commingled
40 materials to fractionation for the formation of
reflux condensate, subjecting reiiux condensate
formed by said fractionation of the vapors to in
45
dependently controlled conversion conditions of
cracking temperature and superatmospheric
pressure, introducing the resulting heated prod
ucts into said enlarged chamber, subjecting
fractionated vapors of the desired end-boiling
point to condensation and recovering and sep
arating the resulting distillate and gas.
In case the charging stock contains desirable
low-boiling fractions, such as materials of satis
factory antiknock value within the boiling range
of gasoline, these may be recovered from the
fractional distilling step of the process without
55 subjecting the same to cracking, in which case
_the hot vaporous conversion products of the proc
ess may be accomplished in the same or in separate zones and in case separate zones arey em
ployed the charging stock may pass in indirect
and in direct heat exchange with the vapors in
any desired sequence.
The method and means provided for heating
and eñecting fractional distillation of the charg
ing stock has a definite advantage in cooperation
with the selective cracking steps of the process
and provides an advantageous method and means
of Y removing
from
the
vaporous
conversion
products high-boiling components which are de
sirable for commingling with the non-vaporous
components of the charging stock subjected to
further treatment Within the system under less
severe conditions than those employed for the
reflux condensate vformed by subsequent fraction
40
2
2,115,794
ation of the remaining vaporous components of
the charging stock fractions and vaporous con
version products.
The accompanying diagrammatic drawing il
lustrates one specific form of apparatus embody
ing the features of the invention and in which
the operation of the process may be accomplished.
The advantages and features of the invention will
be more readily apparent with reference to the
10
drawing and the following description thereof.
Various alternative but non-equivalent methods
of operation, not previously described, are also
shown in the drawing and embodied in the fol
lowing description.
15
the system, are supplied, or the like and such cok
ing equipment, when employed, may be operated
in conjunction and in cooperative relation with
the rest of the system, the vaporous products
from the coking Zone preferably being supplied
to heat exchanger I or to distilling and fraction
ating column 45.
Vaporous products are removed from the upper
portion of chamber 5 and directed through line
8 and valve 9 to heat exchanger I0 wherein they
are partially coo-led and subjected to partial con
densation, as will be later more fully described,
by indirect heat exchange with the charging
stock for the process and by direct contact with
Intermediate liquids recovered from within the
system and supplied, as will be later described,
high-boiling components of the charging stock.
The high-boiling components condensed from
to heating coil I, is subjected therein to the de
sired conversion temperature preferably at a sub
stantial superatmospheric pressure. Heat for the
cracking reaction is supplied to coil i by means
the vapors in heat exchanger I0 are withdrawn
from the lower portion of this zone, together with
of furnace 2.
The heated products are dis
charged from coil I through line 3 and valve 4
into chamber 5.
non-vaporous components of the high-boiling
fractions of the charging stock supplied to this
Zone,l and the commingled high-boiling oils are
directed through line II and valve I2 to pump
I3 by means of which they are fed thro-ugh line
I4 and may be returned, all or in part, through
Chamber 5 may function as a reaction zone
25 wherein the heated products supplied thereto are . line I5 and valve I5 to chamber 5, wherein they 25
subjected to appreciable continued cracking, in
commingle with the heated products supplied to
which case it is preferably operated at a super
atmospheric pressure substantially the same or
this Zone from the two cracking` coils of the sys
tem and are subjected to further treatment
therewith, or these high-boiling oils may be
otherwise utilized, as will be later described, or 30
somewhat lower than that employed at the out
30 let from coil l. On the other hand, chamber 5
may function primarily as a zone wherein separa
tion of vaporous and non-vaporous conversion
products is accomplished and, by employing a
substantially reduced pressure in this Zone rela
35 tive to that employed in heating coil I, appreci
able further vaporization of the liquids supplied
to this zone is accomplished.
Chamber 5 may
be operated for the production of either liquid
residue or substantially dry coke. For the pro
duction of liquid residue this zone is preferably
operated at relatively low pressure although,
when desired, relatively high superatmospheric
pressure may be employed in chamber 5 and the
liquid products therefrom supplied to» a reduced
pressure vaporizing zone for the recovery there
from of desirable low-boiling components which
may be supplied to heat exchanger I0 although,
for the sake of simplicity, this equipment is not
illustrated in the drawing. Coke may be pro
50 duced in chamber 5 either at relatively low or at
a substantial superatmospheric pressure, low
pressure operation normally being preferred.
When liquid residue is produced in chamber 5 it
may be withdrawn from the lower portion there
of through line Ii and valve 'I to cooling and stor
age or to a reduced pressure vaporizing cham
ber, not illustrated, or elsewhere, as desired.
When coke is produced in chamber 5 it may be
allowed to accumulate in this Zone and be re
60 moved therefrom in any suitable well known
manner, not illustrated, after the chamber is sub
stantially filled with coke or after its operation
is completed for any other reason. The inven
tion also contemplates the use of a multiplicity of
coking chambers, although not illustrated, which
may be simultaneously or alternately operated.
It is also within the scope of the invention to
reduce the liquid products withdrawn from
chamber 5 to substantially dry coke in any de
70 sired well known type of coking equipment, not
illustrated, such as, for example, a separate heat
ing coil and communicating coking chamber, an
externally heated coking chamber or oven, a cok
ing Zone to which a heat carrying medium, such
75 as highly heated conversion products from within
may, when desired, be withdrawn, all or in part,
from the system through line I'I and valve I8
to cooling and storage or elsewhere, as desired.
Vapors remaining uncondensed in heat ex
changer ID, including the uncondensed compo-l
nents of the vaporous products from chamber 5
and Vaporous components of the high-boiling
fractions of the charging stock supplied to heat
exchanger I0, are removed from the upper por
tion of this zone and directed through line I9 40
and valve 2E) to fractionation in fractionator 2|.
The components of the vapors supplied to frac
tionator 2I boiling above the range of the desired
final light distillate product of this stage of the
process are condensed in this zone as reflux con
densate. The total reflux condensate removed
from the vapors in fractionator 2I may be with
drawn from the lower portion of this zone through
line 22 and valve 23 to pump 24 by means of which>
it is supplied through line 25 and. valve 26 to 50
cracking in heating coil I. On the other hand,
when desired, although not illustrated in the
drawing, the reiiux condensate removed from the
vapors in fractionator 2l may be separated into
selected relatively low-boiling and high-boiling Lf Ul
fractions, in which case either the relatively low
boiling or the relatively high-boiling fractions
may be subjected to cracking in heating coil I
while the other fraction is removed from the sys
tem or subjected to independently controlled 60
cracking conditions in a separate heating coil, not
illustrated, or the high-boiling fractions may be
supplied to heating coil I and the low-boiling
fractions subjected to cracking in heating coil
51, together with selected low-boiling fractions of 65
the charging stock which are supplied to this
zone, as will be later described.
-
Fractionated vapors of the ydesired end-boiling
point preferably comprising materials of good
antiknock value within the boiling range of gaso 70
line are withdrawn, together with gaseous prod.
ucts of the process, from the upper portion of
fractionator 2| and directed through line 21 and
valve 28 to condenser 29 wherein they are sub
jected to condensation and cooling. The resulting 75.
3
2,115,794
distillate and uncondensed gases pass through
line 30 and valve 3| to collection and separation in
receiver 32. Uncondensed gases may be released
from receiver 32 through line 33 and valve 34.
Distillate may be withdrawn from receiver 32
through line 35 and valve 35 to storage or to- any
desired further treatment.
When desired, regulated quantities of the dis
tillate collected in receiver 32 may be recirculated
by >well known means, not illustrated in the
drawing, to the upper portion of fractionator 2l
to serve as a refluxing and cooling medium in
this zone for assisting fractionation of the va
pors and to maintain the desired vapor outlet
15 temperature therefrom.
'
Charging stock for the processywhich prefer
ably comprises a hydrocarbon oil of relatively wide’
boiling range, is supplied from any suitable source
through line 3l and valve 38 to pump 39 by means
20 of which it is supplied through line lili and Valve
4l to heat exchanger lâ?. It passes in indirect heat
exchange in this zone with the relatively hot va
porous products supplied thereto from chamber
5. A closed coil 52 is provided in the particular
25 case here illustrated, in heat exchanger l5,
through which coil the charging stock is passed.
The resulting preheated charging stock, after
' recovering sufficient heat in heat exchanger l5
to effect vaporization of the desired low-boiling
30 components thereof, is directed from ,coil 42
for assisting fractionation of the vapors vand to
maintain the desired vapor outlet temperature
therefrom.
`
‘
In case the charging stock supplied to column
45 contains no gasoline, or in case the gasoline
components of the charging stock are of unsatis
factory motor fuel characteristics, particularly
with respect to their antiknock value, the selected
low-boiling fractions of the charging stock col
lected in receiver 5l are preferably withdrawn,
all or in part, therefrom through line 62 and
Valve 63 to» pump 64 by means of which they are
supplied through line 65 and valve 66 tocracking
or reforming in heating coil 61. This material,
in addition to any unsatisfactory motor fuel com
ponents of the charging stock, may also include,
when desired, somewhat higher boiling oils such
as naphtha, kerosene, and the like.
In case the charging stock supplied to column
45 contains any substantial quantity of materials 20
Within the boiling range of gasoline which are of
satisfactory antiknock value, such materials are
preferably recovered as the overhead distillate
product from column 45 inreceiver 51, in the
manner previously described. In such cases high 25
er boiling components of the charging stock, com
prising any unsatisfactory gasoline fractions‘and
also including, when desired, higher boiling oils
such as naphtha, kerosene, and the like, aare sep
arately recovered from column 45 and supplied 30
through line 43 and valve @d into distilling and
therefrom to heating coil 61 for cracking or re
fractionating column 55.
Preferably column 45 is operated at substantial
ly atmospheric or relatively low superatmospheric
forming. In the case here illustrated, provision
is made for removing selected intermediate frac
35 pressure in order to assist vaporization of the
preheated charging stock supplied thereto. The
components of the charging stock which remain
unvaporized'in column d5, as well as those which
are condensed as reflux condensate therein, are
40 withdrawn from the lower portion of the frac
tionator through line 45 and valve 5l to pump 4S
by means cf which they are returned through
line ‘i9 and valve 55 to heat exchanger lil.
The unvaporized high-boiling components of
the charging stock supplied from column 45 to
heat exchanger l@ are directly commingled in the
latter` zone with the relatively hot vaporous prod
ucts therein, serving to assist cooling and partial
condensation of the vapors and being thereby
50 subjected to further vaporization. In the case
here illustrated, baffles 5! are provided in heat
exchanger il) for establishing and maintaining
tions of the charging stock from a suitable inter
mediate point from column 55 through line 68 35
and valve 59 to pump 64 by means of which they
are supplied, in the manner previously described,
to heating coil 61.
The relatively low-boiling oils supplied to heat
ing coil 61 are subjected therein to relatively high 40
cracking temperature preferably at substantial
superatmospheric pressure by means of heat sup
plied from a furnace TB and in case motor fuel
or motor fuel fractions are supplied to this zone
the cracking conditions of temperature, pressure
and time maintained therein are regulated to ef
fect a substantial improvement in their antiknock
characteristics without excessively altering their
boiling range. Such reforming conditions may
also be maintained within the range suitable for
cracking any higher boiling oils supplied to this
zone to effect the production therefrom of high
contact between the vapors in this Zone and
yields ofgood quality motor fuel. .
high-boiling fractions of the charging stock sup
The highly heated products are discharged
from heating coil 5l through line 'll and arein
troduced, with or without prior` cooling,_ Ainto
chamber 5 at any desired point or plurality `of
points in this zone. Provision is made, in the case
plied thereto.
Any other suitable means of ac
complishing this, although not illustrated, may
be employed, when desired.
Selected low-boiling components of the charg
ing stock are removed as fractionated vapors from
60 the upper portion of column 45 and are directed
through line 52 and valve 53 to condensation and
cooling in condenser 5d. The resulting distillate
and uncondensed gas passes through line 55 and
valve 56 to collection and separation in receiver
65 5l. Uncondensecl gases may be released from the
receiver through line 55 and valve 59. A regulat
ed portion or all of the distillate collected in
receiver 51 may, when desired, be withdrawn
therefrom through line 55 and valve 5l to storage
01‘ to any desired further treatment.
When de
sired, regulated quantities of the distillate col
lected in receiver 5l may be recirculated by well
known means, not illustrated in the drawing, to
the upper portion of fractionator 45 to serve as
,a refluxing and cooling medium-in >this zone
is
here illustrated, for passing products from heat
ing coil 6l through Valve 'l2 in line 'll into line 3,
wherein they commingle with the heated products
from heating coil and are thence supplied to
chamber 5. Provision is also made for introduc
ing a regulated portion or all of the products from
heating coil El into the lower portion of cham
ber 5 by means of line 'i3 and valve 14.
The highly heated products' discharged from
heating coil 6l may, when desired, be cooled suffi
ciently to arrest or appreciably retard their fur
ther conversion, prior to their introduction into
chamber 5. This may be accomplished by in
direct heat exchange between the heated products
and any suitable cooling medium in any Well
known manner not illustrated, or by introducing
a suitable cooling oilinto line 1|. Provision is
60
65
70
75~
4
2,115,794
made, in the case here illustrated, for supplying
a regulating portion or all of the high-boiling liq
uids withdrawn from heat exchanger I0 to line
‘H by passing the same from line I4 either
whereby it is heated sufficiently to vaporize and
fractionate its low-boiling fractions boiling up
to approximately 450° F. and comprising approx
imately 32-33% of the charging stock. The
through line 14’ and valve 'l5 into line 1| or they
may first be passed, all or in part, through line
heated charging stock is introduced into a dis
tilling and fractionating column operated at sub
16, valve Tl and cooler 18, wherein they are
cooled to any desired temperature, and thence
introduced through line 'I9 and valve 80 into
10 line 1l.
This heat exchange, although it serves to ap
stantially atmospheric pressure Wherefrom said
preciably cool the highly heated products from
heating coil El, may add suñicient heat to the
high-boiling oils from heat exchanger l0 to sub
15 ject the same to relatively mild cracking.
Preferably, in case it is desired to produce coke
as the residual product in chamber 5, the heated
products from heating coil 61, or regulated quan
tities thereof, are introduced into the lower por
20 tion of chamber 5, as previously described, where
in they commingle with and supply additional
heat to the materials undergoing coking in this
F. at a superatmospheric pressure of about 800
pounds per square inch as measured at the outlet
zone. In such cases the products from heating
coil S1 thus supplied to chamber 5 are preferably
not cooled to a temperature below approximately
800 to 950° F. and may, when desired, be supplied
to this Zone with little or no cooling and at a
higher temperature ranging, for example, from
900 to 1050° F.
The preferred range of other operating condi
tions which may be employed to accomplish the
desired results in an apparatus such as illustrated
and above described are approximately as fol
lows: 'I'he heating coil to which reflux condensate
35 from the fractionator of the cracking stage is
supplied may employ an outlet conversion tem
perature ranging, for example, from 900 to 1000D
F., preferably with a superatrnospheric pressure
at this point in the system of from 100 to 500
pounds, or more, per square inch.
The other
cracking or reforming coil to which selected low
boiling fractions of the charging stock are sup
plied preferably employs an outlet conversion
temperature of from 925 to 1050° F. and a super
r atmospheric pressure of from 200 to 1000 pounds
or thereabouts, per square inch as measured at
the outlet from this zone. The reaction or coking
chamber to which heated products from the two
cracking coils are supplied may employ any de
50 sired pressure ranging from substantially atmos
pheric up to substantially the same superatmos
pheric pressure as that maintained at the outlet
from the heating coil utilizing the lowest pressure.
When utilized as a reaction chamber the pres
sure employed in this zone is preferably within
the range of 100 to 500 pounds, or thereabouts,
per square inch. The succeeding separating
fractionating, condensing and collecting portions
of the cracking stage of the system preferably
(50 employ pressures ranging from substantially at
low-boiling fractions are recovered as the over
head distillate product, which material is sup
plied to a reforming coil and therein subjected
to a cracking temperature of approximately 980°
from the reforming coil. The remaining higher
boiling fractions of the charging stock are with
drawn from the distilling and fractionating coil
and introduced into a vaporizing and separating
zone wherein they are directly commingled With
hot vaporous products from the reaction cham
ber whereby their low-boiling fractions amount 20
ing to approximately 35 per cent of the charg
ing stock are vaporized. The components of the
charging stock remaining unvaporized in this
zone are returned to the reaction chamber, to
gether with heavy components condensed from 25
the vaporous conversion products, by their in
direct heat exchange with the charging stock
and by commingling with the bottoms from the
distilling and fractionating column. These high
boiling oils commingle in the reaction chamber 30
with the heated products from both heating coils
of the system and are subjected in this Zone to
the cracking conditions maintained therein. The
vaporized components of said high-boiling frac
tions of the charging stock and the commingled 35
uncondensed components of the vaporous con
version products are subjected to fractionation at
a superatmospheric pressure of approximately 50
pounds per square inch and the resulting reflux
condensate is supplied to the other cracking coil 40
of the system. The reflux condensate is sub
jected in this coil to an outlet conversion tem
perature of approximately 950° F. at a superat
mospheric pressure of about 350 pounds per
square inch as measured at the outlet from the 45
heating coil and the heated products are intro
duced into the reaction chamber. The final mo
tor fuel product of the process is recovered by
condensation of the vaporous products from the
last mentioned fractionating zone. The products
from this operation comprise approximately 62
per cent of gasoline having an octane number
by the motor method of approximately 70 and
about 29 per cent of good quality liquid residue,
the remainder being chargeable, principally, to
uncondensable gas.
In an operation similar to that above described
except that a longer time factor is employed in
both heating coils, the succeeding chamber oper
ated at a superatmospheric pressure of about 30 60
preferred in the distilling and fractionating stage
pounds per square inch which is substantially
equalized in the succeeding portions of the sys
tem and the residual liquid reduced in this cham
ber to substantially dry coke, the yield of 70 oc
tane gasoline is increased to approximately 68
per cent, based on the charging stock, the gas
yield is somewhat increased and approximately
63 pounds of low volatile petroleum coke of good
of the system to which the heated charging stock
structural strength is recovered as the ñnal resid
is supplied.
ual product.
mospheric up to 150 pounds, or thereabouts, per
square inch superatmospheric pressure although
they may employ higher pressures up to Substan
tially the same as that employed in the reaction
or coking chamber.
Substantially atmospheric
or relatively low superatmospheric pressure up to
100 pounds, or thereabouts, per square inch is
As a specific example of the operation of the
process, a charging stock which comprises a
California crude or" about 28° A. P. I. gravity is
passed in indirect heat exchange with hot va
7.5. porous products from the reaction chamber
I claim as my invention:
l. A hydrocarbon oil conversion process which
comprises fractionating cracked vapors in a frac
tionating zone to condense heavier fractions
thereof, independently fractionating charging oil
5
2,115,794
for the process in a second fractionating zone t0
form a distillate cracking stock and residual
ing oil from the second Zone, returning such sep
arated high-boiling fractions of the vapors to the
charging oil, subjecting reiiux condensate from chamber together with unvaporized portions of
the first-named fractionating Zone and said dis the charging oil from the contacting step, in
tillate stock to independently controlled cracking troducing the remaining uncondensed vapors to
conditions of temperature and pressure in sep
arate heating coils and introducing the resultant
products into a common separating chamber
wherein vapors are separated from residue, re
10 moving the vapors from the chamber and sep
arating high-boiling fractions thereof by passing
the removed vapors in indirect heat exchange
with the charging oil prior to introduction of the
latter to said second zone and by direct contact
15 of the removed vapors with said residual charg
the first-named fractionating zone for fractiona
tion therein, and finally condensing therfrac
tionated vapors.
2. The process as deñned in claim 1 further
characterized in that the vapors removed from 10
the separating chamber are ,simultaneously
passed in indirect heat exchange with the fresh
charging oil and in direct contact With said re
sidual charging oil.
ImNNETI-I SWARTWOOD.
15
Документ
Категория
Без категории
Просмотров
0
Размер файла
808 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа