A continuous flow process for the preparation of hydrogenated lecithin with different phosphatidylcholine content

Abstract

This invention discloses a continuous flow preparation process for hydrogenated lecithin with different phosphatidylcholine contents, belonging to the field of organic synthesis technology. Using methanol as a green hydrogen source and methyl source, this invention, by adjusting reaction conditions and catalysts, can achieve the preparation of hydrogenated lecithin products with phosphatidylcholine (PC) contents of ≥20%, ≥80%, and ≥98% from lecithin as raw material. While improving reaction efficiency, it reduces the liquid holdup of the reaction system, fundamentally reducing process risks and meeting different market demands.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology, specifically relating to a continuous flow preparation process for hydrogenated lecithin with different phosphatidylcholine contents. Background Technology

[0002] Hydrogenated lecithin is typically synthesized from soybean lecithin via a catalytic hydrogenation process. After hydrogenation, the number of unsaturated bonds in the unsaturated fatty acids of the soybean lecithin molecule decreases, significantly improving its chemical stability, dispersibility, and emulsifying properties. The hydrogenation process also decolorizes and deodorizes, further enhancing the storage and preservation of (hydrogenated) lecithin products and increasing their effectiveness in pharmaceuticals, high-end cosmetics, and light industry.

[0003] As early as 1933, Shinozaki et al. (Shinozaki, S., Sato, M., Hydrogenation of lecithin isolated from the soybean. Nippon Nogei Kagaku Kaishi, 1933, 9, 728.) catalytically hydrogenated lecithin isolated from soybean lecithin using colloidal palladium, obtaining a product with a melting point of 85°C that was insoluble in MeOAc. In 1934, Shinozald et al. (Shinozaki, Y., Sato, M., The hydrogenation under high pressure. Kogyo Kagaku Zasshi, 1934, 37, 432.) used a Ni catalyst at a reaction pressure exceeding 80 atm to obtain hydrogenated lecithin with an iodine value of 0.38 and a melting point of 84°C. Jin Xijiang et al. (Research and Development of Hydrogenated Soybean Lecithin, Fine Chemicals, 1999, 16, 5.) used Pd / C as a catalyst and dichloromethane as a solvent for catalytic hydrogenation, obtaining a pale yellow hydrogenated soybean lecithin with an iodine value below 30. He Fengying et al. (Preparation of Hydrogenated Soybean Lecithin, Hunan Chemical Industry, 1999, 29, 18.) used a palladium catalyst and dichloromethane or a dichloromethane-ethanol mixture as a solvent to separate the reaction products, obtaining a hydrogenated soybean lecithin with an iodine value of 20-30, a pale yellow color, no unpleasant odor, and a yield of 80%. Japanese Patent JP0403629 reported the use of a mixed solvent of n-heptane and C1-4 lower alcohols as solvents, with Pt as a catalyst for the catalytic hydrogenation of lecithin, yielding 90% hydrogenated lecithin at 80℃. The hydrogenation reaction can be qualitatively characterized by the iodine value; the lower the iodine value, the more complete the hydrogenation. Although numerous patent documents have studied the catalytic processes of palladium, platinum, and nickel catalysts under different reaction conditions, all current lecithin hydrogenation technologies employ a batch-type hydrogenation method. Hydrogenation is one of the 18 key hazardous chemical processes under national supervision. Its reactants, hydrogenation catalysts, and reaction tail gases all possess high flammability and explosion hazards. Furthermore, hydrogenation is a strongly exothermic reaction; when hydrogen gas comes into contact with steel under high temperature and pressure, the carbon molecules within the steel readily react with hydrogen to form hydrocarbons, reducing the strength of steel equipment and causing hydrogen embrittlement.

[0004] Hydrogen transfer reactions are considered an ideal, safer, and greener route for the reduction of unsaturated compounds. Methanol, in particular, has attracted considerable attention in recent years as an ideal hydrogen source, with a hydrogen mass density of 12.5 wt%, and significant advantages such as low toxicity, wide availability, biodegradability, and safe and convenient storage and transportation. If suitable hydrogen transfer hydrogenation catalysts can be developed, a green synthesis route for hydrogenated lecithin using green methanol as the hydrogen source can be realized.

[0005] Crude soybean lecithin is a mixture of phospholipids, comprising phosphatidylcholine PC (lecithin, approximately 25%–32%), phosphatidylethanolamine PE (cephalin, 18%–21%), phosphatidylinositol PI (phosphatidylinositol), phosphatidylglycerol PG (sphingomyelin), phosphatidic acid PA, and other phospholipids. Phosphatidylethanolamine PE can be converted to phosphatidylcholine PC through methylation, thereby increasing the phosphatidylcholine PC content of the product. Methanol is not only an ideal hydrogen source but also an ideal methylation reagent. For the process of preparing hydrogenated lecithin from soybean lecithin, if, based on the methanol-activated hydrogen transfer catalytic reaction, the reaction conditions can be adjusted to simultaneously achieve a multifunctional tandem reaction of methanol dehydrogenation, phosphatidylethanolamine PE methylation, and double bond hydrogen transfer hydrogenation, then lecithin products with higher PC content can be further produced to meet different market demands.

[0006] Furthermore, traditional batch hydrogenation processes are limited by factors such as reaction temperature and pressure, resulting in problems such as high safety requirements for hydrogen and reaction equipment, long reaction times, low conversion rates, and difficulty in controlling over-reduction. Continuous flow microchannel reactions not only enhance the reaction process but also offer a safer, faster, and more efficient approach for drug synthesis and fine chemicals. In continuous flow microchannel reactions, gas-liquid-solid contact is enhanced, increasing mass transfer between phases in the gas-liquid-solid (catalyst) multiphase catalytic system and thus improving the reaction rate. The precise controllability of reaction temperature, pressure, and catalyst contact time in the flow system also enables rapid optimization and reproducibility of reaction conditions. More importantly, the low liquid holdup characteristic of continuous flow hydrogenation technology significantly reduces the hazards of batch hydrogenation processes. Summary of the Invention

[0007] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0008] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0009] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a continuous flow preparation process for hydrogenated lecithin with different phosphatidylcholine contents.

[0010] To solve the above-mentioned technical problems, the present invention provides the following technical solutions, including:

[0011] Lecithin is dissolved in a solvent, and the resulting reaction solution is continuously pumped into a micro-packed bed reaction module filled with a hydrogen transfer reduction catalyst. Under the action of the catalyst, methylation and catalytic hydrogen transfer reduction reactions are carried out.

[0012] The reacted material was cooled and concentrated to obtain crude hydrogenated lecithin, which was then pulped and purified to obtain hydrogenated lecithin.

[0013] As a preferred embodiment of the continuous flow preparation process of hydrogenated lecithin with different phosphatidylcholine contents according to the present invention, wherein: the lecithin includes one or more of soybean lecithin, rapeseed lecithin or egg yolk lecithin;

[0014] The lecithin is selected based on the PC content of the target product;

[0015] When the PC content of the target product is less than 80% and less than 20%, the PC content of the lecithin is 20% to 35%.

[0016] When the PC content of the target product is ≥80%, the PC content of the lecithin is 70% to 75%.

[0017] As a preferred embodiment of the continuous flow preparation process of hydrogenated lecithin with different phosphatidylcholine contents according to the present invention, the solvent includes one or more of methanol, ethanol, isopropanol, dichloromethane, n-hexane, n-heptane, toluene, and chlorobenzene.

[0018] As a preferred embodiment of the continuous flow preparation process of hydrogenated lecithin with different phosphatidylcholine contents according to the present invention, the mass fraction of lecithin in the reaction solution is 10% to 50%.

[0019] As a preferred embodiment of the continuous flow preparation process of hydrogenated lecithin with different phosphatidylcholine contents described in this invention, the pumping rate of the reaction solution is 0.3 to 2.0 mL / min.

[0020] As a preferred embodiment of the continuous flow preparation process of hydrogenated lecithin with different phosphatidylcholine contents according to the present invention, wherein: the loading amount of the hydrogen transfer reduction catalyst is 15-20g; the hydrogen transfer reduction catalyst is a supported nano-metal catalyst with a metal loading of 0.1-5.0wt%, and the support of the supported nano-metal catalyst includes one of alumina, silicon oxide, zinc oxide, cerium oxide, titanium oxide, magnesium oxide, and zirconium oxide; the active metal supported on the supported nano-metal catalyst includes one of Pt, Ir, Ru, and Pd; and the average particle size of the active metal is 1-20nm.

[0021] As a preferred embodiment of the continuous flow preparation process of hydrogenated lecithin with different phosphatidylcholine contents according to the present invention, the micro-packed bed reaction module is cylindrical, the hydrogen transfer reduction catalyst fills the internal space of the micro-packed bed reaction module, and the reaction liquid flows through the axial direction of the micro-packed bed reaction module; wherein, the aspect ratio of the micro-packed bed reaction module is 10 to 60:1, and the ratio of the inner diameter of the micro-packed bed reaction module to the average particle size of the hydrogen transfer reduction catalyst is 15 to 30:1.

[0022] As a preferred embodiment of the continuous flow preparation process of hydrogenated lecithin with different phosphatidylcholine contents described in this invention, the temperature of the reaction module is selected according to the PC content of the target product;

[0023] When the PC content of the target product is less than 80% and less than 20%, the temperature of the reaction module is 80℃~120℃;

[0024] When the PC content of the target product is ≥80%, the temperature of the reaction module is 120℃~180℃;

[0025] The reaction time is 30–600 s.

[0026] As a preferred embodiment of the continuous flow preparation process of hydrogenated lecithin with different phosphatidylcholine contents described in this invention, the solvent for pulping includes one or more of methanol, ethanol, isopropanol, dichloromethane, n-hexane, n-heptane, acetone, and toluene.

[0027] As a preferred embodiment of the continuous flow preparation process of hydrogenated lecithin with different phosphatidylcholine contents according to the present invention, the purification conditions are: recrystallization or column chromatography; wherein, the recrystallization solvent includes one or more of methanol, ethanol, isopropanol, dichloromethane, n-hexane, n-heptane, acetone, and toluene; and the column chromatography solvent includes one or more of petroleum ether, dichloromethane, n-hexane, n-heptane, and toluene.

[0028] Beneficial effects of this invention:

[0029] (1) Compared with the existing batch reactor hydrogenation process, the process of the present invention has a high degree of automation and safety factor, and the production process is economical and environmentally friendly, making it more suitable for industrial scale-up production.

[0030] (2) This invention uses methanol as a green hydrogen source and methyl source to develop a continuous preparation process for hydrogenated lecithin with different PC contents. By adjusting the reaction conditions and catalyst, hydrogenated lecithin products with phosphatidylcholine PC contents of ≥20%, ≥80% and ≥98% can be prepared from lecithin as raw material. While improving the reaction efficiency, the liquid holding volume of the reaction system is reduced, fundamentally reducing the process risk and meeting different market demands. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0032] Figure 1 This is a schematic diagram of a continuous reactor for lecithin hydrogenation; where 1 is the lecithin reaction solution, 2 is the microreactor, 3 is the temperature control module, 4 is the cooler, and 5 is the product collection tank.

[0033] Figure 2 The image shows the HPLC results of hydrogenated lecithin with a PC content ≥20% prepared in Example 1 of this invention.

[0034] Figure 3 The image shows the HPLC results of hydrogenated lecithin with a PC content ≥80% prepared in Example 8 of this invention.

[0035] Figure 4 The image shows the HPLC results of hydrogenated lecithin with a PC content ≥98% prepared in Example 11 of this invention. Detailed Implementation

[0036] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0037] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0038] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0039] Unless otherwise specified, all raw materials used in this invention are commercially available.

[0040] The yield is calculated as yield = (W1 / W2) × 100%, where W1 is the actual mass of hydrogenated lecithin obtained and W2 is the theoretical mass of hydrogenated lecithin obtained.

[0041] Iodine value: determined by titration, with reference to the national standard GB / T 5532-2022.

[0042] PC content: Detected by high performance liquid chromatography, with the detection method referring to the national standard GB / T 35867-2018.

[0043] Example 1

[0044] This embodiment provides a method for preparing hydrogenated lecithin with 20% ≤ phosphatidylcholine (PC) < 80%, referring to... Figure 1 Specifically:

[0045] (1) Dissolve soybean lecithin with a PC content of 20% and an iodine value of 79.0 in a mixed solution of toluene and methanol (v:v) = 1:1 to prepare a reaction solution with a mass fraction of 20%.

[0046] (2) The reaction solution was pumped into the reaction module of the continuous flow microreactor at a flow rate of 1 mL / min. The reaction module was cylindrical with an inner diameter of 5 mm and a length of 50 mm, and was filled with 15 g of activated alumina-supported Pt catalyst (Pt content of 0.5%, Pt average particle size of 3.0 nm). The reaction module temperature was 110℃, the pressure was 3 MPa, and the residence time was 1 min.

[0047] (3) The reacted material enters the gas-liquid separator for cooling. After the reaction liquid is concentrated and dried, crude hydrogenated lecithin is obtained. The crude product is then slurried using a methanol:acetone = 1:1 mixed solution to obtain a light yellow hydrogenated lecithin product.

[0048] The PC content of the above target product was determined by HPLC, such as... Figure 2 As shown, the PC content was ≥30%; the iodine value was determined by titration and the result was 5.

[0049] Based on the above data, the reaction product obtained is hydrogenated lecithin.

[0050] Example 2

[0051] The difference between this embodiment and Example 1 is that the temperature of the reaction module is adjusted to 80°C, while the rest of the preparation process is the same as in Example 1, to obtain hydrogenated lecithin product.

[0052] Example 3

[0053] The difference between this embodiment and Example 1 is that the temperature of the reaction module is adjusted to 120°C, while the rest of the preparation process is the same as in Example 1, to obtain hydrogenated lecithin product.

[0054] The products obtained in the above embodiments were tested, and the comparison results with those of Example 1 are shown in Table 1.

[0055] Table 1

[0056] Example 1 Example 2 Example 3 iodine value 5 23 6 PC content (%) 23.4 22.0 23.1

[0057] As shown in the table above, adjusting the temperature of the reaction module has a significant impact on the hydrogenation effect (i.e., the iodine value of the product). This is because if the reaction temperature is too low, methanol cannot undergo efficient dehydrogenation, resulting in incomplete hydrogen transfer and a higher iodine value in the product. When hydrogenation reaches a certain level (iodine value <10), further increases in temperature cannot further promote hydrogen transfer efficiency, i.e., cannot further reduce the iodine value. According to the results in the table above, for the preparation of hydrogenated lecithin products with 30% ≤ phosphatidylcholine (PC) ≤ 80%, a reaction module temperature of 110℃ yields the best technical results.

[0058] Example 4

[0059] The difference between this embodiment and Example 1 is that the reaction solution is adjusted to toluene:ethanol (v∶v)=1∶1, while the rest of the preparation process is the same as in Example 1, to obtain hydrogenated lecithin product.

[0060] Example 5

[0061] The difference between this embodiment and Example 1 is that the reaction solution is adjusted to n-heptane:methanol (v∶v)=1∶1, while the rest of the preparation process is the same as in Example 1, to obtain hydrogenated lecithin product.

[0062] The products obtained in the above embodiments were tested, and the comparison results with those of Example 1 are shown in Table 2.

[0063] Table 2

[0064] Example 1 Example 4 Example 5 iodine value 5 65 42 PC content (%) 23.4 20.6 22.1

[0065] As can be seen from the table above, changing the reaction solvent has a significant impact on the iodine value of the product. This is because, under the reaction conditions, the hydrogen transfer hydrogenation reaction of lecithin is not effective when ethanol is used as the hydrogen source; and when n-heptane is used as the solvent, the dehydrogenation effect of methanol deteriorates, resulting in a poorer hydrogen transfer hydrogenation reaction, i.e., a higher iodine value. According to the results in the table above, the best technical effect can be obtained when toluene:methanol (v:v) = 1:1 is used as the solvent in this invention.

[0066] Example 6

[0067] The difference between this embodiment and Embodiment 1 is that the length of the reaction module is adjusted to 300 mm, i.e., the aspect ratio is 60:1. The rest of the preparation process is the same as in Embodiment 1, and hydrogenated lecithin product is obtained.

[0068] Example 7

[0069] The difference between this embodiment and Embodiment 1 is that the length of the reaction module is adjusted to 25 mm, i.e., the length-to-diameter ratio is 5:1. The rest of the preparation process is the same as that in Embodiment 1, and hydrogenated lecithin product is obtained.

[0070] The products obtained in the above embodiments were tested, and the comparison results with those of Example 1 are shown in Table 3.

[0071] Table 3

[0072] Example 1 Example 6 Example 7 iodine value 5 12 33 PC content (%) 23.4 21.4 22.3

[0073] As shown in the table above, changing the aspect ratio of the reaction module has a significant impact on the hydrogenation effect of the product. An excessively large aspect ratio leads to an excessively long residence time of the reaction solution within the reaction module, resulting in increased side reactions or over-hydrogenation of the product. An excessively small aspect ratio results in insufficient residence time of the reaction solution, which may prevent the hydrogenation reaction from reaching the expected level, leading to incomplete reaction and insufficient hydrogenation of the product, potentially causing the hydrogenated lecithin to fail to meet quality requirements. Therefore, the preferred aspect ratio of the reaction module in this invention is 10:1.

[0074] Example 8

[0075] This embodiment provides a method for preparing hydrogenated lecithin with 80% ≤ phosphatidylcholine (PC) < 98%, specifically as follows:

[0076] (1) Dissolve egg yolk lecithin with a PC content of 70% in a mixed solution of toluene:methanol (v:v) = 1:1 to prepare a reaction solution with a mass fraction of 20%;

[0077] (2) The reaction solution was pumped into the reaction module of the continuous flow microreactor at a flow rate of 1 mL / min. The reaction module was cylindrical with an inner diameter of 5 mm and a length of 50 mm, and was filled with 15 g of activated alumina-supported Pt catalyst (Pt content of 0.5%, Pt average particle size of 3.0 nm). The reaction module temperature was 150℃, the pressure was 3 MPa, and the residence time was 1 min.

[0078] (3) The reacted material was cooled in a gas-liquid separator. After the reaction solution was concentrated and dried, crude hydrogenated lecithin was obtained. Recrystallization was performed using a 1:1 mixture of n-heptane and acetone to obtain a white hydrogenated lecithin product. HPLC results are shown below. Figure 3 .

[0079] Example 9

[0080] The difference between this embodiment and Example 6 is that the temperature of the reaction module is adjusted to 120°C, while the rest of the preparation process is the same as in Example 1, to obtain hydrogenated lecithin product.

[0081] Example 10

[0082] The difference between this embodiment and Example 6 is that the temperature of the reaction module is adjusted to 180°C, while the rest of the preparation process is the same as in Example 1, to obtain hydrogenated lecithin product.

[0083] Example 11

[0084] This embodiment provides a method for preparing hydrogenated lecithin with 98% ≤ phosphatidylcholine (PC), specifically as follows:

[0085] (1) Dissolve egg yolk lecithin with a PC content of 70% in a mixed solution of toluene:methanol (v:v) = 1:1 to prepare a reaction solution with a mass fraction of 20%;

[0086] (2) The reaction solution was pumped at a rate of 1 mL / min into the reaction module of the continuous flow microreactor. The reaction module was cylindrical with an inner diameter of 5 mm and a length of 50 mm, and was filled with 15 g of alumina-supported Pt catalyst (Pt content of 0.5%, Pt average particle size of 3.0 nm). The reaction module temperature was 150 °C, the pressure was 3 MPa, and the residence time was 1 min.

[0087] (3) The reactants were cooled in a gas-liquid separator. After concentration and drying, crude hydrogenated lecithin was obtained. Column chromatography was used for separation. The separated product was recrystallized from a 1:1 mixture of n-heptane and acetone to obtain a white hydrogenated lecithin product. HPLC results are shown below. Figure 4 PC content ≥98%, iodine value 2.0.

[0088] The products obtained in the above embodiments were tested, and the comparison results with those in Example 8 are shown in Table 4.

[0089] Table 4

[0090] Example 8 Example 9 Example 10 Example 11 iodine value 1.7 5.1 15 2 PC content (%) 82.7 71.2 70.9 >99

[0091] As shown in the table above, adjusting the temperature of the reaction module has a significant impact on the iodine value and PC content of the product. If the reaction temperature is too low, lecithin can only undergo hydrogen transfer reduction, resulting in a better iodine value, but lecithin PE cannot be methylated, leaving the PC content at around 70%. If the reaction temperature is too high, methanol side reactions increase. On the one hand, CO is generated, poisoning the catalyst and worsening the hydrogen transfer reduction reaction. On the other hand, the reaction cannot obtain a high concentration of formaldehyde, preventing the methylation of phosphatidylcholine PE, resulting in the PC content remaining around 70%. Based on the results in the table, for preparing hydrogenated lecithin products with 80% ≤ phosphatidylcholine (PC) ≤ 98%, a reaction module temperature of 150℃ yields the best technical results.

[0092] Example 11 shows that column chromatography can further purify hydrogenated lecithin, resulting in a PC content >99% in the prepared hydrogenated lecithin product.

[0093] Comparative Example 1

[0094] (1) 1.0g of soybean lecithin with a PC content of 20% and an iodine value of 79.0, 10mL of toluene, and 50mg of Pt / Al2O3 catalyst were added to a 25mL reactor and reacted at 110℃ under a hydrogen atmosphere of 3.0MPa for 10h.

[0095] (3) After the reaction, the temperature was cooled down, the catalyst was separated by centrifugation, and the reaction solution was concentrated and dried to obtain crude hydrogenated lecithin. The crude product was then slurried using a methanol:acetone = 1:1 mixed solution to obtain a light yellow hydrogenated lecithin product.

[0096] Comparative Example 2

[0097] The difference between this comparative example and Comparative Example 1 is that the temperature of the reaction module was adjusted to 150℃, while the rest of the preparation process was the same as that of Comparative Example 1, and hydrogenated lecithin product was obtained.

[0098] The products obtained in the above comparative examples were tested, and the comparison results with those of Example 1 are shown in Table 5.

[0099] Table 5

[0100] Example 1 Comparative Example 1 Comparative Example 2 iodine value 5 10 23 PC content (%) 23.4 20.1 21.5

[0101] As can be seen from the table above, the iodine value and PC content of the hydrogenated lecithin obtained by using hydrogen as the hydrogen source did not reach the effect of Example 1; increasing the reaction temperature to 150°C did not yield hydrogenated lecithin with better PC content and iodine value.

[0102] In summary, this invention overcomes the shortcomings of traditional hydrogenation reactions by using methanol as a raw material. Methanol serves as both a green hydrogen source for hydrogenation and a methyl source, converting lecithin (PE) in the raw material into phosphatidylcholine (PC), thus increasing the PC content in the product. This allows for the preparation of hydrogenated lecithin products with phosphatidylcholine (PC) contents of ≥20%, ≥80%, and ≥98%, respectively, using lecithin as a raw material. While improving reaction efficiency, this invention also reduces the liquid holdup of the reaction system, fundamentally reducing process risks and meeting diverse market demands.

[0103] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A continuous flow process for the preparation of hydrogenated lecithin with different phosphatidylcholine content, characterized in that: include, Lecithin is dissolved in a solvent, and the resulting reaction solution is continuously pumped into a micro-packed bed reaction module filled with a hydrogen transfer reduction catalyst. Under the action of the catalyst, methylation and catalytic hydrogen transfer reduction reactions are carried out. The reacted material was cooled and concentrated to obtain crude hydrogenated lecithin, which was then pulped and purified to obtain hydrogenated lecithin. The solvent is methanol; The hydrogen transfer reduction catalyst is loaded with 15-20 g; the hydrogen transfer reduction catalyst is a supported nano-metal catalyst with a metal loading of 0.1-5.0 wt%, and the support for the supported nano-metal catalyst is selected from one of alumina, silicon oxide, zinc oxide, cerium oxide, titanium oxide, magnesium oxide, and zirconium oxide; the active metal supported on the supported nano-metal catalyst is Pt; the average particle size of the active metal is 1-20 nm. The temperature of the reaction module is selected based on the phosphatidylcholine (PC) content of the target product; When the phosphatidylcholine PC content of the target product is 20% to 80%, the temperature of the reaction module is 80℃ to 120℃. When the phosphatidylcholine (PC) content of the target product is ≥80%, the temperature of the reaction module is 120℃~180℃. The reaction time is 30–600 s; The lecithin is selected from one or more of soybean lecithin, rapeseed lecithin, or egg yolk lecithin.

2. The continuous flow preparation process of hydrogenated lecithin with different phosphatidylcholine contents as described in claim 1, characterized in that: The lecithin is selected based on the phosphatidylcholine (PC) content of the target product; When the phosphatidylcholine (PC) content of the target product is 20%–80%, the phosphatidylcholine (PC) content of the lecithin is 20%–35%. When the target product has a phosphatidylcholine (PC) content ≥80%, the phosphatidylcholine (PC) content of the lecithin is 70%–75%.

3. The continuous flow preparation process of hydrogenated lecithin with different phosphatidylcholine contents as described in claim 1, characterized in that: The mass fraction of lecithin in the reaction solution is 10% to 50%.

4. The continuous flow process for the preparation of hydrogenated lecithin with different phosphatidylcholine content according to claim 1, characterized in that: The reaction solution is pumped in at a rate of 0.3 to 2.0 mL / min.

5. The continuous flow process for the preparation of hydrogenated lecithin with different phosphatidylcholine content according to claim 1, characterized by the fact that: The micro-filled bed reaction module is cylindrical, and the hydrogen transfer reduction catalyst fills the internal space of the micro-filled bed reaction module. The reaction liquid flows through the micro-filled bed reaction module along its axial direction. The aspect ratio of the micro-filled bed reaction module is 10~60:1, and the ratio of the inner diameter of the micro-filled bed reaction module to the average particle size of the hydrogen transfer reduction catalyst is 15~30:

1.

6. The continuous flow preparation process of hydrogenated lecithin with different phosphatidylcholine contents as described in claim 1, characterized in that: The solvent used for pulping is selected from one or more of methanol, ethanol, isopropanol, dichloromethane, n-hexane, n-heptane, acetone, and toluene.

7. The continuous flow process for the preparation of hydrogenated lecithin with different phosphatidylcholine content according to claim 1, characterized by the fact that: The purification conditions are recrystallization or column chromatography; wherein the recrystallization solvent is selected from one or more of methanol, ethanol, isopropanol, dichloromethane, n-hexane, n-heptane, acetone, and toluene; and the column chromatography solvent is selected from one or more of petroleum ether, dichloromethane, n-hexane, n-heptane, and toluene.

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