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2,410,102
UNITED STATES2,410,102PATENT OFFICE
Patented Oct. 29, 1946
PROCESS FOR HYDROBLEACHING
GLYCERIDE OILS
William J. Paterson, Newton Highlands, Mass,
assignor to Lever Brothers Company, Cam
bridge, Mass., a corporation of Maine
No Drawing. Application March 31, 1941,
Serial No. 386,086
21 Claims.
(Cl. 260-409)
The present invention relates to the prepara
tion of improved products from glyceride oils
which are susceptible to an improvement in
stability against rancidity and color or odor, or
both.
2
matter are then removed from the oil by ?ltra
tion. It has been observed that bleaching agents
also absorb a substantial amount of oil, and that
factor, in addition to the relatively high cost of,
satisfactory bleaching agents, and the difficulty
and expense of ?ltration, adds greatly to the
expense involved in manufacturing glyceride oil
More particularly, the invention relates
to a novel treatment of glyceride oils with hy
drogen in the presence of a catalyst to provide
products.
an improved product with respect to color, odor,
When a hardened product for use in shorten
ing, for example, is desired, the re?ned and de
The crude oils which are made available to 10 colorized oil is hydrogenated by means of hydro
the manufacturer of glyceride oil products and
gen gas in the presence of a metallic catalyst
which have been prepared in accordance with
such as nickel and generally at elevated tem
the usual practice are generally dark in color and
peratures. Incidental to the hardening of the
contain a substantial amount of undesirable im
oil, a further improvement in color generally
plasticity and stability.
purities, such as free fatty acids, gums, mucilagi
15
nous material, and the like. Moreover, these
oils are normally odoriferous and otherwise ob
jectionable, particularly when the object is to
use them as edible substances for example, for
_ culinary purposes.
Heretoiore, the crude oil generally has been
takes place.
The re?ned and bleached oil, either hy
drogenated or unhardened, may then be de
odorized by subjecting the oil to a treatment with
20 steam under reduced pressure conditions.
It is an object of the present invention to avoid
subjected to a series of re?ning, decolorizing,
the multiplicity of processing steps heretofore
regarded as essential in the manufacture of good
hydrogenating and deodorizing operations to re
grade products from glyceride oils. In particu
move objectionable constituents from the oil and
lar, it is possible by the practice of this invention
to improve its stability, color, odor and ?avor. 25 to dispense with the uneconomical steps of re
The particular procedure followed and the
re?ning With alkali anddecolorizing by the use
severity of the treatment depends to a large ex
of bleaching earths and the like as discussed
tent upon the'type and initial purity of the crude
above. The novel treatment of glyceride oils with
oil as well'as the desired characteristics of the
hydrogen
in accordance with the present inven
30
?nal product.
tion may be substituted in whole or in part for
In general, the initial refining of the oil is
re-re?ning, bleaching, and hydrogenation in ac
accomplished by subjecting the oil to a treat
cordance .with the prior art methods, and when
ment with caustic alkali, which neutralizes and
used in conjunction with ordinary re?ning and
precipitates the free fatty acids as soaps. At
subsequent deodorization, for example, with
35
the same time, a substantial proportion of the
steam, provides glyceride oils products of unex
gums, mucilaginous materials-and coloring mat—
celled color, odor, plasticity and stability, as
ter is coagulated and removed along with the
discussed more fully hereinafter.
,
fatty acid soaps.
A particular object of the present invention is
To provide an oil of particularly good quality,
to provide a method whereby unbleached oils may
be bleached and hardened simultaneously, if de
sired, to at least the degree required in the pro
duction of good grade glyceride oil products.
it is not uncommon to subject the oil to a re
re?ning operation in which the re?ned oil is
again subjected to the action of caustic alkali,
generally in a more dilute solution. A further
The treatment of a prime cottonseed oil for the
removal of “foots,” although smaller in amount,
manufacture
of edible oil products by the meth
45
is thus effected which is highly beneficial in ime
ods described above may be taken as typical and.
proving the quality of the ?nished product with
involves the problem of color removal. A repre
respect to color and freefatty'acid content. An
sentative
crude cottonseed oil ranges from dark
inherent disadvantage of the re-re?ning opera
reddish-brown to almost black in color when ex
tion is a substantial further loss of neutral oil
pressed from the seed. Upon being re?ned with
by saponi?cation and entrainment, and there 50 alkali, ,a representative oil exhibits a color of
fore the use of the re-re?ning operation is un
approximately 5.0 red/35.0 yellow. All, color val
desirable from an economical standpoint.
ues referred to herein are in Lovibond units and
Further, in accordance with the art of pre
have been ‘measured with a Lovibond tintometer
paring glyceride'oil products, the re?ned oil is
generally improved in color by a subsequent 55 provided with a 51/4 inch column. A subsequent
bleach in accordance with the standard procedure
bleaching treatment With a usual bleaching
approved by the American Oil Chemists Society
agent of the carbon or earth type. The bleach
using
6% of the official fuller’s earth and employ
ing agents,‘ it is vbelieved, effect a decolorizing
ing a temperature of 105—120° 'C. improves the
action by absorbing coloring matter from thezoil.
Thebleaching agents and the absorbed coloring
60
color to approximately 2.0 red/20.0 yellow. Upon
2,410,102
3
hydrogenation to shortening consistency, such an
oil usually exhibits a- color of 1.0 red/10.0 yellowf
’
favorably affect the odor and ?avo r of the’food
products made therewith;
The readily available supply of soybean oil
A cottonseed oil which has .been re-re?ned with,
alkali in addition to being subjected to the treat~
merit outlined above, may sometimes, when choice,
oils are used, exhibit after bleaching a color of
1.5 red/15.0 yellow and after hydrogenation a
color of 0.7 red/7 .0 yellow. With respect to. edible.
cottonseed oil, a color reduction below approxi~l
v. makes its utilization attractive to the manufac
turer, Nevertheless, the use of soybean oil has
been, greatly limited, particularly in high grade
edible products, inasmuch as it has been impos
sible to'avoi'd’. the undesirable characteristics of
soybean oil, particularly with respect to deep
frying, unless the oil is hydrogenated to the rela
tively high- titre of 51° 0.. which corresponds to
mately 0.5 red previously has not been believed
to be economically or practically’ possible by; the“
prior methods of the industry even when the
highest grade raw oil is treated.
>
an iodine value of about 50, and consequently
'
I hardened to such an extent that it can be used
Hydrogenated cottonseed oil is utilized princi
only in restricted amounts. In general, an iodine
value in the range of, 70 to 80 and a penetration
pally as. the major ingredient of shortening prod
ucts'. In this connection, it is to be observed that
most commercial shortenings average about 2.0
of 220' to, 25.0 is desired in'a hardened soybean
oil‘ when, the object isto'utilize the'oil in shorten‘
red/29.0 yellow and seldom. are below 1.5 red/15.0
yellow,
I
~
_
It is, known in the art that special methods,’
such as distillation and- heat treatment at high
temperature, will effect a high degree of color
reduction in oils, but these methods, as a rule,v
are-‘too severe as well asicomplex and expensive
for: general use, especially in. thev preparation Qf
edible
oilproducts.
.
.
>
Therefore, it is an, object of the present; inven
tion to provide a method for decolqrlzins glycer
his oils. to asreater deereethanfhas. been possible
heretofore without adversely affectingthe desire...
ble characteristics of theoil. with respect to its
use, for example, for edible. purpose .
'
i
ing. Even with the use of‘ the most effective
hydrogenation methods of] the prior art, a satis
i
.
20
factory shortening capable of'meeting' the high
present-day commercial standards cannot be pre
pared having more- than about 10 to 15% of hy
drogenated'soybean oil.
a
A particular object of this. invention is to pro
‘ vide a method of decolorizing glyceride oils such
. as‘ soybean oil which imparts stability against
reversion and‘ good" deep-fry characteristics to
the
oils.
-
'
_
*
Another object of‘ this invention'isvto provide
a methcdof forming asoybean' oil product; stable _‘
against reversion under‘ .. deep-frying; conditions
and which is sufficiently plastic’ to be used in'
i
unlimited proportionsin shortenings.
A particular object of. this invention isto pro
vide a method for decolorizing cottonseed oil to.
7
It is well known in the chemistry of- oils and
form anedible product which is. characterized 35 fats that the glycerol esters of fatty acids, which ;
are the principalv constituents of‘ glyceride~oils
by an improved water-white appearance;
and fats tend‘ to become rancid due to the formaa
Another object of the invention istoeffect an
tion of various aldehydes' and‘ lower fatty acids
improved decolorization of glyceride. oils in a.
with possibly ketones which are all very un
manner which permits thecontrol of‘ thehardena
ing of the oil whereby an edible oil product of 40 pleasantly odoriferous- substances. Before these
substances are'formed; however, the fat must go
improved color and. odor may- beproduced in‘ a
through a preliminary stage'of oxidation v(usu
liquid stateor having any desired plasticity char-»
acteristics.
.
’
~
7
1
"
ally atmospheric) withthe formation of. organic
11
' The- problem of odor reversion in edible oils 45' peroxide; further oxidation resultinggin the rup
ture, of the fatty acid chains with’ theformation
may be. easily appreciated» by a reference, for
example, to soybean oil. The characteristics of
soybean-oil in this connection are discussed in»
some detail in. the Epstein, et a1.‘ Patent-No.
2,140,794,.issued December 20,1938.
'
'
a
prior methods and even- after the usual’ hydro;
genaticn to a lard-like consistency; undergoes a
saturating the unsaturated fatty acid-components
type‘ of spoilagewhich is characterized as “rever
sion'," particularly-when exposed to light and air
and temperature >conditions,'~ such as’ 385"‘ R,
usually encountered when ‘the shortening- is; used
forideep; frying. The reversion of soybean oil isv
characterized» by the development of various oiT i
?avors and lodorsknownlas a “bean'yif ?avor" or‘
subsequently often becomealtered with the pro
duction of othenundesi-rable ?avors and odors,» .
-
'
-
present in; the oils with hydrogen’. The stability
of the oil, in general-{increases proportionately‘
with ‘the decrease'in- iodine'value of-the oil. It
is understood,‘ howeverithatv complete saturation
7 characterized by‘the formation of a hard, brittle
solid-is undesirable; for example, when the object
isto-use the—oi-l'for- ed-ible purposes»; In general,
it is customary to 'hydrogenate the glyceride oil
‘ odor and sometimes described‘ as “?shy,” which‘
,
the oil unsuitable‘ for Tmostfus'es, particularly
Wherethe object is to'use the oil for edible’ pur
poses.‘ The tendency of the oil to turn rancid as j
the result of’ oxidation -may' be minimized [by
It is well'lknown' that ‘soybean- oilire?ned~~by~
classified" as “oleo”~ and “grassy.”
of low moleculareweight products responsible for
the “off'flavors” and rancidity. The process of
oxidation and development of rancidity renders
to, a degree- which gives a product of lard-like
consistency at room temperatures} Inasmuch as‘
'
‘the usual types of glyceridefoils are not;v com
One of~the~mainobjections to the use, for'ex
arnple; ‘of hydrogenated soybean oil in shorten
pletely saturated at 'thi's‘consistency,’ theoil ‘will .
ings isthe reversion 'to- a’ characteristic but un- ‘
desirable odor of the oil at the» elevated tempera
be ‘susceptible. to undesirable oxidation and the
development of rancidity‘.~
.
a
_
W
.
It is anobject of~the~present-‘invention to pro,
turesemployedfordeep frying‘, *In' the commer
vid'eja method-of hardening- glycerideloils and
cialv practice of; deep' frying, the fat may be 70 fats
whereby the oilsexhi'bitav greater stability
maintained atatemperature of about-385° F. ‘for
against ‘oxidation. and the development of’ ran
several days, any loss from; the fat‘ body; being i .cidity'_>as-.compared1 with oils hardened", to- the
replaced byadditions of furthereshortening. ' The .
same iodine value-or consistency in accordance.
objectionable odors andh?avors which develop are
’ not-‘only undesirable during frying but also un
75
with, theprior art ‘practice; "
‘The “present process which,v for convenience, ' i.
2,410, 102,‘;
6
5
tungsten-oxide, copper-uranium-oxide and cop
is ‘designated as “hydr'obleaching” is not‘ to .be'
confused with the hydrogenation of oils directed
primarily to the saturation of- the unsaturated
per-vanadium-oxide. '
is not regarded as critical and may be varied over
oleaginous components in the oiled-The inven
tion is directed to the improved decolorization
a wide. range depending upon the particular
metals selected and the conditions of operationv
under. which the same is to be used. In‘ general,
and stabilization of glyceride oils to effect an
improved appearance and novel characteristics
with respect to ?avor, color, and in the case of;
oils such as for example, soybean oil, freedpmi
a substantially atomic ratio of X and Y is pre
ferred'for effecting desirable resultsin accordance
from reversion, particularly under deep-frying 10,
conditions.
with theinvention.
‘
,
In general, it is preferred to stabilize thecat
alyst. by the presence of an alkaline earth metal
Hardening of the oil so treated may
or may not result, dependent upon thevcharac
teristics- desired'in the ?nal product. 'The degree
of hardening of the oil effected by the‘ practice‘v
of the invention may be controlled i'within wide
limits’ by a careful selection vof the particular
catalyst used and: by regulating the-conditions of’
>
The proportion of metals indicated by X and Y
oxide, such as barium oxide or calcium oxide, although this is not essential. Substantially an
. atomic ratio of X and Y and m of a mole of al
kaline earth metal has generally been found to
'be preferable, but the proportions may be varied
as desired and depending upon the particular.
metals selected as well as upon the conditions un
operation, as set forth more fully hereinafter.v
Vegetable oil products of reduced iodine value
which the same is to be used.
resulting from the present process may be vreadily 20v der‘The
exact form of the metals or the oxygen in
used in the production of all-purpose shorteningsi
the catalyst is di?icult to determine, and it is not
and, are found to have thehdesirable plasticity
intended that the invention shall be limited to
over a relatively wide range of temperatures,‘ as
any particular chemical or physical combination.
well as color, odor and stability. Notwithstand- ‘
It is-possible that the catalyst maybe a simple
25
ing the preferred use in the process of elevated
mixtureof the separate oxides of the two metals
temperatures and of relatively high pressures as
present in the catalyst, but it is equally ‘possible
compared with the pressures normally used in
hydrogenating vegetable oil in thepresence of a
nickel catalyst, it has been fOllnd that thereis
littletendency to form the hard, brittle products
resulting when similar vconditions are used ‘with
nickel
catalyst.
,
‘
'
that the two metalsand the oxygen may be com
bined .to form a distinct and separate chemical
, compound. It is intended-that the scope of the
invention shall includethe use oftwo or more
.
The catalysts which may be employed satisfac
torily in accordance with this invention‘ comprise
oxides which, for convenience, may be described
as the type X—Y-—O in which X is at least one
metal selected from the minor sub-groups of
metals of the type describedin combination with
oxygen, regardless of the exact chemical’ or phys
ical structure of the composition. It is possible
that even asto those oxide catalysts which, at the
present time,,do not appear to have a preferred
activity, a _ modi?cation may be made in theirv
physical form or structure which'may make their
groups I and II, and Y is at least one metal se-'
use desirable.
_
p
:
' ..
lected from the minor sub-groups of groups V 40
The methods utilized in preparing the oxide
and VI, of the periodic classi?cation. O, of
catalysts described above will have, in-general, an
course, represents oxygen; that is, the metals are
appreciable effect upon their relative effectiveness
in the form of oxides. The minor sub-groups of
and properties. A number ofvariedmethods may
groups I, II, V and VI of the periodic classifica
be employedyit is possible, for example, to pre
tion comprise divisions of the main, groups as " pare-a catalystrhaving the desired composition by
shown, for example, in the periodic chart appear
simply grinding together a mixture of the, selected
ing ‘at page 46 of volume I of “International.
oxides and subsequently heating the, mixtureto
Critical Tables.” The minor sub-group of group
an elevated temperature. It is preferred, how
I comprises copper, silver and gold. The minor
ever, to utilize one of the following methods.
sub-group of group II comprises zinc, cadmium 50
and mercury. The minor sub-group of group V
300 ml. of a solution (80°) containing 8'7 g. of
comprises vanadium, .colu'mbium, tantalum and
hydrated .copper nitrate (Cu(NO3)2.3I-I2O) and’
protoactinium. The minor sub-group of group
6.6g. of calcium nitrate (Ca(NO3‘)2) are added to
VI comprises chromium, molybdenum, tungsten
240 ml. of a solution (25-30°) containing 50.4 g. of
and uranium.
'
ammonium dichrornate and 150 ml. of 28% am;
It will be apparent that a great number of
monium hydroxide... vThe precipitate 'is'?lte'red,
combinations or mixtures of combinations ofthe
_
above designated metals are possible in accord
ance with this invention. It is to be expected that
the activities of the several species of catalysts 60
will vary over a-‘wide range and, in general, it is
preferred to utilize those metals from the groups
designated above which, in general, exhibit the
greatest activity under the preferred conditions
v
Methods
’
"
_
dried-at 75-802 pulverized, and decomposed at
elevated-temperatures.
'
j
‘
.-
»
'
MethodBfa
_
r
..
'
'.
'
.
.
-
.
'10: grams (‘T10- lm.) chromium‘ trioxide (CrOs);
24.2 I g. v(1-1.; m.)
of hydrated copper nitrate
(CufNOz) 23H2O) and.2.6 grams (71/100 m.) barium
of effecting the hydrobleaching of the oils. It is 65 nitrate j(Ba(NOs)‘z) are dissolved in 130 cc. water
and 20 cc. (#7, m.) 28% aqueous ammonia is added
to be understood, however, that the scope of this
with
constant stirring.‘ The precipitate is ?ltered,
invention is not to be limited to the use of the
particular metals so selected.
. -
dried at 100° C. and decomposed at 350° C.
In general, copper and silver comprise the pre~
,MethodC'
,
‘
ferred metals of the group designated by X while 70 v 40 grams (% m.) chromium nitrate
chromium, tungsten, vanadium and uranium are
preferably selected from the group designated
by Y;» [Typical combinations of the’, selected
metals, by way of example comprise copper-chro~
mium - oxide, silver-chromium -, oxide,_,copp_er~_
I
(Cr(NO3)39H20)'
24.2 grams-(T16 m_.)'copper nitrate; }'
'
'
,
(Cu(NO3)2.3I-I2O)..
I’
v
V
' '
,
and 2,6. grams (not m». barium nae (Barron;
2,410,102.
7
8.
are dissolved in 300 cc. water at about 80.°1C..and
above, this invention further provides an opera;
30 grams (slightly more than 1/4 m.) of am
monium carbonate (NH‘elzCOaHzfO): in 15.0 .00.
tion during the hydrobleaeh-ing process? to; effec
tively retard the‘ formation. of’ unsaponi?able
matter. By this process, a. decolorized and hard’
ened product suitable after ‘?ltering, deodoriz
water added slowly with-‘agitation- The. p-recipie‘
tate is. washed, dried, powdered: and decomposed.
at 350° C.
.
‘
_
'
ing, texturizing and like ?nishing operations for
~
The following table illustrates the varying. re
sults which may be obtained: in. treating aprime.
re?ned cottonseed oil with catalysts. prepared in;
accordance with the above methods. andi'under 10
reversion. These products have unsaponi?ablev
similar conditions, i. e., with. 0.2% catalyst/for ’
thirty minutes at 200“ C; and. over 2000 lbs.. per"
with that. ordinarily present in good grade com;
sq. in. pressure.
‘
use. as a shortening is obtainable. 'In addition,
even» with oils such as, for example, soybean oil, ‘
a product is obtained which-is stable against
components, but only inamounts comparable
mercial shortenings. In fact, With this process,
.
uni-form products mayxbemade with lesswthan;
15
Methodtfr prepara' ‘
on
Catalyst
{72311122
~
.
I
1°We‘ed
‘ Red
. Yellow‘
1.0%. unsaponi?able ‘components.
. I
V
I
1
~ In general, the, desired! hydrobleaching o
v
.
' glyceride oils may be accomplishedin accordance,
with this invention by disposing‘ an’ oil, prefer
Method A, ________ __ - Cu-Cr-CIi-O__.___ _.___d0-_ _______ __,
Method’ B _________ __ Cu-Or-Ba-O ._ _ _
Method 0 ______________ __d0_________.
‘IO-16' - O. 1
2
4.
v’
,1. O
;
7.0.
3.0
0:2 ~
2.0
O. 7
0.3
21
It'will ‘be observed that the‘activity of the cat-1v
alyst prepared in accordance‘ with the above
methods vary relatively both with respectto their
color-removing properties and their ability to
hydrogenate or- lower the iodine value of the oil.
20
ably already alkali. re?ned, in a suitable closed
vessel, and preferably under elevated. tempera
tures and pressures. ‘ The .oil is maintained in
contact with: a. relatively small- amount of the pre
ferred oxide catalyst of the type described above.’
Preferably relatively high pressures are utilized,
the hydrogen, being charged at pressures prefer.
ably in the neighborhood of 100 atmospheres. or
vmore.
The oil is maintained in a heated condi
The results e?ected by Method A, however, are
tion. and for a suf?cient period of time, generally
not uniform and are dif?cult to reproduce.
not less than 10 minutes, for the'desired hydro
It
will be apparent that themethod of preparing the 30 ' bleaching to‘go to; completion. After hydro-x
bleaching isco-mpleted, the oil‘ may be treated in
catalyst may be selected on the basis of ‘whether
the conventional manner, such as ?ltering,
decolorizing'with or without substantial harden;
deodorizing, chilling, . aerating, texturizing or
ing is desired.
_
‘
otherwise ?nishing. It is‘desirable, of course, to
In general, special treatment of the oxide cat
alyst prepared in‘ accordance with this invention, 35 minimize its contact withair at least until cooled.
The preferred temperatures which may. be used.
in carrying out the inventionwill generally range
upon the activity of. the catalysts. 1
I
from 130° C.‘ to 250° C. Below 130° ‘C; the ratefoff
It is difficult to determine why catalysts of sub
reaction is‘ reducedlso that the eifective decol
stantially the same chemical composition will
orization and stabilization in general appears to .
vary in their relative merits depending upon the 40 fall below the. standards required, for example, in
the production of edible voil products. ‘At tem
method utilized in preparing the‘ same. It'is-be
peratures above 200° C- there is‘ a tendency to
lieved that the variance may be due to the dif-,
ward‘ the formation of unsaponi?able matter such
ference in physical properties, possibly as-the re
sult of the difference in decomposition conditions:
as ketones; alcohols, hydrocarbons,‘ and the'higher
such as reduction with hydrogen or leaching‘ with
acid, will have no appreciable bene?cial effects
In general, a precipitate decomposition which
takes place spontaneouslyv at low’ temperaturesis
acids, which are usually considered undesirable in
high grade products as discussed above, although
more difhcult to control and there-forethe results‘
obtained thereby are more dif?cult to reproduce.
in certain cases this may not be critical. In"gen-'
eral, it is desired not to- exceed a temperature of
Catalysts prepared by spontaneous decomposie 5“ 250° C. at which point decompositionofglyceride
tion, moreover, tend to exhibit less activity» for
hardening purposes.
.
,
oilsbegins to take'place.
.
Olxide catalysts, of the kind disclosed; above,
"
.
.
'
‘
The amount of- catalyst‘ which is used is pref
erably approximately 02% based on vthe weight‘
have been used heretofore in the hydrogenation
of the oil, although'this may‘ be varied ‘Within
of various organic compounds to. ‘produce al 5;, reasonable limits. It has been found that‘ when
cohols, hydrocarbons, and; similar unsaponi?able
matter. In particular, in accordance with. the
prior art, the hydrogenation of-glyceride oils us
the amount of catalyst; exceedssubstantially 0.5 %,
there is formed an increasing amount of un'-" .
saponi?able material. In general, the catalyst‘.
_
ing a mixed oxide catalyst would result in they
should Ice-present in‘ an amount of at least"0:1%»
formation of unsaponi?able matter comprising 60 inasmuch as when smaller amounts are used the '
time required‘to leife ct desirable results isvgreatly _
higher ketones, such as. palmitone-and stearone; ‘
alcohols, such. as .dis'teanyl carbinol;- hydrocar-i
bons, such as pentatriacontane; aswell as corre
sponding fatty. acids, which are very objection-v
able inasmuch. as. they cannot. be removed by.
ordinary .deodorization. processes. Unsaponi?a
increased.
'
To effect decolor-ization ‘and stabilization to the . I
greatest extent, it‘ is preferred to5carry out-the .
65 process ‘under relatively high pressures such‘ as‘ ' ‘
in- the neighborhood 'ofat; least. 1500- lbs-‘per
ble matter is, objectionable,v for example, in..ed_-' ' square inch, but this ,isznot- regarded asessential
ible food products, because it is not fat. Inac- .
for desirable results; Forexamplej'pressures as
cordance with accepted‘ standards, a good grade ' . low as’ atmospheric» may be used if ‘desired. In
shortening will havexlessthansoneper- cent of un 70 general; a more- effective‘ decolorizationk and sta
saponi?able matter.
"
v
'
'
Accordingly, in addition. to providing for the
hydrobleaching of glyceride .oils. to eifect an im- .
bilization ‘is accomplished at, higherjpressures;
' It is generally- desirable , to avoidj'unduly; lproé,
longing’ the operation- 'tog'avoid the formation or
undesirable‘ ‘by-products] particularly runsaponie .
provement in color or ‘stability 'or both, having
the advantages! and rami?cations discussed 75 ?able material; However, if- a"-subs'tantially
2,410,102
‘ 9
,
water-white oil is desired-the time of hydro
bleachingshould tend toward a maximum pref
erably with an increase in pressure conditions
and amount of catalyst employed. In general, it
is not desirable to exceed a hydrobleaching period
in the neighborhood of 60 minutes.
The process has been disclosed in the speci?c
Color of oil
Treatment
Sample 1 Sample 2 Sample 3
R
Y
R
Y
35
4.7
35
6.6
16
2.0
20
2.8
.9
9
1.5
15
2.2
.1
l
.1
l
.5
examples as a batch operation, as by so doing
Alkali re?ned ______________________ _. 4.8
simple and easily understood standard pressure
equipment may be used. However, it will be ap 10
Bleached with 6% earth for 5 min-
continuously or semi-continuously with or over a
Y
60
-
utes at 110° C ___________________ i. l. 6
28
Hydrogenated to 70 I. V. at 150° C.
Wlth .l% nickel __________________ __
parent that the process may be carried out in a
Hydrogenated at 200° C. and 2,000
lbs. sq.‘ in. Hz pressure for 30 min
continuous manner. For example, the oil may
utes with .2% copper-chromiumbe heated and subjected to hydrogen pressure for
oxide ____________________________ __
Iodine values lowered (during hy
a desired period of time in an elongated restricted
passageway through which the oil may be passed 15 droblcaching) ___________________ __
catalyst. The oil may then be continuously ?l
R
'
25
1
10
16
5
8
It is apparent that the color obtained by treat
ment with a small amount of oxide catalyst, for
example, a Cu-Cr-Ba-O catalyst, in accordance
To illustrate the eifective stabilization against 20 with this invention, represents a decided im
provement over that which can be obtained by
reversion accomplished by the process, reference
fuller’s earth bleaching or hydrogenation with
may be had to the following speci?c example of
tered if desired and treated in any of the con
ventional ways.
an operation applied to dry, re?ned, unbleached
soybean oil.
nickel or both.
To illustrate the improved stability against
A high pressure bomb was charged with 270 25 rancidity obtained by hydrobleaching with an
oxide catalyst, as compared with hydrogenating
grams of dry re?ned (unbleached) soybean oil
in accordance with the prior art utilizing a nickel
and .27 gram (.1%) of the Cu-Cr-Ca-O catalyst.
catalyst, reference may be. had to the following
Air was displaced from the bomb with hydrogen,
tableof results obtained by hardening identical
and hydrogen introduced at a pressure of 1900
samples of the same cottonseed oil to the same
lbs. per square inch. The bomb was agitated and
degree of saturation in accordance with the two
heated to 225° C., at which temperature it was
methods being compared. Hydrobleaching was
maintained for one hour. The bomb was then
carried out in accordance with the invention un
cooled, the oil removed and ?ltered to free it of
der a pressure of about 2500 lbs.‘ per sq. in.
metallic oxide. The oil was still liquid at ordi
nary temperature, being only about 10 iodine 35 and a temperature of 200° C. utilizing a copper
chromium-oxide catalyst. Hydrogenation was
values more saturated than the original oil. The
effected at the same temperature, i. e., 200° C.
color, however, was very close to water-white,
and under atmospheric pressure using a selective
being less than .1 red/1.0 yellow Lovibond in
nickel catalyst prepared in accordance with the
color in a 5% inch column. The oil was then
hydrogenated to 70 iodine value with .10% nickel 40 method disclosed in the patent to Paterson No.
2,123,342, issued July 12, 1938. The quality tests
catalyst at almost atmospheric pressure and 150°
were carried out under carefully standardized
C., ?ltered, treated with a small amount of ful
conditions. The measurements comprised main
ler’s earth, and deodorized.
taining the samples of oil at a temperature of
The oil was tested and compared with a sample
130° C. (:01" C.) and bubbling clean air through
of the same oil which had not received any special 45 the oil at a rate of 10 liters per hour, for a
treatment except that it had been hydrogenated
period of 4 hours, and thereafter determining
to the same consistency as the sample treated at
the amount of peroxide by well known methods
high pressure with the oxide catalyst and de
of analysis. The quality of the sample or its
odorized. The comparative test consisted in
potential stability against oxidation rancidity is
maintaining 50-gram samples of each of the fats 50 expressed in terms of mini-equivalents of oxy
at 160° C. and noting any changes. The samples >
were in 50 mm. x 70 mm. crystallizing dishes
placed on the surface of a thermostatically-con
trolled hot plate. A thin layer of Wood’s metal
gen per kilogram of oil formed under these con
ditions. As has been explained heretofore,
among the ?rst products formed in the oxygen
process are peroxides, and a determination of
was used to make a good thermal contact between 55 the peroxide contents of an oil or fat has been
the hot plate and dishes. The odor and color
accepted by the art as a particularly suitable
of the samples were noted and compared at in
and standard means for calibrating or comparing
tervals over a period of two to three hours, the
the extent of oxidation or decomposition in an
test being intended to simulate the conditions
oil or fat.
of deep-fat frying in household and bakeshop 60
practice. The untreated sample rapidly acquired
the characteristic undesirable odor of hydro~
genated soybean oil and darkened rapidly in color,
t 1
Test No‘
t
0a a 375
Iodine
value
but the treated sample was so greatly improved
that only the faintest residual odor of been oil 65
.
representative prime cottonseed oils eifected by
treatment in accordance with the prior art and
compared with a treatment by hydrobleaching
using a Cu-Cr-Ba-O catalyst in accordance with
this invention.
"
.
Test
10. 0
.____d0 _________________ ...
67. 5
66- 1
63.3
8. 2
7. 1
5.0
Copper-chromium-oxide
70. 9
10. 1
9. 6
76
__..__(lO _________________ ..
67.5
7.1
6.7
____ __
63. 6
3. 7
3. 3
>180
The novel results obtained with respect to color
are further illustrated in the following table
oven
69. 8
‘
showing the improvement of color of selected
Quality
linolein
Days
became apparent and the reversion of color was
considerably retarded.
Percent
(2 double
bonds) Test
16. 7
39
12. 6 ____ _
10. 1 ____ __
5.2
111
It will be noted by comparing Test No. 2 utilizing
a nickel catalyst with Test No. 6 utilizing a
copper-chromium-oxide catalyst, that the oil
. 2,410,102
hydrogenated with oxide-catalyst at an elevated
pressure .to the same degree of saturation, i. e.,
67.5 iodine value,‘ reacts with oxygen at only
I although they Jmaiy' not achieve under 'the same
conditions the ‘most .e?ective ‘color "reduction ‘and
hardening accomplished with a Cu-'Cr4Ba-'O"ty.pe
:of loxide catalyst. It .has been observedth'at the
color, reduction effected by ‘the use of a catalyst
containing vanadium -.or ‘tungsten undensome f
conditions may not 'be stable, but this ‘may be
remedied by treating v‘the oil with ‘causticiimm'e
about half the rate of the oil hardened in ac
cordance with the prior art. This difference may
be explained in part by the more selective hard
ening accomplished with the oxide catalyst, but
it is found-that an oil hydrogenated :in the pres.
ence of nickel catalyst having thesame linolein
diately after hydrobleaching, whereupon the {oil
content (Test No. 3) has an iodine ‘value of 10 is 'found‘to besatisfactory in every respect. " t
66.1 and .a quality test of 10.1, which _is sub
It will be apparent that in accordance ‘with
stantially higher than that of the oil hardened.
with the oxide catalyst (Test No. 6).
‘this invention the process .of decolorizing :and
hardening vegetable ‘oils maybe accomplished
by the'use of various "techniques,._as desired. For
example, the oil ‘may be "simultaneously de
colorized and hardened ‘by the ‘useyof a preferred
oxide catalyst ‘under such conditions of opera
tion that sufficient hardening takes place during
e
The above quality tests were con?rmed by
subjecting Nos. 1, 4, 5, and '7 to a controlled oven
test in which 50 gram samples were incubated
at 63° C. (:0.5° C.) in ‘100 ccfbeakers ‘covered
with a watch glass. ‘The samples were smelled
daily until they became’ rancid and the quality
‘hydrobleaching. The oil may be decolcrized,‘ and ‘
of the samples is expressed as the number of
in'thecase of soybean oil, for-example,v stabilized
days during which they remained fresh. Samples
against reversion ‘in one operation and, ‘if 'de;
sired, may be hardened in a separate operation.
1 and 4 which were hydrogenated to 69.81. V.
and 63.3 I. V. respectively in the usual way with
nickel had an oven test of 39 'and 111 days, re
spectively while Samples 5 and '7 which ‘were
If the amount of hardening accomplished by the
use of an oxide catalyst is not sufficient for the
purposes for which the oil is to be used, it is
possible to harden the oil either prior or subse
hydrobleached to 70.9 I.'V. and 63.6 I. V. respec
tively had an oven test of '76 ‘days and more
than 180 days, respectively.
‘It is not intended ‘that the novel result ob
tained by this process is to be limited ‘to any 30
quently to hydrobl'ea'ching, by the ‘use of an'oxide
catalyst having more suitable‘ hardening charac
teristics, or under more effective hardening con
ditions.
theory of operation, but apparently the hydro
-bleaching process either destroys or converts ex
isting pro-oxygens in the oil or forms additional
anti-oxygens.
_
I
It is to be understood that the hydrobleaching
of oils in accordance with this invention may be
carried ‘out by using any of the variations set
.
forth above and all of these variations are in- ' '
In order that the variations ‘and scope ‘of the 35 tended to be included within the scope of the
‘ _ invention may be ‘more readily understood, ref
erence may be had to the following table of test
‘results showing the e?ect ‘of varying the type
and amount of catalyst, pressure, temperature
and time.
‘Test
N,0.
Amount
Catalyst
-
T
.
Catalyst
per cent ,
0.2
0.2
0.2
invention.
Cottonseed“ ,
_____do ____ __
'
- ’
lbs. sq. in.
'
‘I
ure
o O '
‘
2,000
Time
.
200
-
mm.
Hardening
’
1
‘
g
Fma] color
I. V.
uwered
30
~.
Yellow
Red
21
0.2
2,000
200
30
1
‘0.2’
2.0
'2, 000
200
30
None
1. 4
14. 0
2.0
.0. ,2
0.2 ___1_d0_-
2, 000
2, 000v
200
200
30
30
None
5
1. 5
0.4
15. 0
4.0
0. 2 Soybean- _._
0. 2 1___1do _____ _.
2, 000 ‘
2, 000
200
200
30
30
10
1. 5
0. 1
0. 2,
l. 0
2:0
0. 2
V
that the reduction in color and the hardening
which takes place increases with an increase in
40 the pressure under which the process is carried
e of_oi1 1 Pressure = Temperalkah
re?ned)
‘
In the examples given above, it Will be note
_ _ _ . .do ____ . .
2, 000
200 ‘
30 ,
1. 0
Cottonseed.-
2. 000
250
30
O. 2
0.5
_____do ____ ._
___._do ____ ._
tm. ‘
2,700
200
200
60
.60
None
35
None
0. 5
5.0
Water-white
1. 'l
0.1
11. 0
1.0
Referring to the above table of test results, it 55 out. The relationship ‘which exists between the
will be observed that the amount of decoloriza~
pressure utilized in carrying out the invention
tion and hardening which takes place depends
and the degree of hardening and clecolorization
to a large extent upon the type of catalyst em
e?ected will be more ‘readily understood from the
ployed. In general, suf?cient hardening, that is
‘following test results obtained by hydrobleach
to an iodine value of approximately 70 and 60 ing the same re?ned cottonseed oil having an
simultaneous decolorization to a substantially
iodine value of 106.4 and a, color of 70 yellow/7.5
water-white oil may be obtained by the use of
red for 30 minutes and at a temperature of 200° C.
1.0% of CIu-C'r-Ba-O catalyst, for example, un
der relatively _high pressures for approximately
thirty minutes. .(Test No. 9.) The use of the 65
process under these conditions, however, may not
be desirable because of the formation of un
using a copper-chromium-oxide catalyst under
varying conditions ‘of ~ pressure.
Maximum
Sample No.
saponi?able matter in the oil, particularly if it
lgsrfsszuulgie
'
>
.
135131:
inch
-
Color
Iodme
value ‘
‘imp
Y. R
is used for edible purposes. Therefore, it may be
desirable in some cases to use a smaller amount
of catalyst and a lower temperature, as shown
in Test No. l.
The results obtained by substituting silver for
copper, or by substituting vanadium, tungsten,
or uranium for the chromium are satisfactory,
1 Atmos. pressure,
105. 2
1. 3
125
104. 1
2. 3
175
' 103. 6
2. 8
14‘ 1. 9
7
.7
825
1, 550
2, 075
2, 775
101. 1
96. 3
93. 1
92. 1
5. 3
10. 1
13. 3
14. 3
4
2
2
2
.4
.2
.2
.2
9
.9
2,410,102
14
13
bean oil may be accomplished without an appre
ciable hardening of the oil or by a simultaneous
hardening to any desired plasticity. As a result,
the soybean oil product may be used in good
in the case of color improvement, although a
grade vegetable, shortenings in any desired
fair degree of bleaching is obtained at atmos
amount up to 100%.
pheric pressure, a very marked increase in de
The eifective improvement in color and stabil
colorization is obtained by increasing the pres
ity against rancidity accomplished in accordance
sure to about 500 lbs. per sq. in., and the max
with this invention has been demonstrated in the
imum bleach is obtained by increasing the pres
sure to about 1500 lbs. per sq. in. A further pres 10 case of cottonseed oil, for example, which now by
this invention may be prepared apparently water
sure increase has no appreciable e?ect on the de
It will be noted that the ‘extent of hardening
of the oil (iodine value drop) is almost directly
proportional to the pressure utilized. However,
white as compared to oils of a color of 1.0 or at
.
the best .5 red now available in the industry and
In order to obtain both maximum color re
with a stability substantially 100% greater than
moval and hardening, it is preferred to accom
plish hydrobleaching under a pressure of approx 15 an oil hardened to the same degree in accord
ance with the standard practice.
imately 100 atmospheres or greater, but it will
Although the invention has been described par
be observed that under lower and even atmos
ticularly with reference to cottonseed oil and
pheric pressures desirable results are obtained.
soybean oil, it is to be understood that this has
In order to illustrate the effect of varying the
gree of decolorization.
temperature under which the process is carried 20 been done merely for convenience and to assist
those skilled in the art to appreciate the novel
out, upon the degree of hardening and decolor
and desirable results which may be attained. It
ization obtained, reference may be had to the
will be apparent that the invention is applicable
following table of test results obtained by hydro
to all gylceride oils and fats or mixtures thereof
bleaching identical samples of a representative
cottonseed oil having an original iodine value of 25 of animal, vegetable or marine origin which are
susceptible to an improvement in color or sta—
106 and a color of 6.4 red/35 yellow: for 30 min
bility or both.
utes With .2% of a copper-chromium-oxide cat
Among the oils which have been treated suc
alyst under a pressure of 2250 pounds.
-
Temperature, deg. C.
@531:
100 ________________________________ __
125 . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ .
Iodine
Color
value
drop
R
Y
105. 6
0. 4
2. 7
35
_ . _ . __
103. 9
2.
1
1. 8
18
150 ________________________________ __
98. 5
7. 5
.4
4
175 ________________________________ _.
89‘ 5
16. 5
-2
2
200 ________________________________ __
75. 5
30. 5
.1
1
_ .
_ .
_ . _ _
cessfully with hydrogen in accordance with this
invention
are, for example, palm oil, sesame oil,
30
peanut oil, coconut oil and tallow. The follow
ing table illustrates the effective reduction in col
or obtained by treating the above named oils in
accordance with my invention with 0.2% copper
35 chromium-oxide catalyst for 30 minutes at 200°
C. and about 2500 lbs/sq. in. hydrogen pressure.
Alkali re?ned
color
The above chart indicates that satisfactory hy
drogenation and decolorization is obtained at 40
temperatures beginning in the range between
about 125° and 150° C. and the rate increases as
a function of increasing temperature. In gen
eral, the lowest temperature for obtaining sat
45
isfactory results is believed to be about 130° C.
The preferred temperature under which the
process is carried out to obtain maximum hard
ening and color reduction is approximately 200°
0., although other temperatures, for example, in
the range of 130-250° C. may be used eii’ectively.
At lower temperatures the reduction in color and
iodine value tends to be less, while at more ele
vated temperatures, the oil has a tendency to
decompose and there is formed an undesirable
amount of unsaponi?able material. In general,
however, an increase in temperature will cause a
proportionately greater color and iodine value re
duction. .
Hydrobleached
color
Oil
Y
Cottonseed. _
R
R
5. 3
l
. 1
Soybean.
70
9. 0
l
.1
Palm .
35
70.0
2
. 2
35
35
2. 8
2. 7
l
l
.1
. 1
l1
1. l
l
.1
35
4. 9
4
l. 0
__
Sesame
Peanut
Coconut _________ ._
allow _________________________ _ _
35
Y
It is to be understood that glyceride oils which
have been processed in accordance with this in
vention, in addition to having an improved color
and stability against reversion under deep-frying
conditions, have all of the qualities requisite for
conversion to, and use in, an all-purpose shorten
ing. The glyceride oils which have been hydro
bleached in accordance with the invention will be
?nished in the conventional manner, such as, for
example, by ?ltering, deodorizing, chilling, aerat
ing and texturizing when the same is to be used in
It has been found desirable to limit the time
of operation in some cases to approximately 60 edible products such as shortenings. A shorten
ing made from oils treated in accordance with
thirty minutes or less subsequent to the heating
this invention is plastic and workable over a rea
of the oil to a sufficient temperature for effective
sonable range of temperatures, and may be read
decolorization and stabilization. 'Although the
ily creamed and when used for baking purposes
reduction in color and iodine value will be a func
tion of the amount of time during which the oil 65 produces cakes of good volume and texture.
The variations to which this invention is sus
is maintained at elevated temperature, it will be
ceptible by one skilled in the art are intended to
found that the maintenance of the oil at ele
be included within the scope of the invention.
vated temperatures may act to cause the forma
I claim:
tion of relatively large amounts of ketones, al
1. A process for hydrobleaching glyceride oils
cohols and hydrocarbons.
to form edible products having a minimum of
By hydrobleaching soybean oil in accordance
unsaponi?able components and an improved
with this invention, it is possible to produce a
color and stability comprising treating the oil at
stable product of good color which will not suffer
a temperature of from 130 to 250° C. with hydro
a reversion in odor and ?avor. Moreover, this
improvement in the characteristics of the ‘soy 75 gen under a relatively high pressure in the neigh—
2,410,102
17
13. A method of decolorizing cotton seed oil
to produce a product having a Lovibond color of
.5 red 5 yellow, or lower which comprises treat
ing the oil at an elevated temperature with hy
drogen in the presence of a small amount of a
18
to form products having a minimum of unsaponi
?able components and an improved color and
stability comprising treating the oil at a tem
perature within the range of substantially 130°
to 250° C. with hydrogen in the presence of a
catalyst having the general formula X-—Y——O,
small amount of a catalyst comprising copper, ,
in which X represents at least one metal selected
chromium and oxygen.
15. A process for hydrobleaching glyceride oils
to form products having a minimum of unsaponi
?able components and an improved color and
stability comprising treating the oil at an ele
vated temperature with hydrogen in the pres
20. A method of hydrobleaching glyceride oils
to form products having a minimum of unsaponi
?able components and an improved color and
stability comprising treating the oil at an ele
vated temperature with hydrogen in the pres
18. A process for hydrobleaching glyceride oils
from the minor sub-groups of groups I and II,
to form products having a minimum of unsaponi
and Y represents at least one metal selected from
the minor sub-groups of groups V and VI, of the 10 ?able components and an improved color and
stability comprising treating the oil at a tem
periodic classi?cation.
perature within the range of substantially 130°
14. A process for hydrobleaching glyceride oils
to 250° C. with hydrogen in the presence of a
to form products having a minimum of unsaponi
small amount of a- catalyst comprising silver,
?able components and an improved color and
stability comprising treating the oil at an ele 15 chromium and oxygen.
19. A process for hydrobleaching glyceride oils
vated temperature with hydrogen in the pres
to form products having a minimum of unsaponi
ence of a small amount of a catalyst having the
?able components and an improved color and
general formula X—-Y—-Z—O in which X rep
stability comprising treating the oil at a tem
resents at least one metal selected from the minor
sub-groups of groups I and II, and Y represents 20 perature within the range of substantially 130°
to 250° C, with hydrogen in the presence of a
at least one metal selected from the minor sub
small amount of a catalyst comprising copper,
groups of groups V and VI, of the periodic classi
vanadium and oxygen.
?cation, and Z represents an alkali earth metal.
ence of a small amount of a catalyst having the
ence of a small amount of a catalyst having the
general formula X-—Y—-Z--O in which X repre 30 general formula X—Y-—O, in which X represents
at least one metal selected from the minor sub
sents at least one metal selected from the group
groups of groups I and II, and Y represents at
consisting of copper and silver, and Y represents
least one metal selected from the minor sub
at least one metal selected from the group con
groups of groups V and VI, of the periodic classi
sisting of chromium, vanadium, tungsten and
uranium, and Z represents an alkali earth metal. 35 ?cation, and subsequently similarly treating the
oil in the presence of a catalyst having the gen
16. A process for hydrobleaching glyceride oils
eral formula X--Y—O, in which the metals rep
to form products having a minimum of unsaponi
resented by X and Y comprise at least one other
?able components and an improved color and
metal from the groups designated.
stability comprising treating the oil at an ele
21. A process for hydrobleaching glyceride oils
vated temperature with hydrogen in the pres 40
to form products having a minimum of unsaponi
ence of a small amount of a catalyst having the
?able components and an improved color and
general formula X-Y—-Z—O in which X repre
stability comprising treating the oil at an ele
sents at least one metal selected from the group
vated temperature with hydrogen in the pres
consisting of copper and silver, and Y represents
at least one metal selected from the group con
sisting of chromium, vanadium, tungsten and
uranium, and Z represents an alkali earth metal,
said metals represented by X and Y being pres
ent in substantially atomic relationship and said
metal represented by Z being present in one
tenth molar relationship.
1'7. A process for hydrobleaching glyceride 011s
45 ence of a small amount of a catalyst having the
general formula X-~Y—O in which X represents
at least one metal selected from the minor sub
groups of groups I and II, and Y represents at
least one metal selected from the minor sub
groups of groups V and VI, of the periodic classi
?cation,
-
WILLIAM J. PATERSON.
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