Fixed Bed Decolorization Process For Polyunsaturated Fatty Acid

Abstract

The present invention relates to a fixed bed decolorization process for an polyunsaturated fatty acid, comprising a polyunsaturated fatty acid or a polyunsaturated fatty acid solution is either passed directly through a filler of the fixed bed or recycled in a filler of the fixed bed, a colorless or light-colored polyunsaturated fatty acid product is ultimately produced, at the same time, other than the color, other qualities of the polyunsaturated fatty acid remain unaffected. The decolorization process allows continuous operation or intermittent operation. The filler of the fixed bed comprises one or a mixture of activated carbon, diatomite, carclazyte, silicone and an ion-exchange resin. An upper or a middle or a bottom or a combination thereof is employed to feed a polyunsaturated fatty acid feedstock or a polyunsaturated fatty acid solution. The filler in the fixed bed can be used repeatedly. The filler can be reused after being washed when decolorization effects thereof become deteriorated or ineffective.

Claims

1. A fixed bed decolorization process for polyunsaturated fatty acid, the fixed bed decolorization process comprising: 1) filling a fixed-bed filler in a decolorization fixed bed, and rinsing the decolorization fixed bed with a dissolving solvent; and then rinsing the decolorization fixed bed with a polyunsaturated fatty acid feedstock or a polyunsaturated fatty acid solution for 1˜2 times to obtain a stable decolorization fixed bed; wherein the polyunsaturated fatty acid solution includes the polyunsaturated fatty acid feedstock and the dissolving solvent; 2) mixing the polyunsaturated fatty acid feedstock or the polyunsaturated fatty acid solution with the dissolving solvent together to obtain a mixture; and 3) passing the mixture through an inlet of the decolorization fixed bed to feed, passing the mixture through an outlet of the decolorization fixed bed to discharge, a temperature of the decolorization fixed-bed is 0° C.˜150° C., to obtain a decolorized solution; and then recycle solvent from the decolorized solution under reduced pressures or normal pressures, to obtain a decolorized polyunsaturated fatty acid product; wherein the polyunsaturated fatty acid feedstock is selected from the group consisting of free type polyunsaturated fatty acid, methyl ester type polyunsaturated fatty acid, ethyl ester type polyunsaturated fatty acid and glyceride type unsaturated fatty acid; the fixed-bed filler is selected from the group consisting of activated carbon, diatomite, carclazyte, silica gel and ion exchange resin; the dissolving solvent is selected from the group consisting of alkanes solvent, esters solvent, alcoholes solvent, ethers solvent and ketones solvent.

2. The fixed bed decolorization process according to claim 1, wherein the polyunsaturated fatty acid is selected from the group consisting of fish oil, algal oil, linoleic acid, conjugated linoleic acid, linolenic acid and arachidonic acid.

3. The fixed bed decolorization process according to claim 2, wherein the total content of the polyunsaturated fatty acid in the polyunsaturated fatty acid feedstock is 10˜100% by weight.

4. The fixed bed decolorization process according to claim 1, wherein the activated carbon is selected from the group consisting of powder-type activated carbon, granular-type activated carbon, amorphous particle-type activated carbon, cylinder-shaped activated carbon, and spherical-shaped activated carbon.

5. The fixed bed decolorization process according to claim 1, wherein the silica gel is selected from the group consisting of macroporous silica gel, silochrom, B-type silica gel and pore silica gel.

6. The fixed bed decolorization process according to claim 1, wherein the ion exchange resin is selected from the group consisting of neutral ion exchange resin, weak acid ion exchange resin and weak basic ion exchange resins.

7. The fixed bed decolorization process according to claim 1, wherein the feeding way of the polyunsaturated fatty acid feedstock in the decolorization fixed bed includes upper feeding, middle feeding and bottom feeding; and the discharging way of the polyunsaturated fatty acid feedstock in the decolorization fixed bed includes upper discharging, middle discharging and bottom discharging.

8. The fixed bed decolorization process according to claim 7, wherein a ratio of diameter to height of the decolorization fixed bed is 1:1˜1:20.

9. The fixed bed decolorization process according to claim 1, wherein the alkanes solvent is selected from the group consisting of n-hexane, cyclohexane, n-heptane, octane, nonane, decane, 2,2-dimethyl butane, 2,3-dimethyl butane, 2-methyl pentane, 3-methyl pentane, 2,2,4-trimethyl pentane, 2,3,4-trimethyl pentane, 2,2,3-trimethyl pentane, 2,2,5-trimethyl pentane, isohepane; the esters solvent is selected from the group consisting of methyl formate, ethyl formate, propyl formate, isopropyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, isobutyl propionate, amyl propionate, isoamyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, isobutyl butyrate, amyl butyrate, isoamyl butyrate, methyl isobutyrate, ethyl isobutyrate, propyl isobutyrate, butyl isobutyrate, isobutyl isobutyrate, amyl isobutyrate, isoamyl isobutyrate, methyl valerate, ethyl valerate, propyl valerate, butyl valerate, isobutyl valerate, amyl valerate, isoamyl valerate, methyl isovalerate, ethyl isovalerate, propyl isovalerate, butyl isovalerate, isobutyl isovalerate, amyl isovalerate, isoamyl isovalerate; the ethers solvent is selected from the group consisting of diethyl ether, propyl ether, isopropyl ether, butyl ether, amyl ether, isoamyl ether, methyl ethyl ether, methyl propyl ether, methyl-n-butylether, ethyl butyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, anisole, phenetole, butyl phenyl ether, and amyl phenyl ether; the ketones solvent is selected from the group consisting of acetone, butanone, methyl acetone, 2-pentanone, 3-pentanone, 3-methylbutanone; the alcohols solvent is selected from the group consisting of methanol, alcohol, propyl alcohol, isopropanol, butanol, isobutanol, sec-butyl alcohol, tertiary butanol, pentanol, 2-methyl-1-butanol, isopentyl alcohol, sec-amyl alcohol, 3-Pentanol, tert-amyl alcohol, 3-methyl-2-butanol, neopentyl alcohol.

10. The fixed bed decolorization process according to claim 1, wherein the weight of the dissolving solvent in the polyunsaturated fatty acid solution is 0.1˜10 times as large as the weight of the polyunsaturated fatty acid feedstock.

11. The fixed bed decolorization process according to claim 1, wherein the filler of the decolorization fixed-bed can be repeatedly used; the decolorization fixed-bed can be rinsed and then is repeatedly used after decolorizing getting worse or finishing decolorizing.

12. The fixed bed decolorization process according to claim 1, wherein the fixed-bed filler can be repeatedly used; after decolorizing getting worse or finishing decolorizing, the fixed-bed can be rinsed with a rinsing solvent and then is repeatedly used.

13. The fixed bed decolorization process according to claim 12, wherein the rinsing solvent is water and the dissolving solvent.

14. The fixed bed decolorization process according to claim 1, wherein recovering solvent under reduced pressure or normal pressure to obtain reused solvent and the polyunsaturated fatty acid, after decolorization of the polyunsaturated fatty acid solution.

Description

BRIEF DESCRIPTION OF FIGURES

[0041] FIG. 1 shows a fixed bed decolorization process for polyunsaturated fatty acid.

DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS THEREOF

[0042] Hereafter, the present invention will be described specifically with reference to the examples. The examples are given only for illustration of the technical solution of the present invention and should not be construed to limit the present invention.

EXAMPLE 1

[0043] To select a decolorization fixed bed 1, wherein the diameter of the decolorization fixed-bed is 0.1 m, the height is 0.5 m (the ratio of diameter to height of the decolorization fixed bed is 1:5). To fill a powder type activated carbon in the decolorization fixed-bed, and firstly rinse the decolorization fixed bed with n-hexane, and then rinse the decolorization fixed bed with a free type fish oil feedstock once or twice, to obtain a stable decolorization fixed-bed device, as shown in FIG. 1.

[0044] To mix 500 g of a free type fish oil feedstock (EPA 17.6%, DHA 11.7%, the total content of a free type polyunsaturated fatty acid is 42.1%, with orange-red color) with 500 g of n-hexane, to obtain an homogenous solution with light orange-red color.

[0045] The homogenous solution including a free type fish oil feedstock and n-hexane for decolorization passes through an upper feeding inlet 3 into a bottom discharging outlet 2 (upper-lower path) in the fixed bed. These feedstock directly passes through the fixed-bed without circulation, the temperature of the fixed-bed is at 30° C., the decolorizing time is 0.5 h. After decolorizing, a free type fish oil and n-hexane solution with light yellow color is recovered under reduced pressure, to obtain 496 g of free type fish oil product with light yellow color.

[0046] After finishing the decolorization, all of feedstocks are released from a bottom drain hole 7. And then a rinsing solvent n-hexane passes through a bottom inlet 2, middle inlet 5, and then passes through a partition 6, to discharge from a upper outlet 3. Rinsing a filler 5 of the fixed bed and then all of solvents are released from a bottom drain hole 7.

[0047] Determination of a free type fish oil product: EPA 17.3%, DHA 11.5%, the total content of a free type polyunsaturated fatty acid is 42.0% with light yellow color, the yield is 99.0%.

COMPARSION EXAMPLE 2

[0048] To mix 500 g of a free type fish oil feedstock (EPA17.6%, DHA11.7%, the total content of a free type polyunsaturated fatty acid is 42.1% with orange-red color) with 500 g of n-hexane in a reaction flask, to obtain a homogenous solution with light orange-red color.

[0049] To add 25 g of powder type activated carbon to the reaction flask, and then is decolorized under stirring at 30° C. for 1.0 h; afterwards, to filtrate and remove the activated carbon after finishing decolorization, to obtain a free type fish oil and n-hexane solution with light yellow color, and then remove solvent under reduced pressure to obtain 459 g of product of free type fish oil with light yellow color.

[0050] Determination of a free type fish oil product: EPA17.1%, DHA 11.6%, the total content of the free type polyunsaturated fatty acid is 41.8% with light yellow color, the yield is 91.1%.

[0051] It could be shown from a comparison betwwen the Example 1 of the present invention and the Comparsion Example 2 that the Example 1 of the present invention uses an activated carbon as a filler of the fixed bed for decolorization at 30° C. by a solution including n-hexane and a free type fish oil containing polyunsaturated fatty acid, to obtain a free type fish oil product with quite light color. It could also be shown the decolorization process of the present invention has better decolorization effects, the yield is 99.0%. Other than the color, other qualities of the polyunsaturated fatty acid remain unaffected, and at the same time, the activated carbon can be directly reused.

[0052] The Comparsion Example 2 uses a common kettle type mixing for decolorization under the same process condition, in particular, uses 5% activated carbon at 30° C. for decolorization by a solution including n-hexane and a free type fish oil containing polyunsaturated fatty acid, to obtain a free type fish oil product with light color. It could also be shown the decolorization process of the Comparsion Example 2 has bad effects, the yield is 91.1%. Besides it would be difficult to obtain activated carbon to be reused because of high stickiness of received activated carbon.

[0053] In comparsion with the decolorization process and experimental result of the present invention and the Comparsion Example, it could be seen from it that the decolorization process of the present invention has many advantages such as simple process, better decolorizing effects, higher yield, lower cost and no environmental pollution, and consequently the decolorization process of present invention has feasibility for industrial scale production.

EXAMPLES 3˜15

[0054] Please refer to various of implement objects and their parameters of Table 1 of Examples 3˜15 as follows.

TABLE-US-00001 TABLE 1 State of feedstock/solution Product State of fixed-bed type of poly- total content Feed-in Path total content ratio of unsaturated of poly- decolor- of poly- exam- diameter T/ fatty acid unsaturated solvent feed-in izing unsaturated yield/ ples to height filler ° C. feedstock fatty acid % color g/g path way color fatty acid % % 3 1:1 Powder type 0 glyceride 59.8 orange- — upper- directly Light 59.4 98.9 activated type red lower pass yellow carbon fish oil path 4 1:1 Particle type 20 Ethyl ester 78.3 Light n-hexane lower- cycle Light 78.2 99.2 activated linoleic acid orange- 0.5:1 upper yellow carbon red path 5 1:2 Amorphous 30 Ethyl ester 46.7 orange- Ethanol upper/ cycle Light 46.5 98.8 particle type conjugated red 4:1 middle- yellow activated linoleic acid lower carbon path 6 1:4 cylinder- 30 Ethyl ester 46.9 Light — lower- cycle Light 46.7 98.7 shaped fish oil orange- upper yellow activated red path carbon 7 1:6 Spherical- 30 Free type 42.1 orange- — upper- cycle Light 42.2 99.1 shaped algal oil red lower yellow activated path carbon 8 1:8 Activated 40 glyceride 92.4 Light Ethyl middle/ directly Light 92.6 98.7 diatomite type orange- formate lower- pass yellow algal oil red 2:1 upper path 9  1:10 Activated 50 Methyl ester 11.2 orange- Propyl lower- directly Light 11.6 99.2 carclazyte linoleic acid red formate upper pass yellow 8:1 path 10  1:20 Macroporous 150 Free type 27.8 Light Butyl upper- cycle Light 27.9 99.1 silica gel conjugated orange- isovalerate lower yellow linoleic acid red 6:1 path 11 1:5 silochrom 100 Free type 53.6 Light Isobutyl upper/ cycle Light 53.8 98.8 arachidonic orange- acetate middle- yellow acid red 1:1 lower path 12 1:4 pore 70 Free type 68.5 orange- Ethyl lower- cycle Light 68.4 99.2 silica gel linolenic acid red acetate upper yellow 10:1 path 13 1:5 Weak 30 glyceride 68.2 Light Methanol middle/ cycle Light 68.0 99.1 acidic ion type orange- 3:1 lower- yellow exchange linolenic acid red upper resin path 14 1:8 Neutral ion 60 Ethyl ester 36.7 orange- ether middle/ cycle Light 36.5 98.7 exchange linolenic acid red 6:1 lower- yellow resin upper path 15 1:9 Weak 20 Ethyl ester 46.7 Light Butanone lower- cycle Light 46.4 99.0 basic ion arachidonic orange- 5:1 upper yellow exchange acid red path resin

EXAMPLE 16˜20

Example of Reused Decolorizer

[0055] To select the fix bed of Example 1 (wherein the diameter of the fix bed is 0.1 meter, the heigh is 0.5 m, the ratio of diameter to heigh is 1:5, a powdered type activated carbon filler and 30° C. of temperature), the fix bed is reused for decolorization, as shown in Table 2. Some implement objects and their parameters of Examples 16˜20 are listed in Table 2.

TABLE-US-00002 TABLE 2 State of feedstock/solution Product Type of poly- Total content Total content unsaturated of poly- Feed-in path of poly- Exam- fatty acid unsaturated Decolor- unsaturated Yield/ ples feedstock fatty acid % Color Solvent Feed-in path izing way Color fatty acid % % 16 glyceride type 59.8 orange — upper-lower directly light 59.7 99.2 fish oil red path pass yellow 17 ethyl ester 78.3 orange n-hexane upper-lower directly light 78.2 99.0 linoleic acid red 3:1 path pass yellow 18 ethyl ester 46.7 orange ethanol upper/middle- directly light 46.6 98.9 conjugated red 4:1 lower path pass yellow linoleic acid 19 free type 42.1 orange butanone upper-lower directly light 41.7 98.6 algal oil red 6:1 path pass yellow 20 glyceride type 68.2 orange ether upper-lower directly light 68.2 98.5 linolenic acid red 4:1 path pass yellow

EXAMPLE 21˜22

Example of Reused Fixed Bed After Rinsing

[0056] To select the fix bed of Examples 21˜22 (wherein the diameter of the fix bed is 0.1 meter, the heigh is 0.5 m, the ratio of diameter to heigh is 1:5, the filler is powdered type activated carbon and the temperature is 30° C.). After the fix bed is reused for decolorization, n-hexane is used for rinsing the fixed bed. After finsihing rinsing, the fixed bed is reused for decolorization. Some implement objects and their parameters of Examples 3˜15 are listed in Tables 3.

TABLE-US-00003 TABLE 3 State of feedstock/solution Product Type of poly- Total content Total content unsaturated of poly- Feed-in path of poly- Exam- fatty acid unsaturated Feed-in Decolor- unsaturated yield ples feedstock fatty acid % Color Solvent path izing way color fatty acid % % 21 ethyl ester 46.9 orange n-hexane upper-lower directly light 46.7 98.8 fish oil red 3:1 path pass yellow 22 Cylglycerol 68.2 orange n-hexane upper-lower directly light 68.1 99.1 linolenic acid red 2:1 path pass yellow

[0057] Although the present invention has been described in connection with the above embodiments, it should be understood that the present invention is not limited to such preferred embodiments and procedures set forth above. The embodiments and procedures were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention. It will be apparent to those skilled in the art that various substitution, modifications and changes may be thereto without departing from the scope and spirit of the invention. Therefore, the intention is intended to cover all alternative constructions and equivalents falling within the spirit and scope of the invention as defined only by the appended claims and equivalents thereto.