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Патент USA US2408725

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ou: s, 1946.
TOLUENE rnocnss
Filed Aug.,"r. 1942 '
y .2,408,724y
Patented Oct. 8, 1946
James C. Baìlieand Rodney V. Shankland, VChi
cago.' Ill., assignors »to Standard OÍlCom'pany,
Chicago, Ill., a corporation of ,Indiana>
‘ '
. „ vApplication August 7, 1942„se1f`ialjNq.. 4535929 _
‘ "zV claims._ (c1. l.stof-ccs)l
As a result .the
amount of> toluene which can be produced in a
has .beenw possible*> heretofore. ‘_
This invention relates to a process of making
toluene from petroleum hydrocarbons and more
given installation using our improved toluene di
speciñcally tothe catalytic treatment of a se
rective catalyst can be two to four times the
lected fraction of petroleum naptha at conver
sion temperatures and in the presence of hy-v 5, amount obtainable in the same time with cat-'
~ alysts heretofore employed.
drogen, employing for the purpose a catalyst
which lwe have discovered to be unusually eiiec
tive for producing toluene. ' - i
>Our process is illustrated by a drawingwhich
accompanies the speciñcation and whichmshows
diagrammatically an apparatus for carryingout
It has been -known heretofore that catalytic '
treatment of petroleum hydrocarbonsunder cer-v
tain conditions will produce aromatic hydrocar
bons from hydroaromatics and parafiins.
aromatic hydrocarbons thusproduced range all
the way lfrom benzene thru the Xylenes, higher
alkylated benzenes, napthalene and'other con
’densed ring aromatic compounds. Because of the
extraordinary demandfor toluene in the manu-V
facture of explosives, it has become urgently Yirri'j-
the process.v
Referring to the ‘ drawing, the apparatus'shown
representsy a prefractionator l, a catalytic re
~ actor__2„ andfafterÓ i'ractionators 3 and `4. Heat
ers 5 and 6 maysuitablybepipe heaters in which
coils’of’tubing'are placed,v within a ‘furnace set
‘ ting ‘and the material heated is forced thru the
j The stock employed for our pi‘oces's isV .prefer-_
ably a close-cut straight-run naptha fraction
portant to produce the maximum amount vof
'crude petroleum, but we mayv also employ
toluene instead of other less Vdesirable aromatic 20 cracked
napthas and"v particularly cracked
Íhydrocarbons such `as' benzene and Xylene._ The
processes employed- hereto-fore for convertingi'pe
troleum napthas to aromatics have failed to yield
morethan about-¿'10 to 15% of toluene based on the
petroleum hydrocarbon treated when processing
Mid-Continent light napthas using Yconverti-f
napthas of low unsaturati'on from thermal lor
catalytic cracking.y YTher napthas preferred for
our process are those containinga high concen-A
, ` tration’of cycloparafûnic hydrocarbons and more
particularly >`hy'ç‘iro‘arornatic . hydrocarbons. .ln
tional commercial operating" conditions. «Fur
order to obtain the best yields of toluene wev pre
came deactivated rather rapidly especially `with
respect to their toluene-producing ability. vAsa
result of their
life of ,
those catalysts was even considerably less than
range embracing 4the ‘boiling point> _of toluene,
e. _232° >ET.;4 A fraction .having initial and iinal
thermore, the catalysts prevrviouslyv employed `be
these figures would indicate. In contrasttojthe
priorA processes, ourv process has`v produced> u,
19-20%>of toluene from a selected naptha frac
tion which is a toluene yield 25% greater than
fer to employ a naptha fraction having aboiling ~
boiling points within 25°F. of the boilingupoint of
toluene is very desirable and it is undesirable to
_employ` a _naptha fractionhavinginitial and final
boiling points more thanA about 50° F. away from
vthe boiling >point of toluene. Aj light naptha
fraction having an vinitial boiling point of about
180° F. and a final boiling point of about 280° F‘.
` is characteristic of the widest hydrocarbon frac
has been producible by other processes. '
tion, which it ’isy desirable -to subject to catalytic
ï One object of our invention isto provide a
toluene process and catalyst for converting per 4.0 treatment by our process. vSince poor fractiona
troleum napthas into toluene with a higher de- " ‘
‘gree of conversion than processes known hereto
fore. Another object iswto provide a catalyst with
rgreater stability, particularly stability toward the
high temperatures employed in catalyst regen’- v
eration, *therebyy producing a higher level ofÍ
toluene conversion over the life of the catalyst.
Another object of our invention `is to provide a
vprocess of converting a selectedy petroleum
naptha into aromatic hydrocarbonswhich pro
duces substantially no other hydrocarbons boil
_ingíin the region of the toluene boiling point.> Y As
a result *ofA such clean-cut conversion, substan
tially pure toluene is obtainable by fractionation
without the use. of selective solvents or chemical
reagents.A A still further object of our invention '
tion will often produce la considerable variation
in the initial' and ñnal boiling points, it is some
what preferable control the/boilingy ran'geof
the naptha by the 10%_and9`0% points, ASTM.
A naptha having a 10% point of1 200° F, or’ above
and a 90%, point of: 250° F. or below is verysatîsj
factory. 1
. Referring to the 'drawingpetroleum naptha‘or y_gasoline is charged to the process by line , I0 and
vaporized in coil Il of' furnace 5. >The vap'ors'are
conducted by transfer line l2 toy fractionator l
where heavy naptha is discarded as a residue by
line I3, while light. hydrocarbons undesirable for
our process are withdrawn by vapor line lill. The
desired naptha fraction is trapped out of the
column by line ‘t5 leading to stripper iE wherein
further fractionation takes place-andvundesir
is to provide a catalytic process for making tolu
>ably light hydrocarbons are» returned to the main
ene in which the toluenefproducing activity of
column by vaporili-ne l1. The desired fraction,
the catalyst is suñiciently high to enable the `proc
example a fractionvboiling from about 200
ess to be operated atmuch higher capacitiesl than
to 260° F. is`withdrawn by line I 8 and forced thru
heater 6 where it is heated in coil I9 to the de
sired conversion temperature or somewhat above.
The hot hydrocarbons are conducted by transfer
line 2l] to reactor 2. Hydrogen may be charged
to the process by line 2 I, and hydrogen-contain
ing gas may be recycled by line 22 and coil 23
'I'he amount of hydrogen is suitably about 1 `to 5l
mols per mol of hydrocarbon treated and, in gen
heated to reaction temperature or above by heat
ing coil 23 located in furnace 6, as vpreviously
described. The amount of gas recycled in this
way depends on the net gas production, the
hydrogen- concentration of the gas and other
factors. Excess gas may be withdrawn by valved
ï outlet a4. This recycle gas may be enriched with
respect» to hydrogen content by including an ab
sorber (not shown) in the recycle system to re
eral, about 3 mols of hydrogen is a satisfactory -10 move low boiling hydrocarbons and thus raise
amount. This corresponds roughly to `2500 cubic
the hydrogen concentration in the recycle gas.
feet per barrel of naptha. The hydrogen may
The crude toluene fraction is conducted by line
be introduced directly into the naptha fraction
29 to fractionator `4 -which is preferably an eni
and simultaneously heated with the naptha in
cient fractionating tower with a large number
coil I9, or it may be separately heated and in 15 of plates. In this tower the, toluene is with
troduced into the oil or v.directlyinto the re
drawn as a side stream by trapout line 35 lead~
actor 2.
. `
ing to stripper 36, the vapors being returned to
Reactor 2 is charged 'with the catalyst in
the main tower »by line 3l, while the toluene is
granular or pelleted form. The hydrocarbons
Withdrawn from the ysystem by line 38. On
pass downward thru the catalyst bed and the con
verted `products may be withdrawn by linev 24.
Other methods of contacting the naptha with the
catalyst may rbe employed without departing from
our invention. For example, the catalyst may
be supplied in the >form of a powder and main
tained suspended in thereaction vessel. In this
case, deactivated catalyst maybe withdrawn as
20 account of the presence of a small amount of
para?linic hydrocarbons boiling near the toluene
boiling point, it is not practicable to recover all
' the toluene from the products by fractional dis
tillation. Therefore, in practice the amount of
25 substantially pure, nitration grade toluene re~
covered from the c-rude toluene fraction is about
'7D-80 percent. ySome additional toluene and
a ñuid from time-to-time or continuously regen
close-boiling parañînic hydrocarbons are. present
erated and returned-to the system.
in fractions boiling just above vand just below
Reactor 2 .is preferably operated under pres 30 the toluene boiling'. point. Ay heavier fraction is
sures of the order of 50 to 500 p. s. i., anda
withdrawn as a condensate from fractionator 4
temperature preferably vin the -range of 900 to
by line 39 and recycled by line 40 to the con
1050“ F. Somewhat lower or _ higher temper
atures may be employed, e. g. temperatures as
version step.
Hydrocarbons «boiling `below toluene are with
low as 850° li'.y may be employed with low -space 35 drawnas a vapor stream by line 4I and further
velocities and temperatures >as high as 1100o F.
fractionated in fractionator 42. Substantially
may be maintained with ,high space velocities.
all the toluene carried away with the light prod
The space velocity» employed is usually within
the range .of about 0.1 to5 volumes of naptha
ucts is collected as a condensate in the base of
fractionator 42 whenceV it is conducted by line
per hour per gross volume of catalyst, a space 40 `43 back to the conversion step of the process.
velocity of 0.5 to 2 being most commonly em
Benzene and other light hydrocarbons are with
ployed. The volume of naptha referred to in
drawn by line> 44 to condenser `45 and receiver
indicating the space velocity is the liquid volume
46, whence they are discharged by line 47. Par
of the naptha charged at standard temperature
afñns may be recovered from this fraction by
conditions, while the volume of catalyst referred 45 «further fractionation and/or chemical treatment
to is the gross volume occupied by the catalyst,
or the benzene fraction may be employed in the
not the net volume of the catalyst ywhen cor
manufacture of high knock >rating motor fuels,
rected for voids. It should be understood that
aviation gasoline, etc., for example by blending
the amountfof toluene produced can be generally
with the naptha fractions eliminated in tower
increased by operating at. lower space velocities 50 `I thru lines I3 and I4.
The tower 46 is vented
and/or higher` temperatures, but that in general
byline 48.
vgas losses are increased at the same time. vWhen
using our toluene directive catalysts it is pos
sible to effect conversion at reasonable space
In recycling the fractions bordering on toluene,
i. e. the stocks recycled thru lines 39 and 43„we
obtain, in effect, a catalytic puriñcation of this
velocities, for example, 1 to 2 V. H. V. producing 55 intermediate material from which it has here
high >yields of-toluene with only moderate gas
tofore been diñicult to recover the toluene. The
- "l
toluene contained therein passes thru the cat
The reaction products from 2.pass, by line 24,
alytic reactor 2, substantially unchanged, while
thru cooler 25 and thence» by line 2S to gas
non-aromatic hydrocarbons boiling near the boil
separator 21, thence to fractionator 3 wherein 60 ing point of toluene are converted into additional
a heavy aromatic fraction is separated and with
toluene and/or other products of diiîerent boiling
.drawn by line 28. This heavy fraction, sub
points by the action of the catalyst. Some alkyl
stantially free of toluene,4 may be‘employed in
ation of recycled benzene also appears to take
the manufacture of motor fuels, aviation gaso
lplace in reactor 2, thereby forming additional
line, etc., for example by blendingl with the 65 toluene.
_naptha fractions eliminated in fractionator I by
After the conversion operation has proceeded
lines I 3 and I4. It may also be used> as a solvent
for a period of time, usually about six hours,
in paints, varnishes, etc. A lighter fraction con-A
the activity of the catalyst is diminished by an
taining substantially al1 of the toluene produced
accumulation of carbonaceous deposits which
is withdrawn as a side stream by line 29. A 70 must be removed. This is accomplished by pass
crude light fraction substantially free of toluene
ing an oxygen-containing regeneration gas thru
‘is withdrawn- by vapor line 30. Fixed gases in
the catalyst.> The stream of naptha entering
cluding hydrogen are withdrawn from separator
reactor 2 is interrupted or diverted and air or
21 by line 3l and recycled by blower 32 and line
-other oxygen-containing gas is introduced by line
22 back to the reactor, preferably after being 75 v49 under carefully controlled conditions to pre'
y asesoria.
vent overheating the catalyst.. Spent-regener
Other vslealt` acids may »be -used such as citric,
ation gas »is lwithdrawn »by line .-50., _The 'heat
evolved lduring regeneration 'may bei dissipated
in various-ways, for example, by cooling coils.
not shown.
tration-¿cfabout 1 te 6 percent is satisfactory,
ehloroacetic.. etc.,
The amalgamation may be vaccomplished. >,by
addingapmercury salt or mercurio oxide :to the
acid solution before adding the aluminum. Rapid
solution of the metal takes place with‘the forma
. The'tolueneçfraction withdrawn by line 38 will
ordinarily contain upwards of 95% toluene and
tion of ~asol which _in the case of Aformic acidis
more iluid .than that. obtained with acetic acid.
be coagulated by adding an electro
lyte such aszammonium ycarbonateand in the case
of more highly concentrated sols, coagulation-may
occurspontaneously when standing ¿or on 'heating
Whatever. This desirable result has not been pos- n
The coagulatedrsolîis then dried slowly in a cur
siblewith catalysts employed heretofore because
rent .of warm, dry air and the dried alumina is
of the relatively larger amount of non-aromatic 15 ignited,
for example by heating to a temperature
hydrocarbons occurring in the products, having
of .about-1100?J F. .and Aholding at that temperature
boiling points close to the |boiling point of toluene
about twenty-four to forty-.eight hours. Organic
land inseparable therefrom by fractionation. The
acids adsorbed on the alumina producea certain
use of our new catalysts has made it possible for
us to produce nitration grade toluene directly 20 amount of >carbonization on heating, and carbon
so .producedis `burned away by air during> _the
from the catalytic conversion process with no de
» ignition" Ístep, care being taken to lcontroltl'ie :rate
crease in toluene yield but with even greater yield
of burning to avoid overheating the alumina and
than obtainable by the previous processes. The
impairing its 'catalytic activity. Where formic
toluene fraction may be submitted to additional
acid is usedin preparingthe sol, carbonization is
»purification'by extraction with a-selective solvent,
by extractive distillation using a solvent such as
As indi‘catedhereinabove, themolybdenum-pro
phenol, nitromethane, etc., or by a chemical treat
moter may be Aadded to the alumina during prep
ment when desired to prepare the toluene for. some
aration or after ignition and we have iound .that
special purpose.
The catalysts lwhich ’we-employ rand which We 30 when the promoter is added after ignition the
resulting catalyst is. more khighly directive for the
term “toluene directive catalysts” are comprised
formation of toluene `.than when the promoter is
of aluminum oxide of high purity promotedwith
added before ignition, for example while the alu
molybdenum. . They may' 4‘be prepared conven
mina is inthe sol form. Thusin comparing two
iently by dissolving metallic aluminum under con
ditions to produce an alumina sol, after which the 35 catalysts, one in which the molybdena is added
to the valumina sol, and the »other in which the
>sol is converted to alumina gel. In forming the
`molybdena- is added to `the ignited alumina, we
dry gel from the sol vit is desirable fto kcoagulate
find tha-t whereas thearomatization lcharacteris
>thesol to a firm, solid, vibrant jelly which is dried
tics are Ysubstantially the same, each catalyst pro
and ignited as will be described hereinafter. The
ducing >apprexi-mately the same amount of aro
lalumina is promoted'with molybdenum whichmay
-the distribution -of aromatics is quite dif
be applied either before or after the formation
ferent, the alumina promoted »after ignition giv
ofthe gel, the latter method. producing .a more
ing a higher yield of toluene. The explanation of
it is feasible to operate with toluene concentra
tion above 98%. We may control the fractiona
tion in tower 4 to .produce nitration grade toluene
directly fromithe process without the necessity of
any solvent Vextraction or chemical treatment
toluene-directive catalyst.
Another method'of preparing our'specially pure
aluminum oxide catalyst is by precipitation `of
aluminum hydroxide from aluminum salts .of high
purity followed by extensive `washing-1 untilthe
»this «phenomenon is not understood.
traneous metals therefrom completely’apparently
>miolybdena to purealuminum oxide ignited at 800
to 1100° F., thek ammonium molybdate solution
The >amount Vof promoter employed is usually
about 5 to l0 percent of molybdenum oxide `'based
on the weight of the catalyst and We may use
somewhat greater amounts., for example 15 to 20
Wash water shows no qualitative testfor vextrane
percent'. A convenient way of applying the pro
'ous'metals, particularly metals of the iron group
and the alkali metals. On account of thegel'att 50 moteris by means of the ammonium molybdate
salt which is’easily water-soluble and may be
Vnous nature of aluminum hydroxide it has here
in solution. Thus when applying the
tofore been substantially impossible to wash ex
because of their colloidal -adsorptive retention.
We have found that if the aluminum hydroxide y A
paste obtained on precipitation is solidly frozen ’
and thereafter thawed, the gelatinous character
is largely destroyed and Washing is greatly facili- ~
tated. After complete removal 'of extraneous
metals thealumina obtained in this way is dried
land ignited, and the molybdenum promoter is
can be applied directly to the alumina, which is
then dried ' and reignited.
After 'preparing the catalyst as hereinabove
described, we preferto grind it to approximately
30 to 100 mesh and vpellet >the resulting powder in
-a >suitable pelleting machine. An organic binder
such as rosin, -stearine pitch, -etc.,'may be em
ployed for this purpose,_kthe binder being removed
Subsequently by heating and ignitine.
For the purpose just described, aluminum hy
After operating our process for a period of
droxide may be precipitated ’from _aluminum chlo
for example one, to twenty hours, the
Íride, aluminum nitrate, aluminum sulfate, or .6.5 hours,
activity of the catalyst becomes impaired by an
other soluble aluminum salt, by the addition of
ammonia to the salt solution.
«accumulation of carbonaceous deposits.
'hours is a convenient..time of operation.
The catalyst may be prepared from metallic
aluminum by the method described in U. S..P-atent
2,274,634. The general procedure involved re
quires amalgamation of the aluminum metal, for
It isy
ïthen necessary to interrupt the conversion oper
-ation and regenerate the catalyst by contacting
Y 7.0
example aluminum in theforrn of .foil or granules
is amalgamated andconverted into an alumina
sol in the presence of diluteacid. A Weak organic
acid such as acetic .or formic acid at a ‘concen-- 75
it with air or other oxygen-containing gas, as
.mentioned hereinabove. The use of regenera
ytion `gas containing a relatively small amount of
oxygen, e. g._1 to 5 percent, facilitates the opera»
tion.;:Qontrol-.of,regeneration is improved »by
retaining the catalyst in small diameter tubes
of naptha treated. The following results were
obtained as an average of three successive six
surrounded by a cooling medium." After regen
eration _the catalyst is ready forfurther con
hour reaction periods with the same catalyst,
regenerating the catalyst between runs, and as
tacting of hydrocarbon vapors and it may be re
used and regenerated an indeñnite number of
times. An outstanding characteristic of our cat
an average of two reaction periods at about dou
ble the space velocity. Data obtained with a
commercial catalyst are included for comparison.
alysts made from pure alumina is their high
thermal stability. Thus we have found that the
catalytic activity actually increases in use for a
period of time before it reaches a constant ac
Alumina gel
tivity level where it remains 'for a long period of
The following data show the results obtained
in the production of toluene by our process:
A Mid-Continent straight-run light naptha
having a boiling range of 196 to 258° F., and
A. S. T. M. distillation shown in the table, was
treated with a catalyst prepared in the following
way: Amalgamated aluminum was dissolved in
acetic acid beginning with about 1 per cent con 20
centration and later adding additional acid to
bring :the concentration to 2% as the aluminum`
age of
age of
age of
age of
3 runs
2 runs
7 runs
2 runs
Temperature, ° F ______________ __
Space velocity _________________ _ _
Yields, output basis:
Vol. per cent liquid product__
' Wt. per cent dry gas ______ _ _
l. 00 v
0. 94
l. 9
56. 0
73. 3
83. 7
39. 1
32', l
23. 1
13. 5
0, 32
45. 3
48. 0
0. 18
52. 6
55. 4
In liquid product ___________ _,
L1 cui 204-255° F __________ ._
97. 8
25. 2
79. 8
21. 3
59. 4
15. 5
35. 0
Yield based on naptha feed__
19. 0
16. 0
1.5. 6
l2. 9
Wt. per cent carbon
Gravity of liquid product_ ____ __
Toluene, vol. per cent:
dissolved. The resulting alumina sol containing
about 6% of A1203 congealed to a solid jelly on
The commercial catalyst was an Activated Alu
standing. 'I‘he jelly was dried and ignited for 25 mina containing about 9% of molybdenum ox
twenty-four hours at 1100° F. It was then treat
ide. It will be vseenfrom the data that at a
ed with ammonium molybdate solution, dried
space velocity of about 1 our improved catalyst
and further ignited at 1000° F., 9 percent molyb
shows an increase in toluene production from
denum oxide being impregnated in the catalyst
15.6 to 19% which is approximately‘22%. At the
in this way
30 higher space velocity of approximately 2, the in
crease was from 12.9 to 16%, exactly'24% in
Inspection of Mid-Continent light 'naptha feed
Gravity A. P. I ________________________ __ 61.0
in the fraction 204 to 255° F. This figure gives
A. S. T. M. distillation, °F.:
35 an indication of the completeness of the con
Initial _______________________ _-_ ____ __
version of'parafiln's and napthenes to toluene.
approximately unit Vspace velocity the toluene
20% ________________________________ 211
purity'in this fraction increased from 59.4 to
30% ______________________________ __ 213
97.8%, almost double, while at the higher space
_______ __, _____________________ __ 4216
40 velocity of approximately 2, the increasek was
- ______________________________ __
__.. 219
___ __________ _-_ _______________ __
____________________________ ____ 231
End point _______________________ __ _____ __ 258
Aromatics, v01. per cent- l
Benzene' __________________ __ 0.3
Toluene __________________ __ 2.2
more than double.
Another catalyst was prepared from amal
gamated aluminum in the same Way as that’l'ust
described except that the alumina sol was coag
__________________ __ 0.7
ulated by the addition of ammonium carbonate
and ammonium molybdate, sufficient ammonium
molybdate solution being added to the sol to pro
vide a catalyst containing about 9% of molyb
denum oxide, M003. The catalyst was then dried
50 and ignited. This catalyst, ywhich may be termed
a “co-gelled catalyst,” wasA employed with the
same naptha under the same conditions as just
Total ______________________ __
described and gave the following results at two
different space velocities:
Napthenes, vol. per cent
Initial, 205° F _____________ __12.9
F _______________ __ 13.1
F _______________ __ 12.7
F _______________ __
________ __ ____________ __
Parafûns, vol. per cent
Initial, 205° ,F _____________ __ 22.3
F _______________ __ 11.8
two ô-hr.
Temperature ________________________ _ _
Space velocity ______________________ _.
Yields, output basis:
1. 0
1. 99
Vol. per cent liquid product-.. _..
60. 5
68. 4
Wt. per cent dry gas ____________ _.
Wt. per cent carbon.; ___________ __
Gravity of liquid product API ______ _ _
35. 1
0. 13
48. 9
28. 3
0. 1
52. 2
28. 5
87. 9
17. 2
22. 0
68. 0
In liquid product _______________ _.
In cut 204-255° F ________________ __
Yield based on naptha feed _____ __
F _______________ __ ' 4.3
Total ____________ ___ _______ __
Average oi
two 6-hr.
Toluene, vol. per cent:
22S-255° F ____________ _____ 16.1’
Average of
It will be observed from these data that the
catalyst in which the molybdenum oxide pro
100.0 70 moter is co-gelled with the alumina is consider
ably less effective in producing toluene’than the
The naptha referred to was passed in a stream
catalyst in which' substantially the same alumina
Residue (not examined) _______________ __
-thru the catalyst under a pressure of 200 p. s. i.
gage for a period of six hours, employing '2500
cubic feet of hydrogen per barrel (42 gallons)
was promoted with molybdenum oxide, applied
subsequent to ignition of the alumina. The total
aromatics produced by the two catalysts were
Having» thus described >our invention what.' _we
found to be substantially the same. Apparently
the toluene-directive raction ofthe catalyst isk
considerably influenced by the method of adding
claim is:
1. The process of making toluene in high con
centration from petroleum naptha which com
the' promoter element, the toluene `production
prises contacting said naptha at a lconversion
being improved by `adding thepromoter to the
temperature Within the range of about 850 to
alumina after> ignition. An examination ci the
1100" F. with a catalyst substantially free of alkali
data just presented shows .17.2% average yield 'of
metals consisting essentially of aluminavgelpro
toluene from the co-gelled catalyst and 19% from
moted-withßabout 5 .to 10 per cent of molybdenum
the'catalyst promoted after ignition, an increase
oxide, the boiling range of >said naptha lying
of 10.5% in this case, operating under the same
within about 50° F. of the boiling point of toluene,
conditions with the same. spacevelocity.H Space
supplying t'o the reaction zone about 1 4to 5 mols
Velocity is the volume lof'liquidnaptha per hour
of hydrogen per mol of naptha treated and re-,
charged per gross volume of catalyst. Thus if
toluene from the reaction 4products,‘
two barrels of naptha are charged' per hour thru
alumina gel having been prepared by dissolving
one barrel of catalyst, the space velocity is 2. f
I_n order to determine the chemical changes
occurring in the catalytic process, we made an~
amalgamated metallic aluminum in a weak acid
» thereby forming an alumina sol, gellingsaid sol,
drying and igniting the resulting alumina gel, and
valyses- of the products obtained from two runs
applying the molybdenum promoter to the gel
made with the best commercial catalyst avail»
ableand two runs made with' the impregnated 20 subsequent to igniting by impregnating said gel
With a solution of ar soluble compound of molyb
alumina gel catalyst from amalgamated alumi
denum and re-igniting the catalyst. ;
num. Products obtainedv from runs made _at two
2. The process of‘claim 1 wherein the catalyst
different space velocities, approximately 1 and
has a-n alkali metal content less than
approximately 2, were tested. The conditions
were 980° F., 200 p. s. i., and 6-'-hour reaction 25 0.1,per cent by weight.
3. The` process of producing .toluene in high
Vperiods with about 2500 cubic feet of hydrogen
_concentration from petroleum which comprises
per barrel. The results are shown 1n the follow
ing table:
contactingfa naptha boiling-'within .the range of
196 Ito 258° F. at .au temperature of about 850 to
30 1100° F., with an alumina gel catalyst substan
Naptha.. Aluginma Coiâärlier
y (feed)
Space velocity,~Vn/h'r./Vc_>__«..-. -. _______ __
vYields based‘on feed:
1.00*v 1.90
Carbon ____ ._Wt. per cent.. ........ _, 0. 14
Dry~gas .......'__;
_per cent
Cs’S „__
Toluene .... ......._.-.do_.-r
per cent-.
v255-300° F.: l
Napthenes andvparaiîûns
Higher aromatics_-._do____
liins.___.-_»..v__.:per cent..
0.5 to5 volumes per hour per volume of catalyst
in. .the'reaction zone, introducing 'into `said reac
tion» zone about 1 to 5 mols of hydrogen per mol
of rnaptha-1treatedv and Vrecovering toluene from
the reaction products, said alumina gel having
l A `
from' the class consisting- of acetic and Íormic
acids, »startingthe solution in an acid or about
11% concentration `and=subsequently increasing
lic aluminum in a dilute organic acid selected
been preparedÍ by dissolving amalgamated metal
11.0 11a-9
13.0 15.8
` 23.2
12.7 11.6
28.2- 22.41
2.2 y16.0 19.0
Above 300° F.: 2
` Napthe‘nes ‘and paralnns
feeding said naptha at -a space velocity of about
per sente.
' >9.7 11.8
action zone in the range of about 50 to 500 p. s.’i~.f,
0. 16
`Napthenes and‘paraülns
. .
Benzene...V.... ..`'._'-. ,
0. 19
._.d0_.__ ________ __
1Z0-204° F
tially free of alkali metalsfand impregnated with
about .5,.t'ol20 -per .-cent of molybdenum oxide,
maintaining the pressure' Within'the catalytic'r‘e'l
the'concentration until an alumina sol containing
Vfrom’ about‘l .to 10 percent A1203 is'fobtain'ed; de
hydrating- said sol tor alumina‘gel of «low moist-ure
content, and heating said alumina gel in an at
1 255-270° F. in case of feed.
2 Above 270° F. in case of feed.
Norm-_Percentage is by volume except Where indicated. n
Y50 mosphere oi'controlled oxygen content to remove
adsorbed organic acid.
4. The process of making .toluene in high :con
As indicated hereinabove, we prefer to lprepare
centration from petroleum which comprises con
our toluene directive catalyst from metallic alu
tacting, _in a reaction zone, a petroleum naptha
minum, ñrst forming an alumina sol, then a gel.
boiling in the range of 196 to 258° F. with a cata
Metallic aluminum of high .purity should be used 55 lyst consisting essentially of alumina gel pro
for lthis purpose. All reagents should be substan- -moted with about 5 to 10 per cent of molybdenum
tially free of other metals except the desired pro
oxide, .the said catalyst being substantially free
moter and We have found that the alkali metals
of alkali metals, maintaining said reaction zone
in .particular are objectionable. . The catalyst
at a temperature of about 900 -to '1050° F. and
m-ade from aluminum metal is .substantially free
pressure of about 50 .to 500 pounds per square
of sodium, containing not more than about .01
inch, introducing into said reaction zone about
percent of this element. »We prefer that the
1 Ito 5 mols of hydrogen per mol of naptha hydro
alkali metal content of our .catalyst be not more
carbon treated, charging said naptha .to the re
than 0.1 percent.
If the alumina is prepared by precipitation
from an aluminum salt, it is important to employ
an aluminum salt, for example aluminum nitrate, ï
which is substantially free of alkali metal salts.
This objective may be attained'readily when sub 70
limed aluminum chloride is employed for prepar
ing .the catalyst. The use of distilled Water and
glass, wood or ceramic> mixing vessels in making
up the catalyst is importanti-,o prevent contami
nation. .
action zone at a space velocity of about 0.1 to 5
volumes of liquid naptha per hour per gross vol
ume of catalyst in .the reactionyzone, and recov
ering toluene from the reaction products, said
valumina. gel catalyst having been prepared by
dissolving amalgamated metallic aluminum in a
weak acid thereby forming an alumina sol, co-p
a'gulating said sol to a ñrm, vibrant gel, drying '
and igniting Ithe resulting gel, and impregnating
said gel with a solution of a soluble compound of
molybdenum which on ignition Will be converted
to molybdenum oxide.
the reaction zone, and recovering toluenefrom
the reaction products byV direct distillation, said
5. The process of makingY toluene jfrom .pe
troleum in high concentration sufûciently ‘free
alumina gel catalystA having been prepared by
dissolving amalgamated metallic aluminum ín a
weak acid to form an alumina sol, then jgelling
the sol by adding a solution of’ electrolyte, drying
from contaminating non-aromatic hydrocarbons
of similar boiling points to permit the recovery
of substantially pure to-luene b-y directdistillation
of the, products which comprises contacting, in
and igniting the resulting gel, and impregnating
said gel with a solution of a soluble compound
of molybdenum which on ignition will be con
a reaction zone, at a temperature of about 900
to ,1050° F. a naptha boilingwithin the range 10 verted to molybdenum oxide._ ;
of.l80 .to 280° F. With a Catalyst consisting-es
7. The process of making toluene of high' con
sentially of alumina .gel promoted with. about 5
centration from petroleum which comprises con
to. 10 per cent of molybdenum oxide` and sub
tacting a petroleum naptha boiling Within. the
stantiallyfree of alkali metals at a ypressure of
range of 180° to 280° F. with a porous solid
about50to 500 vpounds per square inchand in
catalyst consisting essentially of alumina gel pre
the presence of aboutl to„5 mols of added hy
pared by dissolving amalgamated aluminum
drogen per mol yof, naptharhydrocarbon treated,
metal in a weak acid, gelling the resulting sol,
charging said naptha to the, catalytic reaction
drying and igniting the resulting gel and pro
zone at a space velocity of about 0.14 to 5.«volmoting it with about 5 to 10 per cent of molyb
urnes of liquid naptha per hour vpergross volume 20 denum oxide by impregnating it With a solution
of _catalyst in the.k reaction zone, and recovering
of a molybdenum compound which on ignition
toluene from . the reaction products >by direct
will be converted to molybdenum oxide, then ig
distillation, saidv alumina gel having --been pre
niting said impregnated gel, maintaining a space
velocity Within the range of about 0.5 to 5 vol
pared by dissolving amalgamated metallicalu
minum in a Weak acid thereby forming `an alu
umes of naptha per hour yper gross voluime of
minasol, gelling said sol, drying and igniting
theresulting gel, and impregnating saidgel with
asolution of a soluble compound of molybdenum
which on _ignition will ,be> converted >to »molyb
The, >process, of, makingtoluene
_. from4
.. .
troleum in lhigliconcentration suilîcientlyfree
from contaminating non-aromatic hydrocarbons
Totsirnilar boiling points topermitthe recovery
lof substantiallyv pure, toluene by _direct distille.,
tionof the products which comprises ~contacting,
catalyst in the reaction zone, maintaining the
reaction temperature at about 900 to 1050° F.
and a pressure of about 50 to 500 pounds per
square inch, supplying to the reaction zone about
30 l to 5 mols of hydrogen per mol of naptha
treated, fractionating 'the reaction products into
a substantially pure toluene fraction,y a heavy
substantially toluene-free Xylene fraction, a light
substantially toluene-free benzene fraction, kand
35 at least one intermediate boiling fraction con
taining toluene and non-aromatic hydrocarbons
boiling close to toluene, recycling said interme
in»4 a> reaction „_ zone,` lat `atemperature v.of .about
900¿ to _1050€ F. a naptha lboiling.,within the range
of 1,80 to 280° F. with a catalyst consistingessen
tially of alumina Vgel promoted With about 5to
10_,per cent of molybdenum oXideandsubstan
tially, freeßf alkalif metals at a pressure .of about
V50u30> 5_00 pounds per squareV inch and. inthe
presence ofabout >_1,to _5 mols lof _added hydrogen
pêlëmol of n_aptha hydrocarbon treated,.charging
Sßfíd, naptha _tothe catalytic reaction zone ,ata
spacel‘velocity of. about 0.1>> to 5 volumesof liquid -
_naptha per _hour per grossvolumeof catalyst in
diate boiling fraction to said catalytic conversion
step, thereby converting said non-aromatic hy
drocarbons into aromatic hydrocarbons and prod
ucts having boiling points less close to the boil
ing point of toluene than the boiling point of said
non-aromatic hydrocarbons in said intermediate
fraction and subsequently separating said last
mentioned products from toluene in» said frac
tionation step.
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