U.S. patent application number 12/840033 was filed with the patent office on 2011-03-03 for removal of impurities from oils and/or fats.
This patent application is currently assigned to CONOCOPHILLIPS COMPANY. Invention is credited to Yun BAO, Dhananjay B. GHONASGI, Lisa L. MYERS, Scott A. SCHOLTEN, Edward L. SUGHRUE, Kathy A. SWALLOWS, Larry D. SWINNEY, Xiaochun XU, Jianhua YAO.
Application Number | 20110047866 12/840033 |
Document ID | / |
Family ID | 43622745 |
Filed Date | 2011-03-03 |
United States Patent
Application |
20110047866 |
Kind Code |
A1 |
BAO; Yun ; et al. |
March 3, 2011 |
REMOVAL OF IMPURITIES FROM OILS AND/OR FATS
Abstract
Disclosed is a process for removing solids, metals, phosphorus
compounds and other impurities from low quality triglyceride
containing feedstock. The final treated triglyceride containing
feedstock may be converted to fuel range hydrocarbons via
hydrotreating process.
Inventors: |
BAO; Yun; (Bartlesville,
OK) ; XU; Xiaochun; (Bartlesville, OK) ; YAO;
Jianhua; (Bartlesville, OK) ; MYERS; Lisa L.;
(Bartlesville, OK) ; GHONASGI; Dhananjay B.;
(Bartlesville, OK) ; SUGHRUE; Edward L.;
(Bartlesville, OK) ; SCHOLTEN; Scott A.; (Katy,
TX) ; SWALLOWS; Kathy A.; (Bartlesville, OK) ;
SWINNEY; Larry D.; (Stillwater, OK) |
Assignee: |
CONOCOPHILLIPS COMPANY
Houston
TX
|
Family ID: |
43622745 |
Appl. No.: |
12/840033 |
Filed: |
July 20, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61238338 |
Aug 31, 2009 |
|
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|
61238351 |
Aug 31, 2009 |
|
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Current U.S.
Class: |
44/605 |
Current CPC
Class: |
C10G 2300/205 20130101;
C10G 2300/805 20130101; C10G 2300/201 20130101; C11B 3/04 20130101;
C10G 2300/1018 20130101; C10G 45/02 20130101; Y02P 30/20 20151101;
C10G 2300/4081 20130101; C11B 3/008 20130101; C10G 2300/44
20130101; C10G 45/08 20130101; C10G 2400/04 20130101; C11B 3/001
20130101; C10G 2300/1014 20130101; C10G 2300/202 20130101 |
Class at
Publication: |
44/605 |
International
Class: |
C10L 1/00 20060101
C10L001/00 |
Claims
1. A process comprising: (a) providing a feedstock comprising at
least one triglyceride and one type of impurities; (b) admixing an
organic solvent with said feedstock for a contacting time to form a
mixture; (c) settling said mixture for a retention time to form a
layer of treated feedstock, a layer of impurities, and a layer of
organic solvent; and (d) recovering said layer of treated feedstock
from said mixture, wherein said treated feedstock comprises less
than 50% of the amount of said impurities than which is in said
feedstock.
2. The process in accordance with claim 1 further comprising the
step of (e) contacting said treated feedstock with a hydrotreating
catalyst in a reaction zone under a condition sufficient to produce
a reaction product containing diesel boiling range hydrocarbons,
wherein said condition includes a pressure of less than about 2000
psig and a temperature in the range of from about 260.degree. C. to
about 430.degree. C.
3. The process in accordance with claim 1, wherein said
triglyceride is selected from the group consisting of vegetable
oils, animal fats, and any combination thereof.
4. The process in accordance with claim 1 wherein said impurities
is selected from the group consisting of phosphorus, metals,
solids, proteins and bone materials, and any combinations
thereof.
5. The process in accordance with claim 1 wherein said organic
solvent is polar organic solvent, wherein said treated feedstock
comprises less than 80% of the amount of said impurities than which
is in said feedstock.
6. The process in accordance with claim 5 wherein said polar
organic solvent is ethylene glycol.
7. The process in accordance with claim 1 where in the amount of
said organic solvent is in the range from 0.1 to 50 wt %,
calculated on the weight of triglyceride.
8. The process in accordance with claim 1, wherein the temperature
of said feedstock is kept in the range of the lowest temperature at
which said mixture remains as a liquid to 150.degree. C. for at
least 1 minute prior to admixing with said solvent; wherein the
temperature of said mixture is kept in the range of the lowest
temperature at which said mixture remains as a liquid to
150.degree. C. during said step b; and wherein the temperature of
said mixture is kept in the range of the lowest temperature at
which said mixture remains as a liquid to 150.degree. C. during
said step c.
9. The process in accordance with claim 1 wherein said contacting
time is at least 1 minute; and wherein said retention time is at
least 1 minute.
10. The process in accordance with claim 1 further comprising a
step of recycling said layer of organic solvent after step c.
11. The process of claim 2, wherein said hydrotreating catalyst
comprises nickel and molybdenum.
12. The process of claim 2, wherein said hydrotreating catalyst
comprises cobalt and molybdenum.
13. A process comprising: (a) providing a feedstock comprising at
least one triglyceride and one type of impurities; (b) subjecting
said feedstock to a first separation device to remove at least 25%
of said impurities from said feedstock and to produce a first
effluent stream; (c) admixing an acid or acid anhydride with said
first effluent stream for a first contact time to form a first
mixture; (d) admixing water with said first mixture for a second
contact time to form a second mixture; (e) subjecting said second
mixture to a second separation device to form an aqueous phase and
oil phase; and (f) subjecting said oil phase to a third separation
device to remove another portion of said impurities from said oil
phase to produce a treated feedstock.
14. The process in accordance with claim 13 further comprising the
step of g) contacting said treated feedstock with a hydrotreating
catalyst in a reaction zone under a condition sufficient to produce
a reaction product containing diesel boiling range hydrocarbons,
wherein said condition includes a pressure of less than about 2000
psig and a temperature in the range of from about 260.degree. C. to
about 430.degree. C.
15. The process in accordance with claim 13, wherein said
triglyceride is selected from the group consisting of vegetable
oils, animal fats, and any combinations thereof.
16. The process in accordance with claim 13 wherein said impurities
is selected from the group consisting of phosphorus, metals,
solids, proteins and bone materials, and any combinations
thereof.
17. The process in accordance with claim 13 wherein said acid or
acid anhydride having a pH of from 0 to 6 as measured at 20.degree.
C. in a one molar aqueous solution.
18. The process in accordance with claim 13 wherein said acid is
phosphoric acid.
19. The process in accordance with claim 13 wherein an aqueous
solution of said acid containing 0.1 to 99.9% of the acid in
H.sub.2O is used.
20. The process in accordance with claim 13 wherein the amount of
water added is in the range from 0.1 to 10 wt %, calculated on the
oil.
21. The process in accordance with claim 13 wherein said first
contacting time is at least 0.1 minute, and where in said second
contacting time is at least 1 minute.
22. The process in accordance with claim 13 wherein the temperature
of said first mixture is maintained in the range of the lowest
temperature at which said first mixture remains as a liquid to
150.degree. C. during said first contacting time.
23. The process in accordance with claim 13 wherein said first
separation device is a filter with a pore size of at least 0.1
.mu.m.
24. The process in accordance with claim 13 wherein said first
separation device is a filter with a pore size from 2 to 7 .mu.m,
where in said filter removes at least 50% of said impurities from
said feedstock to produce said first effluent stream;
25. The process in accordance with claim 13 wherein said second
separation device is a centrifuge.
26. The process in accordance with claim 13 wherein said third
separation device is a filter with pore size of at least 0.1
.mu.m.
27. The process of claim 14 wherein said hydrotreating catalyst
comprises nickel and molybdenum.
28. The process of claim 14, wherein said hydrotreating catalyst
comprises cobalt and molybdenum.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non-provisional application which
claims benefit under 35 USC .sctn.119(e) to both U.S. Provisional
Application Ser. No. 61/238,338 filed Aug. 31, 2009, entitled
"SOLVENT EXTRACTION FOR THE REMOVAL OF IMPURITIES FROM OILS AND/OR
FATS" and U.S. Provisional Application Ser. No. 61/238,351 filed
Aug. 31, 2009, entitled "REMOVAL OF IMPURITIES FROM OILS AND/OR
FATS" which are incorporated herein in their entirety.
STATEMENT OF FEDERALLY SPONSORED RESEARCH
[0002] None
FIELD OF THE INVENTION
[0003] The present invention relates generally to the process for
removing impurities from triglycerides, especially prior to the
conversion of triglycerides to fuel range hydrocarbons.
BACKGROUND OF THE INVENTION
[0004] There is a national interest in the discovery of alternative
sources of fuels and chemicals, other than from petroleum
resources. As the public discussion concerning the availability of
petroleum resources and the need for alternative sources continues,
government mandates will require transportation fuels to include,
at least in part, hydrocarbons derived from sources besides
petroleum. As such, there is a need to develop alternative sources
for hydrocarbons useful for producing fuels and chemicals.
[0005] One possible alternative source of hydrocarbons for
producing fuels and chemicals is the natural carbon found in plants
and animals, such as for example, oils and fats. These so-called
"natural" carbon resources (or renewable hydrocarbons) are widely
available, and remain a target alternative source for the
production of hydrocarbons. For example, it is known that oils and
fats, such as those contained in vegetable oil, can be processed
and used as fuel. "Bio Diesel" is one such product and may be
produced by subjecting a base vegetable oil to a
transesterification process using methanol in order to convert the
base oil to methyl esters. After processing, the products produced
have some what similar combustion properties as compared to
petroleum-derived hydrocarbons. However, the use of Bio-Diesel as
an alternative fuel has not yet been proven to be cost effective.
In addition, Bio-Diesel often exhibits "gelling" thus making it
unable to flow, which limits its use in pure form in cold
climates.
[0006] Unmodified vegetable oils and fats have also been used as
additives in diesel fuel to improve the qualities of the diesel
fuel, such as for example, the lubricity. However, problems such as
injector coking and the degradation of combustion chamber
conditions have been associated with these unmodified additives.
Since cetane (C.sub.16H.sub.34), heptadecane (C.sub.17H.sub.36) and
octadecane (C.sub.18H.sub.38) by definition have very good ignition
properties (expressed as cetane rating), it is often desired to add
paraffinic hydrocarbons in the C.sub.16-C.sub.18 range, provided
that other properties of the additive (such as for example,
viscosity, pour point, cloud point, etc., are congruent with those
of the diesel fuel.
[0007] Laboratory and commercial tests have demonstrated that
vegetable oils and animal fats can be added to a refinery
hydrotreater to produce hydrocarbon/transportation fuels. For
example, contacting a diesel/vegetable oil mixture with a
hydrotreating catalyst. However, the feedstock price accounts for
.about.85% of operational cost for renewable diesel production, and
there has been a rapid price increase for the biorenewable feeds
currently used (e.g. refined soybean oil and technical tallow).
Thus, it is now more economically attractive to use lower quality
and less expensive feeds (e.g. inedible tallow, choice white grease
and etc.) for making renewable diesel. For example, inedible tallow
is about 20% cheaper than technical tallow, so for 1,000 BPD
renewable diesel production, an annual feedstock saving of $4
millions can be realized by using the inedible tallow instead of
technical tallow.
[0008] The problem associated with hydrotreating these lower priced
and poorer quality oils/fats is, however, that these low quality
oils/fats, such as, inedible tallow, choice white grease, etc.,
contain high concentration of solids, metals, phosphorus compounds
and other impurities, which can potentially cause reactor fouling
and poison the hydrotreating catalysts.
[0009] Therefore, development of an effective process for removing
solids, metals, phosphorus compounds and other impurities from low
quality oils and fats would be a significant contribution to the
art.
SUMMARY OF THE INVENTION
[0010] Disclosed is a process for removing solids, metals,
phosphorus compounds and other impurities from low quality
triglyceride containing feedstock. The final treated triglyceride
containing feedstock may be converted to fuel range hydrocarbons
via hydrotreating processes.
[0011] In the first embodiment of the present invention, a process
comprising (a) providing a feedstock comprising at least one
triglyceride and one type of impurities; (b) admixing an organic
solvent with the feedstock for a contacting time to form a mixture;
(c) settling the mixture for a retention time to form a layer of
treated feedstock, a layer of impurities, and a layer of organic
solvent; and (d) recovering the layer of treated feedstock from the
mixture, wherein the treated feedstock comprises less than 50% of
the amount of the impurities than which is in the feedstock.
[0012] In the second embodiment of the present invention, a process
is disclosed comprising contacting the treated feedstock from the
first embodiment of the invention with a hydrotreating catalyst in
a reaction zone under a condition sufficient to produce a reaction
product containing diesel boiling range hydrocarbons, such
condition includes a pressure of less than about 2000 psig and a
temperature in the range of from about 260.degree. C. to about
430.degree. C.
[0013] In the third embodiment of present invention, a process
comprising (a) providing a feedstock comprising at least one
triglyceride and one type of impurities; (b) subjecting the
feedstock to a first separation device to remove at least 25% of
the impurities from the feedstock and to produce a first effluent
stream; (c) admixing an acid or acid anhydride with the first
effluent stream for a first contact time to form a first mixture;
(d) admixing water with the first mixture for a second contact time
to form a second mixture; (e) subjecting the second mixture to a
second separation device to form an aqueous phase and oil phase;
and (f) subjecting the oil phase to a third separation device to
remove another portion of the impurities from the oil phase to
produce a treated feedstock.
[0014] In the forth embodiment of the present invention, a process
is disclosed comprising contacting the treated feedstock from the
third embodiment of the invention with a hydrotreating catalyst in
a reaction zone under a condition sufficient to produce a reaction
product containing diesel boiling range hydrocarbons, such
condition includes a pressure of less than about 2000 psig and a
temperature in the range of from about 260.degree. C. to about
430.degree. C.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Refer to all four embodiments of the invention,
triglycerides or fatty acids of triglycerides, or mixtures thereof,
may be converted to form a hydrocarbon mixture useful for liquid
fuels and chemicals. The term, "triglyceride," is used generally to
refer to any naturally occurring ester of a fatty acid and/or
glycerol having the general formula
CH.sub.2(OCOR.sub.1)CH(OCOR.sub.2)CH.sub.2(OCOR.sub.3), where
R.sub.1, R.sub.2, and R.sub.3 are the same or different, and may
vary in chain length. Examples of triglycerides useful in the
present invention include, but are not limited to, animal fats
(e.g. poultry grease, edible or inedible beef fat also referred as
tallow, milk fat, and the like), vegetable oils (e.g. soybean, corn
oil, peanut oil, sunflower seed oil, coconut oil, babassu oil,
grape seed oil, poppy seed oil, almond oil, hazelnut oil, walnut
oil, olive oil, avocado oil, sesame, oil, tall oil, cottonseed oil,
palm oil, ricebran oil, canola oil, cocoa butter, shea butter,
butyrospermum, wheat germ oil, illipe butter, meadowfoam, seed oil,
rapeseed oil, borage seed oil, linseed oil, castor oil, vernoia
oil, tung oil, jojoba oil, ongokea oil, algae oil, jatropha oil,
yellow grease such as those derived from used cooking oils, and the
like), and mixtures and combinations thereof.
[0016] Generally, the triglyceride comes with impurities such as
phosphorus, metals (e.g. Alkali metals, alkali earth metals, or
etc), solids, proteins and bone materials, or any combinations
thereof. The amounts of these elements/compounds are generally in
the range of from about 0 ppmw to about 10,000 ppmw.
[0017] Now refer to the first and second embodiments of the
invention, the feedstock is generally kept in the range of the
lowest temperature at which the feedstock remains as a liquid to
150.degree. C. for at least 1 minute. After this step, an organic
solvent is added to this feedstock. Any organic solvent may be
used, in one embodiment of the invention, any type of a polar
organic solvent, such as ethylene glycol, may be used.
[0018] Further referring to the first and second embodiments of the
invention, the amount of organic solvent added to the feedstock may
vary depend upon the amount of the feedstock to be mixed. According
to the present invention, the amount of the organic solvent added
is in the range from 0.1 to 50 wt %, calculated on the weight of
triglyceride containing feedstock.
[0019] Further referring to the first and second embodiments of the
invention, the organic solvent added to the feedstock is given
sufficient contacting time to mix with the feedstock to thereby
forming a mixture. The contacting time required for mixing the
organic solvent with the feedstock may be affected by temperature
of the feedstock as well as the types of device for mixing. In one
embodiment, such contacting time is at least 1 minute under dynamic
mixing action provided by devices such as such as stirrer or high
shear mixers. The temperature of the mixture is maintained in the
range of from the lowest temperature at which the mixture remains
as a liquid to 150.degree. C. during the mixing of organic solvent
with the feedstock.
[0020] After the contacting time mentioned above, the mixture is
allowed to set for a sufficient retention time, usually without any
mixing action, to thereby form a layer of treated feedstock, a
layer of impurities, and a layer of organic solvent. The retention
time required in this step may be affected by the temperature of
the mixture. In one embodiment, such retention time is at least 1
minute. The temperature of the mixture is maintained in the range
of from the lowest temperature at which the mixture remains as a
liquid to 150.degree. C. during the setting of the mixture.
[0021] Further refer to the first and second embodiments of the
invention, the layer of the treated feedstock is recovered but not
limited by separation funnel.
[0022] Further refer to the first and second embodiments of the
invention, the treated feedstock after the inventive process
comprises less than 50% of the amount of the impurities than it is
in the feedstock prior to the inventive process. In one embodiment
where a polar organic solvent (e.g. ethylene glycol) is used, the
treated feedstock after the inventive process comprises less than
80% of the amount of the impurities than it is in the feedstock
prior to the inventive process.
[0023] Additionally, in both first and second embodiment of the
invention, the layer of organic solvent may also be recycled for
using in the treating of additional feedstock.
[0024] Now referring to the third and forth embodiments of the
current invention, a feedstock comprising triglyceride and
impurities is subject to a first separation device where in at
least 25% of the impurities may be removed from the feedstock. Any
suitable separation device capable of separating the solid from an
oil phase feed may be used. A first separation device according to
one embodiment of the current invention is a commercially available
bag or cartridge filter with a pore size of at least 0.1 .mu.m. In
another embodiment with the feedstock being the inedible tallow,
the first separation device of choice is a commercially available
bag or cartridge filter with a pore size anywhere from 2 to 7
.mu.m, which removes at least 50% of the impurities from the
inedible tallow feedstock to produce the first effluent stream.
[0025] Further refer to the third and forth embodiments of the
invention, the acid or acid anhydride, in principle all inorganic
and organic acids having a pH of from 0-6 as measured at 20.degree.
C. in a one molar aqueous solution, may be used. For example:
phosphoric acid, sulfuric acid, nitric acid, acetic acid, citric
acid, tartaric acid, succinic acid, etc., or mixtures of such
acids.
[0026] The acids or acid anhydride may be added in any
concentration, in one embodiment of this invention, an aqueous
solution of the acid added contains 0.1 to 99.9% of the acid in
H.sub.2O.
[0027] Further refer to the third and forth embodiments of the
invention, after the acid or acid anhydride being added to the
first effluent stream, it is given a sufficient contacting time to
mix with the first effluent stream to form the first mixture. The
contacting time required for homogeneously mixing the acid or acid
anhydride with the first effluent stream may be affected by
temperature of the first effluent stream as well as the types of
device for mixing. In one embodiment, such contacting time is at
least 0.1 minute under dynamic mixing action provided by devices
such as stirrer or high shear mixers. In another embodiment, such
contacting time is about 0.1 to 60 minutes under dynamic mixing
action provided by devices such as stirrer or high shear mixers.
The temperature of the first mixture is maintained in the range of
from the lowest temperature at which the first effluent stream
remains as a liquid to 150.degree. C. during contacting time
mentioned above.
[0028] After the acid or acid anhydride being sufficiently mixed
with the first effluent stream to form the first mixture, a small
amount of water is added. In one embodiment, the amount of water
added is in the range from 0.1 to 10 wt %, calculated on the
oil.
[0029] After the water being added to the first mixture, it is
given a sufficient contacting time to mix with the first mixture to
form the second mixture. In one embodiment, such contacting time is
at least 1 minute under dynamic mixing action provided by devices
such as stirrer or high shear mixers. In another embodiment, such
contacting time is about 1-1000 minutes under dynamic mixing action
provided by devices such as stirrer or high shear mixers.
[0030] Again refer to the third and forth embodiments of the
invention, the second mixture is then subject to a second
separation device by which an aqueous phase and oil phase are
separated. Any suitable separation device capable of separating an
aqueous from an oil phase may be used. A second separation device
according to one embodiment of the current invention is a
commercially available centrifugation unit.
[0031] Finally the oil phase separated from the second mixture is
subject to a third separation device wherein another portion of the
impurities may be removed from the feedstock. Any suitable
separation device capable of separating solids from an oil phase
feed may be used. The third separation device according to one
embodiment of the current invention is a commercially available bag
or cartridge filter with a pore size of at least 0.1 .mu.m. In
another embodiment with the feedstock being the inedible tallow,
the third separation device of choice is a commercially available
bag or cartridge filter with a pore size between from 0.1 to 0.5
.mu.m.
[0032] Now refer specifically to the second and the forth
embodiments of the invention, the useful catalyst compositions in
the present invention include catalysts effective in the conversion
of triglycerides to hydrocarbons when contacted under suitable
reaction conditions. Examples of suitable catalysts include
hydrotreating catalysts. The term "hydrotreating" as used herein,
generally describes a catalyst that is capable of utilizing
hydrogen to accomplish saturation of unsaturated materials, such as
aromatic compounds. Examples of hydrotreating catalysts useful in
the present invention include, but are not limited to, materials
containing compounds selected from Group VI and Group VIII metals,
and their oxides and sulfides. Examples of hydrotreating catalysts
include but are not limited to alumina supported cobalt-molybdenum,
nickel sulfide, nickel-tungsten, cobalt-tungsten and
nickel-molybdenum.
[0033] Further refer to the second and the forth embodiments of the
invention, the metal of the catalyst useful in the present
invention is usually distributed over the surface of a support in a
manner than maximizes the surface area of the metal. Examples of
suitable support materials for the hydrogenation catalysts include,
but are not limited to, silica, silica-alumina, aluminum oxide
(Al.sub.2O.sub.3), silica-magnesia, silica-titania and acidic
zeolites of natural or synthetic origin. The metal catalyst may be
prepared by any method known in the art, including combining the
metal with the support using conventional means including but not
limited to impregnation, ion exchange and vapor deposition. In an
embodiment of the present invention, the catalyst contains
molybdenum and cobalt supported on alumina or molybdenum and nickel
supported on alumina.
[0034] Still refer to the second and the forth embodiments of, the
invention, this process in accordance with an embodiment of the
present invention can be carried out in any suitable reaction zone
that enables intimate contact of the treated feed and control of
the operating conditions under a set of reaction conditions that
include total pressure, temperature, liquid hourly space velocity,
and hydrogen flow rate. The catalyst can be added first to the
reactants and thereafter, fed with hydrogen.
[0035] In the second and forth embodiments of the present
invention, either fixed bed reactors or fluidized bed reactors can
be used. As used herein, the term "fluidized bed reactor" denotes a
reactor wherein a fluid feed can be contacted with solid particles
in a manner such that the solid particles are at least partly
suspended within the reaction zone by the flow of the fluid feed
through the reaction zone and the solid particles are substantially
free to move about within the reaction zone as driven by the flow
of the fluid feed through the reaction zone. As used herein, the
term "fluid" denotes gas, liquid, vapor and combinations
thereof.
[0036] The reaction conditions at which the reaction zone is
maintained generally include a temperature in the range of from
about 260.degree. C. to about 430.degree. C. Preferably, the
temperature is in the range of from about 310.degree. C. to about
370.degree. C.
[0037] In accordance with the second and forth embodiments of the
present invention, regardless of whether a fixed or fluidized bed
reactor is used, the pressure is generally in the range of from
about 100 pounds per square inch gauge (psig) to about 2000 psig.
Generally, in a fixed bed reactor, the pressure is in the range of
from about 100 psig to about 1500 psig. In a fixed bed reactor, the
pressure can also be about 600 psig. In a fluidized bed reactor,
the pressure is generally in the range of from about 400 psig to
about 750 psig, and can also be about 500 psig.
[0038] The following example is presented to further illustrate the
present invention and is not to be construed as unduly limiting the
scope of this invention.
Example 1
Comparison Study on Impurities Removal from Tallow Using Ethylene
Glycol Vs. Water
[0039] A comparison study was performed on impurities removal from
tallow using ethylene glycol vs. water. The same procedure is
followed. A 100 grams of tallow feedstock is added in a container
and heated at a temperature of 90.degree. C. for 0.5-1 hour. A 10
ml of ethylene glycol or water was added to the container and
stirred with the tallow feedstock at a temperature of 90.degree.
for 2-3 hours. The mixture was then kept at 55-60.degree. C.
overnight without stirring. Three layers were formed comprising a
layer of treated tallow, a brown color layer of impurities, and a
layer of ethylene glycol. The result of the experiment has shown
that under the same procedure and condition, less brown color layer
of impurities were found in the container with water than it was in
the container with ethylene glycol.
Example 2
[0040] An inedible tallow feed stock is provided. Such feedstock
was subject to a commercially available sintered metal filter with
a pore size of 2 .mu.m to remove solids from the feedstock. The
filtered feedstock was then mixed with phosphoric acid at the
concentration of 75-85% for about 3 minutes followed by the
addition of 5 wt % H.sub.2O. The tallow/phosphoric acid/water was
further mixed for 60 minutes followed by a centrifugal step in
which an aqueous phase and oil phase were separated. Sample of
feedstock at the various stages were obtained and measured. As
shown in Table 1, the results of this experiment indicates that
there are a significant (more than 50%) reduction of the metals,
phosphorus and solids concentration achieved by just after passing
the feedstock through a sintered metal filter with pore size of 2
.mu.m alone.
TABLE-US-00001 TABLE 1 Removal of impurities from inedible tallow
Inedible Inedible tallow after mixing Impurities Pre-treated tallow
after with phosphoric acid and (ppm) inedible tallow 2 .mu.m filter
centrifugal separation Metals 146 48 2.2 Phosphorus 129 60 4.5
Solids 1400 210 210
[0041] The oil phase feed is further subject to a commercially
available sintered metal filter with a pore size of 0.5 .mu.m to
remove some solids from the feedstock. Thereby, significantly
purified inedible tallow is obtained.
[0042] While this invention has been described in detail for the
purpose of illustration, it should not be construed as limited
thereby but intended to cover all changes and modifications within
the spirit and scope thereof.
* * * * *