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Патент USA US2094128

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Sept. 28, 1937' v
w, A, LAzlER ET AL
2,094,128
CHEMICAL PROCESS
' Filed June 2'7, 1934
A
IL RESERVQIR
B
GIL FEED DISTRIBUTOR HEAD
.
C
'
FUZED QUARTZ
E
,
FURNACE
HEATING
ELEMENT _ a
F
D
Y
CATALYST BED
C1
FUZED QUARTZ
GAS METER
L
CDN NSER
H
INVENTORS
Wrlbur ?rfhur Layer
G“%%“'AITORNEY.
2,094,12§
Patented- Sept. 28, 1937
UNITED STATES PATENT OFFICE
2,094,128
CHEMICAL rnocnss
Wilbur A. Lazier, Marshalltown, DeL, and John
V. Vanghen, Lakewood, Ohio, assignors to E. I.
du Pont de Nemonrs & Company, Wilmington,
DeL, a corporation of Delaware
Application June 27, 1934, Serial No‘. 732,656
5
10
15
20
25
30
5 Claims. (Cl. l96—52)
This invention relates to the production of low
These objects are accomplished by the followboiling hydrocarbons from petroleum fractions. ‘ing invention wherein a high molecular weight
More particularly it relates to the use of cata
hydrocarbon in the vapor phase is brought in
lysts in such cracking or pyrolyzing operations. contact at an elevated temperature with a cata
The art of converting high molecular weight lyst comprising a solid metallic element of the
hydrocarbons into'more valuable products of low
sixth group intimately associated and preferably
er molecular weight and correspondingly lower combined with a solid non-metallic element also
‘
boiling point by thermal means, with or without of the sixth group.
the aid 01’ catalysts, has been practiced for some
It has been found that sul?de catalysts, par
time. The use of gaseous boron halides, and the ticularly molybdenum sul?de and chromium suluse of solid catalysts have been recommended. i'omolybdate or similar substances, when used in
One of the most e?icient processes for pyrolyz
gas-phase cracking processes, de?nitely activate
ing hydrocarbons consists in heating the hydro
the hydrocarbons undergoing pyrolysis. The fol
carbon mixture to a moderate temperature to lowing examples illustrate the methods of prepa
cause almost complete volatilization and then ration of the improved pyrolysis catalysts and the
conducting the vapors thru a relatively hotter results obtained therewith in the ‘ cracking. of
zone which causes thermal decomposition. The heavy petroleum oils. The examples are-not to
gases and vapors are then quickly cooled and be regarded as limitative, but merely- as illus
the products obtained are found to consist of trative.
gases such as acetylene, methane, ethylene, and
Example 1
ethane, and of intermediate liquid hydrocarbons
A solution of commercial chromium nitrate
useful as gasoline. It has been recognized that
the substances of which the hot-zone walls are was ?rst prepared by dissolving 1500 grams of
constructed may exercise a catalytic in?uence chromium nitrate in 28 liters of water at a tem
on the reaction. This in?uence is manifested perature of about 65°45’ C. A second solution
in an activation of the higher- hydrocarbons, containing 1720 gramsof ammonium molybdate
which generally results in a lowering of the in 9.0 liters of water was added to form an apple
green precipitate of chromium molybdate. Hy
required cracking temperature, with accompany
drogen sul?de was then passed into the slurry
ing decrease in the amount of wasteful gas for
mation, which in turn results in increasing the for a period of about four hours, during which
yield of valuable intermediate liquid hydrocarbon time the precipitate was changed from-apple
products.
- Various catalytic compositions have been sub
Jected to tests but none of the materials known
35 to the prior art exhibit such pronounced activat
ing tendencies toward hydrocarbons as the cata
lysts employed in the present invention. Indeed,
certain so-called catalysts of the prior art are
so low in activity that a comparatively long time
' 40 of contact of the hydrocarbons therewith is re
quired, and this results in too severe cracking,
i. e., the carbon chain is disrupted or broken
into carbon and gaseous fragments which are
too small for successful commercial utilization.
45 Furthermore, the temperature at which certain
thermally unstable catalysts may be used is lim
ited to a range where the desirable type of crack
green to a dark brown color.
V
5
10
15
20
25
30
By this treatment _
the chromium molybdate was converted in great
er part to chromium sulfomolybdate. - The prod
not was ?ltered from the mother liquor and 9.5
dried at 110“ C. After drying, the product was
crushed to a suitable grain size for loading into
the pyrolysis tube.
'
-
The apparatus for conducting the catalyzed
pyrolysis of the high molecular weight hydro- 40
carbons consisted of a stainless steel tube (%"
wall by V4” bore and 36" in length) ?lled with
crushed fused quartz and a central portion of
granular catalyst. This reaction chamber was
50 of a process wherein high molecular weight by
drocarbons are pyrolyzed to lower molecular
weight
bons. A further object of the
heated by a suitable electrical resistance furnace
and‘ the temperature controlled and recorded
by means of thermo-elements fastened to the
tube. The tube was mounted vertically, and the
quartz and catalyst mass was supported by a 50
glass rod. The oil or hydrocarbon mixture en
tered at the top of the tube at a suitable rate
invention is the provision of catalysts for this
“ pyroly?nl operation. Other objects will ap
where a suitable condenser was attached.
'
ing is thermodynamically impossible.
,
This invention has as an object the provision
poarhercinafter.
and the products issued from the lower end'
In the attached drawing, oil from the. oil res-v “ .
8,0“188
ervoir A.is fed through the distributor h
B,
and comes in contact with the fused qu
C,
Tasun
then the catalyst bed D interposed between beds Relative ya: formation in catalytic and none
_
catalytic pyrolysis
(2 and C’ of fused quartz. These are contained ,
in a tube in a furnace E, the tube being heated
Vol. oigasperliquid vol. oigasolino'
by heating element F. The material passes
through valve G and condenser E, whence the
liquid products may be drawn o? for storage
Catalytic _
Nonoatelytic
through valve J. and the gas products are passed
'10
10 through pipe K and gas meter L.
PM
Yielii‘g'
In operating the process as :1. catalyzed pyroly
sis the central portion of the tube was ?lled with
about 5.0 cc. of the granular catalytic mass pre-'
pared as described above, and the remaining free
space was ?lled with broken quartz particles oi
8-14 mesh. When operating the apparatus for
uncatalyzed pyrolysis, the heated chamber was
?lled entirely with the silica'packing. In all cases
' the furnace was heated to the desired tempera
20 ture and a sample of a petroleum fraction boil
ing at 190°-270“ C. corresponding to a furnace
oil was passed into-the top of the tube at a steady
rate of about 60 cc. per hour. The products were
passed thru the water cooled condenser, to which
25 there was connected a gas meter for determining
the quantity of non-condensable gases. The
liquid hydrocarbon mixtures obtained were con
veniently analyzed by the Engler method, which
consists in measuring the temperature at which
30 successive fractions (percentages) of the oil dis
till. The same procedure was carried thru with
an inexpensive grade of cracking stock or coke
distillate, in which case a small quantity of steam
was used with \the oil to prevent excessive car ,
35
bonization.
-
In Table I there are recorded the comparative
results, expressed as gasoline yields, obtained
during the catalyzed and uncatalyzed pyrolysis
of the above described furnace oil.
For the pur- .
40 poses of this example, the hydrocarbons boiling
at 45°-200° C. in the standard Engler distillation
have been considered as “gasoline.’_’
5
'
0. ___________ .__
10.
10
10___________ .__
75.
15
20
70. ___________ .__
125.; _________ .__-
12b.
M.
%
tum-wisps‘
e
on
a $3‘
tan-11),) pen
8
men
t yild
a
tibtliailelldd).
never
In this way it has been demonstrated that for
a given yield of gasoline,'considerably more of
the sto l: is lost in gas formation with the non
catalyze reaction than with the improved process
of this invention.
-
As an alternative procedure, similar results
may be obtained by employing a catalyst prepared
' as follows:
A 25% solution of ammonium molybdate is
treated with hydrogen sul?de until the product
is converted to soluble ammonium sulfomolyb
date. To this solution there is added the theo
retical amount of a solution of cobalt nitrate to
cause complete precipitation of cobalt sulfo
molybdate. The precipitate is ?ltered, washed
and dried at 110° 0., after which it is brought into
suitable physical form by crushing and screening
to the desired size, or by pulverizing and briquet
ting.
E'mample 2
A solution of ammonium sulfomolybdate is pre-_
pared as described in the preceding paragraph‘,
which is then acidi?ed slightly with mineral acid,
preferably sulfuric acid. A precipitate of
molybdenum sul?de is obtained which may be
?ltered off and dried. The physical form of the
product is made suitable for use as described in
TABLE I
Example 1. The furnace oil employed in the
45
Gasoline yield in catalyzed and non-catalyzed
Pyrolysis of furnace oil
Yield of gasoline
50
Temperature oi pyrolysis
Non-cam
Catalytic
ly?c
Percent
6. 0
Percent
5. 0
9. 5
13v 5
20. 0
6. 5
10. 3
17. 0
3D. 0 ,
26. 0
30. 0
28. 5
28. 5
ll. 0
25. 0
21. 5
It is evident that with a catalyst it is possible
to operate at a lower temperature while main
65 taining the gasoline yield, or to operate at a
given temperature and obtainappreciably higher
yields. Furthermore, when an account is made
of the gas formation during pyrolysis (Table II)
it is again evident that de?nite advantages are
offered by the use of catalysts of the type utilized
by this invention.
'
In the following table the volume of gas pro
duced is recorded for each volume of liquid gaso
line when the process is operated to produce the
75 yield indicated in the ?rst column.
'
experiments of Example 1 was passed over 5 cc.
of this catalyst at the rate of 57 cc. per hour at
atmospheric pressure and a temperature of 660°
C. The gasoline yield was 29.7% as compared
with a yield of 26% and 28.5% recorded in Table
I for the uncatalyzed reaction at 650° C. and 7 00°
C.,-respectively.
‘ ~
Although certain de?nite catalyst compositions
have been described in the examples, the inven
tion is not limited to the use of these catalysts.
Suitable catalysts may be prepared from one or
more metallic elements of the sixth group inti
mately associated with but preferably combined
with the solid non-metallic elements also of the
sixth group. The catalysts may also include one 60
or more metallic elements of the ?rst, ?fth, sev
enth, and eighth groups intimately associated
with but preferably so intimately associated as to
be combined with one or more solid non-metallic
elements of the sixth group.
The sul?des of 65
iron, cobalt, copper, silver, vanadium, nickel, and
manganese may be used in conjunction with those
of the sixth group metals. These complex me-
-
tallic sul?des, selenides, and/or tellurides, may be
mechanically mixed with or chemically combined 70
with the sixth group sul?des. Thus, a mixture
of precipitated copper and molybdenum sul?des
may be used. A further variation in the prepara
tion of the catalysts of the present invention con
sists in mixing coprecipitated chromium and 75
2,094,128
3
molybdenum oxides with sulfur. A still further
The catalyst compositions are not necessarily
variation is the admixture of dry active chromium
con?ned to the ratios of the various constituents
given in the examples. It is possible to obtain a
oxide and/or dry active molybdenum oxide with
sulfur, the whole being bound together with a
suitable binding agent. Similar mechanical mix
tures may be prepared with compounds of the
other metallic elements and with selenium, tellu
molybdenum, or of cobalt and molybdenum as
well as from those containing either chromium
rium, etc. ‘Of the sixth group metal catalyst com
or molybdenum in excess.
ponents chromium and molybdenum are perhaps
10 the most useful, altho tungsten and uranium may
also be used.
.
Active catalysts may also be prepared wherein
the constituent elements are bound together in
compositions of the characteristics of chemical
compounds. This type of catalyst may be formed
in the dry way or in the wet way. A compound
catalyst'of high activity from preparations con
taining equivalent amounts of chromium and
The process as described in the examples is
not limited to the use of furnace oil, but any ~10
hydrocarbon mixture capable of being cracked
and handled as described may be used.
It is
often desirable to 'pyrolyze lighter hydrocarbon
mixtures than furnace oil for the production of
lower boiling substances. Kerosene and virgin 15
light crude distillates may be treated in the man
ner described, and not only are lower boiling hy
drocarbons formed, but these when used as gaso
such as chromium molybdate, for example, may line are found to have acquired high anti-knock
20 be formed and the non-metallic activating con
rating as a result of the pyrolysis. Other petro 20
stituents, such as sulfur, introduced in several leum fractions known as coke distillate, gas oil,
ways. The chromium molybdate may be treated paraffin wax distillate, or the foots oil obtained
with hydrogen sul?de, or mixed with sulfur or therefrom may be used in the process of the
with some organic or inorganic sul?de in the wet
present invention. With these substances, as
condition. The substitution of the non-metallic also when crude oil'is used, an auxiliary ?ash 25
solid element of the sixth group in the compound distilling operation may be desirable. When dis
will take place either in the wet condition, as in tillates from high-sulfur crudes are pyrolyzed, it
the case of treating a solution or suspension with is found that the products are relatively free
hydrogen sul?de, or in the dry condition as when from the sulfur compounds present in the origi
30 the catalyst is brought up to reaction temperature,
nal crude oil.
30
as in the case of the admixture vof powdered sul
With respect to temperature and pressure, the
fur. The oxygen may also be replaced by sul
process is not limited to the values given above.
fur, selenium, or tellurium by heating the oxides Altho excellent results in producing gasoline are
in a current of the sixth group non-metal hydride
obtained at about 700° C., it is sometimes desir
- such as hydrogen sul?de, hydrogen selenide, or ' able to vary the temperature from 450° to 1000° C.
hydrogen telluride, or in a current of sulfur vapor.
The process may be operated at pressures vary
Hydrogen selenide or hydrogen telluride may be ing from sub-atmospheric to pressures somewhat
substituted for hydrogen sul?de if the proper ad
in excess of atmospheric pressure. In general,
justments are made for the difference in charac
it is more economical and preferable to operate
having the chromium and molybdenum compo
nent in true chemical combination with oxygen,‘
40 teristics of these gases.
A‘tho the sul?des men
tioned are preferred, the analogous selenium com
pounds are similarly active, and for some pur
poses have de?nite advantages over the sul?de
catalysts.
In carrying out the wet method of catalyst
preparation as outlined in the examples given
above, it is not necessary to follow all the steps
in detail. The use of chromium nitrate as the
source of the chromium component of the vari
ous catalysts has been mentioned. Other salts
of chromium may be used, for example the chlo
ride, sulfate or acetate, necessary adjustments
being made for the difference in molecular weight
of the various salts. Ammonium molybdate may
be replaced by other sources of molybdenum, such
as sodium paramolybdate, care being taken in
this case that the precipitated material is washed
at least moderately well.
It is not necessary to follow the explicit direc
60 tions for sul?ding the precipitates as outlined in
the examples. sul?ding agents other than hy
drogen sul?de, for example ammonium or sodium
sul?de, or polysul?de may be used. In the case
of the sodium salts it is desirable to wash out the
excess of sodium salts before drying.
between atmospheric pressure and a pressure of
10 atmospheres, but in certain instances it is ad
vantageous to use pressures of from 0.5 to 50 at
mospheres.
It is not intended to con?ne the operation of
the process to the rate of oil ?ow mentioned in‘
the examples. While a liquid space velocity of
approximately 13 volumes of oil per volume of
catalyst per hour is preferred at vthe tempera
tures speci?ed in the examples, yet under cer
tain circumstances it is desirable to increase this 50
to a space velocity as high as 65 volumes per
catalyst volume per hour. Furthermore, it is
sometimes desirable to lower the space velocity
to about 5, depending on the results desired. In
general, high space velocities at a given temper 55
ature tend to limit the extent of cracking, while
low space velocities tend to increase the propor
tion of very low boiling hydrocarbons in the prod
uct. Thus, variations in temperature will often
necessitate corresponding changes in the space 60
velocity for the attainment of maximum results.
For a given result the space velocity and tem
perature should be adjusted with respect to each
other. The loss of yield at higher temperatures
as shown in Table I may be reduced by increas 65
ing the space velocity to compensate for increased
temperature. The results recorded in Table I
The sul?ding treatment is susceptible of wide
variations. Various degrees of sul?ding may be
used for certain purposes, altho it is preferred not
to sul?de the catalysts completely, that is, not were determined at the same space velocity
to convert all of the oxygenated metal to sul?ded which was not necessarily the optimum for each 70
temperature shown.
metal.
The recovery of dissolved molybdenum from_
It is sometimes advisable, as pointed out above,
the mother liquor by the addition of dilute acid to use a gaseous diluent along with the hydro—
is not limited to dilute nitric acid, but this step
75 may be accomplished by other mineral acids.
carbon mixture. Steam may thus be used, but
inert gases such as nitrogen, carbon dioxide, or
4
y
.
2,094,128
recycled hydrocarbon gases may ‘also be use
with advantage.
‘
The above description and examples are in
tended to be illustrative only. Any modi?cation
5 of or variation therefrom which conforms to the
spirit ‘of the invention is intended to be included
10
_
15
20
25
C. and at apressure between 1 and 10 atmos
pheres at a space velocity of 13 volumes of liquid
oil per volume of catalyst per hour, in the ab
sence of added hydrogen, to» the gas prior to
pyrolysis in contact with a catalyst comprising 5
essentially chromium suliomolybdate.
within the scope of the claims.
4. In a process for producing hydrocarbons
We claim:
,
boiling at 45° C. to 200“ C. in the standard Engler
1. In a process for producing hydrocarbons distillation, the step which comprises bringing
boiling at 45° C. to 200° C. in the standard a hydrocarbon heavier than gasoline in the vaEngler distillation, the step which comprises por phase at a temperature of 450° C. to 1000° C,
bringing a hydrocarbon heavier than gasoline, and at a pressure below 10 atmospheres, at a
in the vapor phase at a temperature, of 450° C. space velocity of 5 to 65 volumes of liquid oil
to 1000“ C. and a pressure below 10 atmospheres per volume of catalyst per hour in the absence
at a space velocity of 5 to 65 volumes of liquid of added hydrogen to the gas prior to pyrolysis,
oil per volume of catalyst per hour, in the ab- in contact with a catalyst comprising as an es
sence of added hydrogen, to the gas prior to sential component ametallic element of the sixth
pyrolysis in contact with a catalyst comprising group of the Periodic Table combined with bi
as an essential component a sulfomolybdate of a - valent sulfur, said catalyst being prepared by
metal selected from the group consisting of precipitating as a sul?de the said metallic clechromium and cobalt.
ment from an aqueous solution containing the
2. In a process for producing hydrocarbons ammonium salt of said metallic element.
boiling at 45“ C. to 200° C. in the standard
5. In the process for producing hydrocarbons
Engler distillation, the step which comprises boiling‘ at 45° C. to 200° C. in the standard
bringing a hydrocarbon heavier than gasoline, Engler distillation, the step which comprises
in the vapor phase at a temperature of 450° C. bringing furnace oil in the vapor phase at a
to 1000” C. and a pressure below 10 atmospheres temperature of 450° C. to 1000“ C. and at a pres
at a space velocity of 5_ to 65 volumes of liquid sure between 1 and 10 atmospheres, at a space
velocity of 13 volumes of liquid oil per volume of
oil per volume of catalyst per hour,‘ in the ab
sence of added hydrogen, to the gas prior to catalyst per hour in the absence of added hypyrolysis in contact with a catalyst comprising drogen to the gas prior to pyrolysis, in contact
with a catalyst comprising essentially chromium
as an essential component chromium sulfomo
10
15
20
25
'’
sulfomolybdate.
lybdate.
WILBUR A. LAZIER.
JOHN V. VAUGHEN.
3. In a process for the pyrolysis of hydrocar
bons, the step which comprises bringing furnace
oil, in the vapor phase at a temperature of 700°
‘CERTIFICATE OF CORRECTION.
Patent no‘, 2,095,128 .
‘September 28, 1957.
WILBUR A LAZIER, ET AL’.
It is hereby certified that error appears in' the printed specification
of the above numbered patent requiring correction as follows: Page 11,, first
column, lines 514,-55, claim 5, strike out the words "the pyrolysis ofhy
drocarbons" and insert instead producing hydrocarbons boiling at 145°C. to
200°C, in the standard Englerdistivllationrand- that ‘the said Letters Pat-v
ent ‘should be read with this correction therein that the same may conform
to ‘the record of the case: in the'Patent Office.‘
'
Signed and sealed this 1st day ‘of February, A. D. 1958,
(Seal)
Henry Van Arsdale,
Acting Commissioner of Patents.
4
y
.
2,094,128
recycled hydrocarbon gases may ‘also be use
with advantage.
‘
The above description and examples are in
tended to be illustrative only. Any modi?cation
5 of or variation therefrom which conforms to the
spirit ‘of the invention is intended to be included
10
_
15
20
25
C. and at apressure between 1 and 10 atmos
pheres at a space velocity of 13 volumes of liquid
oil per volume of catalyst per hour, in the ab
sence of added hydrogen, to» the gas prior to
pyrolysis in contact with a catalyst comprising 5
essentially chromium suliomolybdate.
within the scope of the claims.
4. In a process for producing hydrocarbons
We claim:
,
boiling at 45° C. to 200“ C. in the standard Engler
1. In a process for producing hydrocarbons distillation, the step which comprises bringing
boiling at 45° C. to 200° C. in the standard a hydrocarbon heavier than gasoline in the vaEngler distillation, the step which comprises por phase at a temperature of 450° C. to 1000° C,
bringing a hydrocarbon heavier than gasoline, and at a pressure below 10 atmospheres, at a
in the vapor phase at a temperature, of 450° C. space velocity of 5 to 65 volumes of liquid oil
to 1000“ C. and a pressure below 10 atmospheres per volume of catalyst per hour in the absence
at a space velocity of 5 to 65 volumes of liquid of added hydrogen to the gas prior to pyrolysis,
oil per volume of catalyst per hour, in the ab- in contact with a catalyst comprising as an es
sence of added hydrogen, to the gas prior to sential component ametallic element of the sixth
pyrolysis in contact with a catalyst comprising group of the Periodic Table combined with bi
as an essential component a sulfomolybdate of a - valent sulfur, said catalyst being prepared by
metal selected from the group consisting of precipitating as a sul?de the said metallic clechromium and cobalt.
ment from an aqueous solution containing the
2. In a process for producing hydrocarbons ammonium salt of said metallic element.
boiling at 45“ C. to 200° C. in the standard
5. In the process for producing hydrocarbons
Engler distillation, the step which comprises boiling‘ at 45° C. to 200° C. in the standard
bringing a hydrocarbon heavier than gasoline, Engler distillation, the step which comprises
in the vapor phase at a temperature of 450° C. bringing furnace oil in the vapor phase at a
to 1000” C. and a pressure below 10 atmospheres temperature of 450° C. to 1000“ C. and at a pres
at a space velocity of 5_ to 65 volumes of liquid sure between 1 and 10 atmospheres, at a space
velocity of 13 volumes of liquid oil per volume of
oil per volume of catalyst per hour,‘ in the ab
sence of added hydrogen, to the gas prior to catalyst per hour in the absence of added hypyrolysis in contact with a catalyst comprising drogen to the gas prior to pyrolysis, in contact
with a catalyst comprising essentially chromium
as an essential component chromium sulfomo
10
15
20
25
'’
sulfomolybdate.
lybdate.
WILBUR A. LAZIER.
JOHN V. VAUGHEN.
3. In a process for the pyrolysis of hydrocar
bons, the step which comprises bringing furnace
oil, in the vapor phase at a temperature of 700°
‘CERTIFICATE OF CORRECTION.
Patent no‘, 2,095,128 .
‘September 28, 1957.
WILBUR A LAZIER, ET AL’.
It is hereby certified that error appears in' the printed specification
of the above numbered patent requiring correction as follows: Page 11,, first
column, lines 514,-55, claim 5, strike out the words "the pyrolysis ofhy
drocarbons" and insert instead producing hydrocarbons boiling at 145°C. to
200°C, in the standard Englerdistivllationrand- that ‘the said Letters Pat-v
ent ‘should be read with this correction therein that the same may conform
to ‘the record of the case: in the'Patent Office.‘
'
Signed and sealed this 1st day ‘of February, A. D. 1958,
(Seal)
Henry Van Arsdale,
Acting Commissioner of Patents.
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