FIELD OF THE INVENTION
The present invention relates to provision of white crystalline fatty acid by way of
colour removal from crude fatty acids, and more particularly, relates to a simple and
cost-effective process of removing said colour from crude fatty acids.
Advantageously, the said process of decolorizing crude fatty acids of the present
invention involves cost effective solvents and regenerated adsorbent that would
accelerates the entire process including decolourizing crude fatty acids by avoiding
intricate use of acids, saline solutions, and membranes and renders it economical
and industrially facile. More advantageously, the white crystalline fatty acids thus
obtained would find its diverse and advantageous end uses/ applications including in
the soap and cosmetic industry and esterification.
BACKGROUND OF THE INVENTION
Decolourisation of fatty acid is a very well known art. The conventional processes of
decolourization involve the desired contact of Alkane or Acidic compounds with the
fatty acid and utilization of charcoal material as adsorbent. Some such available prior
art processes are discussed hereunder which involve colour removal from fatty acids/
glyceride oils.
US20050100994 discloses a process for enzymatically producing physiologically
active dietary sterol fatty acid esters from phytosterols and fatty acids using a lipase
as a catalyst in a controlled environment. This prior art provides for a process of
decolorization of the said ester using one of the adsorbents selected from the group
consisting of activated and/or acidic clay, activated carbon, silica, magnesia and
mainly illustrates the use of activated clay as the adsorbant and hexane as the
organic solvent in the decolorizing process. The treatment with the adsorbent for
several times in this prior art process makes the process unnecessarily lengthy and
costly due to repeated filtration.
US 4787981 teaches the use of hexane to remove two major impurities such as gum
material and wax from crude glyceride oil by diluting it and allowing it to pass
through a semi-permeable membrane under predefined environment. After
membrane filtration the oil, the oil is then treated with at least one kind of an

adsorbent selected from the group consisting of clay, activated clay, activated carbon
and bone black, for bleaching and deodorizing of the said glyceride oil to obtain
purified glyceride oil.
GB 1491170 also is directed to the process of degumming of raw palm oils by
contact with phosphoric acid, further decolourising the product thus obtained by
contacting with an adsorbent such as activated clay and/or active carbon to obtain a
soft marketable palm oil.
GB 912595 discloses the utilization of solvents like Petroleum ether, and a mixture of
butanol and cyclohexane or petroleum ether for the removal of sucrose from the
esterified fatty acids. Petroleum ether is employed to remove unchanged ester and a
free fatty acid from the esterified solution. The said prior art throws light on the
utility of the mixture of alcohol and cyclohexane or petroleum ether for the
subsequent removal of sucrose only but does not hint at decolourisation of the ester
using the said solvents.
As apparent from the teachings flowing from the above state of the art though
there are a number of processes directed to the removal of impurities including
coloring impurities from fatty acid/ glyceride oils there has been a strong continuing
need in the art to provide for a process of removing color from fatty acids that would
be industrially facile and cost effective in requiring less expensive solvents and
conventional color removing material and advantageously with the provisions of
material regeneration and recovery for utilization in the subsequent process steps for
said colour removal with equal efficacy.
OBJECTS OF THE INVENTION
It is thus the basic object of the present invention to provide for colour free (white)
crystalline fatty acids which would favour its diverse and wide scale advantageous
end uses/ applications including in the soap and cosmetic industry and esterification.
Another object of the present invention is to provide for a process of removal of
colour from crude fatty acids involving readily available and cost effective solvents
both non-polar and polar in reduced amounts to yield white crystalline fatty acids.

Yet another object of the present invention is to provide for a process for the
manufacture of white crystalline fatty acid which would avoid the use of expensive
solvents like Hexane in large amounts and further would not require treatment with
adsorbent repeatedly several times as presently done in the art.
Yet another object of the present invention is to provide for the process of removal
of colour from crude fatty acids that would advantageously utilize conventional solid
adsorbent in combination with selective solvents and that can be regenerated for
fresh use over a fresh feed of crude fatty acids for colour removal to make the entire
process less time consuming, economical and industrially facile.
SUMMARY OF THE INVENTION
Thus according to the basic aspect of the present invention there is provided for a
process for removal of colour from crude fatty acids comprising the steps of:
a. solubilising the crude fatty acid in petroleum ether;
b. treating the thus solubilised fatty acid with colour adsorbing solid adsorbent,
capable of ready regeneration involving ethyl alcohol as the suitable solvent, to
favour removal of colour from crude fatty acid and also regeneration of the
adsorbent for possible subsequent use in the process.
According to a preferred aspect of the present invention there is provided the said
process wherein the said step of regeneration of the solid adsorbent comprises
contacting the said solid adsorbent with ethyl alcohol to facilitate extraction of
adsorbed colour and distilling the solvent for recovery of the colour therefreom and
in the process regenerating both the adsorbent and the ethyl alcohol for possible
subsequent use in the process.
According to another preferred aspect of the present invention there is provided the
said process wherein said solid adsorbent is selected from activated carbon, clay,
activated clay, bone black and the like.

According to yet another preferred aspect of the present invention wherein in the
said process after said step of treating the solubilized fatty acid with the adsorbent,
the mass is filtered for recovery and reuse of the Petroleum Ether solvent.
According to another preferred aspect of the present invention wherein in the said
process, the (wt./vol.) ratio range of crude fatty acids and petroleum ether (60-80 °C
cut) varies of from 1:2- 1:4;
the (wt./vol.) ratio range of said solid adsorbent preferably activated carbon and
petroleum ether solubilised crude fatty acid varies of from 1:2-1:1; and
the (wt./vol.) ratio range of solid adsorbent and ethyl alcohol for regenerating the
said solid adsorbent is in the range of 1:10 to 1:20 preferably about 1:14.28.
Particularly, in the said process the colour extracted from the said solid adsorbent is
brownish yellow and the extracted colour: adsorbent ratio is 1:25 tol:40 preferably
about 1:32.
According to yet another preferred aspect of the present invention the (wt./ wt.)
ratio range of fresh solid adsorbent and fresh feed of crude fatty acids varies of from
0.05:1 to 0.1:1.
Advantageously, in the said process the (wt./ wt.) ratio range of recycled solid
adsorbent after about 5 recycles and fresh feed of crude fatty acids varies of from
1.1: 1 to 1.3 :2.
According to another aspect of the present invention there is provided a white
crystalline fatty acid obtained after colour removal from crude fatty acids by the said
process.
According to yet another aspect of the present invention there is provided a process
for removal of colour from fatty acid comprising treating solubilised fatty acid with
colour adsorbing solid adsorbent capable of ready regeneration, involving ethyl
alcohol as the suitable solvent, to favour removal of colour from crude fatty acids
and also regeneration of the adsorbent for possible subsequent use in the process.

Particularly, in the said aforesaid process for removal of colour from fatty acid the
said solid adsorbent is selected from activated carbon, clay, activated clay, bone
black and the like.
In still another aspect of the present invention there is provided a process for the
manufacture of soaps/cosmetics/esters involving fatty acid comprising the step of
pre-treating the fatty acid for removal of its colour comprising the step of
a. solubilising the crude fatty acid in petroleum ether;
b. treating the thus solubilised fatty acid with colour adsorbing solid adsorbent,
capable of ready regeneration involving ethyl alcohol as the suitable solvent, to
favour removal of colour from the fatty acid and also regeneration of the adsorbent
for possible subsequent use in the process of providing colour free white crystalline
fatty acid for use in the process.
The details of the invention, its objects and advantages are explained here under in
greater details in relation to non-limiting exemplary illustrations.
DETAILED DESCRIPTION OF THE INVENTION
As discussed hereinbefore the present invention provides for decolourized fatty acids
and process for providing such decolorized crude fatty acids involving cost effective
solvents such as petroleum ether, ethyl alcohol and regenerated solid adsorbent such
as regenerated activated carbon to remove colouring matter from crude fatty acids
with high efficacy. Advantageously, the decolourization process of the invention is
economical with respect to time in avoiding excess time required for repeated
distillations, filtration and washings with high volume of solvents, acid washings and
not involving other intricate techniques for coloring matter removal. The decolorized
white crystalline fatty acid thus obtained would find ready end use/ applications such
as in soap and cosmetic industry and esterification.
According to an embodiment of the present invention, crude fatty acids containing
colouring matter was subjected to the treatment with cost-effective solvent namely
Petroleum Ether to solubilise the Fatty Acids followed by treatment with a solid
adsorbent to remove the colour wherein the said solid adsorbent used was activated
carbon. The total mass was then filtered and the solvent distilled to recover and

reuse. Further the adsorbent was regenerated using another suitable and also cost-
effective solvent such as ethyl alcohol to extract the colouring impurities and thus,
regenerate the adsorbent. Fresh ethyl alcohol was recovered on distillation wherein
the colouring impurities were left behind in the residue which was found to be
brownish yellow in colour. The thus regenerated adsorbent was found to further
successfully remove colour from fresh feed of fatty acids to the fullest extent with
addition of only small amount of fresh adsorbent.
Example-I: Preferred parametric values for treatment of crude fatty acids
obtained from palm oil are as follows:
1. Range of use of Petroleum Ether (60 - 80 °C cut) was 20 to 40 ml. for 10 gms
of crude fatty acids derived from palm oil.
2. Amount of solid adsorbent namely, activated carbon used was 5 to 10 gm for
10 gm of fatty acids
3. Time of contact between the fatty acids and solid adsorbent was about 30 to
45 mnts for total colour removal in presence of slow stirring.
4. Amount of solvent (ethyl alcohol) used to regenerate the adsorbent and
recovery of colour was 100 ml for 7 gms of used adsorbent.
5. Colour (brownish yellow) recovered after distilling alcohol was 0.22 gm per 7
gm of used adsorbent.
6. Amount of fresh adsorbent used along with recycled adsorbent was 0.5 to 1
gm for treatment of 10 gm of fatty acids
The product obtained after total removal of colour was found to be white crystalline
fatty acid.

Example-II: Comparative data from the prior art processes in comparison to
the present invention are set forth hereunder:

It would be clearly evident form the above Table 1 that the present process as per
the examples 1 and 2 discussed above is much simpler and also superior in terms of
cost-effective and reduced amounts of solvents used and importantly the ready

manner of achieving the regeneration of the solvents and the adsorbents used which
makes the present process more user friendly and industrially viable.
It is thus possible by way of the present invention to decolorize crude fatty acids by
employing selective cost effective solvents and beneficially compatible adsorbent
favouring achieving the decolourization in a very short time period. The regeneration
of the solid adsorbent employed in the process renders the process cost effective and
industrially facile thereby facilitating removal of colouring matter from fresh feeds of
crude fatty acids with high efficacy. Therefore the present invention is a significant
technical advancement over the prior known processes made available for removal of
colour from fatty acids involving the above disclosed cost effective solvents and
regenerated adsorbent to remove colouring matter from crude fatty acids with high
efficacy.

We Claim:
1. A process for removal of colour from crude fatty acids comprising the steps of:
a. solubilising the crude fatty acid in petroleum ether;
b. treating the thus solubilised fatty acid with colour adsorbing solid adsorbent,
capable of ready regeneration involving ethyl alcohol as the suitable solvent, to
favour removal of colour from crude fatty acid and also regeneration of the
adsorbent for possible subsequent use in the process.
2. A process for removal of colour from crude fatty acids as claimed in claim 1
wherein the step of regeneration of the solid adsorbent comprises contacting the said
solid adsorbent with ethyl alcohol to facilitate extraction of adsorbed colour and
distilling the solvent for recovery of the colour therefreom and in the process
regenerating both the adsorbent and the ethyl alcohol for possible subsequent use in
the process.
3. A process for removal of colour from crude fatty acids as claimed in anyone of
claims 1 or 2 wherein said solid adsorbent is selected from activated carbon, clay,
activated clay, bone black and the like.
4. A process for removal of colour from crude fatty acids as claimed in anyone of
claims 1 to 3 wherein after said step of treating the solubilized fatty acid with the
adsorbent, the mass is filtered for recovery and reuse of the Petroleum Ether
solvent.
5. A process for removal of colour from crude fatty acids as claimed in anyone of
claims 1 to 4 wherein
the (wt./vol.) ratio range of crude fatty acids and petroleum ether (60-80 °C cut)
varies of from 1:2- 1:4;
the (wt./vol.) ratio range of said solid adsorbent preferably activated carbon and
petroleum ether solubilised crude fatty acid varies of from 1:2-1:1; and

the (wt./vol.) ratio range of solid adsorbent and ethyl alcohol for regenerating the
said solid adsorbent is in the range of 1:10 tol:20 preferably about 1:14.28.
6. A process as claimed in any of the preceding claims wherein the colour extracted
from the said solid adsorbent is brownish yellow and the extracted colour: adsorbent
ratio is 1:25 tol:40 preferably about 1:32.
7. A process as claimed in any of the preceding claims wherein the (wt./ wt.) ratio
range of fresh solid adsorbent and fresh feed of crude fatty acids varies of from
0.05:1 to 0.1:1.
8. A process as claimed in any of the preceding claims wherein the (wt./ wt.) ratio
range of recycled solid adsorbent after about 5recycles and fresh feed of crude fatty
acids varies of from 1.1: lto 1.3:2.
9. A white crystalline fatty acid obtained after colour removal from crude fatty acids
by a process as claimed in claims 1-8.
10.A process for removal of colour from fatty acid comprising treating solubilised
fatty acid with colour adsorbing solid adsorbent capable of ready regeneration,
involving ethyl alcohol as the suitable solvent, to favour removal of colour from
crude fatty acids and also regeneration of the adsorbent for possible subsequent use
in the process.
11. A process for removal of colour from fatty acid as claimed in claim 10 wherein
said solid adsorbent is selected from activated carbon, clay, activated clay, bone
black and the like.
12. A process for the manufacture of soaps /cosmetics/esters involving fatty acid
comprising the step of pre-treating the fatty acid for removal of its colour comprising
the step of
a. solubilising the crude fatty acid in petroleum ether;

b. treating the thus solubilised fatty acid with colour adsorbing solid adsorbent,
capable of ready regeneration involving ethyl alcohol as the suitable solvent, to
favour removal of colour from the fatty acid and also regeneration of the adsorbent
for possible subsequent use in the process of providing colour free white crystalline
fatty acid for use in the process.
13. A process for removal of colour from crude fatty acids substantially as
hereindescribed and illustrated with reference to the accompanying examples.

A simple and cost-effective process for the removal of colour from crude fatty acids
and a white crystalline fatty acid obtained therefrom wherein the entire process
includes decolourizing crude fatty acids by avoiding intricate and time consuming
techniques.