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Oct. 22, -1946.
E. w. s. NlcHoLsQN I-:rAL
V2, ì
,690
- DESULPHURIZA'I‘ION 0F HYDROGARBON OILS
Filed Dec. l0, 1943
0
Patented Oct. 22, 1946
2,409,690
UNITED STATES PATENT OFFICE
` DESULPHURIZATION OF
\
DROCAR
BON OILS
Edward W. S. Nicholson and Aaron K. Redcay,
Baton Rouge, La., assignors to Standard Oil
Development Company, a corporation of Del
aware
Application December 10, 1943, Serial No. 513,680
6 Claims. (Cl. 196-24)
1
2
.
This invention relates to the refining of petro
leum distillates and pertains more particularly
to» a method of removing sulfur constituents from
said distillates.
It has been proposed heretofore to remove
sulfur compounds from petroleum distillates by
passing the distillates’ in vapor form in an at
mosphere of hydrogen through a bed of desulfur
izing catalyst, such as nickel, alumina, or the like.
During the course of the treatment a substan
tial amount of the sulfur originally contained in
the distillate is deposited. or absorbed on the cata
lyst material. This makes it necessary to inter
The oil vapors formed in the preheating and
vaporizing furnace I3 continue through line I4
into the bottom portion of the treating chamber
I5. A suspension of hydrogen and finely divided
desulfurized catalyst is also introduced into the
bottom of the treating‘chamber I5 through line
IE and intermingles with 'the _oil to be treated.
The treating chamber I5 is preferably provided
with av perforated grid plate I'I positioned above
the point of entry of oil vapors and catalyst
hydrogen suspension to distribute the resulting
mixture over the reaction chamber.V
A mixture of hydrogen, oil vapors, and cata
lyst passes upwardly through the perforated grid
rupt the process periodically to remove the sulfur
and to restore the activity of the catalyst.
15 I1 into the main body of the treating chamber.
The velocity of the hydrogen and oil vapors
The removal of the sulfur from the catalyst
passing through the treating chamber is prefer
may be accomplished by treating the catalyst
ably controlled to permit the catalyst to segregate
with hydrogen so as to `convert the sulfur into
into a dense turbulent layer in the bottom portion
hydrogen sulfide gas which may be subsequently
‘ `
‘
recovered by passing the resulting gas through a 20 of the reaction chamber.
The catalyst employed for removing the sulfur
weak alkaline solution. It has also‘been `sug
from the oil vapors may be any known desul
gested to remove the sulfur by oxidation. When
furizing catalyst such as finely divided metallic
this is done, it is usually necessary to “subject”
nickel supported on activated alumina or other
the catalyst to a reducing treatment before being
reemployed for further sulfur removal. `
25 metal powders such ascopper or zinc, with or
without carriers. The desulfurization treatment
One of the primary objects of the present in
is preferably carried out under a-.relatively low
vention is to provide an improved process for
pressure ranging from atmospheric to 200 pounds
removing sulfur compounds from petroleum oils.
per square inch and the temperature ofthe re
A further object of the invention is to provide
a continuous process for removing sulfur com 30 action zone may be between 400°'and 800° 1F., and
preferably between 600° and r700" F.
pounds from petroleum distillates. Other more
speciñc objects and advantages will be apparent
The oil vapors are retained in the treating
chamber I5 in contact with the catalyst for a
from theV detailed description of the invention
period controlled to remove or materially reduce
With the aboveobjects and advantages in view, 35 the' amount of sulfur compounds contained there
in. The gaseous reaction products comprising the
the invention will bebetter understood by refer
treated oil vapors and hydrogen are removed from
ence to the accompanying drawing which is a
the upper end of the treating chamber I5 through
diagrammatic illustration of an apparatus suit
line IB and maybe passed to suitable separat
able for carrying the invention into effect.
Referring to the drawing, reference character 40 ing device such as a cycloneseparator I9 for re
moval of entrained powder from the reaction
I 0, located at the upper right hand portion of the
products. The entrained catalyst powder sep
drawing, designates a feed line through which
arated from the reaction products in separator
the oil to be treated is introduced into the equip
I9 may be returned to the treating chamber
ment. This oil is preferably a clean distillate
stock such as a naphtha fraction, kerosene frac 45 through conduit 2 l. The vapors and gases after
passing through the cyclone separator I0 are re
tion, heating oil, light gas oil, or the like.
moved through line 22 and- may beV subjected to
The oil introduced through line `I0 is ’passed
further treatment for removal of entrained pOw
through a heat exchanger I I wherein it passes in
der, as desired.` Following this, the reaction prod
heat exchange relation with products from the
process as later described. The oil after passing 50 ucts pass through heat exchanger II in indirect
heat exchange with fresh feed as previously de
through the preheater Il continues through line
scribed. The products then continue through line
I2 to a furnace I3 wherein the oil is vaporized
23 to cooler 24 in which the products are cooled
and heated to the desired reaction temperature.
This temperature may, for example, be of the
to a temperature suf?cientjto condense the oil
appearing
hereinafter.
order from 400° to 800° F.
~
`
`
`
`
'
vapors
therefrom.
«
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`
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2,409,690
3
4
The products from the condenser 24 are then
passed to a product receiver 25 in which the
treated liquid distillate is separated from the un
reacted hydrogen and other gaseous materials.
The treated distillate is withdrawn from the
It has been found that there is an equilibrium
between the sulfur which remains on the catalyst
and the sulfur which is removed by the gas in the
reactivating chamber 42. By employing a rela
tively high proportion of hydrogen in compari
product receiver 25 through line 26 and the gases
are removed overhead from the product receiver
son with the amount of sulfur contained on the
catalyst the sulfur content of the catalyst may
be reduced in the reactivating chamber 42 to a
very low value. Gases resulting from the re
tivating treatment in chamber 42 are withdrawn
overhead therefrom through line 44 leading to a
suitable separating device such as a cyclone sep
arator 45 for removal of entrained catalyst there
from and the separated catalyst may be re
turned to the reactivator chamber 42 through
line 46. The gases after passing through the
cyclone separator 45 continue through line 4l to
a heat exchanger 48 in which the gases pass in
heat exchange relation to treated gases as later
described'. The gases after passing through heat
exchanger 48 are passed through line 48 to a
cooler 5I in which the gases are cooled to tem
through line 21.
The treating chamber I 5 may be provided with
an upwardly extending tube 28positioned in the
bottom of the chamber for continuously with
drawing catalyst from the chamber. The bottom
of the tube 28 is in open communication with a
vertical conduit 29 through which the catalyst
is continuously withdrawn from the treating
chamber and introduced into a stream of hydro
gen containing gas. The vertical conduit 29
preferably forms a standpipe for generating a
fluid pressure for circulating the finely divided
catalyst through the treating chamber and the
reactivating chamber to be later described. A
small amount of an aerating gas should be main
tained in admixture with the catalyst in the ver
tical tube 28 to maintain it in a fluid condition
capable of developing a ñuid pressure at the
base thereof. To this end a small amount of an
perature somewhat below the boiling point of
water so that they may be subsequently scrubbed
with a weak basic solution for the removal of
hydrogen sulfide therefrom.
aerating gas may be introduced at one or more
The sulfur bearing gases after passing
through the cooler 5I continue through line 52
to a scrubbing chamber 53 in which they pass
,spaced points along the column through lines
3I, 32 and 33.
_
The column 29 may be provided with a Valve 30 in countercurrent contact with an aqueous solu
34 for controlling the level of the catalytic ma
tion capable of absorbing or reacting with the
terial maintained in the treating chamber I5,
hydrogen sulfide present in the gas. For ex
It is desirable to maintain the level of the dense
ample, monoethanolarnine, diethanolamine, so
layer of catalytic material in the treating cham
ber I5 a substantial distance below the top of the
chamber in order to reduce the amount of en
trained solids contained in the reaction> products
dium phenolate solutions may be used for this
.
purpose.
The scrubbing liquid is introduced into the
scrubbing tower 53 through line 54 and is re
moved from the bottom of the tower through line
withdrawn through line I8.
The hydrogen-containing gas into which the
55. The sulfur-free gases consisting primarily
catalyst from the column 28 discharges may be 40 of hydrogen are removed from the scrubbing
introduced into the system through line 35 or it
tower 53 through line 56 having the heat ex
may consist in whole or in part of the gases re
changer 48 located therein so that the treated
moved from the product receiver 25. In the
`gases pass in heat exchange relation with the
latter case, a portion of the overhead products
overhead products from the cyclone separator 45
from the receiver 25 withdrawn through line 2l
as previously described.
may be passed through line 36 to a compressor
The treated gas after passing through the heat
3'I wherein it is recompressed to the desired pres
exchanger 48 continues through line 5l 'and may
sure for carrying out the reactivation of the
be used as a carrier gas for returning the re
catalyst. The compressed gas is then passed
activated catalyst to the treating zone.
through linev 38 which merges with line 35 lead
Returning to the reactivating chamber 42, a
ing to the furnace 39 in which the gas is heated
tubular conduit 58 may be provided in the lower
to a temperature suflicient to reduce the sulfur
portion of the chamber for collecting the re
contained on the catalyst. The heated hydro
activated catalyst. The bottom of the reactivat
gen-containing gas after passing through the
ing chamber 42 connects with a vertical pipe 58
furnace 39 continues through line 4I into which
for removing the reactivated catalyst from the
the catalyst from the column 29 discharges,
reactivating chamber. The vertical pipe 59 is
The resulting suspension of hydrogen-con
provided with a control valve 6I for regulating
taining gas and catalyst continues through line
the rate of removal of the reactivated catalyst
4I into the bottom of a reactivating chamber 42
from the chamber and for controlling the time of
below a perforated grid plate 43, through which 60 residence of the catalyst within the chamber.
the suspension passes into the body of the re
The catalyst is preferably withdrawn from the
activating chamber.
chamber 42 at a rate suñicient to maintain the
level of the dense catalytic mass within the
The velocity of the hydrogen-containing gas
passing upwardly through the reactivating cham
chamber a substantial distance below the gas out
ber 42 is also preferably controlled to permit the 65 let to reduce overhead entrainment as previously
described in connection with the treating cham
ber I5.
The reactivated catalyst discharges through
the control Valve 6I of the pipe 59 into the gas
The temperature and pressure conditions
maintained in the reactivating chamber 42 may 70 line 5l carrying the treated gas into the treating
chamber I5. Any excess gas formed in the proc
be substantially the same as those maintained
ess may be removed through the line 82 and fresh
in the treating chamber I5. For example, the
hydrogen makeup gas may be introduced through
temperature may be of the order from 400 to 800°
line 35 as previously mentioned. From the above
F. and the pressure between atmospheric and
200 pounds per square inch.
75 description it will be noted that the invention
ñnely divided catalytic material to settle into a
relatively dense layer in the bottom portion of
the reactivating chamber.
2,409,690
5
provides a continuous process for effecting desul
furization of hydrocarbon distillates wherein the
form, continuously removing the hydrogen con~
taining` ga‘s containing the sulfur compounds
desulfurizing catalyst is continuously circulated
through a treating chamber and a reactivating
from the reactivating zone, treating the gas so
removed to remove the sulfurv therefrom and
chamber. By controlling the rate of circulation
thereafter returning the hydrogen containing gas
of the catalyst through the two chambers the
activity of the- catalyst in the treating zone may
to said desulfurizing zone.
i
3. A method of removing sulfur compounds
from low boiling hydrocarbon oils which com
prises passing a mixture of the oil in vapor form
and hydrogen upwardly through a treating zone
maintained at a desulfurizing temperature be
be maintained at a higher level than in cases
where catalyst is being maintained in static con
dition in the treating zone and subsequently re
generated in situ according to current practices.
The present process also involves less degradation
of the feed stock due to the fact that the activity
and selectivity may be maintained at a higher
tween 40() and 300° F., continuously introducing
a stream of finely divided desulfurizing catalyst
into the oil vapors passing through said zone,
controlling the velocity of the vapors and gas
passing through the treating zone to maintain
a dense turbulent layer of finely divided catalytic
contains a relatively low concentration of sulfur
material in the bottom portion of said treating
substantially no carbon is formed in the process
Zone, keeping said oil vapors in contact with said
and consequently the catalyst may be readily
regenerated by means of hydrogen and without 20 finely divided catalyst for a period sui’ñcient sub
stantially to reduce the amount of sulfur com
the necessity of burning the carbon from the
pounds contained in said vapors but insuflicient
catalyst.
to form substantial carbon deposits on the cata
Having described the preferred embodiment,
lyst, thereafter removing the treated vapors
it will be understood that the invention embraces
such other variations and modifications ‘as come 25 from the treating zone, continuously removing
finely divided catalytic material containing sul
within the scope of the accompanying claims.
fur from the treating zone while the material
We claim:
has a relatively low concentration of sulfur, pass
1. A process for removing sulfur compounds
ing the material so withdrawn into a reactivat
from low boiling hydrocarbon oils which com
prises continuously passing a mixture of hydro~ 30 ing zone, passing a gas consisting substantially
exclusively of hydrogen through said reactivating
carbon oil vapors and hydrogen through a treat
zone in an amount and at temperature sufficient
ing zone, contacting the oil vapors within the
to convert the sulfur on said catalyst into gase
treating zone with a desulfurizing catalyst, main
ous sulfur compounds, contacting the catalyst
taining the vapors in contact with the catalyst
in the reactivating zone with said hydrogen con
for a period and at a temperature suliicientV ma
taining gas for a period sufficient materially to
terially to reduce the amount of sulfur com
reduce the sulfur content of the catalyst obtained
pounds contained in said oil but insufficient to
therein, thereafter withdrawing the reactivated
form substantial carbon deposits onthe catalyst,
catalyst and returning the same to said ñrst
thereafter removing the treated vapors from the
level. By continuously withdrawing the catalyst
from the treating chamber while the catalyst
treating zone, continuously removing catalytic 40 named treating zone.
4. In the process deñned by claim 3, the fur
material from the treating zone while said mate
ther improvement which comprises treating the
rial contains a relatively low concentration of
gas removed from the reactivating zone to re
sulfur, passing the catalyst so removed through
move the sulfur compounds therefrom and there
a reactivating zone, treating the catalyst within
45 after returning the same to the ñrst named
treating zone.
stantially exclusively of hydrogen in an amount
the reactivating zone with a gas consisting sub
and at temperature sufiicient to remove the sul
fur from said catalyst and returning the desul
furized catalyst to the treating zone.
2. A process for removing sulfur compounds
from lower boiling hydrocarbon oils which com
prises passing a mixture of said oil in vapor
form and hydrogen through a desulfurizing zone
containing an active desulfurizing catalyst, main
taining the oil vapors in contact with the catalyst
at elevated temperature for a period sufficient
materially to reduce the amount of sulfur com
pounds contained in said vapors butA insufficient
to form substantial carbon deposits on the cata
lyst, thereafter removing the treated vapors from
the desulfurizing zone, continuously removing
catalyst containing sulfur from said zone while
the catalyst has a relatively low concentration of
sulfur, passing the sulfur containing catalyst so
withdrawn into a reactivating zone, treating said
catalyst within said reactivating zone with a
gas consisting substantially exclusively of hydro
gen, controlling the temperature and the contact
time within the reactivating zone to convert the
sulfur contained on said catalyst into a gaseous
5. In the process defined by claim 3, the fur
ther improvement which comprises segregating a
hydrogen containing gas from the treated oil
50 vapors removed from the treating zone and pass
ing the hydrogen containing gas so segregated
through said reactivating zone.
6. A continuous method of reactivating a de
sulfurizing catalyst used for the desulfurization
55 of petroleum distillates which has become con
taminated in a treating zone with sulfur depositsV
but is substantially free from carbon deposits,
which comprises continuously removing the cata
lyst containing sulfur deposits from the treating
60 zone, passing the catalyst so withdrawn into a
reactivating zone, treating the catalyst within the
reactivating zone with a gas consisting substan
tially exclusively of hydrogen, said gas being pres
ent in an amount and at a temperature suñicient
65 to remove the sulfur deposits from said catalyst,
and returning the reactivated catalyst to the
treating zone.
.
EDWARD W. S. NICHOLSON'.`
70
AARON K. RE'DCAY.
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