U.S. patent application number 11/304996 was filed with the patent office on 2006-10-12 for production of biodiesel.
Invention is credited to Raul Rohr, Rodolfo Rohr.
Application Number | 20060225341 11/304996 |
Document ID | / |
Family ID | 37156026 |
Filed Date | 2006-10-12 |
United States Patent
Application |
20060225341 |
Kind Code |
A1 |
Rohr; Rodolfo ; et
al. |
October 12, 2006 |
Production of biodiesel
Abstract
A process for the production of biodiesel is disclosed. In a
preferred embodiment, the process is based on the production of
biodiesel using refinery soapstock where the process is performed
in an alcoholic medium resulting in the insolubility of certain
byproducts. Other valuable products can also be obtained from the
process.
Inventors: |
Rohr; Rodolfo; (Campinas,
BR) ; Rohr; Raul; (Ladera Ranch, CA) |
Correspondence
Address: |
KNOBBE MARTENS OLSON & BEAR LLP
2040 MAIN STREET
FOURTEENTH FLOOR
IRVINE
CA
92614
US
|
Family ID: |
37156026 |
Appl. No.: |
11/304996 |
Filed: |
December 15, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60655458 |
Feb 23, 2005 |
|
|
|
Current U.S.
Class: |
44/385 ;
44/451 |
Current CPC
Class: |
Y02E 50/13 20130101;
C01D 5/02 20130101; C01D 5/00 20130101; C11C 3/003 20130101; Y02P
30/20 20151101; C10G 2300/1011 20130101; C11B 13/02 20130101; Y02W
30/74 20150501; C10L 1/026 20130101; Y02E 50/10 20130101 |
Class at
Publication: |
044/385 ;
044/451 |
International
Class: |
C10L 1/18 20060101
C10L001/18 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 20, 2004 |
BR |
2004000005705 |
Claims
1. A process for producing biodiesel comprising: saponifying a
soapstock with an alkaline base in an alcohol to yield a saponified
soapstock; filtering the solution of saponified soapstock to remove
substantially insoluble organic material; adding a mineral acid to
the filtered solution of saponified soapstock to form fatty acids
and a mineral salt; and esterifying the fatty acids, thereby
forming biodiesel.
2. The process of claim 1, further comprising neutralizing excess
mineral acid after addition of the mineral acid to the filtered
solution.
3. The process of claim 2, further comprising removing salts formed
from the neutralization.
4. The process of claim 1, further comprising removing the alcohol
after esterification.
5. The process of claim 4, wherein the removal of alcohol is
performed by distillation.
6. The process of claim 1, further comprising removing insoluble
impurities after esterification.
7. The process of claim 6, wherein the removal of insoluble
impurities is performed by centrifugation or filtration.
8. The process of claim 1, further comprising distilling the esters
of fatty acids after esterification.
9. The process of claim 1, wherein the soapstock originated from
refining of an oil selected from the group consisting of soy oil,
rice oil, sunflower oil, coconut oil, castor oil, chicken oil,
cottonseed oil, corn oil, peanut oil, palm oil, and babassu
oil.
10. The process of claim 1, wherein the alcohol is methyl alcohol
or ethyl alcohol.
11. The process of claim 1, wherein the alkaline base is sodium
hydroxide or potassium hydroxide.
12. Biodiesel obtained from a process comprising: saponifying a
soapstock with an alkaline base in an alcohol to yield a saponified
soapstock; filtering the solution of saponified soapstock to remove
substantially insoluble organic material; adding a mineral acid to
the filtered solution of saponified soapstock to form fatty acids
and a mineral salt; and esterifying the fatty acids.
13. Sterols obtained from a process comprising: saponifying a
soapstock with an alkaline base in an alcohol to yield a saponified
soapstock; filtering the solution of saponified soapstock to remove
substantially insoluble organic material; adding a mineral acid to
the filtered solution of saponified soapstock to form fatty acids
and a mineral salt; esterifying the fatty acids; removing insoluble
impurities after the esterification; and distilling the solution of
esters of fatty acids after esterification to obtain sterols.
14. The sterols of claim 13, wherein the distillation step is
performed by thin film evaporation or falling film evaporation.
15. The sterols of claim 14, wherein the process further comprises
short-path distilling the product of distillation of the solution
of esters of fatty acids.
16. The sterols of claim 15, wherein the process further comprises
crystallizing the product obtained by short-path distillation.
17. Organic material obtained from a process comprising:
saponifying a soapstock with an alkaline base in an alcohol to
yield a saponified soapstock; and filtering the solution of
saponified soapstock to obtain substantially insoluble organic
material.
18. Mineral salts obtain from a process comprising: saponifying a
soapstock with an alkaline base in an alcohol to yield a saponified
soapstock; filtering the solution of saponified soapstock to remove
substantially insoluble organic material; adding a mineral acid to
the filtered solution of saponified soapstock to form fatty acids
and a mineral salt; and separating the mineral salt from the
solution.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C.
.sctn.119(e) to U.S. Provisional Application No. 60/655,458, filed
Feb. 23, 2005, and Brazilian Patent Application No. 2004000005705,
filed Dec. 20, 2004, which are incorporated herein by reference in
their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a process for the
production of biodiesel using soapstock.
[0004] 2. Description of the Related Art
[0005] Biodiesel is a clean burning alternative fuel, produced from
domestic, renewable resources. Biodiesel is simple to use,
biodegradable, and nontoxic. Biodiesel is comprised of mono-alkyl
esters of long chain fatty acids. These mono-alkyl esters of long
chain fatty acids have been derived from vegetable oils or animal
fats.
[0006] The processes used today to produce the methyl or ethyl
esters of fatty acids start from animal or vegetable oils
(triglycerides), an esteemed material that has better application
in human and/or animal food. Accordingly, because of the importance
of animal and vegetable oils as food, the use of animal and
vegetable oils in the energy matrix as raw material for the
manufacture of biodiesel results in an overall waste.
[0007] Processes are available to use the fatty acids from
soapstock, a residual by-product from the production of the edible
oils and fats, to produce biodiesel. However, these processes
produce a great quantity of residual acid-water due to the
acidulation of the soapstock with sulfuric acid. The residual water
is acidic, has high sodium sulfate content, and has a very high
Biochemical Oxygen Demand (BOD) because of the lecithin, gums, and
other organic impurities present in the effluent water. The high
cost of the treatment of the effluent water coming from the
acidulation of the soapstock makes the process economically
unviable. The treatment of this residual effluent is an extremely
complicated problem from an environmental point of view. The
problem is technically difficult to solve because of the water's
high content of sodium sulfate and the high BOD resulting from the
gums, lecithin, and other organic impurities.
SUMMARY OF THE INVENTION
[0008] Accordingly, there exists a need to turn the production of
biodiesel from refinery soapstock into a feasible process from an
economic and environmentally adequate point of view.
[0009] One embodiment provides a process for producing biodiesel
comprising: saponifying a soapstock with an alkaline base in an
alcohol to yield a saponified soapstock; filtering the solution of
saponified soapstock to remove substantially insoluble organic
material; adding a mineral acid to the filtered solution of
saponified soapstock to form fatty acids and a mineral salt; and
esterifying the fatty acids, thereby forming biodiesel.
[0010] Another embodiment provides biodiesel obtained from a
process comprising: saponifying a soapstock with an alkaline base
in an alcohol to yield a saponified soapstock; filtering the
solution of saponified soapstock to remove substantially insoluble
organic material; adding a mineral acid to the filtered solution of
saponified soapstock to form fatty acids and a mineral salt; and
esterifying the fatty acids.
[0011] Another embodiment provides sterols obtained from a process
comprising: saponifying a soapstock with an alkaline base in an
alcohol to yield a saponified soapstock; filtering the solution of
saponified soapstock to remove substantially insoluble organic
material; adding a mineral acid to the filtered solution of
saponified soapstock to form fatty acids and a mineral salt;
esterifying the fatty acids; removing insoluble impurities after
the esterification; and distilling the solution of esters of fatty
acids after esterification to obtain sterols.
[0012] Another embodiment provides organic material obtained from a
process comprising: saponifying a soapstock with an alkaline base
in an alcohol to yield a saponified soapstock; and filtering the
solution of saponified soapstock to obtain substantially insoluble
organic material.
[0013] Another embodiment provides mineral salts obtain from a
process comprising: saponifying a soapstock with an alkaline base
in an alcohol to yield a saponified soapstock; filtering the
solution of saponified soapstock to remove substantially insoluble
organic material; adding a mineral acid to the filtered solution of
saponified soapstock to form fatty acids and a mineral salt; and
separating the mineral salt from the solution.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] Preferred embodiments provide a process for the production
of biodiesel utilizing soapstock as a starting material. Soapstock,
as a refining oil byproduct, is an abundant, under-utilized, and
inexpensive starting material. Advantageously, the preferred
process to obtain biodiesel does not substantially use vegetable or
animal oils as raw material, which could find better applications
in animal and human food. Also, the preferred process is
environmentally friendly, as the process does not generate large
quantities of residual acid water. The preferred process also
produces useful reagents, such as polypeptides, lecithin, sodium
sulfate, and sterols.
[0015] As used herein, biodiesel refers to mono-alkyl esters of
long chain fatty acids, preferably methyl or ethyl esters.
Preferred biodiesel made from various starting materials with
various processes can confirm to specifications. In the United
States, the American Society of Testing and Materials (ASTM), a
standard setting organization for fuels and fuel additives, defines
biodiesel according to specifications.
[0016] As used herein, soapstock refers to a refining oil
byproduct. Soapstock comprises a cache of plant esters (sterols),
glycerides (oils), phospholipids (lecithin), sodium soap.
[0017] A preferred embodiment uses soapstock, a residual by-product
from the production of edible oils and fats. While there are other
processes available which also use the fatty acids from soapstock,
in contrast to the preferred embodiments, these other processes
produce a great quantity of residual acid-water due to the
acidulation of the soapstock with sulfuric acid. Accordingly, there
exists a need to turn the production of biodiesel from refinery
soapstock into a feasible process from an economic and
environmentally adequate point of view.
[0018] The processes are based on the production of biodiesel from
the soapstock of vegetable or animal oil refining. In one
embodiment, the processes are preferably performed in an alcoholic
medium, which results in the insolubility of byproducts.
Consequently, certain problems of the prior art biodiesel
productions, such as treatment of the residual water which is
acidic, has high sodium sulfate content, and has high BOD, are
bypassed.
[0019] In one embodiment, a process for producing biodiesel is
disclosed. The process comprises: saponifying a soapstock with an
alkaline base in an alcohol to yield a saponified soapstock;
filtering the solution of saponified soapstock to remove
substantially insoluble organic material; adding a mineral acid to
the filtered solution of saponified soapstock to form fatty acids
and a mineral salt; and esterifying the fatty acids, thereby
forming biodiesel. The process can further comprise neutralizing
excess mineral acid after addition of the mineral acid to the
filtered solution. The process can further comprise removing salts
formed from the neutralization. The process can further comprise
removing the alcohol after esterification. The process can further
comprise removing insoluble impurities after esterification. The
process can further comprise distilling the esters of fatty acids
after esterification.
[0020] In one embodiment, the process comprises the following
steps: [0021] (A) Treating a refinery soapstock with a strong
alkaline base in the presence of an alcohol. The saponification of
the triglycerides present in the refinery soapstock can be achieved
by treating the soapstock with a strong alkaline base. This
treatment can be conducted under heating and alcohol reflux.
Substantial triglycerides present are saponified by the strong
alkaline base. [0022] (B) After finishing the reaction described in
(A), the product is filtered to remove substantially insoluble
organic material. This organic material comprises polypeptides and
lecithin and can be used as an emulsifying agent in industrial
applications or as an additive to animal feed. [0023] (C) A strong
mineral acid is then added to the alcoholic solution. The mixture
is then heated to around the boiling point of the alcohol and
refluxed. Fatty acids can form from the respective soaps. [0024]
(D) In the reaction described above, a mineral salt can form
between the strong alkaline base component of the soap and the
strong mineral acid. The salt is not soluble or sparingly soluble
in an alcoholic medium, where the process is conducted.
Accordingly, filtration and removal of the salt from the reactive
medium is easy to perform. Generally, the filtered salt is a
technical grade and can be sold for industrial applications. [0025]
(E) After filtering the salt, the material is heated under reflux
for esterification of the free fatty acids with the alcohol already
being used. [0026] (F) After esterification, a certain quantity of
base is added to neutralize the excess mineral acid in the
alcoholic solution. [0027] (G) After neutralization, the solution
is filtered again to remove the salts formed during the
neutralization. [0028] (H) The clear solution of esters in alcohol
is ready for the removal of the excess of alcohol. This removal can
be done by distillation of the alcohol. [0029] (J) After recovering
the excess alcohol, insoluble impurities are removed from the
esters. [0030] (K) The ester obtained after removal of insoluble
impurities is then distilled for purification resulting in
biodiesel.
[0031] In another embodiment, the process comprises the following
steps: [0032] (A) Treating a refinery soapstock with a strong
alkaline base in the presence of an alcohol, such as ethanol or
methanol. The saponification of the triglycerides present in the
refinery soapstock is achieved by treating the soapstock with a
strong alkaline base, such as, but not limited to, sodium hydroxide
or potassium hydroxide. This treatment can be conducted under
heating and alcohol reflux. Substantial triglycerides present are
saponified by the strong alkaline base. [0033] (B) After finishing
the reaction described in (A), the product is filtered to remove
substantially insoluble organic material. This organic material
comprises polypeptides and lecithin and can be used as an
emulsifying agent in industrial applications or as an additive to
animal feed. [0034] (C) A strong mineral acid, such as, but not
limited to, sulfuric, phosphoric, or chloridic acid is then added
to the alcoholic solution. The mixture is then heated to around the
boiling point of the alcohol and refluxed. Fatty acids can form
from the respective soaps. [0035] (D) In the reaction described
above, a mineral salt is formed between the strong alkaline base
component of the soap and the strong mineral acid added. The salt
is not soluble or sparingly soluble in an alcoholic medium, where
the process is conducted. Accordingly, filtration and removal of
the salt from the reactive medium is easy to perform. Generally,
the filtered salt is a technical grade and can be sold for
industrial applications. In an embodiment, technical grade sodium
sulfate is obtained. [0036] (E) After filtering the salt, the
material is heated under reflux for esterification of the free
fatty acids with the alcohol already being used. [0037] (F) After
esterification, a certain quantity of base, such as calcium oxide,
calcium hydroxide, or sodium carbonate, is added to neutralize the
excess mineral acid in the alcoholic solution. [0038] (G) After
neutralization, the solution is filtered again to remove the
calcium or sodium salts formed during the neutralization. [0039]
(H) The clear solution of methylic or ethylic esters in alcohol is
ready for the removal of the excess of alcohol. This removal can be
done by distillation of the methanol or ethanol at temperatures
varying from 40.degree. C. to 90.degree. C., at ambient or at
reduced pressure (vacuum). [0040] (J) After recovering the excess
alcohol, the methylic or ethylic esters are centrifuged to
eliminate the insoluble impurities. [0041] (K) The methylic or
ethylic ester obtained in the centrifugation process is then
distilled under vacuum for purification resulting in biodiesel.
[0042] Embodiments utilize soapstock as a starting material.
Soapstock refers to a residual by-product from the production of
edible oils and fats. In one embodiment, the refining soapstock can
come from soy oil refining or any other vegetable or animal oil
chemical refining processes, such as, but not limited to, rice oil,
sunflower oil, coconut oil, castor oil, chicken oil, cottonseed
oil, corn oil, peanut oil, palm oil, and babassu oil. Preferably,
soapstock is derived from oil selected from the group consisting of
soy oil, palm oil, sunflower oil, and rice oil.
[0043] Soapstock water content will vary from process to process. A
soapstock frequently comprises about 40-80% moisture content;
including, about 60-70% moisture content.
[0044] In one embodiment, the process is performed in an alcoholic
medium. Any alcohol can be used such that the resulting biodiesel
comply with specifications for the biodiesel. Preferred alcohols
include methanol and ethanol. Other alcohols include propanol,
butanol, hexanol, and heptanol.
[0045] The preferred process is performed in an alcoholic medium
and produces hardly any residual water besides that already
contained in the vegetable oil refinery soapstock. Any residual
water is substantially free of inorganic salts and has almost no
organic contamination. Therefore, treatment of the water becomes
quite simple, and the usual water treatment systems can make its
reuse efficient and applicable. Thus, the energy balance resulting
from this process is positive, for the energy cost to produce
biodiesel resulting from the preferred process is less than the
energy generated by it. Accordingly, the present process turns the
production of biodiesel from refinery soapstock into a feasible
process from an economic and environmentally adequate point of
view.
[0046] The saponification of soapstock in an alcoholic medium is
facilitated with a strong alkaline base. A base that is soluble in
the alcoholic medium is preferred. Preferred bases include, but are
not limited to, sodium hydroxide and potassium hydroxide.
[0047] When the processes are performed in an alcoholic medium,
certain resulting byproducts are insoluble. Such byproducts can be
filtered from the alcoholic medium. After the saponification of
soapstock with the base, there may be substantially insoluble
organic material. This organic material can comprise polypeptides
and lecithin and can be used as an emulsifying agent in industrial
applications or as an additive to animal feed.
[0048] The saponified soapstock comprises fatty acid salts (soaps).
Addition of a strong mineral acid to the fatty acid salts can yield
respective fatty acids. A preferred acid facilitates exchange of
ions to yield the fatty acids. Preferred acids include, but are not
limited to, sulfuric acid, phosphoric acid, and chloridic acid.
[0049] The exchange of ions between the fatty acid salts and strong
mineral acid also yields a salt. The salt may not be soluble or may
be sparingly soluble in the alcohol medium such that the salt can
be removed from the alcohol medium easily. The recovered salt can
be of technical grade. In certain cases, the recovered salt can be
reused in industrial applications. In a certain embodiment, such as
using a sodium cation containing base (e.g. NaOH) and sulfate anion
containing acid (e.g. H.sub.2SO.sub.4) in the process, the salt is
sodium sulfate.
[0050] After removal of the salt, the alcoholic medium containing
the fatty acid is subjected to esterification conditions. The
esterification is performed with the alcohol already present.
Alternatively, the alcohol can be exchanged for another alcohol.
Preferably, the esterification is performed under acidic
conditions. In an embodiment, the acidic conditions result from
excess mineral acid that reacted with the saponified soapstock. As
stated above, preferred acids include, but are not limited to,
sulfuric acid, phosphoric acid, and chloridic acid.
[0051] After esterification, the excess acid is neutralized with a
base. Any base that can neutralize the excess acid can be used. The
salt resulting from the neutralization may not be soluble or may be
sparingly soluble in the alcohol medium such that the salt can be
removed from the alcohol medium easily. Preferred bases include,
but are not limited to, calcium oxide, calcium hydroxide, sodium
carbonate, and sodium bicarbonate.
[0052] After neutralization and removal of salts, the alcoholic
medium contains esters of fatty acid. Removal of the alcohol yields
esters of fatty acids. Removal of the alcohol can be achieved
through evaporation, such as distillation. Preferably, the
distillation can be performed at temperatures sufficient to remove
the alcohol. The distillation can be performed at ambient or
reduced pressure. The boiling point of methanol is 64.5.degree. C.
The boiling point of ethanol is 78.degree. C. Accordingly, if
methanol or ethanol is used as the alcoholic medium, the
distillation can be performed at temperatures ranging about
40.degree. C. to about 90.degree. C. at ambient pressure to remove
the alcohol.
[0053] The distillation yields esters of fatty acids. Subsequent
purification of the esters of fatty acids can include eliminate
insoluble impurities. The insoluble impurities can be removed by a
separation means, such as centrifugation or filtration. Preferably,
the insoluble impurities are removed by centrifugation.
[0054] Subsequent purification of the esters of fatty acids also
can include a distillation. Preferably, the distillation after
removal of insoluble impurities is done under vacuum. The
distillation after removal of insoluble impurities can yield
valuable products, such as biodiesel and further products obtained
from subsequent workup of the distillation residue. Preferably, the
biodiesel complies with specifications.
Purification of Distillation Residue
[0055] The distillation residue after obtaining biodiesel can be
further worked-up to yield valuable products. One such product is
sterols. The remaining distillation residue after obtaining
biodiesel is generally neutral and has an average of about 2 to
about 20% sterol content. In another embodiment, the sterol content
is about 5 to about 15%. In another embodiment, the sterol content
is about 10%. Examples of some such sterols and methods for
obtaining purified sterols are described in U.S. Pat. No.
6,846,941, which is incorporated herein by reference. Sterols can
be used as a supplement in the diet of animals and humans as a
means to lower cholesterol in the blood serum. There is also
commercial interest in the use of sterols as emulsion stabilizers
and/or viscosity modifiers, especially in cosmetic formulas.
Soybean oil producers and soy-based sterol producers have interest
in methods of obtaining sterols.
[0056] The distillation residue after obtaining biodiesel can be
submitted to additional distillation conditions, such as those
disclosed in U.S. Pat. No. 6,846,941, to obtain purified sterols.
The sterols can be distilled directly in the thin film evaporation
(TFE) under vacuum of about 30 to about 1 mbar and temperature of
about 150.degree. C. to about 210.degree. C. or falling film
evaporation (FFE) preferably under vacuum of about
1.times.10.sup.-1 mbar and temperature of about 180.degree. C. to
about 220 or 230.degree. C. to remove lighter volatiles. Then, on a
subsequent distillation step, the residue can be distilled in a
short-path distillation preferably under vacuum of about
1.times.10.sup.-1 mbar or lower and at a temperature of about 220
or 230.degree. C. to about 240 or 280.degree. C. A concentrated
sterol fraction containing about 40 to about 70% sterols can be
obtained in some embodiments. The distilled sterols can be
submitted to crystallization to produce purer sterols.
[0057] In some embodiments, the process can further comprise
distilling or evaporating one or more compounds selected from the
group consisting of lights, medium-lights, and water from the
distillation residue prior to the distilling to separate at least a
portion of the unsaponifiable compounds.
[0058] The process of purification of the distillation residue
begins by providing the distillation residue after obtaining
biodiesel, wherein the distillation residue can comprise one or
more unsaponifiable compounds. The process further can continue by
subjecting a mixture of one or more unsaponifiable compounds to a
distillation to form a distillate comprising at least a portion of
more pure unsaponifiable compounds.
[0059] In preferred embodiments, the process can further comprise
subjecting the distillate comprising at least a portion of the
unsaponifiable compounds to a subsequent distillation to form a
second distillate and a second residue, thereby further purifying
and/or separating the unsaponifiable compounds.
[0060] The methods disclosed herein comprise multiple steps. Which
steps are used will vary depending on several factors, including,
but not limited to, the identities of the starting material and
desired target(s) and valuable product(s). For some materials, it
is desired to perform one or more steps of pre-treatment with
regard to cleaning up the material for further processing. Such
cleaning methods include, but are not limited to, rinsing, washing,
filtering, and decanting.
[0061] In an embodiment, the process is performed in an alcoholic
medium, which generates sub-products from the contaminants with
adequate quality to be marketed directly, representing an
additional source of earnings for the production of biodiesel.
Because the process is preferably performed in an alcoholic medium,
insolubility of certain byproducts results. These insoluble
byproducts can be easily separated. Separation is preferably by
filtration. The sodium sulfate produced is easily separated from
the rest of the process, and finds application in the industry
generally as commercial grade sodium sulfate. The organic byproduct
material containing materials, such as polypeptides and lecithin,
is easily separated from the rest of the products and can be
marketed as an industrial emulsifier or animal feed additive. The
preferred process also yields other valuable products, such as
sterols, from subsequent purification steps.
[0062] The following non-limiting examples illustrate additional
embodiments of biodiesel (methylic or ethylic esters) production
and separation from refining soapstock. The disclosure below is of
specific examples setting forth preferred methods. These examples
are not intended to limit the scope, but rather exemplify preferred
embodiments.
EXAMPLE 1
[0063] About 1 kg of refinery soapstock, with 65% moisture content,
obtained from refining soy oil, was dissolved in about 5 kg of
ethyl alcohol and saponified under reflux, in the presence of about
40 g of sodium hydroxide solution/50% of concentration. The product
was then heated at atmospheric pressure until the alcohol began to
boil and reflux back to the reacting medium, at a temperature
around 65.degree. C. to 90.degree. C. The reaction was performed
for about 30 to 90 minutes, when substantial oil/triglycerides
present in the refining soapstock were converted into sodium soap.
The alcoholic solution was then filtered to separate the organic
material, mainly composed of lecithin and gums that, under the
conditions above, do not react and are not soluble; about 107.8 g
of lecithin and gums were obtained. This organic contaminant is
present as a crystalline material.
[0064] The filtered lecithin and gums were then dried.
[0065] The alcoholic solution was again heated under the same
reflux conditions for another period of about 30 to 90 minutes,
after the addition of about 240 g of concentrated sulfuric acid.
During this period, the sulfuric acid reacted with the sodium soap
to form fatty acids and sodium sulfate. Under the reacting
conditions, sodium sulfate, which is not soluble, was filtered,
producing 123 g of a white crystalline material.
[0066] After filtering sodium sulfate, the material was again
heated under reflux to esterify the free fatty acids with the ethyl
alcohol present. The reaction was performed for about 30 to 90
minutes. Excess sulfuric acid was neutralized by adding about 90 g
calcium hydroxide. After the neutralization reaction of the free
mineral acid, the material was filtered to remove the calcium salts
formed. About 255.6 g calcium sulfate was produced.
[0067] The alcoholic solution obtained comprises a solution of
ethyl esters of soy fatty acids in ethyl alcohol. The alcoholic
solution was then heated to distill excess ethyl alcohol. The
distillation was performed at temperatures around 75.degree. C. to
90.degree. C. and at pressures around 760 mmHg to 100 mmHg to yield
ethyl alcohol and the ethyl ester/biodiesel.
[0068] The ethyl ester was centrifuged to remove the insoluble
contaminants and other precipitates; about 239.2 g of impurities
were eliminated.
[0069] The clear ethyl ester obtained from the soy oil refinery
soapstock was then distilled for final purification and to meet the
international Biodiesel specifications. This distillation was
performed in a distillation system under vacuum, at a temperature
around 180.degree. C. to 250.degree. C. and a pressure varying from
3 mmHg to 760 mmHg. An ethyl ester from soy fatty acids was
obtained; the analytical data of this product are found in Table 1
and the material meets the biodiesel specification established
worldwide. 326 g of ethyl esters/Biodiesel were obtained.
EXAMPLE 2
[0070] About 1 kg of refinery soapstock, with 65% moisture content,
obtained from refining of soy oil, was diluted in about 5 kg of
methyl alcohol and saponified under reflux, in the presence of
about 40 g of sodium hydroxide solution/50% concentration. The
product was then heated at atmospheric pressure until the point
where the alcohol began to boil and reflux back to the reacting
medium, at a temperature around 65.degree. C. to 90.degree. C. The
reaction was performed for about 30 to 90 minutes, when substantial
triglycerides present in the refining soapstock were converted into
sodium soap. The alcoholic solution was then filtered to separate
the organic material, mainly composed of lecithin and gums that,
under the conditions above, did not react and are not soluble;
about 109 g of lecithin and gums were obtained. This organic
contaminant is present, after filtration, as a crystalline
material.
[0071] The filtered lecithin and gums were then dried.
[0072] The alcoholic solution was heated under the same reflux
conditions for another period of about 30 to 90 minutes, after the
addition of 235 g of concentrated sulfuric acid. During this
period, the sulfuric acid reacted with the sodium soap to form
fatty acids and sodium sulfate. Under the reacting conditions,
sodium sulfate, which is not soluble, was filtered, producing 120 g
of a white crystalline material.
[0073] After filtering sodium sulfate, the material was again
heated under reflux to esterify the free fatty acids with the ethyl
alcohol present. The reaction was performed for about 30 to 90
minutes. Excess sulfuric acid was neutralized by adding about 90 g
calcium hydroxide. After the neutralization reaction of the free
mineral acid, the material was filtered to remove the calcium salts
formed. About 250 g calcium sulfate was produced.
[0074] The alcoholic solution obtained comprises a solution of
methyl esters of soy fatty acids in methyl alcohol. The alcoholic
solution was then heated to distill excess methyl alcohol. The
distillation was performed at temperatures around 75.degree. C. to
90.degree. C. and at pressures around 760 mmHg to 100 mmHg to yield
methyl alcohol and the methyl ester/biodiesel.
[0075] The methyl ester was centrifuged to remove the insoluble
contaminants and other precipitates; about 230 g of impurities were
eliminated.
[0076] The clear methyl ester obtained from the soy oil refinery
soapstock was then distilled for final purification and to meet the
international Biodiesel specifications. This distillation was
performed in a distillation system under vacuum, at a temperature
around 60.degree. C. to 100.degree. C. and a pressure varying from
3 mmHg to 760 mmHg. A methyl ester from soy fatty acids was
obtained; the analytical data of this product are found in Table 1
and the material meets the biodiesel specification established
worldwide. 327 g of methyl esters/Biodiesel were obtained.
EXAMPLE 3
[0077] About 1 kg of refinery soapstock, with 65% moisture content,
obtained from refining soy oil, was dissolved in about 5 kg of
ethylic alcohol and saponified under reflux, in the presence of
about 40 g of sodium hydroxide solution/50% of concentration. The
product was then heated at atmospheric pressure until the alcohol
began to boil and reflux back to the reacting medium, at a
temperature around 65.degree. C. to 90.degree. C. The reaction was
performed for about 30 to 90 minutes, when substantial
oil/triglycerides present in the refining soapstock were converted
into sodium soap. The alcoholic solution was then filtered to
separate the organic material, mainly composed of lecithin and gums
that, under the conditions above, do not react and are not soluble;
about 109 g of lecithin and gums were obtained. This organic
contaminant is present as a crystalline material.
[0078] The filtered lecithin and gums were then dried.
[0079] The alcoholic solution was again heated under the same
reflux conditions for another period of about 30 to 90 minutes,
after the addition of about 240 g of concentrated sulfuric acid.
During this period, the sulfuric acid reacted with the sodium soap
to form fatty acids and sodium sulfate. Under the reacting
conditions, sodium sulfate, which is not soluble, was filtered,
producing 125 g of a white crystalline material.
[0080] After filtering sodium sulfate, the material was again
heated under reflux to esterify the free fatty acids with the ethyl
alcohol present. The reaction was performed for about 30 to 90
minutes. Excess sulfuric acid was neutralized by adding about 90 g
calcium hydroxide. After the neutralization reaction of the free
mineral acid, the material was filtered to remove the calcium salts
formed. About 250 g calcium sulfate was produced.
[0081] The alcoholic solution obtained comprises a solution of
ethyl esters of soy fatty acids in ethyl alcohol. The alcoholic
solution was then heated to distill excess ethyl alcohol. The
distillation was performed at temperatures around 75.degree. C. to
90.degree. C. and at pressures around 760 mmHg to 100 mmHg to yield
ethyl alcohol and the ethyl ester/biodiesel.
[0082] The ethyl ester was centrifuged to remove the insoluble
contaminants and other precipitates; about 240 g of impurities were
eliminated.
[0083] The clear ethyl ester obtained from the soy oil refinery
soapstock was then distilled for final purification and to meet the
international Biodiesel specifications. This distillation was
performed in a distillation system under vacuum, at a temperature
around 180.degree. C. to 250.degree. C. and a pressure varying from
3 mmHg to 760 mmHg. An ethyl ester from soy fatty acids was
obtained; the analytical data of this product are found in Table 1
and the material meets the biodiesel specification established
worldwide. 352 g of ethyl esters/Biodiesel were obtained.
[0084] Below, Table 1, that presents the parameter and conditions
in which the examples described in this descriptive report were
performed. TABLE-US-00001 TABLE 1 Parameters Methodology Results
Flash point in ASTM D 93 166.degree. C. closed vessel Water and
ASTM D 1796 0.0% in volume sediments Cinematic ASTM D 445 4.52 cSt
viscosity at 40.degree. C. Sulfated ashes ASTM D 874 0.001% in
weight Corrosion to ASTM D 130 1a copper at 50.degree. C. Cetane
index ASTM D 4737 63.3 Ramsbotton ASTM D 524 2.06% in weight carbon
residue Sodium plasma spectrometry 7.00 mg/kg Potassium plasma
spectrometry <2.0 mg/kg Calcium plasma spectrometry 10 mg/kg
Magnesium plasma spectrometry 0.5 mg/kg Density 20/4.degree. C.
ASTM D 1298 876.1 kg/m.sup.3 Distillation under ASTM D 1160 start -
318.0.degree. C. vacuum 5% of the volume - 342.0.degree. C. 10% in
volume - 343.0.degree. C. 20% in volume - 344.0.degree. C. 30% in
volume - 346.0.degree. C. 40% in volume - 346.0.degree. C. 50% in
volume - 348.0.degree. C. 60% in volume - 349.0.degree. C. 70% in
volume - 351.0.degree. C. 80% in volume - 353.0.degree. C. 90% in
volume - 354.0.degree. C. 95% in volume - 365.5.degree. C. finish -
377.0.degree. C.
[0085] Many modifications and variations of the embodiments
described herein may be made without departing from the scope, as
is apparent to those skilled in the art. The specific embodiments
described herein are offered by way of example only.
* * * * *