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Patented July 23,‘ 1946
2,404,438
UNITED STATES PATENT OFFICE
2,404,438
PROCESS FOR THE MANUFACTURE OF
OLEFIN OXIDES
Theodore W. Evans, Oakland, Calif., assignor to
Shell Development Company, San Francisco,
Calif., a corporation of Delaware
No Drawing. Application September 7, 1943,
Serial No. 501,501
9 Claims. (Cl. ace-348.5)
1
2
This invention relates to the manufacture of
ole?n oxides, and particularly pertains to a novel
process and catalysts for the economical pro
decomposition is eifected by subjecting the above
or other suitable inorganic or organic silver com' pounds, such as the silver oxide and/or silver
duction of ole?n oxides, particularly ethylene
oxide, by the direct oxidation, in the presence
of such novel catalysts, of the corresponding
oxalate, at substantially atmospheric pressure to
an elevated temperature which is substantially
at or slightly above the decomposition temper
ature of the organic silver compound subjected
to such treatment.
The silver catalysts employed in the catalytic
conversion of ole?ns such as ethylene to the
corresponding ole?n oxide have also been here
tofore promoted by the incorporationthereinto
of small amounts of various hydroxides, oxides
or peroxides of alkali and alkali earth metals.
ole?ns, such as ethylene. The invention is of
particular value in that it provides a novel and
economical process whereby ethylene may be
readily converted to ethylene oxide, while the
formation of undesirable by-products, particular
ly carbon dioxide and water, is suppressed to a
degree heretofore unattainable with known
process and catalysts employed for such direct
catalytic oxidation of ethylene to ethylene oxide. 15 The addition of these promoters ‘to silver cat
The ole?n oxides, and particularly ethylene
alysts resulted in an increase in the ole?n oxide
oxide, are valuable compounds per se, as sol
production. However,‘ this advantage has been
vents, extractants, fumigants, insecticides, and
always oifset'to a great extent by a correspond
the like. In addition, they are highly valuable
ing increase .in the formation of undesirable by
intermediates in the preparation of a wide variety 20 products, particularly carbon dioxide. It is well
of useful organic compounds such as alcohols,
known that two'main reactions occur when an
glycols, halohydrins, aldehydes, carboxylic acids,
ole?n such as ethylene is subjected to direct
ethers, esters, alkylolamines, resins, polymers,
catalytic oxidation in the presence of the here
and the like.
tofore known promoted and/or unpromoted silver
Processes have been disclosed in accordance 25 catalysts. In one of these reactions the ethylene
with which ole?ns are directly catalytically oxi
is converted to ethylene oxide, while in the other
dized to the corresponding ole?n oxides. Gen
the ethylene is oxidized completely to carbon di
erally speaking, the catalytic conversion of ole
oxide andwater. Aside from‘the fact that the
?ns, such as ethylene, to the corresponding ole
formation of ‘carbon dioxide and water in the
?n oxides is effected by subjecting the ole?n and 30 catalytic oxidation of ethylene affects the ef?
oxygen or an oxygen-containing gas, such as air,
ciency of the process in that; it lowers the po
tential yield of the desired product, viz. ethylene
to certain elevated temperatures in the presence
of ‘a silver catalyst. Although silver catalysts
oxide, the production of carbon dioxide is also
undesirable because the heat evolved during such
conversion of ethylene to carbon dioxide is con
- have been employed in the massive form, the use
of such massive catalysts requires too much silver
to render the process commercially attractive.
siderably greater than that evolved during the
Therefore, it has been the general practice to
oxidation of ethylene to ethylene oxide, ‘thus
employ the silver in an active ?nely divided
rendering the control of the reaction temper
state, in which case the active silver catalysts
ature increasingly di?icult, if not impossible. As
have been prepared, for example, by thermally 40 stated, the use of the heretofore known promoted
decomposing suitable silver compounds such as
silver catalysts, although increasing the yield of
silver oxide, and particularly a suitable organic
ethylene oxide (as compared to‘ the yields ob
silver compound which, on being heated, will de
tainable when the catalytic oxidation is, effected
compose with the formation of the aforesaid
under like conditions but in the presence of an
active and ?nely divided silver catalytic material. 45 unpromoted silver catalyst), also causes a corre
As organic silver compounds which may thus be ‘ spending if ‘not greaterincrease in the formation
treated to produce the active silver catalysts,
of undesirable by-products, e. g. the complete
reference may be made to the silver salts of the
oxidation of the ole?n to carbon dioxide. .
carboxylic acids, such as formic, acetic, propionic,
It is therefore the main object of the present
butyric, isobutyric, valeric, oxalic, malic, malonic,
60 invention to provide an e?icient process for the
maleic, lactic, and like acids. Although these
compounds may be used, it is, well known that
the silver oxalate is particularly suitable and
will readily decompose with heat to form an ac
tive silver catalytic materiah Generally, such 66
catalytic oxidation of ole?n hydrocarbons to the
corresponding ole?n oxides. A further object of
the invention is to provide a practical and eco
nomical process for thedirect catalytic oxidation
or‘ ethylene to ethylene oxide wherein the ratio
2,404,431;
3
of ethylene oxide to carbon dioxide in the reac
promote the oxidation of ole?ns to the-curred
tion products is substantially greater than that
sponding ole?n oxides in the presence of active
silver is not possessed by all oxygen-containing
compounds of sodium and lithium, but is shown
to a marked degree by the sodium and lithium
salts of aliphatic carboxylic acids. This ability
obtained by the heretofore known processes and
by the use of the heretofore employed promoted.
and/or unpromoted silver or silver-containing
catalysts. Still another object or‘ the invention
is the provision of a catalyst which is particu
larly effective in selectively catalyzing the oxida
tion of ole?ns, particularly ethylene, to the corre
sponding ole?n oxides, which catalysts are sub‘_ 10
stantially free of any promoting effect on side
is found to be present to a far lesser extent and
often to a negligible degree in such oxygen-con
taining compounds of sodium and lithium ‘as the
oxides, peroxides and hydroxides of these two
alkali metals.
In this connection, reference is
reactions which convert the ole?n hydrocarbons , ~ made to one of the examples, which includes the
to undesirable by-products, particularly carbon
results of a run using a sodium hydroxide-pro
moted silver catalyst. It is seen therefrom that
,
I
It has now been discovered that the above and 15 the selectivity factor of such catalyst is far below
other objects may be attained by using certain
that of a silver catalyst promoted with, for exam
oxygen-containing compounds of sodium and
ple, sodium oxalate or sodium formate. It is also
lithium, namely the sodium and lithium salts of
shown therein that the addition of sodium hy
aliphatic carboxylic'acids, as promoters. It has
droxide,'although it increased to a certain degree
dioxide.
been further discovered that the sodium and 20 the conversion of ethylene to ethyleneoxide over
lithium salts of aliphatic carboxylic acids are
particularly effective in promoting the catalytic
the conversion obtained by the use of an unpro
effect of silver in the oxidation of ole?ns to the
the complete combustion of the ethylene to car
moted silver catalyst, also materially increased
corresponding ole?n oxides without substantially
bon dioxide, the production of carbon dioxide
increasing the production of undesirable oxida 25 being so great as togive a selectivity factor of
only 0.9, as compared to a selectivity factor of 1.2
tion products. These new catalysts are claimed
in copending application Serial No. 659,135, ?led
for the unpromoted silver catalyst. In other
April 2, 1946. With the use of these novel pro
words, the presence of the sodium hydroxide,
moted catalysts in the process of the present in
although increasing the conversion of ethylene
vention it is possible toconvert ole?ns, particu 30 to ethylene oxide, increased the complete com
larly ethylene, to the corresponding ole?n oxide
bustion of the ethylene to carbon dioxide to a
with excellent results and with the attainment
greater extent, thus lowering the selectivity factor
of much greater ratios of ole?n oxideto carbon
.of this silver catalyst containing sodium hydrox
dioxide in the reaction products than is possible
ide. The use of such a silver catalyst would there
with catalysts and processes of the prior art. It 35 fore have but little economic advantage over the
unpromoted silver catalyst.
.
has also been discovered that the novel promoted
catalysts possess a selectivity factor which is not
In a preferred method of preparing the acti
possessed and cannot be attained when the here
vated catalytic material for‘use in the execu
tofore known catalysts are employed for the direct
tion of the process of the invention, sodium
catalytic oxidation of ole?ns to ole?n oxides. 40 and/or lithium salts of aliphatic carboxylic acids
The “selectivity factor" of a catalyst as this term‘
are added in small quantities to active, ?nely di
is employed throughout this speci?cation may be
vided silver. The following are illustrative ex
de?ned as the ratio or the percent of ole?n con
amples of the promoters which may be used in
verted to the corresponding ole?n oxide, to the
the manufacture of the novel catalysts: sodium
percent of ole?n completely oxidized to carbon 45 and lithium salts of formic, acetic, propionic,
dioxide. The addition of the above-mentioned
promoters, and particularly of the sodium salts
of aliphatic carboxylic acids, to an adt've silver
catalyst not only increases the conv'e sion of
butyric, isobutyric, valeric. oxalic, malic, ma
lonic, lactic, maleic acids, and the like. The ac
tive ?nely divided silver may be prepared in any
suitable manner, as for example by the precipi
ethylene to ethylene oxide as compared to the 50 tation of the silver from solution of silver salts
conversion attainable when using the same silver
in the presence of a reducing agent. It may also
catalyst without the promoter, or with the here-'
be prepared in any of the many ways disclosed
tofore known promoters, but also materially in
in the art, comprising thermal decomposition of
creases the selectivity factor of the catalyst. For
an organic compound of silver, such as silver
instance, as shown in one of the examples pre-‘
oxalate, or by the reduction at elevated temper
sented hereinbelow, the addition of even minor
atures of an oxygen-containing compound of sil
amounts of sodium oxalate to an ‘active silver
ver, such as for example silverv oxide or silver
catalyst more than quadrupled the conversion of
carbonate or any other silver compound capable
ethylene to ethylene oxide. over ‘that obtained
of reduction to active silver.
when using the same catalyst ‘without any pro
The sodium or lithium ‘salt of an aliphatic,
00
moter. Also, the presence of this sodium oxalate
carboxylic acid may be added to the active, ?nely
materially increased the selectivityfactor of the
divided silver in quantities ranging from a frac
catalyst. The same example shows that, whereas
tion of a percent, e. g. 0.5%, to about 5% by
the unpromoted silver catalyst had a selectivity
weight of the active silver. This promoter is
factor of 0.21, the addition of the minor amounts
preferably added in such a quantity that the so
of sodium oxalate raised the selectivity factor to
dium or lithium in the added carboxylic acid salt
2.33, i. c. more than an eleven-fold increase in
will amount to, for example, from 0.25% to
the selectivity factor of the catalyst. It is readily
about 2.5% by weight of the active silver in the
catalyst mass. It must be stressed, however, that
70 the amount of the promoter material added'will
‘substantial increase of ole?n oxide in the reaction
depend at least in part upon the method of
apparent that an increase of even only a fraction .
of a percent in the selectivity factor denotes a
products, and therefore'a substantial increase in -
preparing the catalyst, the specific promoter
the economic value of the catalyst? and of the
added, the activity and nature of the ?nal cat
process employing such catalyst.
alyst desired, and the invention is not limited '
'
‘
It has been found that the ability to selectively 75 to any speci?c ratio of promoter to active silver.
8,404,488
,It isvintended‘toi'use'the- optimum amount of
promoter required i-for the particular .oxidation
operation.
-
If ‘desired, more than :one sodium-or lithi
‘
salt of ‘an aliphatic carboxylic acid, or both so
dim. and‘ ‘lithium salts- of aliphatic ‘carboxylic
acids, ‘may be added as activating agents to‘ the
v*Inca'rrying out the process bitithe'present in
vention a stream "of ‘hydrocarbons comprising an
ole?n, : particularly ‘ethylene, in admixture with
‘oxygen or an oxygeng-containin‘g gas'i‘e, 3.‘ air; ‘is
‘passed in a‘ continuous manner at elevated’ tem-.
perature conditions over an active silver cata
lyst‘‘ promoted ‘by-the presence of‘ a'promoting
active silver. - The‘ activating agent or agents
amount of sodium or lithium introduced into
may be added to the catalytic material'during
the ‘catalyst in the form of vthe sodium or lithium
any phase of the preparation of the active silver; 10 salt vof an aliphatic vcarboxylic acid. To assure
for example, either before or after conversion
the attainment and maintenance of the desired
of the silver‘ to the active state. An active sil
reaction temperature, any‘ suitable means may
ver catalyst particularly suitable for the process
be resorted to in order to supply heat to the re
of selectively catalytically converting ethylene
actants onto the reaction zone, or to" withdraw
to ethylene oxide maybe prepared, for example, 15 excess heat therefrom during the course of the
in the following manner: .A mixture is prepared
reaction.
At the conditions of operational: which the ole
?n and oxygen are brought into contact with the
mixture a small quantity or sodium or lithium in
catalyst, the ole?n, e. g. ethylene, will react with
the form of a salt of an aliphatic carboxylic 20 the oxygen to form the corresponding ole?n ox
acid is added, and the mixture thus formed
ide, for example ethylene oxide. In accordance
is then heated to a temperature at which silver
with the invention, the oxygen may be present
oxalate decomposes to yield a ?nely divided sil
as free oxygen or it may be employed in admix
ver, this temperature being in the neighborhood a ture with other gaseous materials such as air,
of about 230° C. The resulting mixture isthen 25 steam, nitrogen, carbon dioxide, etc. The free
heated in a stream of a reducing gas, e. g., hydro
oxygen may, if desired, be liberated or formed
from oxygen-containing substances in situ at the
gen, at a temperature of from about 200° C. to
conditions of operation.
about 300° C., and preferably at a temperature
containingone part by weight of silver oxalate
and two parts by weight of silver oxide. To this
The ratio of oxygen to ole?n may vary widely
of about 250° C., for a period of time su?icient to
reduce any remaining silver oxide to active sil 30 within the scope of the invention, depending upon
the conditions at which the operation is carried
ver. The promoted catalyst prepared in this
out. Although the oxidation of the ole?ns may
manner is particularly suitable for the oxidation
be eifected by employing the oxygen in amounts
of ethylene to ethylene oxide and possesses ex
less than the stoichiometrical amount necessary,
ceptional selective promotional characteristics.
The activated silver catalyst as prepared in ac 36 in the preferred embodiment of the invention
the reaction is effected in the presence of an
cordance with the present invention may be used
amount of oxygen at least equal to and prefer
as such, in the form of a powder, or in the form
ably in excess of the stoichiometric amount
of pellets, pastilles, pills or other shapes of de
needed to combine with the olefin available in the
sired size or form. This promoted active silver
catalyst may or may not be deposited upon or 40 reaction zone.
The process of the invention may be carried out
mixed with any suitable carrying material such
at any suitable temperature in the broad. range
as clay, asbestos, activated carbon, charcoal, sil
of from about 150° C. to about 500° C. How
ica gel, alumina, pumice or the like. If desired,
ever, one of the advantages of the process is that
this supporting material may be incorporated
into the catalytic material before or after the 45 it permits the ei?cient oxidation of olefins to the
corresponding ole?n oxides and particularly of
conversion of the silver to the active state.
ethylene to ethylene oxide, with substantially in
Although the promoted catalysts of the pres
creased yields at temperatures not exceeding
ent invention are particularly applicable to the
about 350°C. For example, the oxidation of
catalytic selective conversion ‘of ethylene to
ethylene oxide, other ole?ns may be similarly 60 ethylene to ethylene oxide may be effected at a
temperature in the range of from about 200° C.
treated to produce the corresponding ole?n ox
to about 350° C. and preferably from about 230°
ides. The ole?ns capable of being thus oxidized‘
to the corresponding ole?n oxides in accordance
C. to about 320° C., in thizpresence of silver acti
vated by the presence of thium or sodium intro
with the process of this invention are the nor
mally gaseous as well ‘as the readily volatile nor 55 duced in the form of the corresponding salt of
an aliphatic carboxylic acid, with an excellent
mally liquid ole?ns such as ethyleneLpropylene,
butylenes, amylenes and their homologues and
' suitable substitution products.
The ole?ns-m‘ay
yield of ethylene oxide and a minimum produc- tion of carbon dioxide.
_
_
-
Although additional inert diluent fluids, such
be employed severally or in mixtures containing
a plurality of different-species thereof, or resort 60 as nitrogen, carbon dioxide, steam, etc., may be
added to the charge subjected to the catalytic
may be made'to the use of mixtures thereof with
oxidation in accordance with the‘proces's or the
relatively unreactive substances, such as mix
present invention, the e?icient operation of the
tures of ole?ns and para?ins, which may be em
process in the relatively low temperature range
ployedwithout resorting to the separation of the
ole?n or ole?ns therefrom prior’ to their being 65 greatly facilitates the problem of heat control.
It has been found that as'a result of the selective
subjected to the oxidation process. Such ole?ns
promotional effect of the novel catalyst in the
or ole?n-containing mixtures ‘may be obtained
process, ‘the material decrease in‘ the tendency
from any suitable source, for example the prod
ucts resulting from any petroleum re?nery op
toward destructive exothermic oxidation reac
eration, e. g. the products resulting from the 70 tions leading to the formation of considerable
simple distillation, thermal cracking, hydro
genation, dehydrogenation, polymerization, etc.,
proportions of carbon dioxide in the reaction
products substantially suppresses the need for
of hydrocarbon ?uids. Also, these fractions may
be obtained from processes encountered in the
these additional diluent ?uids.
natural gasoline industry, etc.
Although it ispreferable to effect the process
75 of the present invention at pressures slightly in
2,404,488
8
7
excessoi atmospheric, the process may if desired
be carried out at subatmospheric or superatmos
pheric pressures. The optimum pressure to be
employed will be governed by the conditions oi’
operation and the nature . or the materials
treated.
'
a
-
,
.
Reaction products resulting from the process
may be subjected to any subsequent treatment to
separate the desired constituent or constituents
from the remaining reaction products. For ex
ample, the ole?n oxide, e. g. ethylene oxide, may
be separated from the remaining reaction prod
ucts by any suitable method of separation, com
1. Silver oxide was heated for one hour at
2i;0° C. to obtain a ?nely divided unpromoted
si ver.
silver oxide and added promoter for one hour at
200° C. to obtain the promoted silver metal-con
taining catalyst. The promoter and quantity
thereof added to the silver oxide prior to heating,
in percent by weight of silver oxide used. are in
dicated in the following table opposite the re
1 spective catalyst number:
prising fractionation, absorption, adsorption,
and/or extraction.
.
For illustrative purposes only, reference is made
to the several examples which describe certain
methods of preparing the novel promoted silver
catalysts and the preferred modes, conditions
'
Three promoted silver metal-containing cata
lysts were prepared by mixing the promoter with
silver oxide and heating the resulting mixture of
No. 2—1% sodium hydroxide. ,
No. 3—3% sodium oxalate.
No. 4—3%.sodium formate.
An ethylene-air mixture consisting of 28% by
volume of ethylene and 72% by volume of air was
and advantages of effecting the catalytic oxida 20 passed over the catalysts at a rate of about one
liter of the gas mixture per 2 grams of catalyst
tion reaction in accordance with the process of
per hour at the temperature indicated in the table
the present invention.
presented below. In this table, the conversion of
Example I
ethylene to ethylene oxide, in percent by weight,
Two silver metal-containing catalysts were pre
pared in the following manner:
1. About one part by weight of silver oxalate
was mixed with‘ about two parts by weight of sil
is given in column A. The ?gures in column C
indicate the ratio of the percent by weight of
ethylene converted to ethylene oxide to the per
cent by weight of ethylene converted to ethylene
oxide and carbon dioxide. The selectivity factor
of each catalyst based upon the indicated results
ver oxide, and the mixture was then heated until
the silver compounds were substantially com 30
is shown in column S.
pletely converted to ?nely divided silver metal.
2. About one part by weight of silver oxalate
was mixed with about two parts by weight of sil
‘
ver oxide. Sodium oxalate was then added in an
240° C
260° 0.
Catalyst
amount equal to about 3% by weight of the mix‘ 35,
A
C
S
A
C
S
ture, which latter was then heated until the sil
ver compounds were substantially completely
1
5.1 0.55 1.2
7.2 0.45
0.8
2
9.7 .47 0.9
6.3 .38
0.6
converted to ?nely divided silver.
3
8.0 .67 2.0 12.4 .67
2.0
Over each of the above catalysts there was
4
9.2 .74 2.8 13.3 .68
2.2
passed about the same volume of an ethylene-air 40
mixture consisting of 28% by volume of ethylene
A comparison of the results presented in the
and 72% by volume of air. This mixture was
above
table shows the advantages of effecting the
passed over the catalysts at a rate of about one
oxidation of ethylene to ethylene oxide in the
liter of the gas mixture per 2 grams of catalyst
presence of a silver catalyst containing minor
per hour. In each case the catalyst was main 45
amounts of sodium oxalate or sodium formate
tained at a temperature of about 240° C.
over the unpromoted catalyst or even one con
In the following table, column‘ A shows the
taining sodium hydroxide. The addition of the
conversion (in percent by weight) of ethylene to
minor amounts of either sodium oxalate or so
ethylene oxide, while column B shows the weight
formate not only increased the conversion
percent of carbon dioxide produced. The se 50 dium
of ethylene to ethylene oxide to a very great ex
lectivity factor is shown in the third column
tent, but also decreased the total combustion of
under “S.”
>
the ethylene to carbon dioxide, thus materially
increasing the selectivity factor of the catalysts
Catalyst
A
B
S
promoted with the sodium salts of the aliphatic
55 carboxylic acids. On the other hand, the addi»
1
2
No promoter ____ ._' ________________________ ._
NBsCrOi promoted ________ ..' .............. ._
3. 0
l2. 2
l2. 0
5. 2
0. 21
2. 33
tion of sodium hydroxide, although it caused an
increase in the conversion of ethylene to ethylene
oxide when the oxidation reaction was effected at
A comparison of'the results presented in this
240° C., also caused a material increase in the
example shows that the addition of about 3%
combustion of ethylene, so that the selec
of sodium oxalate to a silver catalyst produced 60 total
tivity factor of the silver catalyst containing so
by the decomposition of the above mixture of
dium hydroxide was even lower than that of the
silver oxalate and silver oxide more than quad
unpromoted catalyst. A comparison of the re
rupled the conversion of ethylene to ethylene
sults obtained at an operating temperature. of
oxide, as compared to the conversion obtained
C. with the unpromoted catalyst and the
when using the same silver catalyst without the 65 260°
catalyst
containing sodium hydroxide clearly
promoter. Also, this material increase in the
shows
the
negative effects of the addition or in-_~
ethylene oxide was obtained with acarbon dioxide
corporation of sodium hydroxide.
production which amounted to only about one
This application is a continuation-in-part ofv
third of that obtained when using the'unpro
the
co-pending application, Serial No. 351,244,
70
moted silver catalyst.
'
?led August 3, 1940.
Example [I
I claim as my invention:
'
~
1. A process for the production of ethylen
One unpromoted and three promoted silver
oxide by the direct catalytic oxidation of- ethylene
metal-containing catalysts were prepared as fol
lows:
76 which comprises reacting ethylene with oxygen
2,404,488
10
employed in amount less than the stoichiometric
of from about 0.5% to about 5% by weight of a
amount necessary to combine with the ethylene,
sodium salt of an aliphatic carboxylic acid.
and effecting the reaction at a temperature of
6. A process for the production of ethylene
between about 230° C. and about 320° C. in the
oxide by the direct catalytic oxidation of ethylene
presence of a catalyst comprising silver metal 6 which comprises reacting ethylene with oxygen at
activated by the presence of from about 0.5% to
a temperature of between about 200° C. and about
about 5% by weight of sodium oxalate.
350° C. and in the presence of a catalyst compris
2. A process for the production of ethylene
ing silver metal activated by the presence of from
oxide by the direct catalytic oxidation of ethylene
about 0.5% to about 5% by weight of a lithium
which comprises reacting ethylene with oxygen v10 salt of an aliphatic carboxylic acid.
employed in an amount less than the stoichio
'7. A process for the production of ethylene
metric amount necessary to combine with the
oxide by the direct catalytic oxidation of ethylene
ethylene, and e?ecting the reaction at a tempera
which comprises reacting ethylene with oxygen at
ture of between about 230° C. and about 320° C.
a temperature of between about 150° C. and about
in the presence of a catalyst comprising silver 15 500° C. and in the presence of a catalyst compris
metal activated by the presence of from about
0.5% to about 5% by weight of sodium formate.
3. A process for the production of ethylene
ing silver metal activated by the presence of from
about 0.5% to about 5% by weight of a compound
of the group consisting of the sodium and lithium
oxide by the direct catalytic oxidation of ethylene
salts of aliphatic carboxylic acids.
which comprises reacting ethylene with oxygen 20
8. A process for the production of an ole?n
at a temperature of between about 200° C. and
oxide by the direct catalytic oxidation of an ole?n
about 850° C. and in the presence of a catalyst
which comprises reacting an ole?n with oxygen
comprising silver metal activated by the presence
at a temperature of between about 150° C. and
of from about 0.5% to about 5% by Weight of
about 500° C. and in the presence of a catalyst
sodium oxalate.
25 comprising silver metal activated by the presence
4. A process for the production of ethylene
of from about 0.5% to about 5% by weight of a
oxide by the direct catalytic oxidation of ethylene
compound of the group consisting of the sodium
which comprises reacting ethylene with oxygen
and lithium salts of aliphatic carboxylic acids.
at a temperature of between about 200° C. and
9. A process for the production of an ole?n
about 350° C. and in the presence of a catalyst 30 oxide by the direct catalytic oxidation of an ole?n _
comprising silver metal activated by the presence
of from about 0.5% to about 5% by weight of
sodium formate.
which comprises reacting an ole?n with oxygen
in the presence of a catalyst selectively promoting
the oxidation of the ole?n to the ole?n oxide
5. A process for the production of ethylene
which catalyst comprises silver metal activated
oxide by the direct catalytic oxidation of ethylene 35 by the presence of from about 0.5% to about 5%
which comprises reacting ethylene with oxygen
by weight of a compound of the group consisting
at a temperature of between about 200° C. and
about 350° C. and in the presence of a catalyst
of the sodium and lithium salts of aliphatic
comprising silver metal activated by the presence
carboxylic acids.
THEODORE W. EVANS.
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