Method for reducing contents of low-boiling-point substances and high-boiling-point substances in ethyl polyenoate and application of method

Abstract

The invention relates to the technical field of polyenoic acid ethyl ester purification, in particular to a method for reducing the content of low-boiling-point substances and high-boiling-point substances in polyenoic acid ethyl ester and application of the method, and the method comprises the following steps: putting the polyenoic acid ethyl ester into molecular rectification equipment, and sequentially carrying out first molecular rectification and second molecular rectification to respectively remove the low-boiling-point substances and the high-boiling-point substances. According to the method for removing the low-boiling-point substances and the high-boiling-point substances in the ethyl polyenoate, the physical purification principle is adopted, and impurities such as the low-boiling-point substances SDA and ARA and the high-boiling-point substances HPA and DPA in the ethyl polyenoate can be effectively removed through two times of molecular rectification, so that the purity and the quality of the product are improved. In addition, the method is high in yield, low in energy consumption, simple to operate, capable of utilizing conventional treatment devices of chemical plants, low in economic cost and suitable for industrial continuous production, and has important significance on preparation of high-quality ethyl polyenoate drugs.

Description

Technical Field

[0001] The invention relates to the technical field of polyenoic acid ethyl ester purification, in particular to a method for reducing the contents of low-boiling substances and high-boiling substances in polyenoic acid ethyl ester and application thereof. Background Art

[0002] Ethyl polyenoate, as an important class of fatty acid ethyl ester compounds, has a wide range of applications in medicine, health products, cosmetics, food and other fields. Such compounds are usually prepared by chemical synthesis or esterification of natural oils and fats, but during the production process, a series of impurities with different boiling points, including low-boiling substances and high-boiling substances, are often mixed in. The presence of these impurities not only affects the purity of ethyl polyenoate, but may also have an adverse effect on its physical and chemical properties and biological activity, thereby limiting its application in high-end fields.

[0003] Low boiling substances usually refer to compounds that can volatilize at relatively low temperatures. They may come from volatile components in raw materials, by-products in the reaction process, or raw materials that have not been completely reacted. The presence of these low boiling substances will cause polyol ethyl ester to be easily volatilized and lost during storage and use, and will also affect the stability and safety of the product.

[0004] High boiling substances refer to compounds that can only volatilize at higher temperatures, which may include incompletely converted raw materials, high molecular weight byproducts generated by the reaction, or catalyst residues. The presence of high boiling substances will increase the viscosity of polyoleate, reduce its solubility and fluidity, and thus affect the processing performance and final use effect of the product.

[0005] In order to obtain high-purity and high-quality polyolefin ethyl ester, low-boiling and high-boiling impurities must be effectively removed. Traditional removal methods include water washing, solvent extraction, distillation, etc., but these methods often have the disadvantages of complex operation, high energy consumption, and great environmental pollution, and it is difficult to achieve the ideal separation effect.

[0006] In recent years, with the continuous development of separation technology, high vacuum molecular distillation technology has gradually become an effective method for separating multi-component mixtures. This technology uses the difference in intermolecular interaction forces to achieve effective separation of compounds with different boiling points under high vacuum conditions. Compared with traditional distillation methods, high vacuum molecular distillation has the advantages of high separation efficiency, low energy consumption, and simple operation. It is particularly suitable for fields with special requirements for high-purity products.

[0007] However, the application of high vacuum molecular distillation technology to the removal of low-boiling and high-boiling substances in ethyl polyenoate still requires solving a series of technical problems, such as how to optimize the operating parameters to achieve the best separation effect, how to reduce equipment investment and operating costs, etc. Therefore, the development of an efficient, economical and environmentally friendly method for removing low-boiling and high-boiling substances in ethyl polyenoate is of great significance for improving the product quality and market competitiveness of ethyl polyenoate.

[0008] In view of this, the present invention proposes a method for reducing the content of low-boiling substances and high-boiling substances in ethyl polyenoate by using high vacuum molecular distillation technology, aiming to solve the problems existing in the prior art and improve the purity and quality of ethyl polyenoate. Summary of the invention

[0009] The object of the present invention is to provide a method for reducing the content of low-boiling substances and high-boiling substances in ethyl polyenoate. The removal method can remove a large amount of low-boiling substances SDA and ARA and high-boiling substances HPA and DPA in ethyl polyenoate, so that the contents of SDA, ARA, HPA and DPA in ethyl polyenoate are respectively less than 0.3% and 0.5% and 0.3% and 0.1%.

[0010] In a first aspect, the present invention provides a method for reducing the content of low-boiling-point substances and high-boiling-point substances in ethyl polyenoate, comprising the following steps:

[0011] The polyenoic acid ethyl ester is placed in a molecular distillation device to perform a first molecular distillation and a second molecular distillation in sequence to remove low-boiling substances and high-boiling substances respectively.

[0012] The method for reducing the content of low-boiling substances and high-boiling substances in ethyl polyenoate adopts the principle of physical purification and can effectively remove impurities such as low-boiling substances SDA (ethyl octadecatetraenoate), ARA (ethyl arachidonic acid (ethyl eicosatetraenoate)) and high-boiling substances HPA (ethyl heneicosatetraenoate), DPA (ethyl docosatetraenoate) in the ethyl polyenoate through two molecular distillations, thereby improving the purity and quality of the product.

[0013] As a preferred embodiment of the present technical solution, during the first molecular distillation, the feed rate is controlled to be 300-400 kg / h, the low-boiling-point material discharge rate is 100-270 kg / h, and the high-boiling-point material discharge rate is 200-270 kg / h.

[0014] Among them, controlling the feed rate within the range of 300-400kg / h can ensure that the material processing capacity in the molecular distillation equipment is moderate, neither overloaded nor too sparse, which is conducive to the separation and removal of impurities. The discharge rate of low-boiling substances is controlled at 100-270kg / h, and the discharge rate of high-boiling substances is controlled at 200-270kg / h, which helps to discharge the separated low-boiling substances and high-boiling substances from the equipment in time to avoid their interference with the subsequent separation process.

[0015] As a preferred embodiment of the present technical solution, during the first molecular distillation, the heating temperature is controlled to be 200-220°C and the reflux temperature is 100-130°C. The heating temperature is controlled within the range of 200-220°C to ensure that the material has sufficient energy for vaporization and separation during the molecular distillation process, while avoiding thermal deterioration of the material due to excessively high temperature; and the reflux temperature is controlled within the range of 100-130°C, which helps to reflux some of the incompletely separated materials into the tower for further separation and purification.

[0016] As a preferred embodiment of the present technical solution, during the first molecular distillation, the top pressure is controlled to be 0.5-50 mbar and the top temperature is controlled to be 140-160°C. The top pressure is controlled within the range of 0.5-50 mbar and the top temperature is controlled within the range of 140-160°C. These two parameters jointly determine the vacuum degree and temperature distribution in the tower, thereby affecting the vaporization and separation effect of the material. Appropriate top pressure and top temperature help optimize the separation process and improve the purity of the product.

[0017] As a preferred embodiment of the present technical solution, during the first molecular distillation, the reflux ratio is controlled to be 0.5-5, and preferably 1.5-3.5, and the tower pressure difference is 0.5-50mbar. The reflux ratio refers to the ratio of the amount of refluxed material to the amount of produced material. An appropriate reflux ratio can ensure that there is enough material in the tower for circulation and separation, thereby improving separation efficiency and product purity; and the tower pressure difference is controlled within the range of 0.5-50mbar, which helps to maintain a stable flow state in the tower and avoid material retention or blockage in the tower, thereby affecting the separation effect.

[0018] As a preferred embodiment of the present technical solution, during the second molecular distillation, the feed rate is controlled to be 150-250 kg / h, the low boiling point material discharge rate is 90-150 kg / h, and the high boiling point material discharge rate is 60-100 kg / h.

[0019] Specifically, during the second molecular distillation, the heating temperature is controlled to be 200-220°C, and the reflux temperature is controlled to be 100-130°C.

[0020] Specifically, during the second molecular distillation, the top pressure is controlled to be 0.5-50 mbar and the top temperature is controlled to be 150-170°C.

[0021] Specifically, during the second molecular distillation, the reflux ratio is controlled to be 0.5-5, and preferably 1-3, and the tower pressure difference is 0.5-50 mbar.

[0022] The present invention can ensure the high efficiency, stability and controllability of the molecular distillation process by accurately controlling these parameters, thereby effectively removing low-boiling and high-boiling impurities in the ethyl polyenoate, and improving the purity and quality of the product. The selection and optimization of these control parameters are based on a deep understanding of the molecular distillation principle and the accumulation of practical experience, and are the key to achieving high-quality ethyl polyenoate production.

[0023] In a second aspect, the present invention also discloses a polyolefin ethyl ester product prepared by the above method for reducing the content of low-boiling substances and high-boiling substances in polyolefin ethyl ester. Specifically, the contents of SDA, ARA, HPA and DPA in the polyolefin ethyl ester product are respectively below 0.3%, 0.5%, 0.3% and 0.1%.

[0024] The method for reducing the content of low-boiling-point substance and high-boiling-point substance in ethyl polyenoate of the present invention specifically comprises the following steps:

[0025] (1) Under vacuum / negative pressure conditions, the polyenoic acid ethyl ester raw material is pumped into a molecular distillation device through a feed pump for the first molecular distillation;

[0026] (2) In the above step (1), the feed rate is controlled to be 300-400 kg / h; the discharge rate of low-boiling substances is 100-270 kg / h, and the discharge rate of high-boiling substances is 200-270 kg / h;

[0027] (3) During the first molecular distillation in step (1), the heating temperature is controlled at 200-220° C. and the reflux temperature is controlled at 100-130° C.;

[0028] (4) During the first molecular distillation in step (1), the top pressure is controlled to be 0.5-50 mbar and the top temperature is controlled to be 140-160° C.;

[0029] (5) During the first molecular distillation in step (1), the reflux ratio is 1.5-3.5 and the tower pressure difference is 0.5-50 mbar;

[0030] (6) According to the above steps, the low boiling point of ethyl polyenoate is removed, and the heavy phase of the first molecular distillation is collected;

[0031] (7) The heavy phase of the first molecular distillation in step (6) is pumped into a molecular distillation device through a feed pump for a second molecular distillation;

[0032] (8) In step (7), the feed rate is controlled to be 150-250 kg / h, the low boiling point material discharge rate is 90-150 kg / h, and the high boiling point material discharge rate is 60-100 kg / h;

[0033] (9) During the second molecular distillation in step (7), the heating temperature is controlled at 200-220°C and the reflux temperature is controlled at 100-130°C;

[0034] (10) During the second molecular distillation in step (7), the top pressure is controlled to be 0.5-50 mbar and the top temperature is controlled to be 150-170° C.;

[0035] (11) During the second molecular distillation in step (7), the reflux ratio is controlled to be 1-3 and the tower pressure difference is 0.5-50 mbar;

[0036] (12) According to the above steps, high boiling points in ethyl polyenoate are removed, and the light phase of the second molecular distillation is collected to obtain the purified ethyl polyenoate product.

[0037] The method for reducing the content of low-boiling-point substance and high-boiling-point substance in ethyl polyenoate of the present invention at least has the following characteristics:

[0038] Beneficial effects:

[0039] The method for reducing the content of low-boiling substances and high-boiling substances in ethyl polyenoate adopts the principle of physical purification, and can effectively remove impurities such as low-boiling substances SDA and ARA and high-boiling substances HPA and DPA in ethyl polyenoate through two molecular distillations, thereby improving the purity and quality of the product. In addition, the method has high yield, low energy consumption, simple operation, and can utilize conventional processing equipment in chemical plants, with low economic cost, suitable for industrial continuous production, and has great significance for preparing high-quality ethyl polyenoate drugs. DETAILED DESCRIPTION

[0040] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0041] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this description, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0042] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Example 1

[0044] The present embodiment provides a method for reducing the content of low-boiling substances and high-boiling substances in ethyl polyenoate, comprising the following steps:

[0045] The molecular distillation equipment was evacuated to a top pressure of 1 mbar, and the polyolefin ethyl ester raw material was pumped into the molecular distillation equipment through a feed pump, and the feed pump speed was controlled at 300-400 kg / h;

[0046] The heating temperature of the molecular distillation equipment is controlled to be 200° C., and the reflux ratio is controlled to be 3.0 for the first molecular distillation. At the same time, the reflux temperature is controlled to be 100-130° C., the tower top temperature is controlled to be 140-160° C., and the tower pressure difference is controlled to be 0.5-50 mbar. Low boiling substances in ethyl polyenoate are removed by the first molecular distillation, and the discharge rate of the low boiling substances is 100-270 kg / h. The heavy phase of the first molecular distillation is collected, and the discharge rate of high boiling substances is 200-270 kg / h.

[0047] The molecular distillation equipment is evacuated to a top pressure of 1 mbar, and the heavy phase material of the first molecular distillation is pumped into the molecular distillation equipment through a feed pump for a second molecular distillation, and the feed pump speed is controlled at 150-250 kg / h;

[0048] The heating temperature of the molecular distillation equipment is controlled to be 200° C., and the reflux ratio is controlled to be 3.0 for the second molecular distillation. At the same time, the reflux temperature is controlled to be 100-130° C., the tower top temperature is controlled to be 150-170° C., and the tower pressure difference is controlled to be 0.5-50 mbar. The high boiling substances in the ethyl polyenoate are removed by the second molecular distillation, and the discharge rate of the high boiling substances is 60-100 kg / h. The light phase of the second molecular distillation is collected, and the discharge rate of the low boiling substances is 90-150 kg / h.

[0049] After testing, the contents of SDA, ARA, HPA and DPA in the polyenoic acid ethyl ester treated in this example were 0.25%, 0.4%, 0.25% and 0.09%, respectively.

[0050] Example 2

[0051] The present embodiment provides a method for reducing the content of low-boiling substances and high-boiling substances in ethyl polyenoate, comprising the following steps:

[0052] The molecular distillation equipment was evacuated to a top pressure of 1 mbar, and the polyolefin ethyl ester raw material was pumped into the molecular distillation equipment through a feed pump, and the feed pump speed was controlled at 300-400 kg / h;

[0053] The heating temperature of the molecular distillation equipment is controlled to be 220° C. and the reflux ratio is controlled to be 3.0 for the first molecular distillation. At the same time, the reflux temperature is controlled to be 100-130° C., the tower top temperature is controlled to be 140-160° C., and the tower pressure difference is controlled to be 0.5-50 mbar. Low boiling substances in ethyl polyenoate are removed by the first molecular distillation. The discharge rate of the low boiling substances is 100-270 kg / h. The heavy phase of the first molecular distillation is collected. The discharge rate of high boiling substances is 200-270 kg / h.

[0054] The molecular distillation equipment is evacuated to a top pressure of 1 mbar, and the heavy phase material of the first molecular distillation is pumped into the molecular distillation equipment through a feed pump for a second molecular distillation, and the feed pump speed is controlled at 150-250 kg / h;

[0055] The heating temperature of the molecular distillation equipment is controlled to be 220°C, and the reflux ratio is 3.0 for the second molecular distillation. At the same time, the reflux temperature is controlled to be 100-130°C, the tower top temperature is 150-170°C, and the tower pressure difference is 0.5-50mbar. The high boiling substances in the ethyl polyenoate are removed by the second molecular distillation, and the high boiling substance discharge rate is 60-100kg / h. The light phase of the secondary molecular distillation is collected, and the low boiling substance discharge rate is 90-150kg / h.

[0056] After testing, the contents of SDA, ARA, HPA and DPA in the polyenoic acid ethyl ester treated in this example were 0.27%, 0.45%, 0.26% and 0.09% respectively.

[0057] Example 3

[0058] The present embodiment provides a method for reducing the content of low-boiling substances and high-boiling substances in ethyl polyenoate, comprising the following steps:

[0059] The molecular distillation equipment was evacuated to a top pressure of 10 mbar, and the polyenoic acid ethyl ester raw material was pumped into the molecular distillation equipment through a feed pump, and the feed pump speed was controlled at 300-400 kg / h;

[0060] The heating temperature of the molecular distillation equipment is controlled to be 210° C., and the reflux ratio is controlled to be 0.5-5 for the first molecular distillation. At the same time, the reflux temperature is controlled to be 100-130° C., the tower top temperature is controlled to be 140-160° C., and the tower pressure difference is controlled to be 0.5-50 mbar. Low boiling substances in ethyl polyenoate are removed by the first molecular distillation, and the discharge rate of the low boiling substances is 100-270 kg / h. The heavy phase of the first molecular distillation is collected, and the discharge rate of high boiling substances is 200-270 kg / h.

[0061] The molecular distillation equipment is evacuated to a top pressure of 1 mbar, and the heavy phase material of the first molecular distillation is pumped into the molecular distillation equipment through a feed pump for a second molecular distillation, and the feed pump speed is controlled at 150-250 kg / h;

[0062] The heating temperature of the molecular distillation equipment is controlled to be 210°C, and the reflux ratio is 0.5-5 for the second molecular distillation. At the same time, the reflux temperature is controlled to be 100-130°C, the tower top temperature is 150-170°C, and the tower pressure difference is 0.5-50mbar. The high boiling substances in the ethyl polyenoate are removed by the second molecular distillation, and the discharge rate of the high boiling substances is 60-100kg / h. The light phase of the secondary molecular distillation is collected, and the discharge rate of the low boiling substances is 90-150kg / h.

[0063] After testing, the contents of SDA, ARA, HPA and DPA in the polyenoic acid ethyl ester treated in this example were 0.28%, 0.46%, 0.28% and 0.09% respectively.

[0064] Comparative Example 1

[0065] This comparative example is basically the same as Example 1, except that during the first molecular distillation and the second molecular distillation, the molecular distillation equipment was evacuated to a top pressure of 100 mbar.

[0066] After testing, the contents of SDA, ARA, HPA and DPA in the polyenoic acid ethyl ester treated in this control example were 2.7%, 3.2%, 3.6% and 4.5% respectively.

[0067] Comparative Example 2

[0068] This comparative example is basically the same as Example 1, except that: during the first molecular distillation, the heating temperature of the molecular distillation equipment is adjusted to 230°C.

[0069] The results showed that the contents of ethyl polyenoate SDA and ARA in the heavy phase of the first molecular distillation of this comparative example were 1.9% and 2.2% respectively.

[0070] Comparative Example 3

[0071] This comparative example is basically the same as Example 1, except that during the second molecular distillation, the heating temperature of the molecular distillation equipment is adjusted to 230°C.

[0072] After testing: the contents of ethyl polyenoate HPA and DPA in the light phase of the second molecular distillation of this control example were 2.8% and 3.2% respectively.

[0073] In summary, the method for reducing the content of low-boiling-point substance and high-boiling-point substance in ethyl polyenoate of the present invention adopts the principle of physical purification, and can effectively remove impurities such as low-boiling-point substance SDA, ARA and high-boiling-point substance HPA, DPA in ethyl polyenoate by two molecular distillations, thereby improving the purity and quality of the product. In addition, the method has high yield, low energy consumption, simple operation, and can utilize conventional processing equipment of chemical plants, with low economic cost, suitable for industrial continuous production, and is of great significance for preparing high-quality ethyl polyenoate drugs.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for reducing the content of low-boiling substances and high-boiling substances in ethyl polyenoate, characterized in that: The following steps are involved: The polyenoic acid ethyl ester is placed in a molecular distillation device to perform a first molecular distillation and a second molecular distillation in sequence to remove low-boiling substances and high-boiling substances respectively.

2. The method for reducing the content of low-boiling-point substances and high-boiling-point substances in ethyl polyenoate according to claim 1, characterized in that: During the first molecular distillation, the feed rate is controlled to be 300-400 kg / h, the low-boiling-point material discharge rate is 100-270 kg / h, and the high-boiling-point material discharge rate is 200-270 kg / h.

3. The method for reducing the content of low-boiling-point substances and high-boiling-point substances in ethyl polyenoate according to claim 1, characterized in that: During the first molecular distillation, the heating temperature is controlled to be 200-220°C and the reflux temperature is controlled to be 100-130°C.

4. The method for reducing the content of low-boiling-point substances and high-boiling-point substances in ethyl polyenoate according to claim 1, characterized in that: During the first molecular distillation, the top pressure is controlled to be 0.5-50 mbar and the top temperature is controlled to be 140-160°C.

5. The method for reducing the content of low-boiling-point substances and high-boiling-point substances in ethyl polyenoate according to claim 1, characterized in that: During the first molecular distillation, the reflux ratio is controlled to be 0.5-5 and the tower pressure difference is controlled to be 0.5-50 mbar.

6. The method for reducing the content of low-boiling-point substances and high-boiling-point substances in ethyl polyenoate according to claim 1, characterized in that: During the second molecular distillation, the feed rate is controlled to be 150-250 kg / h, the low-boiling-point material discharge rate is 90-150 kg / h, and the high-boiling-point material discharge rate is 60-100 kg / h.

7. The method for reducing the content of low-boiling-point substances and high-boiling-point substances in ethyl polyenoate according to claim 1, characterized in that: During the second molecular distillation, the heating temperature is controlled at 200-220°C and the reflux temperature is controlled at 100-130°C.

8. The method for reducing the content of low-boiling-point substances and high-boiling-point substances in ethyl polyenoate according to claim 1, characterized in that: During the second molecular distillation, the top pressure is controlled to be 0.5-50 mbar and the top temperature is controlled to be 150-170°C.

9. The method for reducing the content of low-boiling-point substances and high-boiling-point substances in ethyl polyenoate according to claim 1, characterized in that: During the second molecular distillation, the reflux ratio is controlled to be 0.5-5 and the tower pressure difference is 0.5-50 mbar.

10. A polyolefin ethyl ester product, characterized in that: Prepared by the method for reducing the content of low-boiling substances and high-boiling substances in ethyl polyenoate according to any one of claims 1 to 9; The contents of SDA, ARA, HPA and DPA in the polyoleate ethyl ester product are respectively below 0.3%, 0.5%, 0.3% and 0.1%.