METHOD OF EFFICIENTLY SEPARATING SOLID FAT FROM POLYUNSATURATED FATTY ACID GREASE

Abstract

The present invention provides a method of efficiently separating solid fat from polyunsaturated fatty acid grease. The method comprises adding a certain amount of inert material to the polyunsaturated fatty acid grease, and cooling crystallization, and then filtering through a filter to obtain clarified polyunsaturated fatty acid grease. Afterwards introducing hot gas through the filter to make solid fat adsorbed on a filter cake in the filter dissolved and then recycling it through a filter plate. Inert solid substances can be applied next time. The method of the present invention can be efficiently separated saturated and low-saturated fatty acids from polyunsaturated fatty acid grease. In the process, the winterization crystallization time is short, the crystallization is complete, the crystal separation is easy. It will not cause some solid fat melted and thus re-enter the filtrate due to long separation and blowing dry in conventional process. The yield of final product is high up to 89.8%-97.8%. After winterization, a lipid clarity of the polyunsaturated fatty acid grease is good, and no crystal precipitation would occur at 0° C. for 5 hrs.

Claims

1. A method of efficiently separating solid fat from polyunsaturated fatty acid grease, comprising the following steps: a) adding a certain amount of inert solid powder to a heated melted polyunsaturated fatty acid grease, and stirring evenly, the inert solid powder is selected from the group consisting of activated carbon, activated clay, diatomite and perlite; b) cooling crystallization the polyunsaturated fatty acid grease containing the inert solid powder obtained by step a), to obtain a crystalline mixture; c) filtering the crystalline mixture obtained by step b) through a filter, to obtain a clarified polyunsaturated fatty acid grease and a filter cake; d) introducing hot gas into the filter to make a solid fat melted into a liquid, and then recovering a liquid solid fat; e) introducing nitrogen into the filter, blowing dry residual solid fat; and f) recovering a filter cake with inert solid powder.

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

3. The method according to claim 1, wherein the polyunsaturated fatty acid is in the form of methyl esters, ethyl esters, glycerides, or free fatty acids.

4. The method according to claim 1, wherein, in step a), a melting temperature of the polyunsaturated fatty acid grease is 30-100° C.

5. The method according to claim 1, wherein, in step a), an additive amount of the inert solid powder is 0.1-6.0% (w/w) of a mass of the polyunsaturated fatty acid grease.

6. The method according to claim 5, wherein, in step a), an additive amount of the inert solid powder is 0.1-1.0% (w/w) of a mass of the polyunsaturated fatty acid grease.

7. The method according to claim 1, wherein, in step b), a temperature of cooling crystallization is −10-5° C.

8. The method according to claim 1, wherein, in step b), after cooling crystallization and before filtering, adding a certain amount of the inert solid powder.

9. The method according to claim 8, wherein, in step b), after cooling crystallization and before filtering, an additive amount of the inert solid powder is 0.5-6.0% (w/w) of a mass of the polyunsaturated fatty acid grease.

10. The method according to claim 1, wherein, in step d), the hot gas is a heating steam, a heating nitrogen, a heating air; a temperature of the hot gas is 30° C.-100° C., preferably, a temperature of the hot gas is 80° C.-100° C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG. 1 is a schematic diagram of a filter used for filtering and recovering solid fat.

DETAILED DESCRIPTION OF THE PRESENT INVENTION AND PREFERRED EMBODIMENTS THEREOF

[0036] Hereafter, the present invention will be described specifically with reference to 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

[0037] Dissolve 1800 g of ethyl ester type polyunsaturated fatty acid fish oil raw material (EPA 22.4%, DHA 8.7% a total content of polyunsaturated fatty acid is 34.2%, color orange red) under keeping warm at 65° C. for 0.5 hrs, and then add 9.0 g of activated clay to obtain a mixture. Afterwards, cool the mixture for winterization crystallization to make a temperature lowered from 65° C. to −2.5° C. within 30 minutes. And then keep warm for crystal growth for 20 minutes. Then add 60.0 g activated clay and 48.0 g activated carbon under stirring for 0.5 hrs to obtain a crystalline liquid.

[0038] As show in FIG. 1, open a crystalline liquid feed valve V101 of the filter to filter the crystalline liquid containing activated clay and activated carbon, put the polyunsaturated fatty acid filtrate through a filter plate to a liquid collection pipe, and then pass through the filtrate outlet valve V201. Collect a filtrate and weigh 1731.6 g with the yield of 96.2%.

[0039] Take 20 ml of the filtrate and keep warm at 0° C. for 5 hrs. The filtrate is still clear and transparent. This shows that the effect of winterization is very good.

[0040] As shown in FIG. 1, close a crystalline liquid feed valve V101, a filter liquid discharge valve V201, and add heated nitrogen gas at 100° C. through V102 to melt the solid fat adsorbed in the filter cake, and then enter into a liquid collection pipe through the filter plate, and then collect it through a valve V202, finally recover 58.8 g of a filtrate (solid fat), afterwards, blow dry a filter cake with nitrogen, open the filter cover. The filter cake recovered may be used for the next winterization process.

Example 2

[0041] Dissolve 3000 g of the same raw materials as that of Example 1 under keeping warm at 100° C. for 0.5 hrs to obtain a mixture. And then slowly cool for winterization crystallization the mixture to make a temperature lowered from 100° C. to −10.0° C. within 3.0 hrs. And then keep warm for crystal growth for 20 minutes to obtain a crystalline liquid. Add 3.0 g of activated carbon and then continue to stir for 0.5 hrs to obtain a crystalline liquid.

[0042] As show in FIG. 1, open a crystalline liquid feed valve V101 of the filter to filter the crystalline liquid containing activated carbon, put the polyunsaturated fatty acid filtrate through a filter plate to a liquid collection pipe, and then pass through a filtrate outlet valve V201. Collect a filtrate and weigh 2934.2 g with the yield of 97.8%.

[0043] Take 20 ml of the filtrate and keep warm at 0° C. for 5 hrs. The filtrate is still clear and transparent. This shows that the effect of winterization is very good.

[0044] As shown in FIG. 1, close a crystalline liquid feed valve V101 and a filter liquid discharge valve V201, and add heated nitrogen gas at 30° C. through V102 to melt the solid fat adsorbed in the filter cake, and then enter into a liquid collection pipe through the filter plate, and then collect it through a valve V202, finally recover 57.9 g of a filtrate (solid fat), afterwards, blow dry a filter cake with nitrogen, open the filter cover. The filter cake recovered may be used for the next winterization process.

Example 3

[0045] Dissolve 3500 g of the same raw materials as that of Example 1 under keeping warm at 65° C. for 0.5 hrs to obtain a mixture. Add 60 g of activated clay and 150 g of activated carbon. And then slowly cool for winterization crystallization the mixture to make a temperature lowered from 65° C. to −2.5° C. within 2.5 hrs to precipitate a large amount of crystals, and then keep warm for crystal growth for 20 minutes to obtain a crystalline liquid.

[0046] As show in FIG. 1, open a crystalline liquid feed valve V101 of the filter to filter the crystalline liquid containing activated clay and activated carbon, put the polyunsaturated fatty acid filtrate through a filter plate to a liquid collection pipe, and then pass through a filtrate outlet valve V201. Collect a filtrate and weigh 3300.5 g with the yield of 94.3%.

[0047] Take 20 ml of the filtrate and keep warm at 0° C. for 5 hrs. The filtrate is still clear and transparent. This shows that the effect of winterization is very good.

[0048] As shown in FIG. 1, close a crystalline liquid feed valve V101 and a filter liquid discharge valve V201, and add superheated steam at 100° C. through V102 to melt the solid fat adsorbed in the filter cake, and then enter into a liquid collection pipe through the filter plate, and then collect it through a valve V202, finally recover 157.2 g of a filtrate (solid fat), afterwards, blow dry a filter cake with nitrogen, open the filter cover. The filter cake recovered may be used for the next winterization process.

Example 4

[0049] Dissolve 2000 g of triglyceride type polyunsaturated fatty acid algal oil raw material obtained by fermentation (EPA 3.4%, DHA 24.6%, a total content of polyunsaturated fatty acid is 31.2%, color orange red) under keeping warm at 30° C. for 1.5 hrs, and then add 2.0 g of pearlite to obtain a mixture. Afterwards, cool the mixture for winterization crystallization to make a temperature lowered to −10.0° C. within 45 minutes. And then keep warm for crystal growth for 30 minutes. Then add 40 g diatomite under stirring for 0.5 hrs to obtain a crystalline liquid.

[0050] As show in FIG. 1, open a crystalline liquid feed valve V101 of the filter to filter the crystalline liquid containing pearlite and diatomite, put the polyunsaturated fatty acid filtrate through a filter plate to a liquid collection pipe, and then pass through a filtrate outlet valve V201. Collect a filtrate and weigh 1902.0 g with the yield of 95.1%.

[0051] Take 20 ml of the filtrate and keep warm at 0° C. for 5 hr. The filtrate is still clear and transparent. This shows that the effect of winterization is very good.

[0052] As shown in FIG. 1, close a crystalline liquid feed valve V101 and a filter liquid discharge valve V201, and add heated airs at 30° C. through V102 to melt the solid fat adsorbed in the filter cake, and then enter into a liquid collection pipe through the filter plate, and then collect it through a valve V202, finally recover 77.9 g of a filtrate (solid fat), afterwards, blow dry a filter cake with nitrogen, open the filter cover. The filter cake recovered may be used for the next winterization process.

Example 5

[0053] Dissolve 3000 g of free conjugated linoleic acid (a content is 78.5%) under keeping warm at 100° C. for 1.0 hr, and then add 30 g of diatomite to obtain a mixture. Afterwards, cool the mixture for winterization crystallization to make a temperature lowered from 100° C. to 5° C. within 60 minutes. And then keep warm for crystal growth for 45 minutes. Then add 75 g diatomite under stirring for 0.5 hrs to obtain a crystalline liquid.

[0054] As show in FIG. 1, open a crystalline liquid feed valve V101 of the filter to filter the crystalline liquid containing diatomite, put the polyunsaturated fatty acid filtrate through a filter plate to a liquid collection pipe, and then pass through a filtrate outlet valve V201. Collect a filtrate and weigh 2826.0 g with the yield of 94.2%.

[0055] Take 20 ml of the filtrate and keep warm at 0° C. for 5 hr. The filtrate is still clear and transparent. This shows that the effect of winterization is very good.

[0056] As shown in FIG. 1, close a crystalline liquid feed valve V101 and a filter liquid discharge valve V201, and add heated airs at 70° C. through V102 to melt the solid fat adsorbed in the filter cake, and then enter into a liquid collection pipe through the filter plate, and then collect it through a valve V202, finally recover 153.8 g of a filtrate (solid fat), afterwards, blow dry a filter cake with nitrogen, open the filter cover. The filter cake recovered may be used for the next winterization process.

Example 6

[0057] Dissolve 2800 g of methyl ester type arachidonic acid raw material (a content is 64.1%) under keeping warm at 60° C. for 0.5 hrs., and then add 3.0 g of pearlite to obtain a mixture. Afterwards, cool the mixture for winterization crystallization to make a temperature lowered to 2° C. within 60 minutes. And then keep warm for crystal growth for 45 minutes. Then add 14 g pearlite under stirring for 0.5 hrs to obtain a crystalline liquid.

[0058] As show in FIG. 1, open a crystalline liquid feed valve V101 of the filter to filter the crystalline liquid containing pearlite, put the polyunsaturated fatty acid filtrate through a filter plate to a liquid collection pipe, and then pass through a filtrate outlet valve V201. Collect a filtrate and weigh 2567.6 g with the yield of 91.7%.

[0059] Take 20 ml of the filtrate and keep warm at 0° C. for 5 hr. The filtrate is still clear and transparent. This shows that the effect of winterization is very good.

[0060] As shown in FIG. 1, close a crystalline liquid feed valve V101 and a filter liquid discharge valve V201, and add superheated steam at 100° C. through V102 to melt the solid fat adsorbed in the filter cake, and then enter into a liquid collection pipe through the filter plate, and then collect it through a valve V202, finally recover 203.7 g of a filtrate (solid fat), afterwards, blow dry a filter cake with nitrogen, open the filter cover. The filter cake recovered may be used for the next winterization process.

Example 7

[0061] Dissolve 3500 g of triglyceride type linolenic acid and linoleic acid mixture raw material (a content of linolenic acid is 12.7%, a content of linoleic acid is 34.5%) under keeping warm at 80° C. for 0.45 hrs. Afterwards, cool the mixture for winterization crystallization to make a temperature lowered to −2.5° C. within 45 minutes. And then keep warm for crystal growth for 45 minutes. Then add 10 g diatomite, 45 g of activated clay and 60 g pearlite under stirring for 0.5 hrs to obtain a crystalline liquid.

[0062] As show in FIG. 1, open a crystalline liquid feed valve V101 of the filter to filter the crystalline liquid containing diatomite, activated clay and pearlite, put the polyunsaturated fatty acid filtrate through a filter plate to a liquid collection pipe, and then pass through a filtrate outlet valve V201. Collect a filtrate and weigh 3143.0 g with the yield of 89.8%.

[0063] Take 20 ml of the filtrate and keep warm at 0° C. for 5 hr. The filtrate is still clear and transparent. This shows that the effect of winterization is very good.

[0064] As shown in FIG. 1, close a crystalline liquid feed valve V101 and a filter liquid discharge valve V201, and add heated nitrogen gas at 80° C. through V102 to melt the solid fat adsorbed in the filter cake, and then enter into a liquid collection pipe through the filter plate, and then collect it through a valve V202, finally recover 287 g of a filtrate (solid fat), afterwards, blow dry a filter cake with nitrogen, open the filter cover. The filter cake recovered may be used for the next winterization process.

[0065] It is required to be declared that the invention contents and specific examples are intended to prove the practical application of the technical solution provided by the present invention, and shall not be interpreted as a limitation of the protection scope of the present invention. It is easy for any persons skilled in the art to carry out further improvement and perfection not from the spirit and scope of the invention, so the present invention is just limited by the content and scope of claims of the present invention, its intention to cover all included all alternative solutions and equivalent solutions within the spirit and scope of the present invention limited by the appendix claims.