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Oct. l5, 1946.
M. H. ARvEscN
REVIVIFYING ADSORPTIVE MATERIAL
Filed Dßc. 31, 1940
NN
MN
2,
,234
2,409,234
Patented Oct. 15,1946
UNITED ' STATES PATENT oFPlcE
2,409,234
REVIVIFYING ADSORPTIVE MATERIAL
Maurice II. Arveson, Flossmoor, Ill., assigner to
Standard Oil Company, Chicago, Ill., a corpo»
ration of Indiana
Application December 31, 1940, Serial No. 372,515
3 claims. (c1. 25a-zeil
This invention relates to the decolorization of
oils with solid sorbent materials and is directed
more particularly to a method and apparatus for
the decoloriaation of oils with clays, bauxite, etc.,
and to the reactivation by burning of the clays,
bauxite, etc.
The use of solid sorbent materials to improve
the color of animal, mineral and vegetable oils
is well known. The process is ordinarily carried
out in one of two ways.
2
sorptlve power. Again, the loss ofactivity may
be due to the presence of local “hot spots” occur
ring during the burning, in which excessive tem
peratures are developed, destroying the decolorlz
ing effect of the clay. Various other factors may
enter into this, but it has been found commer
cially that decolorizing clays have a rather lim
ited life, and can be effectively regenerated only a
comparatively small number of times.
. An object of my invention is to provide a com
In one method the oil l() bination process for the decolorization of oils by
and finely divided solid sorbent material are
mixed together, and thereafter the oil is recovered
from the sorbent by various means such as a'
means of solid sorbent materials and the reacti
vation of spent sorbent material for reuse as a
decolorizing agent;
lilter, which retains the solid material contami
nated with the coloring matter and permits the
improved oil to escape. This is the so-called
“contact method.” In the other method, the oil
'
It is another object of this invention to provide
an improved method and apparatus for the re-l
generation by burning of solid sorbent materials
used in the decolorization of oils.
is allowed to pass down over a body of sorbent
material contained in a vessel, the decolorized oil
,
Still another object of my invention is to pro
vide a method and apparatus for the burning of
20
being recovered therefrom, in a “percolation”
spent decolorizing material under controlled con
manner, The oil is not usually completely de
ditions whereby the impairment of the sorbent
colorized, i. e. not all of the color bodies are re
moved, but suilicient color is removed so that
the product is of lighter color than the original.
qualities is avoided.
.
'
r
Other objects and advantages of my invention
will become apparent as the description thereof
25
A rather finely divided solid is ordinarily em
proceeds, read in ,conjunction with the accom
ployed for the contact process, having a grain size
panying drawing which is a ñow diagram illus
of about 200 to 400 mesh; i. e. at least the greater
tratìng one embodiment of my invention.
part of the solid will pass through a screen having
As has been pointed out, my invention is appli
200 meshes per square inch and the majority will
cable to the decolorization of animal, vegetable
30
be retained on a screen having 400 meshes per
or mineral oils, using solid decolorizing sorbents,
square inch, while the percolation method em
but for the sake of simplicity it will be described
ploys solids of about 30 to 60 mesh.
in connection with the contact treatment of a
As solid sorbent materials I can use clays, such
light viscous oil of petroleum origin.
as fuller’s earth, bauxite, silica gels, bentonite,
Referring now to the drawing: A petroleum oil
montmorillonites, charcoal, particularly activated
from line I0 is mixed with a regenerated solid
charcoal, or any other porous adsorptive contact
sorbent from line II and standpipe I2, passed by ,
material. 'I'he coloring matter together with
line I3 to mixer I4 to obtain the required amount
some of the oil adheres to the surface or enters
of contact, the contacted oil and solid passing
the pores of the sorbent solid, and thereby soon
masks its effectiveness. A portion of the coloring
40
matter, etc. can be removed by the use of solvents,
or washes, such as naphtha, low boiling alcohols
and ketones, as well as other oxygenated or halo-
genated organic compounds, However, in order
to condition the clay for reuse, it generally must
be burned in order to eliminate the remaining
organic material. After a limited number of
burnings, however, the clay no longer exhibits
suñlcient decolorizing action to be elïective for
reuse. This may be due to the fact that the
coloring matter in the pores of the clay was con
verted to carbon during the burning, but the car
bon was sufñciently protected so that it was not
oxidized to one of the oxides of carbon, and re
mained within the pores, iilling it and masking its 55
from mixer I4 to filter I5 via line I6. Although
any solid sorbent suitable for decolorizing oils can
be employed, I will’ describe my process in con
nection with the use of clay. Filter I5 can be any
suitable means for separating the decolorized oil
from the clay, as for example, a rotating ñlter
with a scraper arrangement such that the clay
free oil passes out through line I1 while the clal1
is removed from the rotary filter by a scraper or
other means (not shown) and conducted from
iilter I5 by a screw conveyor or other suitable
means..
The clay passes from ñlter I5 through conduit
I8 and can suitably be directed through conduit
IS to wash vessel 20 which is filled with wash
naphtha from line 2|; . The clay settles through
2,409,284
the naphtha in wash tank 28, the naphtha remov
ing much of the oil and coloring matter contained
on the clay particles and carried therewith by
from about 5 to 30 pounds per cubic foot, pref
the screw conveyor or other removal means from
ñlter I5. The naphtha plus oil can be removed 5
from the upper portion of wash vessel 20 through
line 22 and the oil recovered from the naphtha
by separate distillation or stripping means (not
erably about 10 to about 15 pounds per cubic
i'oot. Under these conditions, the solid is in a
highly turbulent state, with the result that the
temperature in this zone will be uniform. or sub
stantially so, from top to bottom and throughout
the entire mass.
.
It desired, burner 48 can be divided into zones
shown). The clay is withdrawn from vessel 28
at the -base and can be directed to hopper 23 10 48a, 48b, 48e, etc., separated by gratings, per
forated plates or similar dividers, and air and
above standpipe 24 by any suitable means such
-clay injected at various points. This can be ac
as screw conveyor 25. Although other methods oi'
complished by directing air from line 42 and clay
conveying clay from vessel 28 to hopper 23 can
from
line 18 through line 88 and line 18a, respec
be employed, we have illustrated one method in
which hopper 23 is at such a level that conveyor 15 tively, by opening valves 8| and 8l a therein, and
manifolding the air and clay through valved lines
25 acts as a “seal" for the naphtha, the naphtha
82, 83 and/or 84 to zones 48a, 46b and 48e. re
level in vessel 28 and conveyor 25 being equalized,
spectively. Due to the turbulence Within the
and therefore avoiding carrying over great quan
zones, there will be no localized cooling eil‘ect by
tities of naphtha which must subsequently be
the injected air, except possibly at the immedi
stripped out.
20 ate point of injection where it is quickly dis
A fluid is introduced into the bottom of stand
sipated, while the injection of air and clay into
pipe 24 via line 26 and valve 21 to maintain the
clay in a dispersed but nevertheless dense aerated
the various zones serves not only to maintain the
turbulence or "boiling” within burner 48, but also
condition. A particularly suitable aerating fluid
is superheated steam which strips the naphtha 25 assures that an ample supply of oxygen is present
at all points at all times for the oxidation oi' the
from the clay, the steam and naphtha passing
carbonaceous deposits on the clay to volatile gases
overhead from hopper 23 throughiline 28 and
as well as maintaining the temperature in the
cooler 28, wherein the steam is totally condensed,
various zones at the desired level, thus insuring
and directed to separator‘ 38. In separator 30
the substantially complete regeneration of the
the condensed steam is withdrawn from the base
through line 3| while the recovered naphtha 30 clay.
The solids and flue gas plus any excess air
pass from clay burner 48 through line 41 and
cycled to wash tower 20 by opening valve 33 in
waste heat boiler 48. As shown, the vapors and
line 34 which joins naphtha feed line 2l. Addi
tional steam for stripping naphtha from the clay 35 solids pass through a bank of tubes 48 in a down
ward direction but an upilow passage can be uti»
can be introduced into the lower part of hopper
23 via line 35.
lized. Water enters tubes 48 via line 58 and is
converted into steam in this boiler, the steam ex
As an alternative method, the clay and oil from
iting from waste heat boiler 48 via line 5I and
filter I5 and line I8 can be sent directly to hopper
passes overhead through line 32 and can be re
23 by a screw conveyor 36, or other suitable 40 can be used in the refinery or plant for any de
sired purpose by opening valve 52 in line 53. I1'
means, without the intermediate washing step.
In this event it is usually advisable to employ
steam as the aerating iluid, although ilue gas
can be used, the vaporized oil and steam passing
overhead from hopper 23 through line 28 and
line 32 and discharged through line 31 by open
the aerating fluid in standpipe 24 is steam, a
portion of the steam, preferably superheated
steam, from waste heat boiler 48 can be diverted
thereto by opening valve 54 in line 55 which Joins
lines 28 and/or 85 leading to standpipe 24 and
hopper 23, respectively.
ing valve 38 therein to a separate oil recovery
system (not shown). A heater 38a can be in
The cooled stream of solidand ilue gas passes
stalled in line 36 prior to hopper 23 to supply
from waste heat boiler 48 through line 58 to cy
indirect heat to the naphtha-wet clay.
50 clone separator 51. In cyclone separator 51 suf
'I'he stripped clay from standpipe 24 passes
through valve :is 1n line 4o at the base of stand
pipe 24 to line 4I through which air or other gas
containing free oxygen is passed. Air can be
supplied from line 42 and compressor 43 by open
ñcient clay is removed from the stream to provide
a recycle stream of solids. The separated clay
passes to hopper 58 above standpipe 58 via line 88
and is maintained in the standpipe 58 in an
aerated condition to prevent bridging. An aerat~
ing valve 44 in line 4I. 'I'he compressed air and
ing iiuid, which can suitably 4be compressed ilue
clay is then passed via line 45 to clay burner 46
gas, enters standpipe 58 through line 8l con
trolled by valve 62 therein. Additional aeratmg`
maintained at a suitable burning temperature
such as, for instance, from about 950 to 11û0° F.
iluid can be injected into hopper 58 via line
In clay burner 46 the air and generated ilue gas 60 63 and valve 84, the iluids from both sources pass
with the clay pass upward at low velocity, the
ing from hopper 58 via line 65 which joins line
velocity preferably being suñlciently low so that
66 from cyclone separator 51. Clay from stand
there will be considerable hold-up of clay in the
pipe 58 passes through line 81 and valve 88 which
burning zone. For example, linear velocities o1'
can be any suitable metering valve, slide valve,
the order of 1 to 2 feet per second are suitable 65 star valve, etc., and is picked up by a stream of
for contact clays of 200 to 400 mesh and higher
air in line 10 and recycled to clay burner 48
velocities for coarser clays. Under these condi
through line 45 together with the clay-and-air
tions there is a decided increase in the concen
stream from standpipe 24 and injected into the
tration of clay per unit volume in the clay burner
various zones in clay burner 48 by line 88 as pre
as compared with the entering concentration of 70 viously described. The combined streams are
clay, this being due to a "settling" of the clay
discharged to clay burner 46 at a rate sumcient
with respect to the upwardly ilowing stream of
to maintain the desired temperature level in the
gas. A preferred operating condition is to main
burning zones. The air for recycling the clay
tain such a quantity of clay in the burner 46
from standpipe 5-8 can be obtained from the same
that the density of the clay plus vapors will be
source_as that used for directing the clay from
2,409,234
standpipe 2l by opening valve 89 in line 10 which
6
ing, wherein the temperature of one part of the
catalyst mass escapes control and the temperature
rises
to such heights that the decolorizing activity
The balance of the clay and the ilue gas from
of the clay is substantially destroyed, is eliminated
cyclone separator 51 passes via line 86 and further
cooling equipment 1I to a series of solid-vapor 5 in my process. DueI to the turbulent effect at
tained in the low velocity upiìow burner, the
separators 12 and 13, a portion of the solid mate
temperature from top to bottom is substantially
rials being separated in cyclone separator 12 while
uniform, with no opportunity for localized over
the remainder plus the ñue gas passes overhead
heating. Also, the recirculation of cooled clay has
through line 14 to cyclone separator 13 wherein
substantially all of the remaining solids are re 10 a temperature controlling effect. Since there is
no organic material present to burn in the
covered, solids from both cyclone separator 12
presence of oxygen, the recirculated» clay does
and cyclone separator 13 passing via lines 15, and
not become heated by combustion, and absorbs
16, respectively, to hopper 11 and standpipe l2.
heat from the surrounding particles from which
Flue gas is vented from cyclone separator 13 via
line 19 and line 8U by opening valve 8| therein, 15 organic matter is being burned. The recirculated
clay is dispersed throughout the clay burner and
or can be recycled by opening valve 82 in line
removes heat substantially equally from all parts
> 83 having compressor 84 therein to line 82 and/or
within the burner zones. For these reasons none
63 in standpipe 59 and hopper 58, respectively,
of the decolorizing emciency of the clay is de
and/or to line 85 and/or line 88 to standpipe 18
stroyed or impaired.
and hopper 11 by opening valve 81 in line 88 lead
leads from line I2.
.
Another advantage of my process is that it can
ing from line 83. The clay is accumulated in
be carried out in'a “closed system,” i. e. the clay
hopper 11 and standpipe l2 and stored pending
or other solid sorbent material need not be ex
its introduction into oil line I0 as previously de
posed to the atmosphere at any time. In the
scribed. Fluid from outside sources can also be
introduced through line 85 to standpipe I2 or 25 ordinary commercial regeneration of spent clay
from the decolorization of oils, the clay is allowed
through line 86 to hopper 11 in order to maintain
to remain in storage bins until used for decoloriza
` the clay in an aerated condition without bridging.
It is perfectly possible t0 employ my process
tion of further quantities of oil. This permits
i5 will be replaced by a percolation vessel illled
with c1ay of from about 3o to sd mesh, the clay
bodies from oils, it does make the clay somewhat
less eiiicient, since al1 moisture must be replaced
by oil in the clay, so that the clay becomes prefer
the clay to pick up various amounts of moisture
for the reactivation of clay or other solid sorbent
material in a percolation process rather than a 30 from the atmosphere, and while this does not
destroy the" ability of theA clay to remove color
contact process as illustrated. In this event ?llter
being directed from‘standpipe l2 to the percola
tion unit. As soon as the decolorizing activity 35 entially oil-wettable, rather than Water-wettable.
In case a considerable amount of moisture was
of the clay is exhausted, as evidenced by the
present in the clay, the oil therefrom may at ñrst
failure of the clay to remove suilicient coloring
have a “haze” or cloud, due to the presence of
bodies from the oil, the stream of oil may be dis
minute amounts of Water. In my process, the
continued and the clay removed from the percola
tor and processed according to either of the 40 clay is recycled within a moisture-free system,
and returned to the decolorization step, whether
previously described methods, i. e. either by
contact or percolation,` without exposure to the
naphtha washing with steam stripping of the
atmosphere. Moreover, by maintaining the clay
naphtha from the clay, or by steam stripping of
in the storage bin and accompanying standpipe in
the oil and color bodies prior to burning.
Alternately, after the oil stream has been di 45 an aerated condition, bridging of the solid sorbent
is avoided, and crushing or packing of the clay
verted from the percolation unit, the oil remain
reduced to a minimum.
ing and a part of the coloring matter can be
Another advantage of my process is that it is
washed from the clay by flooding the unit with
continuous. The ordinary decolorization process
naphtha or other suitable solvent, the oil-solvent
wash withdrawn, and the clay steamed to remove 50 is carried out batchwise, particularly as regards
the clay regeneration, there being so far as I
the remaining solvent prior to withdrawing the
know, no provisions in which a solid sorbent ma
clay from the percolation unit for burning. It is
terial is continuously removed from a. decoloriza
usually desirable, particularly with percolation
tion zone, reburned and returned to the decolori
processes, to employ a series of percolation vessels
so that while one is being regenerated the percola 55 zation without intermittent storage, either before
tion can continue in an alternate vessel. '
or after reviviiicatlon.
Although I have illustrated one embodiment of
my invention, it should be understood that this
ñcient use of solid sorbent material in the de
is by way of illustration and not by way of limi
colorization of oils, including a higher yield of oil
of a desired color per ton of clay. During re 60 tation, and that I do not intend to be strictly
bound thereby. Also, for. the sake of simplicity
generation in a low velocity upñow burner of the
various details have been omitted, such as pumps,
type described there is more opportunity for the
By my process I am able to obtain a more ef
iutomatic control means, heat exchanges, etc., all
of which will be readily supplied by one skilled in
the previously employed clay-burning furnaces, 65 the art wishing to practice my invention.
individual clay particles to be freed of their mask
ing deposits than is possible in such apparatus as
where the solid material is heated substantially as
a mass. The upiiow turbulence of my process per
I claim:
,
1. 'I'he process for the reviviñcation of solid
contacting material contaminated with adsorbed
mits each particle to be contacted with oxygen
hydrocarbon matter from the decolorization of
bearing gas at elevated temperatures, so that all
parts of the particle can be reached while in the 70 oils which comprises dispersing said solid con
tacting material in a stream of air, introducing
ordinary apparatus the particles, resting one upon
said stream of air and solid contacting material
the other, may act as a shield to prevent the com
into an up-flow burning zone, continuously set
plete burning out of all the coloring matter and
tling out a portion of the solid contacting mate
hydrocarbon materials contained thereon. More
over, the development of “hot spots” during burn
75 rial from the stream continuously passing through
7
2.4mm
the burning zone whereby the solid contacting
material within the burning mno is maintained
in a turbulent mass having a density of between
about 5 and about 30 pounds per cubic foot. main
8
a substantially constant regeneration tempera
ture level. separating regenerated contact mate
rial from regeneration gases, eiiecting transfer ot
the separated contact material by the pressure
taining uniform temperature throughout said -5 head developed by an aerated column of said ma
burning zone suilicient to' remove substantially
terial and introducing a gas into said column for
all of the adsorbed hydrocarbon matter iromsaid
solid contacting material, introducing at'verueal.
maintaining the solids therein in aerated condi
` tion.
ly spaced points additional quantities of gases
3. The method oi.' revivii’yingsolid contact ina
into the turbulent mass maintained within the 'l0 terial of small particle size which has become de
burning zone continuously withdrawing reviviiled
solid contacting material overhead from said
burning zone, cooling the withdrawn stream oi’
gases and reviviiied contacting material, recover
. activated by liquid phase contact with an oil in a
decolorizing process which method comprises in
troducing such deactivated contact material at
the .top of a column, introducing a gas into said
ing the revivifled contacting material from the m column tor maintaining the solids therein in
said gases, and accumulating the recovered solid
aerated condition and for eiIecting a stripping of
contacting material in an aerated dense phase.
said solids, dispersing solids from the base ot said
2. The method of revivifying solid contact ma
column into a stream of an oxidizing gas, the
terial having an average particle size smaller than
pressure head at the base oi.' said column being
200 mesh which material has been deactivated by 20 sumcient to effect the dispersing of said solids in
liquid phase contact with an oil in a decoloriza
said stream. transferring dispersed solids by said
tion process which method comprises conveying
stream to a vertical regeneration zone oi' large
such contact material to the top of a standpipe,
horizontal cross-sectional area and introducing
introducing an aerating and stripping gas at a
said stream into said zone at a low level therein,
low point in said standpipe, passing said contact 25 passing gases upwardly in the regeneration zone
material downwardly through said standpipe
at such vertical velocity as to maintain the con
countercurrent to upfiowing aeration and strip
tact material as a suspended dense turbulent
ping gas, dispersing stripped contact material
mass therein characterized by substantially uni
from the base of the standpipe into a stream of
form temperature from ' top to bottom and
an oxidizing gas, introducing said oxidizing gas 30 throughout the entire mass of contact material.
stream at a low point in a vertical regeneration
abstracting heat from said regeneration zone at
zone of large horizontal cross-sectional area, pass
such a rate as to maintain a uniform temperature
ing gases upwardly in the regeneration zone at
at a substantially constant regeneration temper
a velocity in the range of about 1 foot to about 2
ature level, separating regenerated contact mate
feet per second whereby a large amount of said 35 rial from regeneration gases, removing the sep
contact material is maintained in said zone as a
arated material as a downwardly moving aerated
suspended dense turbulent mass characterized by
solids column, introducing a gas into said column
a substantially uniform temperature from top to
for maintaining the solids therein in aerated con
bottom and throughout the entire mass, abstract
dition and dispersing solids from the base of said
ing heat from said regeneration zone at such a 40 column in a second iluid stream.
rate as to maintain the uniform temperature at
'
MAURICE H. ARVESON.
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