Note: Descriptions are shown in the official language in which they were submitted.
1209160
CONTINUOUS SELECTIVE REDUCTIO _OF EDIBLE OILS AND FATS
BACKGROUND OF THE INVENTION
Although some edible oils are used per se, by far the largest
portion are hydrogenated, or hardened, prior to their end use. The
reason for such hydrogenation is to increase the stability of the final
product. For example, processed soybean oil is susceptible to oxidation
resulting in deterioration of its organoleptic properties upon storage
even at ambient temperature. Where the oil is to be used at higher tem-
peratures, for example, as a frying oil, the adverse organoleptic con-
sequences of oxidation become even more pronounced.
The commonly accepted origin of oxidative deterioration is
the presence of highly unsaturated components, such as the triene
moiety, linolenate, in soybean oil. Partial hydrogenation to remove
most of this component leads to a marked increase in the oxidative
stability of the resulting product, thereby facilitating storage and
permitting unobjectionable use at higher temperatures. Ideally, one
desires this hydrogenation to be highly specific, reducing only triene
to the diene, linoleate, without effecting cis to trans isomerization.
In practice, this goal is unachievable.
The fats and oils which are the subject of this invention,
hereinafter collectively referred to as fatty materials, are trigly-
cerides of fatty acids, some of which are saturated and some of which
are unsaturated. In vegetable oils, the major saturated fatty acids
are lauric (12:0), myristic (14:0), palmitic (16:0), stearic (18:0),
arachidic (20:0), and behenic (22:0) acids. The notation, "18:0,"
for example, means an unbranched fatty acid containing 18 carbon atoms
and O double bonds. The major unsaturated fatty acids of vegetable
oils may be classified as monounsaturated, chief of which are oleic
--1--
12091~;0
(18:1) and erucic (22:1) acids, and polyunsaturated, chief of which
are the diene, linoleic acid (18:2) and the triene, linolenic acid
(18:3). Unhardened vegetable fats and oils contain virtually exclu-
sively cis-unsaturated acids.
In the context of partial hydrogenation, the ultimate goal
is the reduction of triene to diene without attendant trans acid
formation or saturate formation. In practice, it is observed that
partial reduction results in lowering both triene and diene and
increasing the monoene, saturate, and trans levels. Because it is
desired that the product of partial hydrogenation itself be a liquid
oil relatively free of sediment or even cloudiness upon storage at,
for example, 10C, the formation of saturated and trans acids in such
hydrogenation is a vexing problem. Removal of these solids, whose
relative amount is measured by the Solid Fat Index (SFI), is a rela-
tively costly and inefficient process attended by large losses associated
with the separation of gelatinous solids from a viscous liquid. It is
known in the art that such solids are composed largely of triglycerides
containing at least one saturated fatty acid moiety and/or trans mono-
unsaturated fatty acid moiety with the predominant culprits having at
least 18 carbon atoms. It is further known in the art that fatty acid
analysis alone may be an insensitive analytical tool, that is to say,
two products of hydrogenation of, for example, soybean oil may show
different SFI profiles while having virtually identical fatty acid
analysis. This arises because the distribution of the saturated moieties
in the triglyceride is important. The solubility in the soybean oil of
disaturated triglycerides is much less than twice the amount of monoun-
saturated triglycerides, and the solubility of monounsaturated tri-
glycerides may depend upon whether the other fatty acid moieties of the
triglyceride are monounsaturated, diunsaturated, etc., and may also
-2-
1209i60
depend upon whether the saturated portion is at the one- or two-
position of the triglyceride. Hence, hydrogenation of edible fats
and oils is largely an empirical process, whose analytical tools include
Solid Fat Index (SFI) supported by fatty acid analysis. The difficulty
of achieving desirable results, in the context of selectivity in Solid
Fat Index, has largely limited such hydrogenation to a batch type pro-
cess. Although the transition from a batch to a continuous process,
especially of the fixed bed type, is conceptually facile, it will be
recognized by the skilled worker that impediments have been substantial.
Thus, U. S. Patent 2,971,016 describes the vapor-phase hydro-
genation of unsaturated fatty acids and esters in a fluidized bed,
which enabled the disadvantages of liquid phase hydrogenation and the
use of solid bed catalysts to be avoided. It will be recognized that
vapor-phase hydrogenation is unfeasible for oils and fats. A continu-
ous process based on a mixture of oil and suspended catalyst flowing
along a tortuous path on the top surface of a series of perforated
plates, with hydrogen admitted through the bottom face counter-current
to the oil flow and minimum mixing along the various plates, is the
subject of U. S. Patent 3,634,471. The process described in U. S.
Patent 3,792,067, which has had limited commercial application, is
based on a turbulent two-phase gas-liquid flow with minimal back-mixing,
the liquid phase consisting of oil containing catalyst suspended therein.
Both U. S. Patents 3,823,172 and 3,988,329 describe continuous hydrogen-
ation processes where the flowing mass of oil containing suspended
catalyst is subject to high shear forces. U. S. Patent 3,444,221
describes a continuous process which requires a high ratio of liquid
(catalyst suspended in oil) to gas phase using a plurality of reaction
chambers.
lZ09160
The processes represented in the latter four references all
suffer from the common disadvantage of necessitating the additional
unit process of removal of suspended catalyst from partially hydrogen-
ated oil, as by filtration. It is well known in the art that this unit
5 process entails substantial product loss and requires use of relatively
large amounts of filter aid, which adds to processing cost and presents
subsequent disposal problems. Because use of a fixed bed continuous
operation obviates the necessity of catalyst removal, such a mode of
operation is greatly preferred. Both U. S. Patents 3,123,626 and
3,123,627 describe fixed bed processes using sulfur- or nitrogen-
poisoned nickel respectively, on a macroporous silica support. At
least in part, success of the method is attributable to the large pore
structure of the support with catalyst contained within the pores. A
diametrically opposed approach to fixed bed hydrogenation is described
in U. S. Patent 4,163,750, where metals, including nickel and cobalt,
are deposited almost entirely on the outer surfaces of the particles
of the support. The support itself may be porous, and in fact advantages
are ascribed to porous supports, such as porous carbon, as compared with
non-porous supports, as stainless steel. The method of achieving surface
20 deposition of the metal, which appears to be critical to the success of
this process, does not seem to be disclosed.
Reports on the use of cobalt as a catalyst in the reduction of
edible oils have been sparse. U. S. Patent 4,169,101 describes the use
of micrometallic and ferromagnetic cobalt resulting from the decomposi-
25 tion of dicobalt octacarbonyl as a catalyst in the hydrogenation ofedible oils. Although the process is there characterized as a selective
hydrogenation, the data presented belie this description. It should be
noted that in no reduction described by the patentee is the stearate
1209160
(18:0) level under 7.8%, and even at such a relatively high saturate
level the triene content is 2.4%. Thus, it is questionable whether
the cited prior art method constitutes a selective hydrogenation of
edible oils as that term is commonly used in the art, and this prior
art method definitely is not selective as that term is defined within.
In the context of this application, a method of hydrogenation
of edible oils is selective if it is capable of reducing the iodine
value of soybean oil from about 10 to about 30 units with a concomitant
increase in saturates of less than about 1.5% and.a decrease in triene
level to at least 3%, and where the Solid Fat Index of the partially
hydrogenated product is less than about 5+1 at 50F, less than about
2+0.5 at 70F, less than 1.0+0.5 at 80F, and 0~0.2 at 90F.
It must be clearly recognized and understood that although
this definition of selective hydrogenation utilizes a specific decrease
in iodine value of a particular edible oil, a selective hydrogenation
may cause a greater decrease in iodine value and/or be effected with
a different edible oil. That is to say, the definition of selective
hydrogenation does not restrict a selective hydrogenation to the condi-
tions of its definition.
The observation upon which the subject invention of this
application is founded is that alpha-alumina of low surface area and
low porosity functions at hydrogenation conditions as an effective
support for catalytically active zerovalent metals selected from Group
VIII of the Periodic Table including iron, cobalt, nickel, ruthenium,
rhodium, palladium, osmium, iridium, and platinum in a fixed bed
hydrogenation of edible fats and oils, affording partially hydrogenated
product with the desired selectivity. This observation seems unknown
in the prior art, and stands in sharp contrast to the prior art require-
ments of a porous support.
120g~60
It is an object of this invention to provide a method of
selective hydrogenation of edible oils and fats by a continuous pro-
cess. One embodiment comprises hydrogenat;ng a vegetable oil by
contacting the vegetable oil with a fixed bed of hydrogenation catalyst
consisting essentially of a catalytically active zerovalent metal
selected from Group VIII of the Periodic Table impregnated on a low
surface area alpha-alumina. In a specific embodiment, the metal
selected from Group VIII of the Periodic Table is present at a level
from about 1 to about 25% based on alpha-alumina. In a preferred
embodiment, the catalytically active zerovalent metal selected from
Group VIII of the Periodic Table including iron, cobalt, nickel,
ruthenium, rhodium, palladium, osmium, iridium, and platinum, is cobalt
or nickel. Nickel is especially preferred. In a more specific embodi-
ment, the alumina has a surface area less than about 5 square meters
per gram. In a still more specific embodiment, the vegetable oil is
passed upflow over the fixed bed.
DESCRIPTION OF THE INVENTION
The subject matter disclosed is a continuous method for the
selective hydrogenation of edible oils and fats which comprises con-
tacting a flowing mass of edible oils and fats at a temperature from
about 150 to about 260C in the presence of hydrogen at a pressure up
to about 150 psig (1000 kPa gauge) with a fixed mass of catalyst con-
sisting essentially of a catalytically active zerovalent metal selected
from Group VIII of the Periodic Table supported on alpha-alumina having
a'surface area less than about 10 m2/g and a micropore volume less than
about 0.1 ml/g, and recovering the resultant hydrogenated product.
The method described herein is generally applicable to edible
oils and fats. Because the partial hydrogenation of liquid oils to
lZ0916
afford hardened, but still liquid, oils occupies a prominent part within
the doma;n of hydrogenat;on of ed;ble oils and fats, the method of th;s
invention is particularly applicable to such partial hydrogenation. Thus,
the descr;bed method of hydrogenat;on ;s espec;ally useful to partially
harden edible liquid oils whereby the iodine value (IV) is lowered from
about 10 to about 30 un;ts by hydrogenat;on, whereby the increase in
saturates attending hydrogenation is less than about 1.5%, and whereby
the triene level is reduced to about 3% or less. Such a partially
hydrogenated product preferably has an SFI of less than about 5+1 at
50F, less than about 2+0.5 at about 70F, less than about 1.0+0.5 at
80F, and 0~0.2 at 92F. The term "iodine value" is a measure of the
total extent of unsaturation in an edible oil or fat as performed by a
standard test. In the context of soybean oil, which is a particularly
important liquid vegetable oil, partial hardening is continued to an
IV drop of from about 15 to about 25 units, with the product having less
than about 6% stearate and about 3% linolenate or less.
Although the method claimed herein is especially valuable
when applied to the partial hydrogenation of liquid vegetable oils, it
must be explicitly recognized that the selectivity of the cla;med
method ;s also manifested in more extensive hydrogenations. Thus, as
is shown below, the claimed method may be used generally in hydrogen-
ating edible o;ls whenever selective hydrogenation is desired.
The method of this invention is especially applicable to
liquid vegetable oils. Examples of such oils include soybean oil,
cottonseed oil, sunflower oil, safflower oil, rapeseed oil, corn oil,
and liquid fractionations from palm oil. The application of this
method to soybean oil is especially important. As will be recognized
by those skilled in the art, partial hydrogenation of liquid oils to
~zog~
afford partially hardened liquid oils is especially demanding, hence
it is to be expected that a method suitable for this task also is
suitable for more extensive hydrogenation. Thus, the method described
herein also is suitable for more extensive hydrogenation, where the IV
of the product may be as low as about 70. Oils and fats which can be
so hydrogenated include those above, their partially hydrogenated
products, and also such feedstocks as palm oil.
The hydrogenation catalyst used in this method is essentially
a catalytically active zerovalent metal selected from Group VIII of the
Periodic Table deposited on low surface area alpha-alumina. It is to
be understood that by alpha-alumina is meant alumina whose crystallinity
as measured by X-ray diffraction corresponds to that characterized in
ASTM file number 10-173. Although zerovalent Group VIII metals are
widely used in this art area, they are generally used on supports,
such as kieselguhr and alumina, of high surface area and large porosity.
A discovery of this invention is that continuous hydrogenation using
zerovalent Group VIII metal in a fixed bed mode can be successfully
performed, in the context of the criteria elaborated above, only on
an alpha-alumina support characterized by relatively low surface area
and porosity. In particular, the hydrogenation catalyst of this method
consists essentially of catalytically active zerovalent Group VIII
metal on alpha-alumina with a surface area less than about 10 m2 per
gram, with a surface area less than about 5 m2 per gram preferred.
Additionally, the micropore volume of the support must be less than
about 0.1 ml/g, with those supports having a micropore volume less
than about 0.05 ml/g, being advantageous. The macropore volume of the
supports used in this invention is related to the surface area of the
support. Consequently the supports used herein are further characterized
~209160
by a macropore volume less than about 0.6 ml/g, with a macropore
volume under about 0.3 ml/g being preferred. By micropore volume
is meant the total volume of pores under about 117 angstroms in
size; by macropore volume is meant the total volume of pores greater
than about 117 angstroms in size.
It is believed that, because of transport problems associ-
ated with fatty materials in the smaller pores, the selectivity in
hydrogenation of a catalyst of a given surface area, micro- and macro-
pore volume will change with macropore distribution. In particular,
it is believed that a distribution skewed toward relatively large pore
sizes will favor selectivity. As an example, with other variables
being held constant it is believed that a catalyst whose support con-
tains 90% of its macropores larger than about 3500 angstroms will be
more selective than one where 90% of the macropores are larger than
300 angstroms, but only 10% larger than 3500 angstroms.
The concentration of Group YIII metal may range from 1 to
about 25 percent by weight of alumina. The choice of metal loading
will depend, inter alia, on the degree of selectivity and catalyst
life desired in a particular operation. Metals selected from Group
VI I I of the Periodic Table include iron, cobalt, nickel, ruthenium,
rhodium, palladium, osmium, iridium, and platinum. Of these Group VIII
metals, cobalt and nickel are preferred catalytically active components
of the hydrogenation catalyst. Nickel is most especially preferred.
The cobalt catalyst used in the method of this invention
typically is prepared by reducing a suitable cobalt salt impregnated
on the support. Such reduction is most conveniently effected by a
stream of hydrogen at a temperature between about 400 and about 600C.
Other methods are also satisfactory, as for example, the methods commonly
g_
120g~60
employed to prepare Raney-type cobalt. The cobalt catalysts used ;n
this invention are effective in amounts from about 0.01 to about 5%
cobalt, based on edible oil hydrogenated, with the range from about
0.01 to about 1% being preferred, and with the lower end of this range
being particularly preferred.
When a cobalt catalyst is employed hydrogenation conditions
embrace a temperature from about 150 to about 300C at a hydrogen
pressure from atmospheric up to about 200 psig. Because the selectivity
of hydrogenation seems to increase with increasing temperature and
decreasing pressure, there is some advantage to operating at the highest
possible temperature and lowest possible pressure consistent with an
acceptable reaction rate. Operationally, a temperature range from about
200 to about 260C is preferred. The preferred range of pressure is
from about 25 to about 150 psig, with a range from about 50 to about
100 psig being still more preferred.
When a nickel catalyst is employed hydrogenations are con-
ducted at a temperature from about 150 to about 250C, with the range
of 175 to 225C being preferred. Hydrogenations may be conducted at
pressures up to about 150 ps;g. Frequently there is some advantage to
conducting such hydrogenations at a pressure less than about 50 psig,
and a pressure from about 5 to about 45 psig often is preferred.
The following description is applicable to a fixed bed oper-
ation, although it will be recognized that by suitable changes it may
also be applicable to expanded or fluidized bed operation. The catalyst
bed may be in the form of pellets, granules, spheres, extrudate, and so
forth. The reactor is heated to the desired reaction temperature in a
hydrogen atmosphere, often with a small hydrogen flow. After attain-
ment of the desired temperature, the feedstock of edible fats and oils
--1 C--
~zog~o
is made to flow over the fixed bed. The flow rate of the oil may be
from about 0.2 to about 20 LHSV depending upon the degree of hydrogena-
tion sought. When the flow of edible fats and oils is initiated, it
is desirable to mix the hydrogen with said fats and oils so as to main-
tain the desired pressure. Often it is advantageous to admit excess
hydrogen, maintaining pressure by partial venting. As the reaction
proceeds and the activity of the catalyst bed decreases, adjustments
may be made either in the LHSV or the temperature to maintain the
desired characteristics of the product. Partially hardened oil is
recovered as the effluent in a state suitable for further processing,
such as blending, bleaching, or deodorization.
The flow may be either downflow, as in a trickle bed opera-
tion, or upflow, as in a flooded bed operation. By downflow is meant
that the feedstock flows with gravity, that is, a trickle bed operation.
By upflow is meant that the feedstock is made to flow against gravity,
as in a flooded bed operation. Upflow is generally thought to be pre-
ferred to downflow because of a demonstrated enhanced selectivity of
hydrogenation.
Although the reason for enhanced selectivity in the upflow
mode is not known with certainty, it may arise from an overabundance
of hydrogen at the catalyst surface in the downflow mode relative to
a flooded bed operation.
One index of selectivity as used herein is the Solid Fat
Index, as described above. Obtaining SFI data for large numbers of
samples is laborious and time consuming. Another index of selectivity
relied upon here and commonly used elsewhere can be better understood
from the following partial reaction sequence, where k is the rate
~Zo9~60
constant for the ind;cated hydrogenation step.
k3
18:3 ) 18:2
18:2 2 ) 18:1
k
18:1 1 ) 18:0
SLN = k3/k2
SLO = k2/kl
SLN is termed the linolenate selectivityj a high value is
characterized by relatively high yields of dienoic acid in the reduction
of an unsaturated triglyceride containing trienoic acids. SLo is the
linoleate selectivity; a high value is characterized by relatively high
yields of monoenoic acid in a reduction of an unsaturated triglyceride
containing dienoic acids. An oil such as soybean oil contains both
trienoic and dienoic acids, thus SLN and SLo may be measured simultaneously.
In the context of linolenate and linoleate selectivity, in a
continuous method of hydrogenation as describedhereinwhere fatty material
is passed upflow over a fixed catalyst bed, SLN usually is greater than
about 2, and SLo usually is greater than 10, and generally will be greater
than about 15.
The examples herein are cited for illustrative purposes only
and are not to be construed as limiting this invention in any way.
EXAMPLES 1 - 4
All hydrogenations were conducted in a reactor of conventional
design containing a fixed bed of about 50 ml catalyst. The reactor had
a preheater section for bringing feedstock to temperature and a heater
-12-
~Z09~60
for the reaction zone. The feedstock, which was soybean oil in these
samples, was passed by a metering pump either upflow or downflow and
mixed with hydrogen before the preheater stage. In all cases there
was a net excess of hydrogen, that is, hydrogen in excess of that
necessary for reaction was introduced into the reaction zone and excess
hydrogen was vented so as to maintain a constant pressure.
Iodine values were determined by AOCS method CDl-25 or were
calculated from the measured fatty acid distribution. Solid fat index
was determined by AOCS method CD10-57. Fatty acid distribution was
determined by AOCS method CE2-66. Macropore volume was determined by
the mercury intrusion method as described in ANSI/ASTM D 2873-10 using
the porosimeter of U.S. Patent 3,158,02n.
The catalyst used in all runs consisted of 5% nickel on alpha-
alumina, of surface area 3 m2/g in the form of 1/16" spheres. It was
prepared by mixing the alumina with an aqueous solution of nickel nitrate
hexahydrate, evaporating the water while mixing, calcining the resulting
solid at 450C in air for 3-4 hours, then reducing the material in hydro-
gen for 2-4 hours at the same temperature. The alpha-alumina had the
following macropore volume characteristics (in ml/g): 117-500 Angstroms,
0.0000; 500-1000 Angstroms, 0.0003; 1000-3500 Angstroms, 0.0000; 3500-
17,500 Angstroms, 0.2037; 17,500-58,333 Angstroms, 0.0000. The micro-
pore volume was less than about 0.03 ml/g.
Results of some typical hydrogenations are given in Table 1.
Each period of an example corresponds to a four hour time interval.
The SFI of some representative samples from upflow hydrogenation are
given in Table 2. Values of SLN, SLo were calculated using a computer
program furnished by the U.S. Department of Agriculture, Northern Regional
Laboratories, as described in J. Amer. Oil Chemists Soc., 56, 664 (1979).
~2091G0
O 0 O In ED l N l I CD N el O
V~ _I N N N N _I _I N N N N I') N _~ _I N
., .
C 1 N I N IS
It N N ED 0 In OD CO _~ It O O
O N _I _I N N N I N _I _ O N _I O
o
C O _I N l n l N N Us D In cr do
O O O O O O O O O O O O O O O O O
O 0 0 it 0 N Us
0~ 0 l CO ED us on a 0 a 0 0 0
Us it _i ID O O In O l ED l I.D ~7 Ox 00 Of ED N Ox Ox
7 N N N 1
O N O _ N et U-) N C~J et ED O
tlO l l en 0 O 0- O N O ' N CO CO
O L
ON O O O O O O O O O O O O O O O O O O O O O
O ; N N N
l N^
l _ Nn _ UN~ Us Ln U>
o o u ox o m cD co cL O ED O co N ln ox O do
E _ _I N N N ~7 I) el
X N j o o N Us N N N
--1 4--
~209~60
Ox el Ln O 0 N l 0 0 Us 10 O Ir) N 0 d' OD l ED
Irk O Ox _10 01~ Ox D O N 0 In O it Ox 0) ED l
I N _~ N N 1 0 _I N I N N N N
Z N O _ Ox '> l _4 _I Irk l _I et-- l 0 0 N 0 l
V) 0 0 N 0 O N N N Us 0 0 Us N 0 0 _~ O t~J O _ N _I N _ _i N
U:> O O 0 0 0 Us It OD N lo O N 0 Of
0 to 0 In 0 0 I N l Us N 0 0 _~ 0 Ox _'
g
Lo ') l N O 0 _10 N O l I.r> N O Ox l.n N 0 _~
..~ D 0 0 0 o 0 0 on
O U'~ U') elm N O N N N N _ N elm l Irk elm Us
00000000000000 00000000000000
-- O O 0 O N O 0 0 O O 0 U'~ O
0 Us Ox N it j elm o o. 0 u o ox ED u- o l ei us ox j ox on j ED
O 0 0 N _~1~1~ JO l en 0 U7 O O O N O Ox D f 0 Ox r_
0 D 0 1~1 it 10 U In ED U'> 0 0 _I _I 0 N
O N O N l D U l N D N l l N N O
0 _ ED rN--~ I D N
0 N O O O O O I) O O O
O
INO OOOOOOOOOOOOOO OOOOOOOOOOOOOO
Ox N~--Nl--N~ NN _~ N N --N~ N N N N N N
O
N? o~o~o -I ,,0,o,0"o""o"o"""0",0,~0~0~
CL O
O O O N 0 0 ON ED N OD ox 0 0 .D N N No
LI _ _ N N 0 0 d' Us 1~1~ 0 Ox I N N N 0 d- 2 JO ED l 1
--1 5--
~Z09160
Table 2. Solid Fat Index of Upflow Hydrogenation Products
IV 109 75 69
SFI: 50F 4.5 52 52
70F 1.7 40 41
80F 0.6 33 36
92F 0 18 22
104F 0 2.7 6.9
As is clearly shown by comparison of SLN SLo measured in
the upflow and downflow modes, the selectivity of continuous hydrogen-
ation to various IV levels is enhanced when hydrogenation is performed
upflow.
EXAMPLE 5
The cobalt catalyst was prepared in the following general way.Material used as the support was mixed with an aqueous solution of
Co(N03)2 6H20 containing an amount of cobalt sufficient to provide the
desired catalyst loading. Water was removed by evaporation with mixing,
and the resulting solid was calcined in air at 450C for about 2 hours
followed by reduction in a stream of hydrogen at about 450C for about
2 hours.
-16-
~209~1;0
TABLE 1. PROPERTIES OF ALPHA-ALUMINA
alpha-Alumina
Apparent bulk 1.4
Dens;ty, g/ml
Surface area, 3
m2/9
Micropore D 0.03
volumea, ml/g
Macropore 0.2
volumeb, ml/g
a. Micropore volume is the total volume of pores under about 117
Angstroms in size.
b. Macropore volume is the total volume of pores greater than about
117 Angstroms in size, as determined by ANSI/ASTM D 2873-10.
EXAMPLE 6
Batch reactions were performed in a 350 cc stirred autoclave
using 55 ml soybean oil and 5 9 of a 5 Co catalyst. After being
purged with nitrogen, hydrogen was admitted and the temperature was
adjusted to the desired point. When the desired temperature was
attained, hydrogen pressure was adjusted and stirring was begun.
Aliquots were taken at intervals and filtered through Celite prior
to analysis. Representative results at 220C and 50-100 psig hydrogen
are presented in Table 2.
TABLE 2. BATCH REDUCTION OF SOYBEAN OIL
25 IV(Calcd) 119.6 107.4
16:0 10.6 11.0
18:0 4.7 5.0
18:1 34.6 45.3
18:2 46.5 37.0
18:3 3.6 1.7
-17-
~209160
EXAMPLES 7 and 8
Hydrogenations were conducted in a reactor of conventional
design containing a fixed bed of 15 to about 70 ml catalyst. The
reactor had a preheater section for bringing feedstock to temperature
and a heater for the reaction zone. The feedstock, which was soybean
oil in these samples, was passed upflow by a metering pump and mixed
with hydrogen before the preheater stage. In all cases there was a
net excess of hydrogen, that is, hydrogen in excess of that necessary
for reaction was ;ntroduced into the reaction zone and excess hydrogen
was vented so as to maintain a constant pressure.
Iodine values were determined by AOCS method CDl-25 or were
calculated from the measured fatty acid distribution. Solid fat index
was determined by AOCS method CD10-57. Fatty acid distribution was
determined by AOCS method CE2-66.
-18-
~20g~.60
,.
I, .
z on
Cal
_ ,~ o
., __
l us .D
_I oo
l I I`
I
o _ ,~
..
ClC~ Us
_
o
U ,~
.. . .
o oo Lt~
o
~o~
O
Coy
_
Ox _ l 0
ILL 00
Z~
I_I O
o E
ON
_ O
J
.~ 0 0
Us Ox
O
In O O
S O
O
-
E r_ oo
x
LLI
._
E
C
oo
I_
_1 9_
~209~60
TABLE 4. TRANS CONTENT OF PARTIALLY HARDENED SOYBEAN OIL
Catalyst IV % Trans
5% Co on 123.1 18.4
al pha-al umi na
-20 -
