Choline-amino acid ionic liquid for efficiently enriching TG, EPA or DHA in oil and its preparation method and application

Abstract

The application discloses a kind of choline-amino acid ionic liquid for efficiently enriching TG, EPA or DHA in oil, and a preparation method and application thereof, and belongs to the technical field of ionic liquid preparation.The method comprises dissolving amino acid in water, adding choline hydroxide, then heating to 50-70 DEG C to react, after reaction is completed, purification is carried out, and choline-amino acid ionic liquid is obtained, wherein the molar ratio of amino acid to choline hydroxide is 1: (0.5-2.5).The choline-amino acid ionic liquid is green and pollution-free, and can be used for crude oil refining in food, medicine and other fields, especially suitable for crude oil containing DHA, EPA, such as algal oil and fish oil, and can complete degumming, deacidification and decolorization process in one step, significantly simplifying the crude oil refining process, reducing energy consumption and waste discharge.

Description

Technical Field

[0001] This invention relates to the field of ionic liquid preparation technology, specifically to a choline-amino acid ionic liquid for efficiently enriching TG, EPA or DHA in oils and fats, its preparation method and application. Background Technology

[0002] The refining and purification process of crude oil typically includes degumming, deacidification, decolorization, and deodorization. Degumming aims to remove phospholipids, proteins, and mineral salt impurities. A common method is acid degumming, with phosphoric acid as the acid reagent, which is characterized by low pollution, convenient operation, and high removal efficiency. Deacidification aims to remove a large amount of free fatty acids and phospholipids from crude oil. Common methods include adding sodium hydroxide solution or adding substances that readily react with triglycerides to form saponifications, but this can cause significant environmental pollution. Decolorization removes colored substances from crude oil to improve its sensory quality. It often requires multiple decolorization processes using various decolorizing agents, such as activated carbon and bleaching clay, making the process complex. Summary of the Invention

[0003] To address the above problems, this invention provides a choline-amino acid ionic liquid for efficiently enriching TG, EPA, or DHA in oils, along with its preparation method and applications. This choline-amino acid ionic liquid is green and pollution-free, and its use in crude oil refining enables degumming, deacidification, and decolorization in a single process.

[0004] The technical solution of the present invention is as follows: First, this invention provides a method for preparing a choline-amino acid ionic liquid for efficiently enriching TG, EPA, or DHA in oils, comprising the following steps: After dissolving the amino acids, choline hydroxide was added, and the mixture was heated to 50-70°C to react. After the reaction was completed, the mixture was purified to obtain a choline-amino acid ionic liquid, wherein the molar ratio of amino acids to choline hydroxide was 1:(0.5-2.5).

[0005] Preferably, the amino acid is one or more of serine, histidine, glycine or proline; more preferably, the amino acid is an L-type amino acid.

[0006] Preferably, after obtaining the choline-amino acid ion solution, the method further includes the following steps: passing dry CO2 into the choline-amino acid ion solution to adjust its pH to near neutral.

[0007] Preferably, the purification includes the following steps: removing water under vacuum to near dryness at a temperature below 60°C; then washing with anhydrous ethanol, collecting the ethanol solution, and removing the alcohol under vacuum; and finally drying under vacuum at a temperature below 60°C.

[0008] Second, the present invention provides a choline-amino acid ionic liquid, which is obtained by the above-mentioned method for preparing a choline-amino acid ionic liquid for efficiently enriching TG, EPA or DHA in oils.

[0009] Preferably, the water content of the choline-amino acid ionic liquid is <1wt%.

[0010] Third, the present invention provides the application of the above-mentioned choline-amino acid ionic liquid in crude oil refining.

[0011] Preferably, the application of choline-amino acid ionic liquid in crude oil refining includes the following steps: The crude oil was mixed with choline-amino acid ionic liquid under vacuum conditions for removal treatment, wherein the mass ratio of crude oil to choline-amino acid ionic liquid was 1: (0.01~0.5).

[0012] More preferably, the crude oil is pretreated to remove moisture before being mixed and stirred with choline-amino acid ionic liquid for removal.

[0013] More preferably, the reaction time is 0.5 to 10 h when the mixture is stirred with choline-amino acid ionic liquid for removal treatment; particularly preferably, the reaction temperature is 50 to 85 °C when the mixture is stirred with choline-amino acid ionic liquid for removal treatment.

[0014] Beneficial effects: The choline-amino acid ionic liquid prepared by the method of this invention is green and pollution-free, and can be used for crude oil refining in the food, pharmaceutical and other fields. It is especially suitable for crude oil containing DHA and EPA, such as algal oil and fish oil. It can complete the degumming, deacidification and decolorization processes in one step, which significantly simplifies the crude oil refining process, reduces energy consumption and waste emissions, and the choline-amino acid ionic liquid used is green, non-toxic and harmless. Attached Figure Description

[0015] Figure 1 A colorimetric comparison chart of crude oil before and after using choline-serine amino acid ionic liquid; Figure 2 A colorimetric comparison chart of crude oil before and after using choline-glycine ionic liquid; Figure 3 A colorimetric comparison chart of crude oil before and after using choline-proline ionic liquid; Figure 4 A colorimetric comparison chart of crude oil before and after using choline-histamine ionic liquid. Detailed Implementation

[0016] The specific embodiments listed in this invention are merely examples, and the invention is not limited to the specific embodiments described below. For those skilled in the art, any equivalent modifications and substitutions to the embodiments described below are also within the scope of this invention. Therefore, all equivalent transformations and modifications made without departing from the spirit and scope of this invention should be covered within its scope. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. All reagents or instruments whose manufacturers are not specified are commercially available conventional products. To better illustrate this invention, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this invention can be practiced even without certain specific details. In other embodiments, methods, means, equipment, and steps well known to those skilled in the art are not described in detail in order to highlight the main points of this invention.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. Unless otherwise specified, all units used in this specification are International Standard Units (SI), and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors unavoidable in industrial production.

[0018] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0019] In this embodiment of the invention, the crude oil used is sardine crude fish oil with an EPA content of 14% and a DHA content of 10%.

[0020] The choline hydroxide used in this invention is a 44% aqueous solution of choline hydroxide with a concentration of 1.2 g / mL; L-glycine is 90% L-glycine solid; L-serine is 90% L-serine solid; L-proline is 90% L-proline solid; L-histidine is 90% L-histidine solid.

[0021] pH adjustment: The pH of the dehydrated ionic liquid system may be high (alkaline). Dry CO2 can be introduced to gently adjust the pH to near neutral.

[0022] During the vacuum drying process, the moisture content was monitored using a Karl Fischer moisture titrator.

[0023] The gum value was tested according to GB / T 5537—2008 Grain and Oil Inspection - Determination of Phospholipid Content; the acid value was tested according to GB5009.229—2016 National Food Safety Standard - Determination of Acid Value in Food; and the color was measured using a Gardner instrument, with a maximum value of 18.5.

[0024] Example 1 This embodiment provides a method for preparing a choline-serine amino acid ionic liquid for efficiently enriching TG, EPA, or DHA in oils, the steps of which are as follows: L-serine was dissolved in an appropriate amount of ultrapure water at room temperature and magnetically stirred until dissolved. Choline hydroxide was then added dropwise. After the addition was complete, the temperature was raised to 55°C and the reaction was magnetically stirred for 2 hours. The molar ratio of choline hydroxide to L-serine was 1:1.

[0025] After the reaction was completed, the solution was dehydrated under vacuum at a temperature below 60°C until nearly dry; then it was washed with anhydrous ethanol, the ethanol solution was collected, and the alcohol was removed under vacuum; finally, it was dried under vacuum at a temperature below 60°C until a choline-serine amino acid ionic liquid with a water content of <1wt% was obtained.

[0026] Example 2 This embodiment provides a method for preparing a choline-glycine ionic liquid for efficiently enriching TG, EPA, or DHA in oils, the steps of which are as follows: L-glycine was dissolved in an appropriate amount of ultrapure water at room temperature and magnetically stirred until dissolved. Choline hydroxide was then added dropwise. After the addition was complete, the temperature was raised to 50°C and the reaction was magnetically stirred for 6 hours. The molar ratio of choline hydroxide to L-glycine was 1:0.5.

[0027] After the reaction was completed, the solution was dehydrated under vacuum at a temperature below 60°C until nearly dry; then it was washed with anhydrous ethanol, the ethanol solution was collected, and the alcohol was removed under vacuum; finally, it was dried under vacuum at a temperature below 60°C until a choline-glycine ionic liquid with a water content of <1wt% was obtained.

[0028] Example 3 This embodiment provides a method for preparing a choline-proline amino acid ionic liquid for efficiently enriching TG, EPA, or DHA in oils, the steps of which are as follows: L-proline was dissolved in an appropriate amount of ultrapure water at room temperature and magnetically stirred until dissolved. Choline hydroxide was then added dropwise. After the addition was complete, the temperature was raised to 65°C and the reaction was magnetically stirred for 5 hours. The molar ratio of choline hydroxide to L-proline was 1:1.8.

[0029] After the reaction was completed, the solution was dehydrated under vacuum at a temperature below 60°C until nearly dry; then it was washed with anhydrous ethanol, the ethanol solution was collected, and the alcohol was removed under vacuum; finally, it was dried under vacuum at a temperature below 60°C until a choline-proline amino acid ionic liquid with a water content of <1wt% was obtained.

[0030] Example 4 This embodiment provides a method for preparing a choline-histamino acid ionic liquid for efficiently enriching TG, EPA, or DHA in oils, the steps of which are as follows: L-histidine was dissolved in an appropriate amount of ultrapure water at room temperature and stirred magnetically until dissolved. Choline hydroxide was then added dropwise. After the addition was complete, the temperature was raised to 70°C and the reaction was stirred magnetically for 1 hour. The molar ratio of choline hydroxide to L-histidine was 1:2.5.

[0031] After the reaction was completed, the oil was dehydrated under vacuum at a temperature below 60°C until nearly dry; then it was washed with anhydrous ethanol, the ethanol solution was collected, and the alcohol was removed under vacuum; finally, it was dried under vacuum at a temperature below 60°C until a color control of the crude oil before and after using choline-histamino acid ion solution with a water content of <1wt% was obtained.

[0032] Application Example 1 This application example provides the application of the choline-serine amino acid ionic liquid obtained in Example 1 in crude oil refining, as detailed below: Take 30g of crude oil and dehydrate it under vacuum at 95℃ for 2h. After dehydration, cool it down to 65℃ and keep it under vacuum. Slowly add 3g of choline-serine amino acid ionic liquid under gentle stirring. Stir and react at constant temperature for 0.5h. After the reaction is completed, let it stand and separate into layers. Take the upper oil phase and centrifuge it at 4000rpm for 5min. Take the upper oil after centrifugation and test its colloidal value, acid value and color. The results are shown in Table 1.

[0033] Table 1. Comparison of crude oil gum value, acid value, and color before and after using choline-silicone amino acid ion solution.

[0034] The color comparison chart of crude oil before and after using choline-serine amino acid ionic liquid is as follows: Figure 1 As shown.

[0035] Application Example 2 This application example provides the application of the choline-glycine ionic liquid obtained in Example 2 in crude oil refining, as detailed below: Take 30g of crude oil and dehydrate it under vacuum at 95℃ for 2h. After dehydration, cool it down to 60℃ and keep it under vacuum. Slowly add 5g of choline-glycine ionic liquid under gentle stirring. Stir and react at constant temperature for 8h. After the reaction is completed, let it stand and separate into layers. Take the upper oil phase and centrifuge it at 4000rpm for 5min. Take the upper oil after centrifugation and test its colloidal value, acid value and color. The results are shown in Table 2.

[0036] Table 2 Comparison of crude oil gum value, acid value, and color before and after using choline-glycine ionic liquid.

[0037] The color comparison chart of crude oil before and after using choline-glycine ionic liquid is as follows: Figure 2 As shown.

[0038] Application Example 3 This application example provides the application of the choline-proline amino acid ionic liquid obtained in Example 3 in crude oil refining, as detailed below: Take 30g of crude oil and dehydrate it under vacuum at 95℃ for 2h. After dehydration, cool it down to 85℃ and keep it under vacuum. Slowly add 0.3g of choline-proline amino acid ionic liquid under gentle stirring. Stir and react at constant temperature for 10h. After the reaction is completed, let it stand and separate into layers. Take the upper oil phase and centrifuge it at 4000rpm for 5min. Take the upper oil after centrifugation and test its colloidal value, acid value and color. The results are shown in Table 3.

[0039] Table 3 Comparison of crude oil gum value, acid value, and color before and after using choline-proline ionic liquid.

[0040] The color comparison chart of crude oil before and after using choline-proline ionic liquid is as follows: Figure 3 As shown.

[0041] Application Example 4 This application example provides the application of the choline-histamino acid ionic liquid obtained in Example 4 in crude oil refining, as detailed below: Take 30g of crude oil and dehydrate it under vacuum at 95℃ for 2h. After dehydration, cool it down to 75℃ and keep it under vacuum. Slowly add 15g of choline-histamine ionic liquid under gentle stirring. Stir and react at constant temperature for 5h. After the reaction is completed, let it stand and separate into layers. Take the upper oil phase and centrifuge it at 4000rpm for 5min. Take the upper oil after centrifugation and test its colloidal value, acid value and color. The results are shown in Table 4.

[0042] Table 4 Comparison of crude oil gum value, acid value, and color before and after using choline-histidine ion solution

[0043] The color comparison chart of crude oil before and after using choline-histamine ionic liquid is as follows: Figure 4 As shown.

[0044] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. A method for preparing a choline-amino acid ionic liquid for efficiently enriching TG, EPA, or DHA in oils, characterized in that, Includes the following steps: After dissolving the amino acids, choline hydroxide was added, and the temperature was raised to 50-70°C for reaction. After the reaction was completed, the mixture was purified to obtain a choline-amino acid ionic liquid. The molar ratio of the amino acid to the choline hydroxide is 1:(0.5~2.5).

2. The method for preparing the choline-amino acid ionic liquid for efficiently enriching TG, EPA, or DHA in oils according to claim 1, characterized in that, The amino acid is one or more of serine, histidine, glycine, or proline.

3. The method for preparing a choline-amino acid ionic liquid for efficiently enriching TG, EPA, or DHA in oils according to claim 2, characterized in that, The amino acid in question is an L-type amino acid.

4. The method for preparing the choline-amino acid ionic liquid for efficiently enriching TG, EPA, or DHA in oils according to claim 1, characterized in that, After obtaining the choline-amino acid ionic liquid, the following steps are also included: passing dry CO2 into the choline-amino acid ionic liquid to adjust its pH to near neutral.

5. A choline-amino acid ionic liquid, obtained by the preparation method of the choline-amino acid ionic liquid for efficiently enriching TG, EPA or DHA in oils according to any one of claims 1-4.

6. The choline-amino acid ionic liquid according to claim 5, characterized in that, The choline-amino acid ionic liquid has a water content of <1 wt%.

7. The application of the choline-amino acid ionic liquid as described in claim 5 in crude oil refining.

8. The application of the choline-amino acid ionic liquid according to claim 7 in crude oil refining, characterized in that, The crude oil refining process includes the following steps: the crude oil is mixed and stirred with the choline-amino acid ionic liquid under vacuum conditions for degreasing treatment, wherein the mass ratio of the crude oil to the choline-amino acid ionic liquid is 1: (0.01~0.5).

9. The application of the choline-amino acid ionic liquid according to claim 8 in crude oil refining, characterized in that, Before the "removal treatment by mixing and stirring with the choline-amino acid ionic liquid", the crude oil is pretreated to remove the water from the crude oil.

10. The application of the choline-amino acid ionic liquid according to claim 8 in crude oil refining, characterized in that, When the process of "removing the choline-amino acid ion liquid by mixing and stirring" is carried out, the reaction time is 0.5 to 10 hours.

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