A high-efficiency farnesene purification method and device based on molecular distillation technology

Abstract

The application relates to the field of chemical purification technology, in particular to a high-efficiency farnesene purification method and device based on a molecular distillation technology, which comprises the following steps: at least two-stage molecular distillation processes are adopted to separate raw material liquid containing beta-farnesene and an extractant, wherein the operation temperature of the highest-stage molecular distillation process is less than or equal to 70 DEG C, and the absolute pressure is less than or equal to 40 Pa. The method is operated at extremely low temperature and extremely high vacuum, the thermal polymerization of beta-farnesene is fundamentally inhibited, and high-efficiency, continuous and high-yield purification is realized without adding a polymerization inhibitor.

Description

Technical Field

[0001] This invention relates to the field of chemical purification technology, specifically to a highly efficient farnesene purification method and apparatus based on molecular distillation technology. Background Technology

[0002] Synthetic rubber, as an important industrial material, is traditionally produced with a high dependence on non-renewable petroleum resources. To reduce this dependence, the development of non-petroleum-based biosynthetic rubbers has become a global research hotspot. β-Farnesne, a chain-like sesquiterpene compound, has polymers that are high-performance precursors for bio-based synthetic rubbers and also have broad application value in the fragrance, pharmaceutical, and agricultural fields.

[0003] With the development of synthetic biology technology, the bio-fermentation production of β-farnesene has become increasingly mature, and costs have been significantly reduced. However, the efficient and economical separation of high-purity β-farnesene from complex fermentation broths remains a key bottleneck restricting its large-scale industrialization. Currently, high-purity β-farnesene is mainly prepared by extraction with isopropyl myristate or other solvents followed by distillation. However, β-farnesene has a high boiling point and a diene structure, making it highly prone to self-polymerization during distillation. Even with the addition of large amounts of polymerization inhibitors, polymerization cannot be completely prevented. For example, Chinese patent application (publication number CN119552283A) discloses a farnesene composite polymerization inhibitor and its application method. The multi-component composite polymerization inhibitor provided was tested at 150°C under normal pressure and nitrogen protection, showing a good effect in inhibiting the self-polymerization of farnesene, but it cannot completely prevent polymerization from occurring. Farneseene has a boiling point of approximately 272.5°C. If the distillation temperature is around 150°C, the actual pressure is approximately 0.0005-0.01 MPa (this patent discloses a distillation pressure of 0.005-0.1 MPa). Reduced pressure promotes olefin polymerization, and this vacuum environment, being a high vacuum, would significantly accelerate farneseene self-polymerization. The inhibitory effect of the polymerization inhibitor in the real high vacuum and relatively high temperature distillation environment may be greatly reduced, making it impossible to fundamentally prevent polymerization losses. Furthermore, introducing the polymerization inhibitor itself increases subsequent separation steps and costs, and may introduce new impurities. Summary of the Invention

[0004] To address the problems of severe polymerization, low yield, high energy consumption, discontinuous process, and potential introduction of additional chemicals in the purification of β-farnesene due to high temperatures in existing technologies, this invention provides a multi-stage purification method and dedicated apparatus based on molecular distillation technology. This method, by operating at extremely low temperatures and extremely high vacuum, fundamentally inhibits the thermal polymerization of β-farnesene, achieving efficient, continuous, and high-yield purification without the addition of polymerization inhibitors.

[0005] This invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: separating the feed liquid containing β-farnesene and extractant using at least two-stage molecular distillation processes, wherein the operating temperature of the highest-stage molecular distillation process is ≤70℃ and the absolute pressure is ≤40 Pa.

[0006] In one embodiment, the farnesene purification method specifically employs a three-stage molecular distillation process, including the following steps: a) The feed liquid containing β-farnesene and extractant is subjected to primary molecular distillation to obtain a primary light component with β-farnesene purity ≥80% and a primary heavy component rich in extractant; the primary heavy component is recycled until the β-farnesene content is below 0.5wt%, and then reused as extractant; b) The primary light component is subjected to secondary molecular distillation to obtain a secondary light component with β-farnesene purity ≥93% and a secondary heavy component; the secondary heavy component is returned to step a) for primary molecular distillation with the feed liquid; c) The secondary light component is subjected to tertiary molecular distillation to obtain a product with β-farnesene purity ≥98% and a tertiary heavy component; the tertiary heavy component is returned to step b) for secondary molecular distillation with the primary light component.

[0007] In one embodiment, the temperature of the heat medium for primary molecular distillation is 55-70°C, the temperature of the cold medium is -5 to 5°C, and the absolute pressure is 15-40 Pa.

[0008] In one embodiment, the temperature of the heat medium for the primary molecular distillation is 60-65°C, and the temperature of the coolant is 0°C.

[0009] In one embodiment, the heat medium temperature of the secondary molecular distillation is 50-65°C, the coolant temperature is -5~5°C, and the absolute pressure is 15-30 Pa. After secondary molecular distillation, a secondary light component with a purity of ≥95% of β-farnesene is obtained.

[0010] In one embodiment, the temperature of the heat medium for the secondary molecular distillation is 50-55°C, and the temperature of the coolant is 0°C.

[0011] In one embodiment, the heat medium temperature of the tertiary molecular distillation is 30-45°C, the coolant temperature is -5~5°C, and the absolute pressure is 15-20 Pa. The tertiary molecular distillation yields a product with a β-farnesene purity ≥99%.

[0012] In one embodiment, the temperature of the heat medium in the tertiary molecular distillation is 35-40°C, and the temperature of the cold medium is 0°C.

[0013] In one embodiment, the β-farnesene content in the feed liquid is 20%-50% by mass percentage, with the extractant making up the remainder.

[0014] In one embodiment, the extractant is selected from ester extractants.

[0015] In one embodiment, the ester extractant includes at least one of isopropyl myristate or butyl acrylate.

[0016] The principle of molecular distillation is roughly as follows: a liquid mixture flows along a heating plate and is heated. Light and heavy molecules escape from the liquid surface and enter the gas phase. Due to the different free paths of light and heavy molecules, molecules of different substances travel different distances after escaping from the liquid surface. There is a certain distance between the internal condenser and the liquid surface. Light molecules reach the condenser and are condensed and discharged, while heavy molecules do not reach the condenser and are discharged along the liquid mixture. However, in actual use of molecular distillation, it has been found that because both large and small molecules exhibit thermal motion, some large molecules will always reach the condenser, preventing the light components from completely separating the heavy components. Since β-farnesene and the extractant isopropyl myristate have a 40°C difference in boiling point and a 70°C difference in molecular weight, β-farnesene, with its smaller molecular weight and simpler molecular structure, is more likely to reach the internal condenser. Primary β-farnesene has the lowest content, and higher temperatures help to quickly separate large amounts of product from the extractant. As the content increases, lowering the temperature helps reduce the thermal motion of large molecules, effectively reducing extractant vaporization and the amount of vaporized extractant reaching the condenser and mixing with the light components.

[0017] This invention designs a three-stage molecular distillation process, which reduces the maximum operating temperature of the purification process from above 150°C in traditional distillation to below 70°C. Molecular distillation relies on the difference in molecular free path for separation, rather than boiling, so it can be carried out at temperatures far below the boiling point of the substance, avoiding β-farnesene polymerization caused by high temperature and significantly improving the yield.

[0018] The three-stage molecular distillation process provided by this invention operates at low temperatures, eliminating the need for any chemical polymerization inhibitors, resulting in a greener process and purer products. This not only reduces raw material costs and avoids the potential adverse effects of residual polymerization inhibitors on downstream polymerization reactions, but also simplifies subsequent processing steps, making the products more compliant with the purity requirements of high-end applications (such as pharmaceuticals and fragrances).

[0019] The significant reduction in separation temperature in the purification method provided by this invention directly leads to a sharp decrease in heat energy consumption. Simultaneously, the short heating time and high thermal efficiency of the molecular distillation materials further reduce overall energy consumption.

[0020] This invention is designed for extractants commonly used in upstream fermentation broth extraction processes. Through the purification and reuse of heavy components via primary distillation, in-situ regeneration and closed-loop recycling of the extractant are achieved, resulting in no waste solvent generation. Simultaneously, the heavy components from secondary and tertiary distillations are returned to the upstream processing stage in a stepwise manner, ensuring full recovery of the target product. The entire system generates no waste liquid or solid waste discharge, meeting the requirements of green chemistry and clean production.

[0021] Another aspect of the present invention provides a highly efficient β-farnesene purification device based on molecular distillation technology, comprising: a primary molecular distillation device, a secondary molecular distillation device, and a tertiary molecular distillation device connected in series via pipelines and a delivery pump; The heavy component outlet of the primary molecular distillation unit is connected to the primary heavy component tank via a pipeline. The outlet of the primary heavy component tank is connected to the feed inlet of the raw material storage tank via a circulation pipeline, and a branch line is connected to the extractant recycling tank. The light component outlet of the primary molecular distillation unit is connected to the primary light component tank via a pipeline, and the outlet of the primary light component tank is connected to the secondary feed tank via a pipeline. The heavy component outlet of the secondary molecular distillation device is connected to the secondary heavy component tank via a pipeline; the outlet of the secondary heavy component tank is provided with a circulation pipeline connected to the feed inlet of the raw material storage tank; the light component outlet of the secondary molecular distillation device is connected to the secondary light component tank via a pipeline, and the outlet of the secondary light component tank is connected to the tertiary feed tank via a pipeline. The heavy component outlet of the three-stage molecular distillation apparatus is connected to the three-stage heavy component tank via a pipeline; the outlet of the three-stage heavy component tank is provided with a circulation pipeline connected to the inlet of the two-stage feeding tank; the light component outlet of the three-stage molecular distillation apparatus is connected to the high-purity β-farnesene product tank via a pipeline.

[0022] In one embodiment, the primary molecular distillation apparatus, the secondary molecular distillation apparatus, and the tertiary molecular distillation apparatus are each independently equipped with a heat medium temperature control system, a refrigerant system, and a vacuum system.

[0023] The multi-stage molecular distillation apparatus provided by this invention is easy to integrate and allows for continuous feeding and discharging. The design of the recombinant component circulation process is reasonable, making it very suitable for building continuous production lines, thereby greatly improving production efficiency and stability and meeting the needs of large-scale industrial production.

[0024] Beneficial effects 1. This invention provides a highly efficient farnesene purification method and apparatus based on molecular distillation technology. This method fundamentally inhibits the thermal polymerization of β-farnesene by operating at extremely low temperatures and extremely high vacuum, achieving efficient, continuous, and high-yield purification without the addition of polymerization inhibitors.

[0025] 2. This invention designs a three-stage molecular distillation process, which reduces the maximum operating temperature of the purification process from above 150°C in traditional distillation to below 70°C. Molecular distillation relies on the difference in molecular free path for separation, rather than boiling, so it can be carried out at temperatures far below the boiling point of the substance, avoiding β-farnesene polymerization caused by high temperature and greatly improving the yield.

[0026] 3. The three-stage molecular distillation process provided by this invention operates at low temperatures and does not rely on any chemical polymerization inhibitors, making the process greener and the product purer. This not only reduces raw material costs and avoids the potential adverse effects of polymerization inhibitor residues on downstream polymerization reactions, but also simplifies subsequent processing steps, making the product more compliant with the purity requirements of high-end application fields (such as pharmaceuticals and fragrances).

[0027] 4. The significant reduction in separation temperature in the purification method provided by this invention directly leads to a sharp decrease in heat energy consumption. Simultaneously, the short heating time and high thermal efficiency of the molecular distillation materials further reduce overall energy consumption.

[0028] 5. This invention is designed for extractants commonly used in upstream fermentation broth extraction processes. Through the purification and reuse of heavy components via primary distillation, in-situ regeneration and closed-loop recycling of the extractant are achieved, resulting in no waste solvent generation. Simultaneously, the heavy components from secondary and tertiary distillations are returned to the upstream processing stage in a stepwise manner, ensuring full recovery of the target product. The entire system produces no waste liquid or solid waste discharge, meeting the requirements of green chemistry and clean production.

[0029] 6. The multi-stage molecular distillation device provided by this invention is easy to integrate and allows for continuous feeding and discharging. The design of the recombinant component circulation process is reasonable, making it very suitable for building a continuous production line, thereby greatly improving production efficiency and stability and meeting the needs of large-scale industrial production. Attached Figure Description

[0030] Figure 1 The diagram shows the structure of the high-efficiency β-farnesene purification device based on molecular distillation technology provided in Example 1. In the diagram, 1: raw material storage tank; 2: primary molecular distillation device; 3: primary light component tank; 4: primary heavy component tank; 5: secondary feeding tank; 6: secondary molecular distillation device; 7: secondary light component tank; 8: secondary heavy component tank; 9: tertiary feeding tank; 10: tertiary molecular distillation device; 11: high-purity β-farnesene product tank; 12: tertiary heavy component tank. Detailed Implementation

[0031] Example 1 Example 1 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) The feed liquid containing β-farnesene and extractant is subjected to primary molecular distillation to obtain a primary light component with β-farnesene purity of 85.07% (no polymer detected) and a primary heavy component rich in extractant (β-farnesene content of 0.55%, no polymer detected); the primary heavy component is recycled until the β-farnesene content is below 0.5 wt%, and then reused as extractant; b) The primary light component is subjected to secondary molecular distillation to obtain a secondary light component with β-farnesene purity of 96.03%. The product is divided into two parts: a) a secondary light component (with no detected polymers) and a secondary heavy component (with a β-farnesene content of 40.1% and no detected polymers); the secondary heavy component is returned to step a) for primary molecular distillation with the feed liquid; c) the secondary light component is subjected to tertiary molecular distillation to obtain a product with a β-farnesene purity of 99.13% (with no detected polymers) and a tertiary heavy component (with a β-farnesene content of 85.08% and no detected polymers); the tertiary heavy component is returned to step b) for secondary molecular distillation with the primary light component.

[0032] The primary molecular distillation process uses a heat transfer medium at 60°C, a coolant at 0°C, and an absolute pressure of 15-40 Pa.

[0033] The temperature of the heat medium for the secondary molecular distillation is 55°C, the temperature of the cold medium is 0°C, and the absolute pressure is 15-30 Pa.

[0034] The temperature of the heat medium in the three-stage molecular distillation is 40℃, the temperature of the cold medium is 0℃, and the absolute pressure is 15-20 Pa.

[0035] The β-farnese content in the feed solution is 40.31% by mass, with the balance made up by extractant. The extractant is isopropyl myristate.

[0036] See Figure 1 In another aspect, Embodiment 1 of the present invention provides a highly efficient β-farnesene purification device based on molecular distillation technology, comprising: a primary molecular distillation device 2, a secondary molecular distillation device 6, and a tertiary molecular distillation device 10 connected in series via pipelines and a delivery pump; The heavy component outlet of the primary molecular distillation unit 2 is connected to the primary heavy component tank 4 via a pipeline. The outlet of the primary heavy component tank 4 is provided with a circulation pipeline connected to the feed inlet of the raw material storage tank 1, and a branch line is provided connected to the extractant recycling tank. The light component outlet of the primary molecular distillation unit 2 is connected to the primary light component tank 3 via a pipeline. The outlet of the primary light component tank 3 is connected to the secondary feed tank 5 via a pipeline. The heavy component outlet of the secondary molecular distillation device 6 is connected to the secondary heavy component tank 8 via a pipeline; the outlet of the secondary heavy component tank 8 is provided with a circulation pipeline connected to the inlet of the raw material storage tank 1; the light component outlet of the secondary molecular distillation device 6 is connected to the secondary light component tank 7 via a pipeline, and the outlet of the secondary light component tank 7 is connected to the tertiary feeding tank 9 via a pipeline. The heavy component outlet of the three-stage molecular distillation apparatus 10 is connected to the three-stage heavy component tank 12 via a pipeline; the outlet of the three-stage heavy component tank 12 is provided with a circulation pipeline connected to the inlet of the secondary feeding tank 5; the light component outlet of the three-stage molecular distillation apparatus 10 is connected to the high-purity β-farnesene product tank 11 via a pipeline.

[0037] Each of the primary molecular distillation apparatus 2, the secondary molecular distillation apparatus 6, and the tertiary molecular distillation apparatus 10 is independently equipped with a heat medium temperature control system, a refrigerant system, and a vacuum system.

[0038] Example 2 Example 2 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) The feed liquid containing β-farnesene and extractant is subjected to primary molecular distillation to obtain a primary light component with β-farnesene purity of 85.07% (no polymer detected) and a primary heavy component rich in extractant (β-farnesene content of 0.55%, no polymer detected); the primary heavy component is recycled until the β-farnesene content is below 0.5 wt%, and then reused as extractant; b) The primary light component is subjected to secondary molecular distillation to obtain a secondary light component with β-farnesene purity of 96.10%. The product is divided into two parts: a) a secondary light component (with no detected polymers) and a secondary heavy component (with a β-farnesene content of 40.1% and no detected polymers); the secondary heavy component is returned to step a) for primary molecular distillation with the feed liquid; c) the secondary light component is subjected to tertiary molecular distillation to obtain a product with a β-farnesene purity of 99.09% (with no detected polymers) and a tertiary heavy component (with a β-farnesene content of 86.81% and no detected polymers); the tertiary heavy component is returned to step b) for secondary molecular distillation with the primary light component.

[0039] The primary molecular distillation process uses a heat transfer medium at 60°C, a coolant at 0°C, and an absolute pressure of 15-40 Pa.

[0040] The temperature of the heat medium for the secondary molecular distillation is 55°C, the temperature of the cold medium is 0°C, and the absolute pressure is 15-30 Pa.

[0041] The temperature of the heat medium in the three-stage molecular distillation is 35°C, the temperature of the cold medium is 0°C, and the absolute pressure is 15-20 Pa.

[0042] The β-farnese content in the feed solution is 40.31% by mass, with the balance made up by extractant. The extractant is isopropyl myristate.

[0043] Example 3 Example 3 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) The feed liquid containing β-farnesene and extractant is subjected to primary molecular distillation to obtain a primary light component with β-farnesene purity of 85.07% (no polymer detected) and a primary heavy component rich in extractant (β-farnesene content of 0.55%, no polymer detected); the primary heavy component is recycled until the β-farnesene content is below 0.5 wt%, and then reused as extractant; b) The primary light component is subjected to secondary molecular distillation to obtain a secondary light component with β-farnesene purity of 96.10%. The product is divided into two parts: a) a secondary light component (with no detected polymers) and a secondary heavy component (with a β-farnesene content of 40.1% and no detected polymers); the secondary heavy component is returned to step a) for primary molecular distillation with the feed liquid; c) the secondary light component is subjected to tertiary molecular distillation to obtain a product with a β-farnesene purity of 98.72% (with no detected polymers) and a tertiary heavy component (with a β-farnesene content of 84.19% and no detected polymers); the tertiary heavy component is returned to step b) for secondary molecular distillation with the primary light component.

[0044] The primary molecular distillation process uses a heat transfer medium at 60°C, a coolant at 0°C, and an absolute pressure of 15-40 Pa.

[0045] The temperature of the heat medium for the secondary molecular distillation is 55°C, the temperature of the cold medium is 0°C, and the absolute pressure is 15-30 Pa.

[0046] The temperature of the heat medium in the three-stage molecular distillation is 45℃, the temperature of the cold medium is 0℃, and the absolute pressure is 15-20 Pa.

[0047] The β-farnese content in the feed solution is 40.31% by mass, with the balance made up by extractant. The extractant is isopropyl myristate.

[0048] Example 4 Example 4 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) The feed liquid containing β-farnesene and extractant is subjected to primary molecular distillation to obtain a primary light component with β-farnesene purity of 85.07% (no polymer detected) and a primary heavy component rich in extractant (β-farnesene content of 0.55%, no polymer detected); the primary heavy component is recycled until the β-farnesene content is below 0.5 wt%, and then reused as extractant; b) The primary light component is subjected to secondary molecular distillation to obtain a secondary light component with β-farnesene purity of 96.05% (no polymer detected) and a secondary heavy component (β-farnesene content of 42.53%, no polymer detected); the secondary heavy component is returned to step a) for primary molecular distillation with the feed liquid; the process conditions of step b) are verified, but step c is not performed.

[0049] The primary molecular distillation process uses a heat transfer medium at 60°C, a coolant at 0°C, and an absolute pressure of 15-40 Pa.

[0050] The temperature of the heat medium for the secondary molecular distillation is 50°C, the temperature of the cold medium is 0°C, and the absolute pressure is 15-30 Pa.

[0051] The β-farnese content in the feed solution is 40.31% by mass, with the balance made up by extractant. The extractant is isopropyl myristate.

[0052] Example 5 Example 5 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) The feed liquid containing β-farnesene and extractant is subjected to primary molecular distillation to obtain a primary light component (no polymer detected) with a β-farnesene purity of 85.07% and a primary heavy component rich in extractant (β-farnesene content of 0.55%, no polymer detected); the primary heavy component is recycled until the β-farnesene content is below 0.5 wt% and then reused as extractant; b) The primary light component is subjected to secondary molecular distillation to obtain a secondary light component (no polymer detected) with a β-farnesene purity of 94.84% and a secondary heavy component (β-farnesene content of 38.91%, no polymer detected); the secondary heavy component is returned to step a) for primary molecular distillation with the feed liquid; the process conditions of step b) are verified, but step c is not performed.

[0053] The primary molecular distillation process uses a heat transfer medium at 60°C, a coolant at 0°C, and an absolute pressure of 15-40 Pa.

[0054] The temperature of the heat medium for the secondary molecular distillation is 60°C, the temperature of the cold medium is 0°C, and the absolute pressure is 15-30 Pa.

[0055] The β-farnese content in the feed solution is 40.31% by mass, with the balance made up by extractant. The extractant is isopropyl myristate.

[0056] Example 6 Example 6 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) The feed solution containing β-farnesene and extractant is subjected to primary molecular distillation to obtain a primary light component (no polymer detected) with a β-farnesene purity of 85.07% and a primary heavy component rich in extractant (β-farnesene content of 0.55%, no polymer detected); the primary heavy component is recycled until the β-farnesene content is below 0.5 wt% and then reused as extractant; b) The primary light component is subjected to secondary molecular distillation to obtain a secondary light component (β-farnesene purity of 93.67%) and a secondary heavy component (β-farnesene content of 37.05%, no polymer detected); the secondary heavy component is returned to step a) for primary molecular distillation with the feed solution; the process conditions of step b) are verified, but step c is not performed.

[0057] The primary molecular distillation process uses a heat transfer medium at 60°C, a coolant at 0°C, and an absolute pressure of 15-40 Pa.

[0058] The temperature of the heat medium for the secondary molecular distillation is 65°C, the temperature of the cold medium is 0°C, and the absolute pressure is 15-30 Pa.

[0059] The β-farnese content in the feed solution is 40.31% by mass, with the balance made up by extractant. The extractant is isopropyl myristate.

[0060] Example 7 Example 7 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) The feed liquid containing β-farnesene and extractant was subjected to primary molecular distillation to obtain a primary light component with a β-farnesene purity of 85.03% (no polymer detected) and a primary heavy component rich in extractant (β-farnesene content of 0.46%, no polymer detected); the primary heavy component was recycled until the β-farnesene content was below 0.5 wt%, and then reused as extractant; the process conditions of step a) were verified, but step b) was not performed.

[0061] The primary molecular distillation process uses a heat transfer medium at 65°C, a coolant at 0°C, and an absolute pressure of 15-40 Pa.

[0062] The β-farnese content in the feed solution is 40.31% by mass, with the balance made up by extractant. The extractant is isopropyl myristate.

[0063] Example 8 Example 8 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) The feed liquid containing β-farnesene and extractant was subjected to primary molecular distillation to obtain a primary light component with a β-farnesene purity of 84.57% (no polymer detected) and a primary heavy component rich in extractant (β-farnesene content of 0.45%, no polymer detected); the primary heavy component was recycled until the β-farnesene content was below 0.5 wt%, and then reused as extractant; the process conditions of step a) were verified, but step b) was not performed.

[0064] The primary molecular distillation process uses a heat transfer medium at 70°C, a coolant at 0°C, and an absolute pressure of 15-40 Pa.

[0065] The β-farnese content in the feed solution is 40.31% by mass, with the balance made up by extractant. The extractant is isopropyl myristate.

[0066] Example 9 (Step-by-Step Experiment) Example 9 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) 5 kg of feed liquid containing 40.31% β-farnesene and the balance myristoyl isopropyl ester was subjected to primary molecular distillation. The primary molecular distillation was controlled with the heat medium temperature at 65℃, the coolant temperature at 0℃, and the absolute pressure at 15-40 Pa. The primary heavy component was fed twice in a cycle to obtain 2.31 kg of primary heavy component with a β-farnesene content of 0.47%; and 2.03 kg of primary light component with a β-farnesene content of 85.10%.

[0067] Add 5 kg of the same raw material solution and repeat the first-stage molecular distillation conditions to obtain 2.67 kg of primary heavy fraction with a β-farnesene content of 0.44%; and 2.33 kg of primary light fraction with a β-farnesene content of 85.02%.

[0068] Add 5 kg of the same raw material solution again, and repeat the first-stage molecular distillation conditions to obtain 2.59 kg of first-stage heavy fraction with a β-farnesene content of 0.49%; and 2.40 kg of first-stage light fraction with a β-farnesene content of 85.07%.

[0069] b) The primary light components (secondary raw materials) were mixed three times and subjected to secondary molecular distillation. The heat medium temperature was controlled at 55°C, the cold medium temperature at 0°C, and the vacuum was 15-30 Pa. The equipment was rinsed with 0.7 kg of secondary raw materials to obtain a total of 0.11 kg of secondary light and secondary heavy components.

[0070] Under the same secondary conditions, 3 kg of secondary raw material was added, and the secondary heavy component was fed in a cycle 3 times to obtain 2.27 kg of secondary light component containing 96.07% β-farnesene; and 0.53 kg of secondary heavy component containing 40.31% β-farnesene was obtained.

[0071] Add 3 kg of secondary raw material again, and feed the secondary heavy component three times in a cycle to obtain 2.44 kg of secondary light component containing 96.10% β-farnesene; and obtain 0.66 kg of secondary heavy component containing 40.08% β-farnesene.

[0072] c) The two secondary light components were mixed (tertiary raw materials) and subjected to tertiary molecular distillation. The temperature of the heat medium was controlled at 40°C, the temperature of the cold medium was 0°C, the vacuum was 15-20 Pa, and the equipment was rinsed with 0.7 kg of tertiary raw materials to obtain a total of 0.14 kg of tertiary light components and tertiary heavy components.

[0073] Under the same conditions, 4 kg of tertiary raw material was added, and the tertiary heavy component was fed in a cycle 4 times to obtain 3.07 kg of tertiary light component containing 99.25% β-farnesene; and 0.89 kg of tertiary heavy component containing 85.03% β-farnesene.

[0074] Example 10 (Application Experiment) Example 9 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) 15 kg of feed liquid containing 40.31% β-farnesene and the balance myristoyl isopropyl ester was subjected to primary molecular distillation. The primary molecular distillation was controlled with the heat medium temperature at 65℃, the coolant temperature at 0℃, and the vacuum at 15-40 Pa. The primary heavy component was fed twice in a cycle to obtain 7.97 kg of primary heavy component with a β-farnesene content of 0.45%; and 6.99 kg of primary light component with a β-farnesene content of 85.17%.

[0075] b) All of the primary light components were used for secondary molecular distillation, with the heat medium temperature controlled at 55℃, the coolant temperature at 0℃, and the vacuum at 15-30 Pa. The secondary components were fed in a cycle 3 times to obtain 5.28 kg of secondary light components with a content of 96.22%, and 1.69 kg of secondary components with a β-farnesene content of 40.14%.

[0076] c) All of the secondary light components were used for tertiary molecular distillation, with the heat medium temperature controlled at 40°C, the coolant at 0°C, and the vacuum at 15-20 Pa. The tertiary heavy components were fed in a cycle 4 times, yielding 4.05 kg of tertiary light components containing 99.09% β-farnesene (colorless oily liquid, with a yield of 99% and no polymer detected); and 1.23 kg of tertiary heavy components containing 85.06% β-farnesene.

[0077] Secondary restructuring and application: The secondary heavy component was replenished with fresh feed liquid to a total of 15 kg, and fed under the conditions of primary molecular distillation. The primary heavy component was recycled twice to obtain 7.01 kg of primary light component containing 85.11% β-farnesene and 7.93 kg of primary heavy component containing 0.41% β-farnesene.

[0078] Three-level restructuring application: The tertiary heavy component was mixed with the primary light component obtained by combining the above-mentioned secondary heavy components, and fed under the conditions of secondary molecular distillation to obtain 6.30 kg of secondary light component containing 96.07% β-farnesene; and 1.91 kg of secondary heavy component containing 40.05% β-farnesene.

[0079] Comparative Example 1 Comparative Example 1 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) The feed liquid containing β-farnesene and extractant is subjected to primary molecular distillation to obtain a primary light component with β-farnesene purity of 84.05% (no polymer detected) and a primary heavy component rich in extractant (β-farnesene content of 0.40%, polymer detected at 54 ppm); the primary heavy component is recycled until the β-farnesene content is below 0.5 wt%, and then reused as extractant; if polymer is detected in the primary heavy component, no further steps are performed.

[0080] The primary molecular distillation process uses a heat transfer medium at 75°C, a coolant at 0°C, and an absolute pressure of 15-40 Pa.

[0081] The β-farnese content in the feed solution is 40.31% by mass, with the balance made up by extractant. The extractant is isopropyl myristate.

[0082] Comparative Example 2 Comparative Example 2 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) The feed liquid containing β-farnesene and extractant is subjected to primary molecular distillation to obtain a primary light component with β-farnesene purity of 83.65% (no polymer detected) and a primary heavy component rich in extractant (β-farnesene content of 0.38%, polymer detected at 225 ppm); the primary heavy component is recycled until the β-farnesene content is below 0.5 wt%, and then reused as extractant; if polymer is detected in the primary heavy component, no further steps are performed.

[0083] The primary molecular distillation process uses a heat transfer medium at 80°C, a coolant at 0°C, and an absolute pressure of 15-40 Pa.

[0084] The β-farnese content in the feed solution is 40.31% by mass, with the balance made up by extractant. The extractant is isopropyl myristate.

[0085] Comparative Example 3 Comparative Example 3 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) The feed liquid containing β-farnesene and extractant is subjected to primary molecular distillation to obtain a primary light component with β-farnesene purity of 82.71% (5 ppm of polymer detected) and a primary heavy component rich in extractant (β-farnesene content of 0.36%, 489 ppm of polymer detected); the primary heavy component is recycled until the β-farnesene content is below 0.5 wt%, and then reused as extractant; if polymer is detected in the primary heavy component, no further steps are performed.

[0086] The primary molecular distillation process uses a heat transfer medium at 85°C, a coolant at 0°C, and an absolute pressure of 15-40 Pa.

[0087] The β-farnese content in the feed solution is 40.31% by mass, with the balance made up by extractant. The extractant is isopropyl myristate.

[0088] Comparative Example 4 Comparative Example 4 of the present invention provides a highly efficient farnesene purification method based on molecular distillation technology, comprising the following steps: a) The feed liquid containing β-farnesene and extractant is subjected to primary molecular distillation to obtain a primary light component with β-farnesene purity of 80.44% (polymer detected at 146 ppm) and a primary heavy component rich in extractant (β-farnesene content of 0.31%, polymer detected at 1244 ppm); the primary heavy component is recycled until the β-farnesene content is below 0.5 wt%, and then reused as extractant; if polymer is detected in the primary heavy component, no further steps are performed.

[0089] The primary molecular distillation process uses a heat transfer medium at 100°C, a coolant at 0°C, and an absolute pressure of 15-40 Pa.

[0090] The β-farnese content in the feed solution is 40.31% by mass, with the balance made up by extractant. The extractant is isopropyl myristate.

[0091] Comparative Example 5 Comparative Example 5 of this invention describes the preparation of β-farnesene using a distillation process. The feed solution contained 80% β-farnesene and the remainder butyl acrylate (extractant). The feed solution was added to a bottle, and a 300mm spindle-shaped distillation column was connected to a circulating water vacuum pump. The pressure was controlled at 80,000 Pa, and the distillation temperature in the vessel was controlled at 100°C. Distillation was stopped when no more product was collected, and the residue in the vessel was the product. The obtained β-farnesene was a yellow oily liquid with a purity of 94.14%, a polymer content of 3.35%, and a yield of 77.9%.

[0092] Comparative Example 6 Comparative Example 6 of this invention describes the preparation of β-farnesene by distillation. The feed liquid contained 40.31% β-farnesene and the balance being isopropyl myristate. A 300 mm spiky distillation column was used, the distillation temperature was 145 °C, and the absolute pressure was 500 Pa. The obtained β-farnesene was a colorless oily liquid with a purity of 99.22%. 1356 ppm of polymer was detected, and the yield was 57.3%.

[0093] Comparative Example 7 The comparative example of this invention is the preparation of β-farnesene by rotary evaporation. The raw material liquid is a raw material liquid containing 40.31% β-farnesene and the balance isopropyl myristate. The rotary evaporation temperature is 190°C and the absolute pressure is 500 Pa. The obtained β-farnesene is a colorless oily liquid with a purity of 95.41%, a polymer detection of 974 ppm, and a yield of 67.1%.

Claims

1. A highly efficient method for purifying farnesene based on molecular distillation technology, characterized in that, Includes the following steps: The feed liquid containing β-farnesene and extractant is separated by at least two-stage molecular distillation process, which includes a first-stage molecular distillation process and a second-stage molecular distillation process; the operating temperature of the first-stage molecular distillation process is ≤70℃ and the absolute pressure is ≤40 Pa.

2. The efficient farnesene purification method according to claim 1, characterized in that, The at least two-stage molecular distillation process is a three-stage molecular distillation process, including the following steps: a) The feed liquid containing β-farnesene and extractant is subjected to primary molecular distillation to obtain a primary light component with β-farnesene purity ≥80% and a primary heavy component rich in extractant; the primary heavy component is recycled until the β-farnesene content is below 0.5wt%, and then reused as extractant; b) The primary light component is subjected to secondary molecular distillation to obtain a secondary light component with β-farnesene purity ≥93% and a secondary heavy component; the secondary heavy component is returned to step a) for primary molecular distillation with the feed liquid; c) The secondary light component is subjected to tertiary molecular distillation to obtain a product with β-farnesene purity ≥98% and a tertiary heavy component; the tertiary heavy component is returned to step b) for secondary molecular distillation with the primary light component.

3. The efficient farnesene purification method according to claim 2, characterized in that, The temperature of the heat medium for the primary molecular distillation is 55-70℃, the temperature of the cold medium is -5~5℃, and the absolute pressure is 15-40 Pa.

4. The efficient farnesene purification method according to claim 2, characterized in that, The heat medium temperature for the secondary molecular distillation is 50-65℃, the coolant temperature is -5~5℃, and the absolute pressure is 15-30 Pa. After secondary molecular distillation, a secondary light component with a purity of ≥95% of β-farnesene is obtained.

5. The efficient farnesene purification method according to claim 2, characterized in that, The heat transfer medium temperature for the three-stage molecular distillation is 30-45℃, the coolant temperature is -5~5℃, and the absolute pressure is 15-20 Pa. The three-stage molecular distillation yields a product with a β-farnesene purity ≥99%.

6. The efficient farnesene purification method according to claim 1, characterized in that, The β-farnese content in the feed solution is 20%-50% by mass percentage, with the extractant making up the remainder.

7. The efficient farnesene purification method according to claim 6, characterized in that, The extractant is selected from ester extractants.

8. The efficient farnesene purification method according to claim 7, characterized in that, The ester extractant includes at least one of isopropyl myristate or butyl acrylate.

9. An apparatus for carrying out the method according to any one of claims 2-8, characterized in that, include: A primary molecular distillation unit, a secondary molecular distillation unit, and a tertiary molecular distillation unit are connected in series via pipelines and delivery pumps. The heavy component outlet of the primary molecular distillation unit is connected to the primary heavy component tank via a pipeline. The outlet of the primary heavy component tank is connected to the feed inlet of the raw material storage tank via a circulation pipeline, and a branch line is connected to the extractant recycling tank. The light component outlet of the primary molecular distillation unit is connected to the primary light component tank via a pipeline, and the outlet of the primary light component tank is connected to the secondary feed tank via a pipeline. The heavy component outlet of the secondary molecular distillation device is connected to the secondary heavy component tank via a pipeline; the outlet of the secondary heavy component tank is provided with a circulation pipeline connected to the feed inlet of the raw material storage tank; the light component outlet of the secondary molecular distillation device is connected to the secondary light component tank via a pipeline, and the outlet of the secondary light component tank is connected to the tertiary feed tank via a pipeline. The heavy component outlet of the three-stage molecular distillation apparatus is connected to the three-stage heavy component tank via a pipeline; the outlet of the three-stage heavy component tank is provided with a circulation pipeline connected to the inlet of the two-stage feeding tank; the light component outlet of the three-stage molecular distillation apparatus is connected to the high-purity β-farnesene product tank via a pipeline.

10. The apparatus according to claim 9, characterized in that, The primary molecular distillation apparatus, secondary molecular distillation apparatus, and tertiary molecular distillation apparatus are each independently equipped with a heat medium temperature control system, a refrigerant system, and a vacuum system.

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