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Патент USA US2406117

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REFQRMING
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2,406,117
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ïquent stage of this process‘as will subsequently
ess may be carried out in one orfmore of the
appear, or from some extraneous source.
others.
This
Y
`hydrogen is discharged from line II into line Ill
Another method for maintaining continuity of
land thereafter with the oil into reactor I2, the
operation is to inject into the vapors in line I0 a
`amount of hydrogen employed being from 1000 i5 powdered catalyst to form a _suspension which is
to 4000 cubic feet of hydrogen per barrel of liquid
forced through a reaction zone, which suspension Y
oil. It is pointed out that in reactor I2~I main
will then pass through a separator usually lo
tain a pressure preferably of >theorder iof'from
cated outside the reactor toQsîeparatethe catalyst
`150 to 400 l-bs, per square inch. It should also
from the reaction- products.- «The separated cata
be noted that in the type ofV operation contem
iO lyst may be regenerated in a regeneration zone
plated, the catalyst is in the form of pills, pellets,`Y Í! ï- vand returned continuously to the reaction Zone
extruded lengths, granules, and the like and is
in the form of active catalyst, thus maintaining
supported on the trays T, which trays have " continuity of operation, but my process is pri
foraminous bases. The oil yis fed Ato the. reactor
marily concerned with the stationary Ibed type of
at a rate of say from 0.5 to 2 volumesof'oil per 15 voperation described above employing one or more
volume of catalyst per hour on a cold oil basis.
reactors containing spaced beds of pilled cata
Under the conditions stated, the feed stock
lyst or a continuous bed of catalyst. As previous
undergoes transformationv of the character indi;
’ ly indicated, the pressure imposed on the re
cated, and the productY is withdrawn through line . » actants in I2 as indicated in pressure gauge I4
28 and discharged into a separation drum 42 ¿o would be considerably elevated and may be as
much as 400‘lbs. per square inch, although lower
hydrogen are recoveredroverhead,through line 30
pressures, such as 190 lbs; ¿per square inch, are
and¿recycled to line II vfor further use in the
often used during the reforming operation.Y
process. .YWVhile it‘does not form an important
Specifically describing my improvements Vin re
phase -of the present invention, it may be and .,¿5 generating a catalyst,‘the following procedure is
`from_which normally4 gaseous hydrocarbonsÍ and
oftenjjis desirable,y to remove the' hydrocarbons
contained in recycled stream 30 in Whole or in
employed. First, the oil supply is discontinued '
and in so» doing, I close valve 3l in line II' and
Yp_art .so that the hydrogen will be more pure as
open valve‘32 in line 30 and discharge through
it enters -line II. This may be accomplished in , the reactor the hydrogen and/or recycle gas (con
any `known manner in equipment not illustrated, 3() taining hydrogen) _in order to purgeV out of the »
for example, the gas in line 30 could be scrubbed j catalyst all of the >volatilizable oils, that is to
with `a narrow-boiling kerosene fraction to> prefer
say, the catalyst being an adsorptive substance
; »entiaklly absorb the hydrocarbons and the hydro
adsorbs normally liquid oils, or at least readily.`
gen' recycled to I2 would -be substantially pure.
>`vaporizable hydrocarbons and these are removedv
The bottoms from separation drum 42are with 35 by ñowing the recycled gas upwardly through
drawnIthrough VlineV 43 and discharged into a ` line 33 through the reactor for a period of about
fractionator‘- 44; from 'which fractionator the
l5 minutes. The oif gases- from the operation are
product isY recoveredas a side stream through
withdrawn through line 35 and they may «be'sent
line 5I.. An overhead fraction containing hydro
to an absorption zone (not shown). to recover
gen Vand light hydrocarbons is recovered through 40
line V52'vandY thisV product may Vbe processed `to 1'
recover hydrogen in means not shown; for ex
l
ample, it may be scrubbed with kerosene or other
scrubbing,agent-to- remove a substantial portion
normally liquid products therefrom, and there-.
after the hydrogen purified of> hydrocarbons is
recycled to line I I. Following the purging opera
tion, I close valve 32 in line 30, and I next inject
an inert gas, such as'nitrogen or flue gas, via
of ¿the hydrocarbons whereby the hydrogen-is ‘1:5 line 60, in the reactor to purge the hydrogenVV
enriched and is rendered suitable for recycling
toreactor I2. The hydrocarbons themselves may
be; stripped fromthe solvent and dehydrogenated
to‘jform'olefìns and dioleflns which may be used
from the reactor. The purging gas used for dis- Q
placing hydrogen from the reactor’is preferably
a portionV of the spent regeneration gas, orrather
the exit gases from a previous regeneration co1
asintermediatesrfor the, production of aviation 50 lected at the beginning of said regeneration in a
gasoline or ¿rubber substitutes.
l
storage drum 59, and contains Vless than 6% Oxy---
.QA bottoms fraction is recovered through line
gen andV preferably'less than 2% Afree oxygen. Y
55 and recycled to the 'inlet side of vpump 3 for
`The catalyst is treated with this inert gas, whether
further use inthe process. A portion Yof these
it belnitrogenor -spent Yregeneration gas, for a
heavy Ybottoms may be withdrawn through line 55 periodof about l5 minutes. ,Boththe ‘hydrogen
58- andV rejected from the system.
purge and the linert flue gas purge are conducted
l In-„the foregoing description, I have outlined ‘ at about the same pressure as used during the
. for the purpose of clarity a procedure generally
productive phase of reforming. The reactor fol,
employed in reforming a naphtha in the presence
lowing these purgings is substantially free of vola
ofv hydrogen and a suitable catalyst so that my 60 tile hydrocarbons and hydrogen and is .ready to
specific improvements regarding regeneration of
be treated with an oxygen-'containing gas to burn
the catalyst will be better understood.. Asrindi
cated,lthe. reforming operation, in spite of the
off the flxed'carbon contaminating _the catalyst.
The Voxygen-containing gas, ' which mayr be v air,
factthat it- was conducted in the presenceV of
is discharged into‘the reactor throlvlg‘hv line vIII lo
hydrogen, tends to progressively build up con 65 cated at the bottom cf saidreactorl andv hows up-.
taminants'on the catalyst in reactor I2. These
wardly therethrough whereit contacts the Ycata
contaminants vimpair the activity of the catalyst
and makeit necessary tov discontinue _the re
formingoperation to purify the catalyst.l This
lyst and causes combustionlof theucontamfnants.
This regeneration is carried out-atrpressuresA of
v the same order and of the same Arange,_aswthose
may be accomplished by burning off the con 7o employed during the reforming.y TheoXygen
taminant's. It will be understood that in .ordercontaining gas entering through line III Aprefer-`
to maintain continuity of overall operation it is . ably maybe' heated -to a temperature of say _600°
preferable to provide two or. more reactors I2 „ F. to '700° FQas it enters the reactor, .anda't this
so that while the catalyst »in one or more reactors
temperature it will upon -contact with the cata1yst,f
is undergoing.regeneration,> the on-'stream proc '(5 whichis `ordinarily at a temperaturev around 900°
2,406,117
Y s
î erationwhether the feed stock be a more `or less `
1 pure compound or whether it be a naphtha such i v
;
as a cracked or virgin naphtha.
'
ing gas at pressures not substantially-exceeding Y
about 1 atmosphere gauge pressure.,
Y
'
6.V The method set forth in claim 4 in which fol
Numerousl modifications of my invention' fall
lowing the .purging Withinert gas the pressure
l ing within the spirit thereof may be made by 5 imposed on the catalyst is reduced to about at
â those familiar with this art.
mospheric within a space of from about 5 to 15
vWhat I claim is:
,
Y
minutes.
1. 'I'he method of> reforming a hydrocarbon in
-
7. In the method of reforming a normally liquid
hydrocarbon oil containing naphthenic compo
, the> presence of` a catalyst which consists essen
1 vtially of a reducible metal oxide of group VI of
l the periodic system carried on an alumina-con- ‘
nents under superatmospheric pressure and ele
vated temperatures and inthe presence of added
3 tainingbasey and added free hydrogen in which 1 l free hydrogen and a reforming catalyst consisting
. operation the reaction takes place under super- `
essentially of ka reducible metal oxide selected
1 atmospheric pressure and which operation re
from the class consisting of molybdenum oxide
` quires periodic regeneration of the catalyst, the
15 and chromium oxide carried on an alumina sup
l improvement which comprises subjecting the cat- î port, lthe improvement which comprises purging
î aylst after regenerationxto a purging operation `
` with free. hydrogen or free hydrogen-containing
„ " gas carried out at pressures substantially less
the catalyst following the necessary regeneration
of said catalyst with a free hydrogen-containing
gas at pressures not exceeding about 50 lbs. per
3 than those employed during the said reforming 20 square inch gauge pressure until such time as hy
; operation.
drogen appears in large quantities in the exit gas.
§ f 2. The method set forth in claim 1 in which the
8. The method set forth in claim 4 in which fol
I purging operation with free hydrogen-containing
lowing purging With a freev hydrogen-containing
;gas is carried out at substantially atmospheric
gas at reduced pressures the system is repressured
with a gas containing hydrogen.
3. The method set forth in claim 1 in which a 25
9. In the process of catalytic reforming of hy
ïfeed stock containing methylcyclohexane is sub
drocarbon
distillates in the presence of free hy
ijected to reforming conditions to produce tolu
drogen under superatmospheric pressure in which
the catalyst consisting essentially of a reducible
y '4. . The method of producing toluene from a hy
drocarbon fraction containing methylcyclohexane 30 metal Yoxide selected from the class consisting of
molybdenum oxide and chromium oxide carried
ìw'hich comprises contacting the said feed stock
on an alumina support, is gradually deactivated
¿With'la reforming catalyst consisting essentially
by a formation of carbonaceous deposits thereon,
of a reducible metal oxide selectedV from the class
steps of regenerating the catalyst for reuse
"consisting of molybdenum oxider and chromium 35 the
which comprises purging the catalyst of oil Va-‘ 1
:oxide carried‘on an alumina support, inthe pres
por by directing a current of free hydrogen there
pressure.`
zene.
.
Y
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.
\
~
’ ïence of added free hydrogen and under reform
-ing -conditions of temperature and pressure, with
' Qdrawing reaction products, discontinuing the flow
`of feed stock to the catalyst, regenerating the cat
alyst, purging with inert gas and prior to return
ing the feed stock to the catalyst, purging the said
catalyst with a free hydrogen-containing gas at
pressures substantially below those employed dur
ing the reforming operation.’
’
' '
>5. The method set forth in claim 4 ifi which
catalyst is purged with a flue gas at pressures
prevailing during the reforming operation and
thereafter vpurged with a free hydrogen-contain-Y
through,` purging the catalyst of hydrogen by
passing therethrough a current of inert gas, re
moving carbonaceous deposits from the catalyst
by oxidation with a gas containing free oxygen,
L purging the catalyst of oxygen by passing a stream
of inertl gas therethrough, passing the stream of
hydrogen 'through the catalyst and'maintaining
a low` pressure below that employed in the hydro
forming operation, then building pressure with
, hydrogen to the level employed for hydroforming
and thereafter again recommencing the feed of
oil and hydrogen for the hydroforming step.
ALBERT B. WELTY, JR.
Disclaimer
2,406,117.---Albert B. Welty, Jr., Mountainside, N. J. REFORMING. Patent dated
Aug. 20, 1946. Disclaimer íiled Apr. 15, 1949, by the assignee, vStotmtmct
Oil Development Gompel/ny,
Hereby disclaims from claims 1, 2, 3, 4, 8, and 9, and each of them, any process
of the type defined in Which the step of purging the catalyst With free hydrogen or free
hydrogen-containing gas is not continued until hydrogen begins to appear in large
quantities in the eXit gas.
[Oßïc’ial Gazette, May 17, 1949.]
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