TECHNICAL FIELD
[0001] The present invention relates generally to the field of reclamation of fatty acids. More specifically, the present invention relates to a method of extraction of oleic acid or salt thereof from a degraded vegetable oil.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] For many years, lubricity of automobile fuel distilled out of fossil was sufficient to provide the protection needed to maintain adequate performance. Recent changes in the composition of automobile fuel, primarily the need to reduce fuel sulfur and aromatic compound levels, and the common chemical process used to accomplish these changes have inadvertently caused the removal of some of the compounds that provide lubricity to the fuel. Lubricity of the fuel plays a very important role in determining the life and safety of an automobile. It determines the amount of wear or scarring that occurs between two parts covered with the fuel when they come in contact with each other. Low lubricity fuel may cause high wear and scarring, and high lubricity fuel may provide reduced wear and longer component life.
[0004] A vegetable oil is a triglyceride extracted from a oil producing plant, and their availability as a used and degraded oil is rapidly increasing due to progressive rise in population. Such degraded vegetable oil is not suitable for cooking purpose due to presence and/or accumulation of various undesired chemicals therein. Degraded vegetable oil can act as an excellent fuel additive that can improve the lubricating properties of the fuel. However, its purity as a lubricating additive is still a matter of grave concern. Numerous incidence are reported where lack of lubricity or presence of an impurity has caused premature equipment breakdowns, and in some cases catastrophic failures.
[0005] Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. Chemically, it is classified as a monounsaturated omega-9 fatty acid. It is a potential lubricating additive in a fuel, at a very low concentration. Oleic acid forms a protective lubricating film on the contacting surface, reduces friction and limits wear and tear.
[0006] Presently, the process for complete separation of such additive in its purest form from the degraded vegetable oil is still lacking. Using distillation alone is not a practical approach to produce pure oleic acid, as the boiling points of all fatty acids such as stearic, oleic, linoleic and linolenic acids are very close to each together, hence, effective separation requires efficient skills and expense. Further, high temperatures and longer duration of the process may results in isomerization and/or polymerization of the unsaturated acids.
[0007] There is therefore, a need in the art to develop a new or improved method of reclamation of oleic acid from degraded vegetable oil to obviate the problems associated with the existing method of extraction.

OBJECTS OF THE INVENTION
[0008] An object of the present disclosure is to overcome the disadvantages associated with the conventional method of reclamation of fatty acid(s), specifically oleic acid, from a degraded vegetable oil.
[0009] Another object of the present disclosure is to provide a method for extraction of a fatty acid from a degraded vegetable oil.
[0010] Another object of the present disclosure is to provide a method of extraction of oleic acid or salt thereof from a degraded vegetable oil.
[0011] Another object of the present disclosure is to provide a method of extraction of oleic acid or salt thereof from a degraded vegetable oil with a purity grade sufficient to use as a lubricating fuel additive.
[0012] Another object of the present disclosure is to provide a method of extraction of oleic acid or salt thereof from a degraded vegetable oil that is less time consuming.
[0013] Another object of the present disclosure is to provide a method of extraction of oleic acid or salt thereof from a degraded vegetable oil that is easy to setup.
[0014] Another object of the present disclosure is to provide a method of extraction of oleic acid or salt thereof from a degraded vegetable oil that is safe.
[0015] Another object of the present disclosure is to provide a method of extraction of oleic acid or salt thereof from a degraded vegetable oil that is cost-effective.
[0016] Sill further object of the present disclosure is to provide degraded vegetable oil as a source of biodiesel.
[0017] Sill further object of the present disclosure is to provide degraded vegetable oil as a source of fatty acid esters.

SUMMARY
[0018] The present invention relates generally to the field of reclamation of fatty acids. More specifically, the present invention relates to a method of extraction of oleic acid or salt thereof from a degraded vegetable oil.
[0019] An aspect of the present disclosure relates to a method of extraction of oleic acid or salt thereof from a degraded vegetable oil, the method including the steps of: subjecting the degraded vegetable oil to a vacuum distillation process to obtain a distillate rich in triolein; subjecting the distillate to a de-esterification process to render free fatty acid(s); subjecting the de-esterified distillate to a precipitation process, wherein the precipitation process affords to substantially segregate unsaturated fatty acid(s) from saturated fatty acid(s); and subjecting the unsaturated fatty acid(s) to a crystallization process, wherein the crystallization process affords segregation of substantially pure oleic acid from other unsaturated fatty acid(s). In an embodiment, the degraded vegetable oil includes a mixture of a plurality of saturated fatty acids and/or derivatives thereof and unsaturated fatty acids and/or derivatives thereof. In an embodiment, the method is devoid of utilization of a catalyst.
[0020] In an embodiment, the vacuum distillation process includes a fractional vacuum distillation, and wherein the fractional vacuum distillation is operated at a pressure ranging from about 6 torr to about 10 torr. In an embodiment, the distillate rich in triolein is obtained at a temperature ranging from about 220 degree Centigrade to about 250 degree Centigrade. In an embodiment, the de-esterification process includes: treating the distillate with a base at an elevated temperature; and separating glycerol and salt of free fatty acid(s) by subjecting the de-esterified distillate to a filtration. In an embodiment, the de-esterification process includes treating the distillate with NaOH at the temperature ranging from about 100 degree Centigrade to about 150 degree Centigrade for a time ranging from about 120 minutes to about 180 minutes. In an embodiment, the salt of free fatty acid(s) can be subjected to neutralization by preparing an aqueous solution of the salt of free fatty acid(s) and treating it with an acid to render the free fatty acid(s).
[0021] In an embodiment, the precipitation process includes the steps of: dissolving the free fatty acids in a solvent including a mixture of water and an organic solvent at a temperature ranging from about 40 degree Centigrade to about 50 degree Centigrade; cooling the solution of the dissolved free fatty acids to a temperature ranging from about 30 degree Centigrade to about 37 degree Centigrade; allowing formation of precipitate in the cooled solution of free fatty acids; and segregating the precipitate to afford a solution substantially including unsaturated fatty acids. In an embodiment, the precipitation process further includes the step subjecting the solution substantially including unsaturated fatty acids to evaporation, at least in part, to afford unsaturated fatty acid(s).
[0022] In an embodiment, the crystallization process includes the steps of: preparing a homogenous solution of the unsaturated fatty acid(s); cooling the homogenous solution to afford crystallization of unsaturated fatty acid(s) other than oleic acid; and separating the crystals of unsaturated fatty acid(s) other than oleic acid to afford the substantially pure oleic acid. In an embodiment, the oleic acid is used as a lubricant additive in a fuel. In an embodiment, the oleic acid is utilized for production of biodiesel. In an embodiment, the oleic acid is utilized for production of fatty acid esters.
[0023] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

DETAILED DESCRIPTION
[0024] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0025] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the “invention” may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the “invention” will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0026] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0027] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0028] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0029] The present invention relates generally to the field of reclamation of fatty acids. More specifically, the present invention relates to a method of extraction of oleic acid or salt thereof from a degraded vegetable oil.
[0030] An aspect of the present disclosure relates to a method of extraction of oleic acid or salt thereof from a degraded vegetable oil, the method including the steps of: subjecting the degraded vegetable oil to a vacuum distillation process to obtain a distillate rich in triolein; subjecting the distillate to a de-esterification process to render free fatty acid(s); subjecting the de-esterified distillate to a precipitation process, wherein the precipitation process affords to substantially segregate unsaturated fatty acid(s) from saturated fatty acid(s); and subjecting the unsaturated fatty acid(s) to a crystallization process, wherein the crystallization process affords segregation of substantially pure oleic acid from other unsaturated fatty acid(s). In an embodiment, the degraded vegetable oil includes a mixture of a plurality of saturated fatty acids and/or derivatives thereof and unsaturated fatty acids and/or derivatives thereof. In an embodiment, the method is devoid of utilization of a catalyst. In an embodiment, the degraded vegetable oil includes any or a combination of vegetable oil(s) already used in the cooking and the like purposes, further utility of which, in the cooking and like purposes, is undesired due to accumulation of various chemicals/degradation products therein.
[0031] In an embodiment, the vacuum distillation process includes a fractional vacuum distillation, and wherein the fractional vacuum distillation is operated at a reduced pressure ranging from about 6 torr to about 10 torr. In an embodiment, the distillate rich in triolein is obtained at a temperature ranging from about 220 degree Centigrade to about 250 degree Centigrade. In an embodiment, the de-esterification process includes: treating the distillate with a base at an elevated temperature; and separating glycerol and salt of free fatty acid(s) by subjecting the de-esterified distillate to a filtration. In an embodiment, the de-esterification process includes treating the distillate with NaOH at the temperature ranging from about 100 degree Centigrade to about 150 degree Centigrade for a time ranging from about 120 minutes to about 180 minutes. In an embodiment, the salt of free fatty acid(s) are subjected to neutralization by preparing an aqueous solution of the salt of free fatty acid(s) and treating it with an acid to render the free fatty acid(s).
[0032] In an embodiment, the precipitation process includes the steps of: dissolving the free fatty acids in a solvent including a mixture of water and an organic solvent at a temperature ranging from about 40 degree Centigrade to about 50 degree Centigrade; cooling the solution of the dissolved free fatty acids to a temperature ranging from about 30 degree Centigrade to about 37 degree Centigrade; allowing formation of precipitate in the cooled solution of free fatty acids; and segregating the precipitate to afford a solution substantially including unsaturated fatty acids. In an embodiment, the precipitation process further includes the step subjecting the solution substantially including unsaturated fatty acids to evaporation, at least in part, to afford unsaturated fatty acid(s).
[0033] In an embodiment, the crystallization process includes the steps of: preparing a homogenous solution of the unsaturated fatty acid(s); cooling the homogenous solution to afford crystallization of unsaturated fatty acid(s) other than oleic acid; and separating the crystals of unsaturated fatty acid(s) other than oleic acid to afford the substantially pure oleic acid. In an embodiment, the oleic acid is used as a lubricant additive in a fuel. In an embodiment, the reclaimed oleic acid as realized in accordance with embodiments of the present disclosure is utilized for production of biodiesel therefrom utilizing method(s) as known to or appreciated by a person skilled in the pertinent art. In an embodiment, the reclaimed oleic acid is utilized for production of fatty acid esters therefrom utilizing method(s) as known to or appreciated by a person skilled in the pertinent art.
[0034] In an embodiment, extraction of oleic acid or salt thereof from a degraded vegetable oil includes the fractional vacuum distillation of the degraded vegetable oil to obtain a distillate rich in triolein. In an embodiment, fractional vacuum distillation is operated at a reduced pressure ranging from about 6 torr to about 10 torr, preferably, from about 7 torr to about 8 torr. In an embodiment, the fractional vacuum distillation is operated at a temperature ranging from about 220 degree Centigrade to about 250 degree Centigrade, preferably, from about 230 degree Centigrade to about 240 degree Centigrade. In an embodiment, the fractional vacuum distillation is operated at a reduced pressure ranging from about 7 torr to about 8 torr and at a temperature ranging from about 230 degree Centigrade to about 240 degree Centigrade. In an embodiment, the fractional vacuum distillation of the degraded vegetable oil gives a distillate rich in triolein. In an embodiment, triolein is a triglyceride derived from glycerol and three units of the unsaturated fatty acid oleic acid. In an embodiment, triolein is a rich source of oleic acid includes about 75% to about 85% oleic acid. In an embodiment, a setup for fractional vacuum distillation can be of any type as known to or appreciated by a person skilled in the art to serve its intended purpose of collection of distillate rich in triolein from the degraded vegetable oil as laid down in the present disclosure without departing from the scope and spirit of the present invention.
[0035] In an embodiment, the distillate rich in triolein obtained by the fractional vacuum distillation of the degraded vegetable oil is subjected to de-esterification process to render free fatty acid(s). In an embodiment, de-esterification process includes the treatment of distillate with a base at an elevated temperature over a time-period to obtain a salt of free fatty acid(s) and glycerol. In an embodiment, the base can be of any type as known to or appreciated by a person skilled in the art to serve its intended purpose of formation of salt with the distillate as laid down in the present disclosure without departing from the scope and spirit of the present invention. In an embodiment, the base includes but not limited to NaOH, KOH, Mg(OH)2, Ca(OH)2 and the likes or combination thereof.
[0036] In an embodiment, de-esterification process can be carried out at a temperature ranging from about 100 degree Centigrade to about 150 degree Centigrade, preferably from about 100 degree Centigrade to about 130 degree, and more preferably about 100 degree Centigrade. In an embodiment, de-esterification can be carried out for a time ranging from about 120 minutes to about 180 minutes, preferably about 160 minutes, and more preferably about 180 minutes. In an embodiment, de-esterification process of the distillate rich in triolein is carried out in the presence of NaOH at about 100 degree centigrade for about 180 minutes to obtain a sodium salt of free fatty acid(s) and glycerol. In an embodiment, glycerol is separated from salt of free fatty acid(s) by conventional filtration method.
[0037] In an embodiment, the salt of free fatty acid(s) is neutralized by treating an aqueous solution of the salt of free fatty acid(s) with an acid to render free fatty acid(s). In an embodiment, the acid can be of any type as known to or appreciated by a person skilled in the art to serve its intended purpose of neutralization of the aqueous solution of salt of free fatty acid(s) laid down in the present disclosure without departing from the scope and spirit of the present invention. In an embodiment, the acid includes but not limited to, HCl, H2SO4, and the likes or combination thereof.
[0038] In an embodiment, the free fatty acid(s) obtained after de-esterification process can be precipitated by a precipitation process that affords to substantially segregate unsaturated fatty acid(s) from saturated fatty acid(s). In an embodiment, the free fatty acid(s) is dissolve in a suitable solvent or a combination of suitable solvents at a specific temperature range followed by cooling to form precipitate of saturated fatty acids(s) and a filtrate containing unsaturated fatty acids. In an embodiment, the precipitate of saturated fatty acids(s) is separated from the filtrate by conventional filtration method. In an embodiment, the process further includes evaporation of solvent present in the filtrate to obtain saturated fatty acid(s) as a solid residue.
[0039] In an embodiment, the suitable solvents include but not limited to, acetonitrile, acetone, tertiary butanol, methanol, ethanol, isopropyl alcohol, ethylacetate, water and the likes or a combination thereof. However, a person skilled in the art would appreciate that any other solvent or a combination of solvents can be utilized to serve the intended purpose without departing from the scope and spirit of the invention. In an embodiment, the suitable solvent is a combination of acetonitrile and water. In an embodiment, the combination includes at least one solvent in an amount ranging from about 92 % to about 97% by volume of the mixture of solvents, preferably 95%. In an embodiment, acetonitrile is present in an amount of about 95% and water in an amount of about 5% by volume of the mixture of solvents.
[0040] In an embodiment, the free fatty acid(s) dissolve in a suitable solvent are heated to a temperature ranging from about 40 degree Centigrade to about 50 degree Centigrade, preferably about 45 degree centigrade. In an embodiment, solution of the free fatty acid(s) dissolve in a suitable solvent is cooled to a temperature ranging from about 30 degree Centigrade to about 37 degree Centigrade, preferably about 35 degree centigrade to obtain the precipitate of saturated fatty acids(s) and a filtrate. In an embodiment, the precipitate of saturated fatty acids(s) accounts for about 35 to about 45% of the original degraded vegetable oil feedstock, and is consist essentially of about 93% to about 95% saturated acid(s) and about 5% to about 7% unsaturated acids. In an embodiment, a solid residue obtained after the evaporation of the above filtrate accounts for about 55% to about 65% of the original degraded vegetable oil feedstock, and is consist essentially of about 93% to about 95% unsaturated acid(s) such as but not limited to, oleic acid, linoleic acid, linolenic acid and the likes, and about 5% to about 7% saturated acids such as but not limited to, stearic acid, palmitic acid and the likes.
[0041] In an embodiment, the solid residue of unsaturated fatty acid(s) is dissolve in a suitable solvent or a combination of suitable solvent to form a homogenous solution followed by cooling to afford crystallization of unsaturated fatty acid(s) other than oleic acid and separation of crystals of unsaturated fatty acid(s) other than oleic acid to afford the substantially pure oleic acid.
[0042] In an embodiment, the suitable solvents include but not limited to, acetonitrile, acetone, tertiary butanol, methanol, ethanol, isopropyl alcohol, ethylacetate, water and the likes or a combination thereof. However, a person skilled in the art would appreciate that any other solvent or a combination of solvents can be utilized to serve the intended purpose without departing from the scope and spirit of the invention. In an embodiment, the suitable solvent is a combination of acetonitrile and water. In an embodiment, the combination includes at least one solvent in an amount ranging from about 75% to about 98% by volume of the mixture of solvents, preferably in an amount ranging from about 80% to about 95% by volume of the mixture of solvents. In an embodiment, the suitable solvent is a combination of acetonitrile in an amount ranging from about 80% to about 95% by volume of the mixture of solvents and water in an amount ranging from about 5% to about 20% by volume of the mixture of solvents.
[0043] In an embodiment, the homogenous solution is cooled upto a temperature ranging from about 3 degree Centigrade to about 5 degree Centigrade above to the temperature at which the oleic acid and solvent separate into two immiscible layers to afford crystallization of unsaturated fatty acid(s) other than oleic acid. In an embodiment, the homogenous solution is cooled upto a temperature of about 5 degree Centigrade above the temperature at which the oleic acid and solvent separate into two immiscible layers to afford crystallization of unsaturated fatty acid(s) other than oleic acid. In an embodiment, crystals of unsaturated fatty acid(s) other than oleic acid are separated from oleic acid by conventional filtration method to afford the substantially pure oleic acid as filtrate. In an embodiment, pure oleic acid obtained above accounts for about 75% to about 80% of the unsaturated acid(s) of the original degraded vegetable oil feedstock.
[0044] In an embodiment, oleic acid can be used as lubricant additive in an automobile fuel. In an embodiment, the fuel includes such as but not limited to petrol, diesel, kerosene and the likes or a combination thereof. However, a person skilled in the art would appreciate that any other fuel or a combination of fuel can be utilized to serve the intended purpose without departing from the scope and spirit of the invention.
[0045] In an alternate embodiment, the method used in the present invention for the reclamation of oleic acid from the degraded vegetable oil is advantageous as it is devoid of utilization of a catalyst. In an embodiment, a monosaturated C18 fatty acid exists in two isomeric forms; a cis-isomer (Oleic Acid) and a trans-isomer (elaidic acid). Oleic acid i.e. the cis-isomer exists as a liquid at room temperature (melting point of about 13.2 degree Centigrade). The trans-isomer i.e elaidic acid exists as a white solid at room temperature (melting point of about 43.7 degree Centigrade) and is thermodynamically more stable than oleic acid. In an embodiment, use of any catalyst for the synthesis of oleic acid will produce large amount of eladic acid until equilibrium is established, wherein the mixture will majorly consist of elaidic acid.
[0046] The present disclosure is further explained in the form of an example. However, it is to be understood that the foregoing example is merely illustrative and is not to be taken as limitations upon the scope of the invention. Various changes and modifications to the disclosed embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the scope of the invention.
EXAMPLE - Reclamation of oleic acid from degraded vegetable oil
[0047] Fractional distillation of degraded vegetable oil
[0048] In a five litre of round bottom flask, about two litres of degraded vegetable oil was taken and was distilled by fractional vacuum distillation under a pressure of about 7-8 torr and temperature of about 230 degree Centigrade to 250 degree Centigrade. The distillate was obtained at a temperature range of about 230 degree Centigrade to 240 degree Centigrade. It was collected and analysed by gas chromatography (GC) and was found to contain high percentage of triolein.
[0049] De-esterfication of the distillate
[0050] One litre of the above distillate was taken in a five litre one neck round bottom flask and about 1300 g to 1500 g of 10% sodium hydroxide was added to it. The mixture was stirred and reflux for about 3 hours at about 100 degree Centigrade to 150 degree Centigrade. Thereafter, it was heated to about 100 degree Centigrade to evaporate the water, leaving behind the sodium salts of oleic acid, linolenic acid, linoleic acid, stearic acid and other oils in glycerol. The solution was cooled to room temperature and glycerol was filtered. The filtrate containing sodium salts of oleic acid, linoleic acid, linolenic acid, stearic acid and palmitic acid were diluted ten times with water. The dilution was followed by the addition of one molar equivalent 12M hydrochloric acid, and was stirred for about 0.5 hr to 1.0 hr to obtain a double layer solution. Thereafter, water was decanted from the above double layered solution, and a thick liquid of free fatty acids feedstock containing oleic acid, linoleic acid, linolenic acid, stearic acid and palmitic acids was obtained.
[0051] Precipitation of the free fatty acid feedstock to segregate unsaturated fatty acid from saturated fatty acid
[0052] One part of the above free fatty acid feedstock was taken, and dissolved in three parts of a solvent system consisting of about 95% acetonitrile and about 5% water, at about 45 degree Centigrade. Later, the above mixture was cooled to about 35 degree Centigrade, and a solid matter precipitated out that was removed by filtration. This precipitate accounts for about 40% of the original degraded vegetable oil feedstock and consisted essentially of about 95% saturated acids with only 5% unsaturated acids. The filtrate (liquid part) was heated to evaporate the solvents and the residue was collected. This residue accounts for about 60% of the original degraded vegetable oil feedstock and consisted essentially of about 95% unsaturated acids (oleic acid, linoleic acid and linolenic acid) with only 5% saturated acids (stearic acid and palmitic acid).
[0053] Crystallization of unsaturated fatty acid to obtain pure oleic acid
[0054] Thereafter, the above residue was dissolved in an aqueous acetonitrile solution (containing about 5 to 20% water) by heating till a homogenous solution was obtained. The homogenous solution was cooled to facilitate the crystallization of stearic acid and palmitic acid to a temperature being above but not over 5 degree Centigrade above the temperature at which the oleic acid and solvent separate into two immiscible layers. Stearic acid and palmitic acid crystals are removed from the solution by conventional filtration techniques. The filtrate or the liquid left behind is the pure oleic acid liquid.
[0055] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE INVENTION
[0056] The present disclosure provides a method to overcome the disadvantages associated with the conventional method of reclamation of fatty acid(s) from an oil source.
[0057] The present disclosure provides a method for extraction of a fatty acid from a degraded vegetable oil.
[0058] The present disclosure provides a method of extraction of oleic acid or salt thereof from a degraded vegetable oil.
[0059] The present disclosure provides a method of extraction of oleic acid or salt thereof from a degraded vegetable oil with purity good enough to use as a lubricating fuel additive.
[0060] The present disclosure provides a method of extraction of oleic acid or salt thereof from a degraded vegetable oil that is less time consuming.
[0061] The present disclosure provides a method of extraction of oleic acid or salt thereof from a degraded vegetable oil that is easy to setup.
[0062] The present disclosure provides a method of extraction of oleic acid or salt thereof from a degraded vegetable oil that is safe.
[0063] The present disclosure provides a method of extraction of oleic acid or salt thereof from a degraded vegetable oil that is cost-effective.
[0064] The present disclosure provides a method of extraction of oleic acid or salt thereof from a degraded vegetable oil that can find utility in production of any of biodiesel and fatty acid esters.

Claims:
1. A method of extraction of oleic acid or salt thereof from a degraded vegetable oil, the method comprising the steps of:
subjecting the degraded vegetable oil to a vacuum distillation process to obtain a distillate rich in triolein;
subjecting said distillate to a de-esterification process to render free fatty acid(s);
subjecting said de-esterified distillate to a precipitation process, wherein said precipitation process affords to substantially segregate unsaturated fatty acid(s) from saturated fatty acid(s); and
subjecting said unsaturated fatty acid(s) to a crystallization process, wherein said crystallization process affords segregation of substantially pure oleic acid from other unsaturated fatty acid(s).
2. The method as claimed in claim 1, wherein said method is devoid of utilization of a catalyst.
3. The method as claimed in claim 1, wherein said vacuum distillation process comprises a fractional vacuum distillation, and wherein said fractional vacuum distillation is operated at a reduced pressure ranging from about 6 torr to about 10 torr.
4. The method as claimed in claim 3, wherein said distillate rich in triolein is obtained at a temperature ranging from about 220 degree Centigrade to about 250 degree Centigrade.
5. The method as claimed in claim 1, wherein said de-esterification process comprises: treating said distillate with a base at an elevated temperature; and separating glycerol and salt of free fatty acid(s) by subjecting said de-esterified distillate to a filtration.
6. The method as claimed in claim 5, wherein said de-esterification process comprises treating said distillate with NaOH at the temperature ranging from about 100 degree Centigrade to about 150 degree Centigrade for a time ranging from about 120 minutes to about 180 minutes.
7. The method as claimed in claim 5, wherein said salt of free fatty acid(s) are subjected to neutralization by preparing an aqueous solution of said salt of free fatty acid(s) and treating it with an acid to render the free fatty acid(s).
8. The method as claimed in claim 1, wherein said precipitation process comprises the steps of:
dissolving said free fatty acids in a solvent comprising a mixture of water and an organic solvent at a temperature ranging from about 40 degree Centigrade to about 50 degree Centigrade;
cooling said solution of the dissolved free fatty acids to a temperature ranging from about 30 degree Centigrade to about 37 degree Centigrade;
allowing formation of precipitate in said cooled solution of free fatty acids; and
segregating said precipitate to afford a solution substantially comprising unsaturated fatty acids.
9. The method as claimed in claim 8, wherein said precipitation process further comprises the step subjecting said solution substantially comprising unsaturated fatty acids to evaporation, at least in part, to afford unsaturated fatty acid(s).
10. The method as claimed in claim 1, wherein said crystallization process comprises the steps of:
preparing a homogenous solution of the unsaturated fatty acid(s);
cooling said homogenous solution to afford crystallization of unsaturated fatty acid(s) other than oleic acid; and
separating said crystals of unsaturated fatty acid(s) other than oleic acid to afford the substantially pure oleic acid.
11. The method as claimed in claim 1, wherein said oleic acid is used as a lu e method as claimed in claim 1, wherein said oleic acid is used for production of any or a combination of biodiesel and fatty acid esters.