FORM 2
THE PATENT ACT 1970
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION
METHOD FOR THE PURIFICATION OF CRUDE RICE BRAN WAX
2. APPLICANT
(a) NAME: PRAJ INDUSTRIES LIMITED
(b) NATIONALITY: Indian Company
(b) ADDRESS: PRAJ Tower, 274-275, Bhumkar
Chowk - Hinjewadi Road, Hinjewadi, Pune-411057, INDIA
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

4. DESCRIPTION
FIELD OF INVENTION
The invention relates to a method for the purification of crude rice bran wax using an alcohol as a purifying solvent. It particularly relates to the use of ethyl alcohol as said solvent for efficient and economic purification of crude rice bran wax into economically valuable high purity wax products.
BACKGROUND
Rice is one of the most important grains in the world and India is second largest producer of it. The rice bran is a valuable by-product of rice milling industry. It is recently used for prepare edible rice bran oil as a valuable product. The bran contains about 12% to 25% oil component. Beside oil, the bran also contains about 5% waxy materials called rice bran wax, which is by-product of rice bran oil refining process. The crude wax has certain low value applications; however if purified to certain higher degree it forms a valuable product as being used in cosmetics and food preparations.
Chemically the rice bran wax is a heterogeneous product with made up of saturated monoesters of long chain fatty acid [C-22 to C-26] and long chain fatty alcohols [C-26 to C-30], Up on refining or purification the wax becomes a relatively homogenous mixture having physical

characters like melting point of about 78 °C to 82 °C , saponification value of about 70 to 120 units and iodine value of about 4 to 10 units. This purified rice bran wax then has many industrial applications like leather polishes, crayons, candles, shoe creams, paper coatings, carbon papers, lubricants etc. Other major applications are in food industry like in chocolate enrobes, vegetable coatings and wax Emulsions for fruit preservation. It is further used in pharmaceuticals products like tablets, ointments, suppositories and cosmetic products like moisturizing lotions, lipsticks, skin creams etc.
In the prior art one of the methods the rice bran wax is purified or refined is by removing the residual oil from it by hydraulic pressing to maximum extent possible, followed by extracting it in solvents like isobutanol or isopropanol with water. However, these extractions are costly for recycling of isobutanol or isopropanol in the process is expensive and efficiency of the process is limited. As the crude rice bran wax contains about 10% to 50% resinous materials besides the oil, its purification greatly increases its value and applicability. The disclosed invention describes a novel method of purification of crude rice bran wax to high purity waxes.
BRIEF DESCRIPTION OF THE INVENTION
The disclosure provides a method for purifying crude rice bran wax comprising: mixing said wax with ethanol forming a mixture; refluxing

said mixture for a desired time dissolving said wax; allowing said mixture to stand idle for desired time; separating undissolved matters from liquid fraction; cooling said liquid fraction allowing formation of crystallised wax; removing said crystallised wax by filtration; washing said crystallised wax by ethanol; repeating steps above up to four times with said undissolved matters to extract remaining wax; and pooling and drying said crystallised wax under vacuum forming a final product that is a purified rice bran wax with consistent characters of physical and chemical properties
DETAILED DESCRIPTION OF THE INVENTION
In an embodiment of the invention, the crude rice bran wax obtained as a by-product of rice bran oil refining process is dissolved in absolute ethyl alcohol. In the first step, about five parts of ethanol and one part the wax is refluxed at about 75 °C in a reflux vessel for about 1 hour to allow dissolution of rice bran wax into ethanol leaving resinous impurities undissolved in the mixture. The oil present in the crude is also dissolved in ethanol. After refluxing the mixture, the liquid fraction is decanted and allowed to cool to room temperature for the wax to crystallize out from the solution. Then the solid, wax is removed by filtration under vacuum, one washed with ethanol, optionally decoloured with an oxidizing agent, and dried to get the white to pale yellow solid mass of purified rice bran wax having consistent physical and chemical Pproperties like melting temperature

and purity. The resinous matters obtained are further subject to ethanol refluxing to recover remaining wax up to 4 times, if required. On average, the crude rice bran wax contains up to 50% oil, which is obtained as a by-product of the process disclosed herein. Further remaining resinous matters may also be as crude waxy material.
In another embodiment of the invention, ethanol used as the solvent for refluxing of the crude rice bran wax is absolute ethanol or ethanol at least 99% pure by volume. Any reduction in the purity of ethanol below 99% leads to drastic reduction in the final yield of purified rice bran wax as the presence of water in ethanol leads to reduction in dissolution of wax in ethanol.
In yet another embodiment of the invention, the refluxing of said wax and ethanol mixture is performed for at least one hour at temperature about 75 °C with an efficient condenser to prevent loss of the solvent.
In further embodiment of the invention, the purified rice bran wax is used in preparation of pharmaceutical or cosmetic products that required unique characters of the wax like its melting temperature, texture, colour, etc.

ADVANTAGES OF THE DISCLOSED PROCESS:
• The disclosed process is simple, carried out in two vessels, and hence is scalable for the large volume applications.
• The steps used for recovery are simple and efficient due to simplicity of the process.
• The disclosed process is substantially more economical compared with earlier processes.
• Ethanol is recycled in the process after simple pretreatment.
EXAMPLES
Examples provided below give wider utility of the invention without any limitations as to the variations that may be appreciated by the person skilled in the art. A non-limiting summary of various experimental results is given in the examples, which demonstrate the advantageous and novel aspects of the process disclosed herein.
EXAMPLE 1
About 100 g of crude rice bran wax containing oil and resinous matter impurities was taken in a refluxing vessel with about 500 mL of ethanol [99.9% pure by volume] forming a mixture. Then said mixture was refluxed at about 75°C for about 1 h to dissolve the wax part

and then allowed to stand idle at room temperature for about 30 min to settle the resinous mattes at the bottom of reactor. Next, the top liquid fraction containing mostly wax and oil was decanted and collected in a vessel. The' undissolved resinous matters were again subjected to the above refluxing steps with reduced amounts of ethanol at each subsequent repeat at 400 mL, 300 mL and 200 mL respectively to remove any undissolved wax. The liquid fractions after each step were collected and pooled. Next, said liquid fraction pool was cooled at room temperature, allowed to stand idle for dissolved wax to crystallize out from oil and other impurities, and then separated by vacuum filtration. Said crystallized wax was once washed with about 100 mL of ethanol and dried under vacuum to form the final wax product [purified rice bran wax]. These steps afforded about 36 g of highly pure final wax product with acid value of about 6.5 units, saponification value of about 84 units and iodine value of about 16 units with white to pale yellow coloration. Further, about 40 g of oil and about 22 g of solid resinous matters were recovered as by-products.
EXAMPLE 2
About 100 g of crude rice bran wax containing oil and resinous matter impurities was taken in a refluxing vessel with about 500 mL of ethanol [98% pure by volume] forming a mixture. Then said mixture was refluxed at about 75o C 1 h to dissolve the wax part

and then allowed to stand idle at room temperature for about 30 min to settle the resinous mattes at the bottom of reactor. Next, the top liquid fraction containing mostly wax and oil was decanted and collected in a vessel. The undissolved resinous matters were again subjected to the above refluxing steps with reduced amounts of ethanol at each subsequent repeat at 400 mL, 300 mL and 200 mL respectively to remove any undissolved wax. The liquid fractions after each step were collected and pooled. Next, said liquid fraction pool was cooled at room temperature, allowed to stand idle for dissolved wax to crystallize out from oil and other impurities, and then separated by vacuum filtration. Said crystallized wax was once washed with about 100 mL of ethanol and dried under vacuum to form the final wax product [purified rice bran wax]. These steps afforded about 18 g of highly pure final wax product with acid value of about 7 units, saponification value of about 82 units and iodine value of about 15 units with white to pale yellow coloration. Further, about 39 g of oil and about 41 g of solid resinous matters were recovered as by-products.
EXAMPLE 3
About 100 g of crude rice bran wax containing oil and resinous matter impurities was taken in a refluxing vessel with about 500 mL of ethanol [95% pure by volume] forming a mixture. Then said mixture was refluxed at about 75o C 1 h to dissolve the wax part

and then allowed to stand idle at room temperature for about 30 min to settle the resinous mattes at the bottom of reactor. Next, the top liquid fraction containing mostly wax and oil was decanted and collected in a vessel. The undissolved resinous matters were again subjected to the above refluxing steps with reduced amounts of ethanol at each subsequent repeat at 400 mL, 300 mL and 200 mL respectively to remove any undissolved wax. The liquid fractions after each step were collected and pooled. Next, said liquid fraction pool was cooled at room temperature, allowed to stand idle for dissolved wax to crystallize out from oil and other impurities, and then separated by vacuum filtration. Said crystallized wax was once washed with about 100 mL of ethanol and dried under vacuum to form the final wax product [purified rice bran wax]. These steps afforded about 12 g of highly pure final wax product with acid value of about 7.5 units, saponification value of about 83 units and iodine value of about 23 units with white to pale yellow coloration. Further, about 34 g of oil and about 50 g of solid resinous matters were recovered as by-products.
While the invention has been particularly shown and described with reference to embodiments enlisted in examples, it will be appreciated that several of the above disclosed and other features and functions, or alternatives thereof, may be desirably combined into many different systems or applications. Also that various presently unforeseen and unanticipated alternatives, modifications, variations, of improvements therein may be subsequently made by

those skilled in the art which are also intended to be encompassed by the following claims. Although the invention has been described with reference to specific preferred embodiments, it is not intended to be limited thereto; rather those having an ordinary skill in the art will recognize that variations and modifications may be made therein which are within the spirit of the invention and within the scope of the claims.

5. CLAIMS
We Claims:
1. A method for purifying crude rice bran wax comprising:
a) mixing said wax with ethanol forming a mixture;
b) refluxing said mixture for a desired time dissolving said wax;
c) allowing said mixture to stand idle for desired time;
d) separating undissolved matters from liquid fraction;
e) cooling said liquid fraction allowing formation of crystallised wax fraction;
f) removing said crystallised wax fraction by filtration;
g) washing said crystallised wax fraction by ethanol;
h) repeating steps (a) to (g) up to four times with said undissolved matters to extract remaining wax; and
i) pooling said crystallised wax fractions and drying under vacuum forming a final product.
2. A method of claim 1, wherein purity of ethanol is not less than 99% by volume.
3. A method of claim 1, wherein said refluxing is performed for at least for one hour.
4. A method of claim 1, wherein said refluxing is performed at about 75 °C.

5. A method of claim 1, wherein said liquid fraction is gradually cooled to room temperature.
6. A method of claim 1, wherein said crystallised wax fraction is filtered by vacuum filtration.
7. A method of claim 1, wherein said crude rice bran wax contains between 10% to 50% oil by weight.
8. A method of claim 1, wherein said final product is optionally decoloured using an oxidising agent.
9. A method of claim 1, wherein said final product is clear white to pale yellow in colour upon vacuum drying.
10. A wax product according to claim 1, used in cosmetic or food preparations.