Claims:WE CLAIM:
1. A process for preparing a bleaching clay adsorbent composition, said process comprising the following steps:
a) obtaining a predetermined amount of clay;
b) crushing said clay to obtain crushed particles having a particle size in the range of 0.5 to 20 mm;
c) grinding said crushed particles of clay obtained in step b) to obtain a fine particles of clay having a particle size in the range of 0.01 to 0.2 mm;
d) activating said fine particles of clay with a predetermined amount of at least one organic acid at a predetermined temperature for a predetermined time period to obtain an organic acid activated clay having a particle size distribution in the range of 0.002 to 0.080 mm; and
e) sieving said organic acid activated clay through a sieve having a mesh size in the range of 100 to 400 to obtain said bleaching clay adsorbent composition;
wherein, a moisture content of said fine particles of clay is in the range of 4 to 12% with respect to the total weight of the clay.
2. The process as claimed in claim 1, wherein said predetermined amount of said clay is in the range of 85 to 99.5 wt.% with respect to the total weight of the bleaching clay adsorbent composition.
3. The process as claimed in claim 1, wherein said organic acid is at least one selected from the group consisting of tartaric acid, oxalic acid and maleic acid.
4. The process as claimed in claim 1, wherein said predetermined amount of said organic acid is in the range of 0.5 to 15 wt.% with respect to the total weight of the bleaching clay adsorbent composition.
5. The process as claimed in claim 1, wherein a weight ratio of said clay to said organic acid is in the range of 5:1 to 200:1
6. The process as claimed in claim 1, wherein said predetermined temperature is in the range of 25 °C to 90 °C.
7. The process as claimed in claim 1, wherein said predetermined time period is in the range of 12 minutes to 90 minutes.
8. The process as claimed in claim 1, wherein at least one inorganic acid is optionally added to activate the smectite clay with said organic acid in step (c).
9. The process as claimed in claim 8, wherein said inorganic acid is at least one selected from the group consisting of sulphuric acid, nitiric acid, and hydrochloric acid.
10. The process as claimed in claim 1, wherein said adsorbent composition has a pH in the range of 5.0 to 7.5.
11. A bleaching clay adsorbent composition obtained by the process as claimed in claim 1 comprising:
i. 85 to 99.5 wt% of a clay with respect to the total weight of the bleaching clay adsorbent composition; and
ii. 0.5 to 15 wt.% of an organic acid with respect to the total weight of the bleaching clay adsorbent composition,
said composition is characterized by having;
o a surface area in the range of 70 to 180 m2/g;
o a pore size in the range of 25 to 75 Å;
o a particle size distribution in the range of 2 to 80 µm; and
o needle like particle shape.
12. The composition as claimed in claim 11, wherein said organic acid is at least one selected from the group consisting of tartaric acid, oxalic acid and maleic acid.
13. The composition as claimed in claim 11, wherein said clay is at least one selected from the group consisting of Smectite, Fullers Earth, Siliceous Earth, Kaolinite, and Feldspar.
14. The composition as claimed in claim 11, wherein said clay comprises:
(a) silicon dioxide (SiO2) in amount in the range of 27 to 78%;
(b) aluminum dioxide (Al2O3) in an amount in the range of 4 to 40%;
(c) ferric oxide (Fe2O3) in an amount in the range of 1 to 20%; and
(d) alkali metal oxides in an amount in the range of 0.5 to 20%.
, Description:FIELD
The present disclosure relates to a process for the preparation of a bleaching clay adsorbent composition.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used to indicate otherwise.
Adsorbent: The term “Adsorbent” refers to a substance that adsorbs another substance.
Bleaching: The term “bleaching” refers to a process of removing unwanted impurities in the form of color, pigment, metal, non-metal, and oxidizable compounds.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Animal or vegetable oils are produced in huge amounts for use in food trade. These oils, for example, vegetable triglyceride oils such as sunflower, soybean, rapeseed, coconut, palm, and peanut oils, contain a variety of ingredients/contaminants in the extracted or partially processed form that influences color, stability, flavor or smell of the oil which need to be removed before the actual use of oil. Further, the other contaminants from the extracted or partially processed oils include trace metals, soaps, and pigments such as carotenoids and chlorophylls, that also required to be removed before the use of oil. Acid-activated clay adsorbs colored pigments (carotenoids, chlorophyll) and colorless pigments (phospholipids) from edible and inedible oils. This process is called "whitening" and serves both aesthetic and chemical purposes. The conventional processes for producing acid activated bleaching clay employs bentonite-calcium clays and require comparatively high doses of acid to achieve maximum bleaching efficiency. The calcium bentonites used in the conventional process, are hydrated sodium and calcium aluminosilicates, which are usually slightly basic and hence a high dose of acid is required. Due to the use of high doses of acid, the acid salts are formed during the activation of the bentonite-calcium clay and the residual acid, so formed, is required to be washed and separated by filtration. If large amounts of un-used acid and acid salts remain in the clay, the quality of the bleached oil will be degraded. Therefore, the acid salts and acid residues (leachate) that contain materials harmful to aquatic organisms needs to be neutralized and/or disposed off in an environmentally acceptable manner. This leads to an additional cost for the production of the pure calcium bentonite bleaching clays.
Various methods for making the acid-activated clays have been anticipated in the literature that has drawbacks such as low removal efficiency for impurities, highly acidic, and has lesser stability. Further, the use of inorganic acids in the preparation of acid activated bleaching clays leads to the product having very low pH value (2.0 to 4.0).
There is, therefore, felt a need for a bleaching clay adsorbent composition and a process for its preparation that can mitigate the drawbacks mentioned herein above.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
Another object of the present disclosure is to provide a bleaching clay adsorbent composition.
Still another object of the present disclosure is to provide a bleaching clay adsorbent composition having low to neutral pH value.
Yet another object of the present disclosure is to provide a simple and efficient process for the preparation of a bleaching clay adsorbent composition.
Yet another object of the present disclosure is to provide a process for the preparation of a bleaching clay adsorbent composition which is economic and environment friendly.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure provides a process for preparing a bleaching clay adsorbent composition. The process comprises the steps of obtaining a predetermined amount of clay and crushing the clay to obtain crushed particles of clay having a particle size in the range of 0.5 to 20 mm. The crushed particles are grinded to obtain the fine particles of clay having a particle size range in the range of 0.01 to 0.2 mm and then activated the fine particles of clay with a predetermined amount of at least one organic acid at a predetermined temperature for a predetermined time period to obtain an organic acid activated clay having a particle size distribution in the range of 0.002 to 0.080 mm. The organic acid activated clay is sieved through a sieve having a mesh number in the range of 100 to 400 to obtain the bleaching clay adsorbent composition. A moisture content of the fine particles of clay is in the range of 4 to 12% with respect to the total weight of the clay. The present disclosure further provides a bleaching clay adsorbent composition comprising 85 to 99.5 wt.% of a clay with respect to the total weight of the bleaching clay adsorbent composition and 0.5 to 15 wt.% of an organic acid with respect to the total weight of the bleaching clay adsorbent composition. The bleaching clay adsorbent composition is characterized by having a surface area in the range of 70 to 180 m2/g, a pore size in the range of 25 to 75 Å, a particle size distribution in the range of 2 to 80 µm, and having a needle like particle shape.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates the needle like particle shape of fullers earth magnified at 10000x visualized by scanning electron microscopy in accordance with an embodiment of the present disclosure;
Figure 2 illustrates the needle like particle shape of fullers earth magnified at 15000x visualized by scanning electron microscopy in accordance with an embodiment of the present disclosure;
Figure 3 illustrates the flake like structure of smectite clay magnified at 10000x visualized by scanning electron microscopy in accordance with an embodiment of the present disclosure;
Figure 4 illustrates the sphere and porous like structure of siliceous earth magnified at 10000x visualized by scanning electron microscopy in accordance with an embodiment of the present disclosure;
Figure 5 illustrates the Brunauer-Emmett-Teller (BET) graph and adsorption isotherm of bleaching clay adsorbent for the characterization of surface area and pore size in accordance with an embodiment of the present disclosure;
Figure 6 illustrates the particle size distribution of 0.045 mm bleaching clay adsorbent measured using Malvern in accordance with an embodiment of the present disclosure; and
Figure 7 illustrates the particle size distribution of 0.074 mm bleaching clay adsorbent measured using Malvern in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open-ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
The conventional processes for producing acid activated bleaching clay employs bentonite-calcium clays and require comparatively high doses of acid to achieve maximum bleaching efficiency. The calcium bentonite clays used in the conventional processes are hydrated sodium and calcium aluminosilicates, which are usually slightly basic and hence a high dose of acid is required. Due to the use of high doses of acid, the acid salts are formed during the activation of the bentonite-calcium clay and the residual acid so formed is required to be washed and separated by filtration. If large amounts of un-used acid and acid salts remain in the clay, the quality of the bleached oil will be degraded. Therefore, the acid salts and acid residues (leachate) that contain materials harmful to aquatic organisms needs to be neutralized and/or disposed off in an environmentally acceptable manner. This leads to an additional cost for the production of the pure calcium bentonite bleaching clays.
Various methods for making the acid-activated clays have been anticipated in the literature that has drawbacks such as low removal efficiency of impurities, highly acidic, and has lesser stability. Further, the use of inorganic acids in the preparation of acid activated bleaching clay leads to the product having very low pH value (2.0 to 4.0).
The present disclosure provides a bleaching clay adsorbent composition and a process for its preparation. The bleaching clay adsorbent composition of the present disclosure has a low to neutral pH and provides high bleachability performance.
In a first aspect, the present disclosure provides a process for the preparation of a bleaching clay adsorbent composition. The process is described in details as follows:
Firstly, a predetermined amount of clay is obtained from a commercially or a naturally available clay.
The so obtained clay is crushed to obtain crushed particles.
In an embodiment of the present disclosure, the size of crushed particles of clay is in the range of 0.5 to 20 mm.
Further, the crushed particles are grinded to obtain the fine particles of clay having a particle size in the range of 0.01 to 0.2 mm and activated with a predetermined amount of at least one organic acid at a predetermined temperature for a predetermined time period to obtain an organic acid activated clay.
In an embodiment of the present disclosure, the particle size distribution of the organic acid activated clay is in the range of 0.002 to 0.080 mm. In an exemplary embodiment, the average particle size of the organic acid activated clay is 0.045 mm. In another exemplary embodiment, the average particle size of the organic acid activated clay is 0.074 mm.
In an embodiment of the present disclosure, the organic acid is at least one selected from the group consisting of 2, 3-Dihydroxybutanedioic acid (tartaric acid), oxalic acid, and maleic acid.
In an exemplary embodiment, the organic acid is ethanedioic acid (oxalic acid). In another exemplary embodiment, the organic acid is a combination of oxalic acid and 2, 3-dihydroxybutanedioic acid. In still another exemplary embodiment, the organic acid is a combination of 2, 3-dihydroxybutanedioic acid (tartaric acid), ethanedioic acid (oxalic acid), and maleic acid.
In an embodiment of the present disclosure, the amount of the organic acid is in the range of 0.5 to 15 wt. % with respect to the total weight of the bleaching clay adsorbent composition. In an exemplary embodiment, the amount of organic acid is 5 wt. %.
In an embodiment of the present disclosure, the weight ratio of the clay to the organic acid is in the range of 5:1 to 200:1. In an exemplary embodiment, the weight ratio of the clay to the organic acid is 19:1.
In an embodiment of the present disclosure, the predetermined temperature is in the range of 25 °C to 90 °C. In an exemplary embodiment, the predetermined temperature is 45 °C.
In an embodiment of the present disclosure, the predetermined time period is in the range of 12 minutes to 90 minutes. In an exemplary embodiment, the predetermined time period is 60 minutes. In another exemplary embodiment, the predetermined time period is 30 minutes.
In an embodiment of the present disclosure, the moisture content of the fine particles of clay is in the range of 4 to 12% with respect to the total weight of clay. In an exemplary embodiment, the moisture content of the fine particles of clay is 8.23%.
Further, at least one inorganic acid is optionally added to activate the clay.
In case if the moisture content of the clay is more than 12%, it is essential to optimize the moisture content in the range of 4 to 12 %, by drying the raw clay up by natural or mechanical means at a temperature in the range of 150°C to 450°C for 20 minutes to 80 minutes.
Besides the surface area, fineness, and amount (w/w), the moisture content of clay is also a critical parameter and has a substantial impact on the final product i.e. adsorbent composition. If the moisture content of the clay is high the clay particles agglomerates due to the hydrophilicity and hydrophobicity that further decreases the interaction of the clay with oil. Due to reduced interaction with oil, the actual weight of the adsorbent is reduced during dosing. If the moisture content of the clay is low, the adsorbent composition is more susceptible to the excessive heating, non-uniformity in the activation process and the blowing of the clay in the air.
In an embodiment of the present disclosure, the inorganic acid is at least one selected from the group consisting of sulphuric acid, nitric acid, and hydrochloric acid. In an exemplary embodiment, the inorganic acid is sulphuric acid.
In accordance with the present disclosure, the amount of the inorganic acid is in the range of 0 to 40 wt.% with respect to the total weight of the bleaching clay adsorbent composition. In an exemplary embodiment, the amount of inorganic acid is 35 wt.%.
The organic acid activated clay is sieved through a sieve having a mesh size in the range of 100 to 400 to obtain the bleaching clay adsorbent composition.
To improve the product performance, mixing is done using a locally designed mixer and grinding is performed using roller/pulverizer mills.
In accordance with the present disclosure, the raw material fullers earth has pH of 7.5 to 9.5 and the finished product bleaching clay adsorbent composition has a pH in the range of 5.0 to 7.5. In an exemplary embodiment, the pH of the bleaching clay adsorbent composition is 6.10.
The process of the present disclosure employs organic acids, which are comparatively weak acids as compared to the inorganic acids (strong acids) used in the conventional processes for preparing acid activated clay adsorbent. Thus, the acid activated bleaching clay adsorbent composition of the present disclosure has a low to neutral pH, i.e. in the range of 5.0 to 7.5, whereas the conventionally prepared acid activated adsorbents have very low pH (2.0 to 4.0). Further, the process of the present disclosure is environmental friendly as the process of the present disclosure uses weak acids for the preparation of the acid activated bleaching clay adsorbent composition.
Thus, the process of the present disclosure is simple and energy efficient.
The process of the present disclosure employs inexpensive and easily available reagents. Thus, the process of the present disclosure is economical.
Further, the present disclosure provides a bleaching clay adsorbent composition obtained from the process of the present disclosure. The bleaching clay adsorbent composition comprising 85 to 99.5 wt. % of a clay with respect to the total weight of the bleaching clay adsorbent composition and 0.5 to 15 wt. % of an organic acid with respect to the total weight of the bleaching clay adsorbent composition.
In an exemplary embodiment, the bleaching clay adsorbent composition comprises 95 wt. % of the clay with respect to the total weight of the bleaching clay adsorbent composition and 5 wt. % of the organic acid with respect to the total weight of the bleaching clay adsorbent composition.
The clay is at least one selected from the group consisting of Smectite, Fullers Earth, Siliceous Earth, Kaolinite, and Feldspar. In an exemplary embodiment, the clay is Fullers Earth. In another exemplary embodiment, the clay is a mixture of Fullers earth and Smectite clay. In still another exemplary embodiment, the clay is a mixture of Fullers earth and Siliceous Earth.
Fullers earth allows to pass the oil quickly and doesn’t hold the oil on the surface due to its morphology (needle like structure), that results in improving the filtration rate.
Smectite clay has flake like structure with very less voids in between the flakes. So, due to its tightly packed structure, oil gets retain on the surface that result in slowing down the filtration rate of oil.
Siliceous earth has sphere and porous like structure. It has voids in between the spherical structure that allows to percolate the oil faster through the voids. Due to its morphology it absorbs very less oil in its surface and improves the filtration rate.

In accordance with the present disclosure, the clay comprises silicon dioxide (SiO2) in an amount in the range of 27 to 78%, aluminium dioxide (Al2O3) in an amount in the range of 4 to 40%, ferric oxide (Fe2O3) in an amount in the range of 1 to 20%, and alkali metals oxides in an amount in the range of 0.5 to 20%.
In accordance with the present disclosure, the alkali metal is at least one selected from the group consisting of lithium, sodium, calcium, magnesium, and potassium.
The organic acid is at least one selected from the group consisting of tartaric acid, oxalic acid, and maleic acid. In an exemplary embodiment, the organic acid is a combination of oxalic acid and tartaric acid. In another exemplary embodiment, the organic acid is oxalic acid. In still another exemplary embodiment, the organic acid is a combination of tartaric acid, oxalic acid, and maleic acid.
In an embodiment of the present disclosure, the weight ratio of the clay to the organic acid is in the range of 5:1 to 200:1. In an exemplary embodiment, the weight ratio of the clay to the organic acid is 19:1.
In accordance with the present disclosure, organic acid improves the filtration rate in two ways, Firstly, when oil comes in contact with organic acid it just allows to pass them quickly due to less absorption. Secondly, when organic acid used along with clay, it activates the clay and forms a very thin layer around the bleaching clay adsorbent that allows the oil to travel faster and improve the filtration rate.
In accordance with the present disclosure, the bleaching clay adsorbent composition is characterized by having a surface area in the range of 70 to 180 m2/ and pore size in the range of 25 to 75 Å, a particle size distribution which is measured by using a Malvern particle size analyzer in the range of 2 to 80 µm having a needle like particle shape.
In an exemplary embodiment of the present disclosure, the bleaching clay adsorbent composition has the surface area of 133.38 m2/g and pore size of 36.24 Å, and the average particle size distribution of D50 are 9.043 µm and 19.424 µm which is measured by using the Malvern particle size analyzer. In another exemplary embodiment of the present disclosure, the particle size distribution of bleaching clay adsorbent composition having a mean particle size distribution of D10=4.68 µm, D50=16.34 µm, and D90=55.42 µm.
The particle size distribution and the particle shape of the bleaching clay adsorbent composition play an important role in enhancing the filtration rate. A well distributed particle size and needle like particle shape create voids between the particles, which allowed the oil to pass through, in less time to improve the filtration rate.
The bleaching clay adsorbent composition of the present disclosure is used in removing the unwanted impurities in the form of color, pigments, metals, non-metals, and oxidizable compounds from edible and non-edible oil. The bleaching clay adsorbent composition of the present disclosure provides the excellent bleachability performance with required stability even in a very low dose i.e. 0.5 to 15% dosing of an adsorbent. Further, the adsorbent composition of the present disclosure provides high percent (%) removal efficiency of unwanted impurities in different kinds of edible oil (Soybean Oil, Palm Oil, Sunflower Oil, and Rice Bran Oil etc.) and non-edible oil (used and unused Petroleum oils, and Animal oils etc.).
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment but are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The following experiments can be tested to scale up to industrial/commercial scale and the results obtained can be extrapolated to the industrial scale.
EXPERIMENTAL DETAILS:
Experiment 1: Preparation of bleaching clay adsorbent composition in accordance with the present disclosure

Example 1:
450 g of Fullers Earth as illustrated in fig. I and II and 50 g of Smectite clay as illustrated in fig. III was procured and crushed to obtain crushed particles having a particle size 0.5 to 20 mm. The crushed particles were grinded in the particle size range of 0.01 to 0.2 mm having moisture content 9.08% and then activated with 15 gm oxalic acid at 35°C for 30 min to obtain organic acid activated clay having an average particle size of 0.045 mm as illustrated in fig. VI. Further, 50 gm of smectite clay was activated with 35% (58 ml) of sulphuric acid (inorganic acid) at 85°C for 14 hrs to obtain inorganic acid activated clay. The organic acid activated clay so obtained was mixed with the inorganic acid activated clay in a ratio of 90:10 to obtain a mixture and the mixture was sieved through a sieve having mesh size 100 to obtain the bleaching clay adsorbent composition.

Example 2:
450 g of Fullers Earth as illustrated in fig. I and II and 50 g of Siliceous Earth as illustrated in fig. IV was procured and crushed to obtain crushed particles having a particle size 0.5 to 20 mm. The crushed particles were grinded in the particle size range of 0.01 to 0.2mm having moisture content 8.64% and then activated with 15 gm oxalic acid at 35°C for 30 min to obtain an organic acid activated clay having an average particle size of 0.045 mm as illustrated in fig. VI. The organic acid activated clay was sieved through a sieve having mesh size 100 to obtain the bleaching clay adsorbent composition.

Fig.5 shows the complete adsorption isotherm (BET graph and adsorption isotherm) of bleaching clay adsorbent composition. The red line shows the adsorption at different points and pressure and the blue line shows the desorption. The adsorption and desorption were carried out at 10 different points to obtain the consistence surface area and pore size. The surface area and pore size were found to be 133.38 m2/g and 36.24 Å respectively.

Fig. 6 shows the Malvern average particle size distribution (9.043 micron) for 0.045 mm fineness bleaching clay adsorbent and Fig 7 shows the Malvern average particle size distribution (19.424 micron) of 0.074 mm bleaching clay adsorbent. 0.045 mm particle size is the average particle size [d (0.5)] of the bleaching clay adsorbent and is corresponds to 9.043 micron particle size calculated/obtained by the Malvern particle size analyzer. Further, 0.074 mm particle size is the average particle size [d (0.5)] of the bleaching clay adsorbent and is corresponds to 19.424 microns calculated/obtained by the Malvern particle size analyzer. The particle size of the product is 0.045 mm (45 micron) and 0.074 mm (74 micron) shows the Graph with 9.043 and 19.424 micron for respective particle size. This difference is due to the methodology, but the values are true by their own method.

Therefore, the particle size of 0.074 mm fineness bleaching clay adsorbent has a comparatively faster filtration rate as compared to 0.045 mm.

Example 3:
450 g of Fullers Earth as illustrated in fig. I and II and 50 g of Siliceous Earth as illustrated in fig. IV was procured and crushed to obtain crushed particles having a particle size 0.5 to 20 mm. The crushed particles were grinded in the particle size range of 0.01 to 0.2mm having moisture content 7.48% and then activated with 15 gm oxalic acid and 10 gm tartaric acid at 45°C for 30 min to obtain an organic acid activated clay having a particle size of 0.074 mm as illustrated in fig. VII. The organic acid activated clay was sieved through a sieve having mesh size 150 to obtain the bleaching clay adsorbent composition.

Example 4:
450 g of Fullers Earth as illustrated in fig. I and II and 50 g of Siliceous Earth as illustrated in fig. IV was procured and crushed to obtain crushed particles having a particle size 0.5 to 20 mm. The crushed particles were grinded in the particle size range of 0.01 to 0.2mm having moisture content 9.47% and then activated with a mixture of 5 gm oxalic acid, 5 gm of maleic acid and 5 gm of tartaric acid at 45°C for 60 min to obtain an organic acid activated clay having a particle size of 0.05 mm. The organic acid activated clay was sieved through a sieve having mesh size 170 to obtain the bleaching clay adsorbent composition.

Example 5:
450 g of Fullers Earth as illustrated in fig. I and II and 50 g of Siliceous Earth as illustrated in fig. IV was procured and crushed to obtain crushed particles having a particle size 0.5 to 20 mm. The crushed particles were grinded in the particle size range of 0.01 to 0.2mm having moisture content 8.23% and then activated with 25 gm of Oxalic acid at 30°C for 60 min to obtain an organic acid activated clay having an average particle size of 0.074 mm as illustrated in fig. VII. The organic acid activated clay was sieved through a sieve having mesh size of 150 to obtain the bleaching clay adsorbent composition.

Experiment 2: Evaluation of filtration rate of the adsorbent composition of examples 1-5
15 g of the bleaching clay adsorbent composition prepared in example 1 was mixed with 150 ml of Sunflower oil/Soybean oil and stirred at 300 rpm at 100±5°C for 25±5 minutes to obtain a slurry mass. The slurry mass was filtered using Whatman filter paper no.2 to separate impurities adsorbed on the adsorbent composition as a residue and the purified oil as a filtrate. The filtration rate was calculated.
The same procedure was repeated to study the filtration rate of the bleaching clay adsorbent composition prepared in examples 2 to 5.
The filtration rates for the bleaching clay adsorbent composition of examples 1 to 5 are summarized in Table 1.
Table 1:
Example Filter Rate Sec/150ml
1 620 secs
2 590 secs
3 574 secs
4 425 secs
5 397 secs

Inference:
It is evident from table 1 that example 5 has enhanced filtration rate in comparison with examples 1 to 4. In example 1, the clay mixture (fullers earth and smectite clay) was used, which gives the equivalent bleaching performance but increases the filtration rate. Fullers earth allows to pass through the oil quickly and doesn’t hold the oil on the surface due to its morphology (needle like structure), that results in improvement of the filtration rate. On the contrary, smectite clay has flake like structure with very less voids in between the flakes. So, due to its tightly packed structure, oil gets retain on the surface that result in slowing down the filtration rate of oil. In example 2, the mixture of fullers earth and siliceous earth were used. Siliceous earth has sphere and porous like structure. It has voids in between the spherical structure that allows percolating the oil faster through the voids. Due to its morphology it absorbs very less oil in its surface and improves the filtration rate.
The filtration rate of example 2 was comparatively better as compared to the example 1, which confirms that the presence of smectite clay comparatively lowers the filtration rate. In example 5, the particle size of the clay, activation temperature, and activation time was maintained at 0.074 mm, 30°C for 60 min respectively which collectively responsible for the enhanced filtration rate. The filtration rate depends on the fineness of the bleaching clay adsorbent composition, the type of acid used for activation, activation type, and time. Higher the fineness slower is the filtration rate.

Experiment 3: % removal efficiency of impurities or bleachability in different kinds of edible and non-edible oil
0.6 g of the bleaching clay adsorbent composition was mixed with 40 ml of Sunflower Oil and stirred at 300 rpm at 110°C for 30 minutes to obtain slurry mass. The slurry mass was filtered using Whatman filter paper no.2 to separate the impurities adsorbed on the adsorbent composition as a residue and the purified oil as a filtrate. The filtrates were collected and sent for the analysis of color in Lovibond tintometer. Bleachability or removal efficiency of impurities was calculated by calculating the color difference between the filtrate mass and raw oil color.
The similar experiment was carried out by using Soybean Oil Palm oil, Castor oil and Rice bran oil.
The results are provided in Table 2.

Table 2:
Oil Type Bleachability (%)
Sunflower oil/ Soyabean oil 65-90
Palm oil/Castor oil/Rice Bran oil 20-65

Inference: It is evident from table 2 that the Sunflower oil and Soybean oil shows highest removal efficiency as compare to the Palm, Castor, and Rice bran oil. The removal efficiency or percent bleachability of the oil depends on the type of oil used for the analysis. Different oils carried different type and percentage of impurities in it, and accordingly, the acceptance criteria of bleachability in the market for different oils are fixed.
TECHNICAL ADVANCEMENTS
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of a bleaching clay adsorbent composition that:
• has a low to neutral pH in the range of 5.0 to 7.5;
• has higher removal efficiency of unwanted impurities in a different kind of edible oil and non-edible oil;
• has excellent bleachability performance with required stability in 0.5- 15.0% dosing of adsorbent; and
• has improved filtration rate.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.