FORM 2
THE PATENTS ACT, 1970
(39 OF J970)
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
[SECTION 10; RULE 13]
"A PROCESS FOR PREPARING FATTY ACIDS"
APPLICANT: GODREJ CONSUMERS PRODUCT LTD.
NATIONALITY: COMPANY INCORPORATED UNDER THE COMPANIES ACT, 1956
ADDRESS: PIROJSHANAGAR, EASTERN EXPRESS
HIGHWAY, VIKHROLI, MUMBAI- 400 079, MAHARASHTRA STATE, INDIA
THE FOLLOWING SPECIFICATION DESCRIBES THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED: -

FIELD OF INVENTION:
The present invention relates to a process of preparing fatty acids. Particularly, it relates to a process for preparing light coloured and storage stable fatty acids. The invention has been developed primarily for use in premium quality products like foods, pharmaceuticals and cosmetics and will be described hereinafter with reference to this application. However it will be appreciated that the invention is not limited to this particular field of use.
BACKGROUND OF THE INVENTION:
Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field.
Fatty acids are used in premium quality products like foods, pharmaceuticals and cosmetics. White or light coloured products signify purity and are hence more attractive to a customer. Furthermore, consumer products need to have long life spans, originating from the date of manufacture to the time they are purchased and used up by the customer. It is due to this life span that the products of commercial value need to have very good long-term storage stability. Since fatty acids are the raw materials to make these white coloured commercial products, it is important that the fatty acid prepared is very light coloured and stable upon storage.
Vegetable oils are one of the major sources of fatty acids. They contain a number of naturally occurring coloured and colour forming bodies. In the course of obtaining a vegetable oil from seed or fruit physical operations such as steaming, expelling and extraction are involved. Besides these processes, there are natural biochemical reactions that are simultaneously taking place, such as enzymatic hydrolysis, oxygenation etc. The combination of the physical operations, as well

as natural reactions, lead to degradation products of the triglycerides and fatty acids which are coloured and colour forming molecules. The degradation or breakaway molecules of the original coloured or colour forming bodies create newer coloured or colour forming bodies. Normal refining or purification processes - alkali refining, degumming, adsorptive bleaching, chemical bleaching, distillation/ deodorization can be used up to a limit to remove colour forming bodies in vegetable oil. But refining a crude oil is a very expensive option and can only be affordable for manufacture of edible oil. Oleochemical manufacturers can only afford to use crude vegetable oil for the manufacture of fatty acids.
As we progress further downstream, the crude oils undergo typical oleochemical reactions splitting, hydrogenation, and distillation. These high temperature / high pressure or high temperature / low pressure processes further affect the original and breakaway coloured and colour forming bodies in crude oil. Only limited amount knowledge is available on the structures of the original and breakaway coloured and colour forming bodies.
9
Prior Art
Our earlier patent application (241/MUM/2000) described the impurities in most of the crude oils as being saturated and unsaturated, cyclic and acyclic hydrocarbons, alcohols, esters, aldehydes, ketones and lactones. As can be seen most of the moieties are functionally unsaturated or carbonyl in nature. Hence the tendency to further degrade into smaller coloured moieties on storage and heat.
Routine hydrogenation i.e. saturation of double bond of a fatty acid are too numerous to be listed. But Hydrogenation as a means of colour reduction or colour removal or to lighten colour have been recorded.

US patent No. 4,992,157 and US Patent No. 4,897,175, describe invention for improving the colour and colour stability of a hydrocarbon fraction such as kerosene. The process involves contacting the hydrocarbon fraction with a selective hydrogenation catalyst such as sulfide nickel on an alumina/clay support in the presence of hydrogen at a temperature of about 180°C and at 100 psig reaction conditions. This results in the selective hydrogenation of conjugated unsaturates, thereby improving the colour and colour stability of the hydrocarbon fraction. That is because in the case of this hydrocarbon fraction, only unsaturated moieties are the cause of the colour instability.
The processes described in both the above mentioned patents are for improving colour and stability of only hydrocarbon fractions such as kerosene. There have been no reports of using similar treatments for fatty acid.
However, only hydrogenation will not give the desired result of obtaining a light coloured and colour stable fatty acid, since it only reduces unsaturated moieties whereas carbonyl moieties remain unchanged under these process conditions.
Sodium borohydride is a well known reducing agent for carbonyl group aldehydes, ketones, lactones and esters. All these functional groups are present in oils and fatty acids as the chromophoric coloured and colour forming bodies. Sodium borohydride as a reducing agent is well documented but its use for oils and fatty acids is rather limited.
US Patent No. 5,034,509 describes an invention for improving the colour and the stability of the colour of carboxylic acid or a mixture of the same by treating the carboxylic acid or its mixture with a hydride-yielding substance at an elevated temperature of 200 to 250°C and by distilling the mixture thus obtained. The colour and the stability of the colour of the distillate thus obtained are better than the corresponding quantities of a distillate of untreated carboxylic acid or an untreated mixture of the same. Sodium borohydride and lithium aluminum

hydride are preferred hydride-yielding substances. The method according to the invention can be applied to all carboxylic acids, advantageously to fatty acids and resin acids.
Our process of using sodium borohydride differs from that described above. But sodium borohydride reduces only carbonyl moieties not the unsaturated moieties, hence sodium borohydride treatment alone is not enough to obtain a light coloured and colour stable fatty acid. This will also be amply illustrated from the examples to follow.
OBJECT OF INVENTION:
It is an object of the invention to obviate the aforesaid drawbacks by providing a process to prepare light coloured and storage stable fatty acids.
Our inventive step therefore combines the benefits of a hydrogenation step for reducing unsaturated moieties, followed by a treatment with sodium borohydride for reduction of carbonyl moieties in the fatty acids.
The present invention discloses a process to make fatty acids obtained from vegetable oils and fats with the following distinct features:
a) White or very light colour
b) Long-term storage stability
c) Even chained carbon atoms ranging from C6 to C24.
SUMMARY OF THE INVENTION:
The present invention relates to a process for preparing fatty acids comprising the steps of:
a) Hydrogenating the crude fatty acids;
b) Distilling the hydrogenated fatty acid;

c) Treating the distilled mixture with a reducing agent;
d) Distilling the resultant mixture.
DETAILED DESCRIPTION OF THE INVENTION:
The present invention envisages a process for preparing light coloured & storage stable fatty acids, comprising the following steps:
a. Hydrogenating the given crude fatty acid.
b. Distilling the hydrogenated fatty acid (the process conditions being
maintained) depending upon the type of fatty acid in consideration.
c. Treating the distilled hydrogenated fatty acid with a reducing agent, preferably
Sodium Borohydride.
d. Distilling the treated fatty acid, the process conditions being maintained,
depending upon the type of fatty acid in consideration.
The hydrogenation at step (a) is carried out between 180°C to 210°C for a period of 1 to 6 hours.-Preferably, it is carried out at 185°C - 200°C for 2 hours. The hydrogenating reactant used in step (a) is Nickel used in 0.8% w/v. The fatty acid is selected from C6 to C24. Preferably the fatty acid is selected from C6 to CI8 (coconut fatty acid). The reduction is carried out at temperature of 28°C to 30°C for a period of 2 hours, when 100 ppm of sodium borohydride is used. Distillation is carried out at 160°C to 210°C at 1mm Hg.
The present invention will now be described with reference to the following examples. However, the examples in no way limit the scope of the invention.
Examples
The following examples are shown in respect of coconut fatty acid. However, any other fatty acid in the range from C6 to C24 can be used to show similar results.

The examples show how the combination of hydrogenation reaction and reducing reaction is inventive.
Example I
250 gms of crude Coconut fatty acid (CNFA) is taken in a two necked flask, • attached with a Vigreaux column, Perkin triangle and a receiver. The material is heated to 50°C and vacuum started. Throughout the distillation the vacuum is maintained at 1mm Hg. The distillation is carried at 210°C. The amount of distillate collected and the yield is noted. The original colour and the colour after reversion (i.e. keeping the fatty acid at 105°C for 1 hour) is read using an automatic Tintometer (see table).
Example II
550 gms of crude CNFA is taken in an autoclave and heated to 100°C under vacuum to remove any moisture if any. The vacuum is stopped and hydrogen gas is started at 400 psi. 0.8% of nickel catalyst is dosed in the autoclave. The temperature of the hydrogenation is maintained at 185-200°C. The hydrogenated sample is then distilled as per Comparative Example I. The original colour and colour after reversion (i.e. keeping the fatty acid at 105°C for 1 hour) of the hydrogenated and distilled fatty acid is read using an automatic Tintometer (see table).
Example HI
The crude CNFA is distilled by the distillation method described earlier in example 1. The distilled fatty acid is treated with 100 ppm Sodium Borohydride at room temperature for 3 hrs with constant magnetic stirring in a sealed flask. The treated fatty acid is distilled as mentioned above. The original colour and the colour after reversion (i.e. keeping the fatty acid at 105°C for 1 hour) of the once

distilled, treated and distilled fatty acid is read using an automatic Tintometer (see table).
Example IV
The crude CNFA is distilled by the distillation method described earlier in comparative example 1. The distilled fatty acid is then hydrogenated 0.8 % Nickel catalyst at 400 psi and 185 - 200°C. The hydrogenated fatty acid is again distilled as above. The origmal colour and the colour after reversion (i.e. keeping the fatty acid at 105°C for 1 hour) of the once distilled, hydrogenated and distilled fatty acid is read using an automatic Tintometer (see table).
Example V
The crude CNFA is distilled as per Example 1. The distilled fatty acid is first treated with 100 ppm Sodium Borohydride at room temperature for 3 hrs with constant magnetic stirring in a sealed flask. The fatty acid is then distilled as mentioned earlier. The distilled fatty acid is then hydrogenated with 0.8 % Nickel catalyst at 400 psi and 185 - 200°C. The hydrogenated fatty acid is again distilled as described above. The original colour and the colour after reversion (i.e. keeping the fatty acid at 105°C for 1 hour) of the fatty acid is read using an automatic Tintometer (see table).
Example VI showing Inventive Step
The crude CNFA is distilled as per Comparative Example 1. The distilled fatty acid is then hydrogenated with 0.8 % Nickel catalyst at 400 psi and 185 - 200°C. The hydrogenated fatty acid is again distilled as above. The distilled fatty acid is further treated with 100 ppm Sodium Borohydride at room temperature for 3 hrs with constant magnetic stirring in a sealed flask. The fatty acid is distilled as mentioned above. The original colour and the colour after reversion (i.e. keeping

the fatty acid at 105°C for 1 hour) of the fatty acid is read using an automatic Tintometer (see table).
Measurement Colour Values I
The Colour Values are expressed in the Lovibond R + Y scale. This scale is the universal standard for measuring the colour of oils and fatty acids in the oleochemical industry. These Colour Values are measured by the Lovibond Tintometer model PFX 990 / 995, manufactured by The Tintometer Limited, England. This instrument is the standard and approved for automatic reading of colours in the oleochemical industry. The colour of light coloured products is measured in a 5.25" long quartz cell. The "Original Colour" represents the colour bodies present in the fatty acid after treatment described in each of the examples. The colour developed after subjecting the fatty acid to the Reversion Test represents the potential colour forming bodies in the fatty acids. The Reversion Test is an accelerated storage stability test, which represents about six months of storage at room temperature in the presence of air and light. A low original colour represents a very light coloured fatty acid which also means very small amount of colour bodies in the fatty acid. A small change from the original colour to the colour after reversion indicates a smaller amount of potential colour forming bodies. This therefore indicates a truly storage stable fatty acid.
Reversion Test
Following procedure is followed for fatty acid whose colour after reversion is to be checked: About l00g of fatty acid sample is taken in a clean 150 ml hard glass test tube. The tube is then immersed in preheated constant temperature oil bath, such that the fatty acid inside the glass tube is 2" below the oil level in the bath. The temperature of bath is maintained at 105°C for 1 hour during the reversion test. After 1 hour the sample is taken out of oil bath and is cooled to a temperature which is about 10-15°C above its solidification point. The sample is

then poured in to the 5.25" long quartz cell to measure the colour. Using Lovibond Tintometer colour is measured and recorded as the "Colour after Reversion".
Results Table

Original Colour (R+Y) 5.25" cell Colour after Reversion Test (R+Y) 5.25" Cell
Example I Out of scale * Not Applicable
Example II 3.8 + 26.7 4.7 + 39.0
Example III 2.8 + 8.9 3.2 +10.1
Example IV 2.2 + 5.1 2.3 + 6.6
Example V 1.4 + 3.6 1.5 + 3.9
Example VI 0.6+1.4 0.7+1.5
* The maximum readable limit by this instrument is 70Y

We Claim:
1. A process for preparing fatty acids comprising the steps of:
a) Hydrogenating the crude fatty acids;
b) Distilling the hydrogenated fatty acid;
c) Treating the distilled mixture with a reducing agent;
d) Distilling the resultant mixture.

2. A process as claimed in claim 1, wherein said reducing agent in step (c) is sodium borohydride.
3. A process as claimed in claim 1, wherein said hydrogenating reactant in step (a) is Nickel.
4. A process as claimed in any of the Claims 1 to 3, wherein said fatty acid is selected from C6 to C24.
5. A process as claimed in Claim 4, wherein said fatty acid is C6 to C18.
6. A process as claimed in Claim 3, wherein 0.8% Nickel is used.
7. A process as claimed in Claim 3, wherein said hydrogenation is carried out between 180°C to 210°C for a period of 1 to 6 hours.
8. A process as claimed in Claim 2, wherein 100 ppm of sodium borohydride is used.
9. A process as claimed in Claim 2, wherein the reduction is carried out at a temperature of 28°C to 30°C for a period of 2 hours.
10. A process as claimed in Claim 1, wherein said distillation is carried out at 160°C to 210°C at lmm Hg.

11. A process for preparing fatty acids substantially described herein with reference to examples.
12. Light coloured and storage stable fatty acid obtained by employing the process as claimed in any of the aforesaid claims.
Dated this 28th day of March 2006.

Himanshu W. Kane (Applicants' Patent Agent)