Microchannel reaction equipment and method for continuously synthesizing beta-ionone

Abstract

The invention discloses microchannel reaction equipment and a method for continuously synthesizing beta-ionone. The micro-channel reaction equipment comprises a low-temperature pipe section and a high-temperature pipe section communicated with the tail end of the low-temperature pipe section; the low-temperature pipe section and the high-temperature pipe section respectively comprise two wavy reaction pipes which are arranged in a staggered manner; the two reaction tubes of the low-temperature tube section accord with the trend of a cosine function curve along the axial extension direction, and the two reaction tubes of the high-temperature tube section accord with the trend of a sine function curve along the axial extension direction. By adopting the micro-channel reaction equipment to continuously react and synthesize beta-ionone, the generation of other isomers and tar substances can be controlled, so that the reaction is mainly carried out towards the generation direction of the beta-ionone, and the subsequent separation operation does not need rectification operation with a high theoretical plate number; therefore, a high-purity beta-ionone product can be obtained.

Description

Technical Field

[0001] The present invention relates to a microchannel reactor and a method for synthesizing β-ionone by using the same, and particularly to a microchannel reaction device and a method for continuously synthesizing β-ionone. Background Art

[0002] β-ionone [4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-buten-2-one, β-ionone] has a molecular formula of C 13 H 20 O, and appears as a colorless to light yellow transparent liquid. It is a very important pharmaceutical intermediate and an important raw material for synthesizing vitamin A, β-carotene, carotenoids, retinoic acid, etc.

[0003] The synthesis of β-ionone generally occurs by cyclization of pseudoionone under acid catalysis. Currently, in the synthesis methods of β-ionone that have been industrialized, sulfuric acid is used as the acid catalyst. In the synthesis process of β-ionone, in addition to the main component β-ionone being generated, α and γ isomers will also be generated, as well as cis, trans, and optical isomers corresponding to the three isomers of α, β, and γ. Since the structures of isomers are very similar, in order to obtain a high-purity β-ionone product, it is necessary to separate β-ionone and its isomers, which is very difficult technically, and will inevitably lead to an increase in production costs.

[0004] For example, the literature "Shu Mingjie, et al. Separation of ionone isomers by vacuum batch distillation [J]. Modern Chemical Industry, 2017, 37(12): 160-163." uses a high number of theoretical plates for vacuum distillation to separate ionone isomers. However, the distillation operation that requires a high number of theoretical plates will undoubtedly increase the equipment investment cost and operating cost.

[0005] In other existing technologies, for example, patent CN1041302C mentions that by adding a rearrangement inhibitor during the synthesis process, the conversion of β-ionone to α-ionone can be prevented, and finally β-ionone with a purity of 96% can be obtained, and the yield can reach 87%. However, the addition of the new substance rearrangement inhibitor inevitably brings new problems - the separation between the rearrangement inhibitor and ionone.

[0006] Patent CN101381293B provides a method for preparing high-purity β-ionone. This method uses α-ionone, γ-ionone, or a mixture of them and β-ionone as raw materials, and generates β-ionone through ultraviolet photocatalysis. The content of β-ionone in the final product can be as high as 98%. However, the raw materials of this synthesis method are limited. They are not only difficult to obtain, but it is also unknown whether other ionone isomers except α-ionone and γ-ionone have the effect of catalytically synthesizing β-ionone, so it is not universal.

[0007] Therefore, it is necessary to develop a more advantageous method for synthesizing high-purity β-ionone. Summary of the Invention

[0008] To solve the above technical problems, the present invention proposes a microchannel reaction device and a method for continuously synthesizing β-ionone.

[0009] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0010] Based on the first aspect of the present invention, first, a microchannel reaction device is provided, which includes a low-temperature pipe section and a high-temperature pipe section connected to the end of the low-temperature pipe section; the low-temperature pipe section and the high-temperature pipe section each include two wavy reaction pipes arranged in an alternating manner;

[0011] The two reaction pipes of the low-temperature pipe section conform to the cosine function curve in the axial extension direction:

[0012] Low-temperature reaction pipe 1:

[0013] Low-temperature reaction pipe 2:

[0014] Wherein, x 1 is the axial displacement of the low-temperature reaction pipe, and f 11 (x 1 ) and f 12 (x 1 ) are the corresponding longitudinal displacements of the low-temperature reaction pipe when the axial displacement is x 1 ; A 1 is the amplitude of the cosine function, and its value is 3-20 times the inner diameter of the low-temperature reaction pipe, preferably 5-10 times; T h1 is the half-period of the cosine function, and its value is 3-20 times the inner diameter of the low-temperature reaction pipe, preferably 5-10 times;

[0015] The two reaction pipes of the high-temperature pipe section conform to the sine function curve in the axial extension direction:

[0016] High-temperature reaction pipe 1:

[0017] High-temperature reaction tube 2:

[0018] Among them, x 2 is the axial displacement of the high-temperature reaction tube, and f 21 (x 2 ) and f 22 (x 2 ) are the longitudinal displacements corresponding to the high-temperature reaction tube when the axial displacement is x 2 ; A 2 is the amplitude of the sine function, and its value is 1 - 20 times, preferably 3 - 10 times, of A 1 ; T h2 is the half-period of the sine function, and its value is 1 - 20 times, preferably 3 - 10 times, of T h1 .

[0019] In some preferred examples, the inner diameter of the low-temperature reaction tube and the inner diameter of the high-temperature reaction tube are each independently 0.2 - 10 mm, preferably 2 - 6 mm. When their inner diameters are different, they can be smoothly connected at the joint.

[0020] In some preferred examples, a plurality of collision contact elements are arranged in the low-temperature reaction tube and the high-temperature reaction tube;

[0021] Preferably, the collision contact element is spherical, and the diameter of the spherical element is 0.4 - 0.8 times the inner diameter of the reaction tube where it is located;

[0022] Preferably, the collision contact elements are evenly fixed at the peaks, valleys, and intersection points of the reaction tube as much as possible.

[0023] In the present invention, the design of the microchannel reactor can produce strong turbulent mixing and staggered mixing effects on the reaction materials, and further preferably produce a collision and disturbance effect on the reaction materials through the collision contact elements, thereby greatly enhancing mass transfer and avoiding local hot spots. Using the microchannel reactor provided by the present invention for continuous synthesis of β-ionone can fundamentally reduce the generation of other isomers and polymerization tars, improve the product yield of β-ionone, and thus greatly reduce the difficulty of subsequent purification and separation, having strong application advantages.

[0024] Based on the second aspect of the present invention, a method for continuous synthesis of β-ionone is further provided, which is characterized in that the microchannel reaction device described above is used, and the reaction is carried out with pseudoionone solution and acid material as raw materials to continuously synthesize β-ionone.

[0025] In some preferred examples, the acid material is concentrated sulfuric acid, preferably sulfuric acid with a concentration of 85 - 98 wt%, more preferably 90 - 95 wt%;

[0026] Preferably, the dosage of raw materials is 1:(1-6) based on the mass ratio of pseudoionone to the acid in the acid material.

[0027] Preferably, the solvent used in the pseudoionone solution is selected from alkanes, chloroalkanes, and benzene series compounds, preferably one or more of n-hexane, n-heptane, dichloromethane, dichloroethane, and toluene.

[0028] In some preferred examples, the reaction temperature in the low-temperature pipe section is -30°C to 10°C, preferably -20°C to 0°C;

[0029] Preferably, the reaction temperature in the high-temperature pipe section is 20-50°C, preferably 30-40°C.

[0030] In some preferred examples, the reaction residence time in the low-temperature pipe section is 1-20 s, preferably 2-10 s;

[0031] Preferably, the reaction residence time in the high-temperature pipe section is 10-40 s, preferably 15-25 s.

[0032] The cyclization of pseudoionone mainly occurs in the low-temperature pipe section, and the cyclization reaction is favored under low-temperature conditions; while in the high-temperature pipe section, the conversion of other isomers of ionone to β-ionone is mainly controlled, and an appropriate high temperature is beneficial to the formation of β-ionone.

[0033] In some preferred examples, the pseudoionone solution and the acid material are fed into the two reaction pipes in the low-temperature pipe section respectively, continuously mixed and reacted in the low-temperature pipe section first, and then flow into the high-temperature pipe section to continue the mixing reaction.

[0034] In some preferred examples, after the reaction is completed, it is quenched, phase-separated, deacidified in sequence to obtain the oil phase and purified, and then the light components and heavy components in the oil phase are removed to obtain the product β-ionone.

[0035] In some preferred examples, the quenching is carried out using an aqueous solution, preferably quenching the reaction with water, and the dosage of water is, for example, 1-5 times the feeding amount of the acid material. Preferably, the quenching temperature is 5-50°C.

[0036] In some preferred examples, the phase separation is carried out in a phase separator, preferably controlling the phase separation temperature to be 5-50°C to obtain the oil phase.

[0037] In some preferred examples, the deacidifying agent used for deacidification is selected from inorganic weak bases and / or organic bases, preferably one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, monoethanolamine, diethanolamine, triethanolamine, n-propanolamine, di-n-propanolamine, tri-n-propanolamine, isopropanolamine, diisopropanolamine, and triisopropanolamine. The dosage of the deacidifying agent is (100 - 2500):1 based on the mass ratio of the oil phase to the deacidifying agent. After deacidifying the oil phase with an aqueous solution of the deacidifying agent, phase separation is carried out again to obtain the oil phase, and then light components and heavy components are removed by distillation / evaporation to obtain the product β-ionone.

[0038] The beneficial effects of the present invention are as follows: First, a microchannel reaction device including a low-temperature tube section and a high-temperature tube section that satisfies a specific function curve is provided. Then, the microchannel reaction device is used for continuous reaction synthesis of β-ionone, which can control the generation of other isomers and tar substances, making the reaction mainly proceed in the direction of β-ionone generation. The reduction in the generation of isomers also enables subsequent separation operations not to use distillation operations with a high number of theoretical plates, that is, a high-purity β-ionone product can be obtained, thereby greatly saving equipment investment and operating costs, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of the main structure of the microchannel reaction device provided by the present invention.

[0040] Figure 2 It is a schematic diagram of the installation position of the collision contact element in the microchannel reaction device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0041] The present invention will be further described below through specific examples. The examples described in the present invention are only for the purpose of explaining the present invention and do not limit the scope of the present invention.

[0042]

Example 1

[0043] A microchannel reaction device includes a low-temperature tube section and a high-temperature tube section connected to the end of the low-temperature tube section; the low-temperature tube section and the high-temperature tube section each include two corrugated reaction tubes arranged in an alternating manner; the inner diameter of each reaction tube is 0.2 mm;

[0044] The two reaction tubes in the low-temperature tube section conform to the cosine function curve trend along the axial extension direction:

[0045] Low-temperature reaction tube 1:

[0046] Low-temperature reaction tube 2:

[0047] where x 1 is the axial displacement of the low-temperature reaction tube, and f11 (x 1 ) and f 12 (x 1 ) are the longitudinal displacements corresponding to the low-temperature reaction tube at an axial displacement of x 1 ; A 1 is 4 mm; T h1 is 4 mm;

[0048] The two reaction tubes of the high-temperature tube section conform to the sine function curve in the axial extension direction:

[0049] High-temperature reaction tube 1:

[0050] High-temperature reaction tube 2:

[0051] Among them, x 2 is the axial displacement of the high-temperature reaction tube, and f 21 (x 2 ) and f 22 (x 2 ) are the longitudinal displacements corresponding to the high-temperature reaction tube at an axial displacement of x 2 ; A 2 is 80 mm; T h2 is 80 mm.

[0052] At the intersection of the low-temperature tube section and the high-temperature tube section, as well as at the peaks, valleys, and intersection points of the two reaction tubes of each section, collision contact elements are fixedly arranged; the collision contact elements are spherical, and the diameter of the spherical elements is 0.08 mm.

[0053] [Embodiment 2]

[0054] A microchannel reaction device, which is different from that in Embodiment 1 in that the inner diameters of the reaction tubes are all 10 mm; A 1 is 30 mm; T h1 is 30 mm; A 2 is 30 mm; T h2 is 30 mm. The collision contact elements are spherical, and the diameter of the spherical elements is 8 mm.

[0055] [Embodiment 3]

[0056] A microchannel reaction device, which is different from that in Embodiment 1 in that the inner diameters of the reaction tubes are all 4 mm; A 1 is 32 mm; T h1 is 32 mm; A 2 is 192 mm; T h2 is 192 mm. The collision contact elements are spherical, and the diameter of the spherical elements is 2.4 mm.

[0057] [Embodiment 4]

[0058] A microchannel reaction device, which is different from that in Example 1 in that the inner diameters of the reaction tubes are all 2 mm; A 1 is 20 mm; T h1 is 20 mm; A 2 is 200 mm; T h2 is 200 mm. The collision contact element is spherical, and the diameter of the spherical element is 1 mm.

[0059]

Example 5

[0060] A microchannel reaction device, which is different from that in Example 1 in that the inner diameters of the reaction tubes are all 6 mm; A 1 is 30 mm; T h1 is 30 mm; A 2 is 90 mm; T h2 is 90 mm. The collision contact element is spherical, and the diameter of the spherical element is 4.2 mm.

[0061]

Example 6

[0062] Using the microchannel reaction device provided in Example 1 to continuously synthesize β-ionone:

[0063] Prepare a 5 wt% pseudoionone solution with n-hexane as the solvent. Continuously introduce the pseudoionone solution and 98 wt% sulfuric acid into the microchannel reaction device at 30.0 kg / h and 1.53 kg / h respectively. The residence times t 1 and t 2 in the low-temperature tube section and the high-temperature tube section are 1 s and 10 s respectively, and the reaction temperatures are 10 °C and 50 °C respectively. The outlet of the microchannel reaction device and the quenching water (7.65 kg / h) are continuously introduced into the quenching kettle, maintaining the liquid holdup in the quenching kettle at 78 kg, adjusting the material balance of the inlet and outlet of the quenching kettle, ensuring that the residence time t 3 of the quenching reaction is 120 min, and adjusting the temperature in the quenching kettle to 50 °C. The outlet of the quenching kettle is continuously introduced into the phase separator I, maintaining the liquid holdup in the phase separator I at 78 kg, adjusting the material balance of the inlet and outlet of the phase separator I, ensuring that the phase separation time t 4 is 120 min, and adjusting the temperature in the phase separator I to 50 °C. The oil phase I (30 kg / h) coming out after the phase separator I separates the aqueous phase is sampled and analyzed by gas chromatography for its composition (β-ionone 4.88 wt%, isomers 0.08 wt%, tar 0.07 wt%, and the rest is the solvent), and the reaction yield of β-ionone is calculated to be 97.32%.

[0064] The oil phase I and the 0.5 wt% sodium carbonate aqueous solution (48.6 g / min) of the deacidifying agent are continuously introduced into the deacidifying kettle, maintaining the liquid holdup in the deacidifying kettle at 66 kg, adjusting the material balance of the inlet and outlet of the deacidifying kettle, ensuring the residence time t5 is 120 min, and the temperature inside the deacidification kettle is adjusted to 50 °C. The discharged material from the deacidification kettle is continuously fed into the phase separator II, maintaining the liquid hold-up in the phase separator II at 66 kg, adjusting the material balance of the inlet and outlet of the phase separator II to ensure the phase separation time t 6 is 120 min, and the temperature inside the phase separator II is adjusted to 50 °C. The oil phase II coming out after the phase separator II separates the deacidifying agent phase continuously enters the desolventizing rectification column (rectification column plates 10, rectification column pressure 4 kPaA, bottom temperature of the column 110 °C, top temperature of the column 20 °C). The solvent is distilled out from the top of the column, and the material after desolventizing is distilled out from the bottom of the column. The material after desolventizing continuously enters the scraper evaporator (pressure 0.15 MPaA, heating temperature 140 °C, distillation temperature after gas-phase condensation 110 °C). The removed tar is discharged from the bottom, and the product is distilled out from the top (1.47 kg / h). The composition is analyzed by gas chromatography after sampling (β-ionone 98.29 wt%, isomers 1.71 wt%), and the overall process yield of β-ionone is calculated to be 96.57%.

[0065]

Example 7

[0066] Continuously synthesize β-ionone using the microchannel reaction equipment provided in Example 2:

[0067] Prepare a 35 wt% pseudoionone solution with dichloromethane as the solvent. Continuously feed the pseudoionone solution and 85 wt% sulfuric acid into the microchannel reaction equipment at 416.2 kg / h and 1028.3 kg / h respectively. The residence times t 1 and t 2 are 20 s and 40 s respectively, and the reaction temperatures are -30 °C and 20 °C respectively. The discharged material from the microchannel reaction equipment and the quenching water (1028 kg / h) are continuously fed into the quenching kettle, maintaining the liquid hold-up in the quenching kettle at 412 kg, adjusting the material balance of the inlet and outlet of the quenching kettle to ensure the residence time t 3 of the quenching reaction is 10 min, and the temperature inside the quenching kettle is adjusted to 5 °C. The discharged material from the quenching kettle is continuously fed into the phase separator I, maintaining the liquid hold-up in the phase separator I at 412 kg, adjusting the material balance of the inlet and outlet of the phase separator I to ensure the phase separation time t 4 is 10 min, and the temperature inside the phase separator I is adjusted to 5 °C. The oil phase I (416 kg / h) coming out after the phase separator I separates the water phase is sampled and analyzed by gas chromatography for its composition (β-ionone 34.08 wt%, isomers 0.51 wt%, tar 0.45 wt%, and the rest is the solvent). The reaction yield of β-ionone is calculated to be 97.23%.

[0068] The oil phase I and the 10 wt% potassium carbonate aqueous solution of the deacidifying agent (29.3 kg / h) are continuously fed into the deacidification kettle, maintaining the liquid hold-up in the deacidification kettle at 74 kg, adjusting the material balance of the inlet and outlet of the deacidification kettle to ensure the residence time t 5The time is 10 min, and the temperature inside the deacidification kettle is adjusted to 5°C. The discharged material from the deacidification kettle is continuously fed into the phase separator II, maintaining the liquid hold-up in the phase separator II at 74 kg, adjusting the material balance of the inlet and outlet of the phase separator II, and ensuring the phase separation time t 6 is 10 min, and the temperature inside the phase separator II is adjusted to 5°C. The oil phase II coming out after the phase separator II separates the deacidifying agent phase continuously enters the solvent stripping distillation column (10 distillation trays, distillation column pressure 4 kPaA, column bottom temperature 80°C, top temperature 20°C). The solvent is distilled out from the top, and the material after solvent stripping is distilled out from the column bottom. The material after solvent stripping continuously enters the scraper evaporator (pressure 0.15 MPaA, heating temperature 140°C, distillation temperature after gas phase condensation 110°C). The removed tar is discharged from the bottom, and the product is distilled out from the top (143.2 kg / h). The composition is analyzed by gas chromatography after sampling (β-ionone 98.50 wt%, isomers 1.50 wt%). The overall yield of β-ionone in the whole process is calculated to be 96.83%.

[0069]

Example 8

[0070] Continuously synthesize β-ionone using the microchannel reaction equipment provided in Example 3:

[0071] Prepare a 20 wt% pseudo-ionone solution with n-heptane as the solvent. Continuously feed the pseudo-ionone solution and 92 wt% sulfuric acid into the microchannel reaction equipment at 384.3 kg / h and 250.6 kg / h respectively. The residence times t 1 and t 2 are 6 s and 20 s respectively, and the reaction temperatures are -10°C and 35°C respectively. The discharged material from the microchannel reaction equipment and the quenching water (752 kg / h) are continuously fed into the quenching kettle, maintaining the liquid hold-up in the quenching kettle at 1387 kg, adjusting the material balance of the inlet and outlet of the quenching kettle, and ensuring the residence time t 3 of the quenching reaction is 60 min, and the temperature inside the quenching kettle is adjusted to 30°C. The discharged material from the quenching kettle is continuously fed into the phase separator I, maintaining the liquid hold-up in the phase separator I at 1387 kg, adjusting the material balance of the inlet and outlet of the phase separator I, and ensuring the phase separation time t 4 is 60 min, and the temperature inside the phase separator I is adjusted to 30°C. The oil phase I (384 kg / h) coming out after the phase separator I separates the water phase is sampled and analyzed by gas chromatography for its composition (β-ionone 19.78 wt%, isomers 0.15 wt%, tar 0.14 wt%, and the rest is the solvent). The reaction yield of β-ionone is calculated to be 98.84%.

[0072] The oil phase I and the deacidifying agent triethanolamine (7.9 g / min) are continuously fed into the deacidification kettle, maintaining the liquid hold-up in the deacidification kettle at 385 kg, adjusting the material balance of the inlet and outlet of the deacidification kettle, and ensuring the residence time t 5The time is 60 min, and the temperature inside the deacidification kettle is adjusted to 30 °C. The discharged material from the deacidification kettle is continuously fed into the phase separator II, maintaining the liquid hold-up in the phase separator II at 385 kg, adjusting the material balance of the inlet and outlet of the phase separator II, and ensuring the phase separation time t 6 is 60 min, and the temperature inside the phase separator II is adjusted to 30 °C. The oil phase II coming out after the phase separator II separates the deacidifying agent phase continuously enters the solvent removal rectification column (10 rectification plates, rectification column pressure 4 kPaA, bottom temperature of the column 140 °C, top temperature of the column 20 °C). The solvent is distilled out from the top of the column, and the material after solvent removal is distilled out from the bottom of the column. The material after solvent removal continuously enters the scraping evaporator (pressure 0.15 MPaA, heating temperature 140 °C, distillation temperature after gas phase condensation 110 °C). The removed tar is discharged from the bottom, and the product is distilled out from the top (76.1 kg / h). The composition is analyzed by gas chromatography after sampling (β-ionone 99.25 wt%, isomers 0.75 wt%), and the overall process yield of β-ionone is calculated to be 98.28%.

[0073]

Example 9

[0074] Continuously synthesize β-ionone using the microchannel reaction equipment provided in Example 4:

[0075] Prepare a 15 wt% pseudoionone solution with dichloroethane as the solvent. Continuously feed the pseudoionone solution and 95 wt% sulfuric acid into the microchannel reaction equipment at 318.3 kg / h and 100.5 kg / h respectively. The residence times t 1 and t 2 in the low-temperature pipe section and the high-temperature pipe section are 2 s and 15 s respectively, and the reaction temperatures are 0 °C and 40 °C respectively. The discharged material from the microchannel reaction equipment and the quenching water (402 kg / h) are continuously fed into the quenching kettle, maintaining the liquid hold-up in the quenching kettle at 1231 kg, adjusting the material balance of the inlet and outlet of the quenching kettle, and ensuring the residence time t 3 of the quenching reaction is 90 min, and the temperature inside the quenching kettle is adjusted to 40 °C. The discharged material from the quenching kettle is continuously fed into the phase separator I, maintaining the liquid hold-up in the phase separator I at 1231 kg, adjusting the material balance of the inlet and outlet of the phase separator I, and ensuring the phase separation time t 4 is 90 min, and the temperature inside the phase separator I is adjusted to 40 °C. The oil phase I (318 kg / h) coming out after the phase separator I separates the water phase is sampled and analyzed by gas chromatography for its composition (β-ionone 14.82 wt%, isomers 0.12 wt%, tar 0.10 wt%, and the rest is the solvent), and the reaction yield of β-ionone is calculated to be 98.74%.

[0076] The oil phase I and the 5 wt% potassium bicarbonate aqueous solution of the deacidifying agent (53.2 kg / h) are continuously fed into the deacidification kettle, maintaining the liquid hold-up in the deacidification kettle at 557 kg, adjusting the material balance of the inlet and outlet of the deacidification kettle, and ensuring the residence time t 5The time is 90 min, and the temperature inside the deacidification kettle is adjusted to 40 °C. The discharged material from the deacidification kettle is continuously fed into the phase separator II, maintaining the liquid hold-up in the phase separator II at 557 kg, adjusting the material balance of the inlet and outlet of the phase separator II to ensure the phase separation time t 6 is 90 min, and the temperature inside the phase separator II is adjusted to 40 °C. The oil phase II coming out after the phase separator II separates the deacidifying agent phase continuously enters the solvent stripping distillation column (10 distillation trays, distillation column pressure 4 kPaA, bottom temperature of the column 125 °C, top temperature of the column 20 °C). The solvent is distilled out from the top of the column, and the material after solvent stripping is distilled out from the bottom of the column. The material after solvent stripping continuously enters the wiped film evaporator (pressure 0.15 MPaA, heating temperature 140 °C, distillation temperature after gas phase condensation 110 °C). The removed tar is discharged from the bottom, and the product is distilled out from the top (47.2 kg / h). The composition is analyzed by gas chromatography after sampling (β-ionone 99.17 wt%, isomers 0.83 wt%), and the overall process yield of β-ionone is calculated to be 98.03%.

[0077]

Example 10

[0078] Continuously synthesize β-ionone using the microchannel reaction equipment provided in Example 5:

[0079] Prepare a 25 wt% pseudo-ionone solution with toluene as the solvent. Continuously feed the pseudo-ionone solution and 90 wt% sulfuric acid into the microchannel reaction equipment at 405.7 kg / h and 450.8 kg / h respectively. The residence times t 1 and t 2 in the low-temperature pipe section and the high-temperature pipe section are 10 s and 25 s respectively, and the reaction temperatures are -20 °C and 30 °C respectively. The discharged material from the microchannel reaction equipment and the quenching water (902 kg / h) are continuously fed into the quenching kettle, maintaining the liquid hold-up in the quenching kettle at 879 kg, adjusting the material balance of the inlet and outlet of the quenching kettle to ensure the residence time t 3 of the quenching reaction is 30 min, and the temperature inside the quenching kettle is adjusted to 15 °C. The discharged material from the quenching kettle is continuously fed into the phase separator I, maintaining the liquid hold-up in the phase separator I at 879 kg, adjusting the material balance of the inlet and outlet of the phase separator I to ensure the phase separation time t 4 is 30 min, and the temperature inside the phase separator I is adjusted to 15 °C. The oil phase I (405 kg / h) coming out after the phase separator I separates the aqueous phase is sampled and analyzed by gas chromatography for its composition (β-ionone 24.37 wt%, isomers 0.40 wt%, tar 0.27 wt%, and the rest is solvent), and the reaction yield of β-ionone is calculated to be 97.30%.

[0080] The oil phase I and the 2 wt% aqueous sodium bicarbonate solution of the deacidifying agent (42.6 kg / h) are continuously fed into the deacidification kettle, maintaining the liquid hold-up in the deacidification kettle at 224 kg, adjusting the material balance of the inlet and outlet of the deacidification kettle to ensure the residence time t 5The time is 30 min, and the temperature inside the deacidification kettle is adjusted to 15°C. The discharged material from the deacidification kettle is continuously fed into the phase separator II, maintaining the liquid hold-up in the phase separator II at 224 kg, adjusting the material balance of the inlet and outlet of the phase separator II, and ensuring the phase separation time t 6 is 30 min, and the temperature inside the phase separator II is adjusted to 15°C. The oil phase II coming out after the phase separator II has separated the deacidifying agent phase continuously enters the solvent removal distillation column (10 distillation trays, distillation column pressure 4 kPaA, bottom temperature of the column 150°C, top temperature of the column 20°C). The solvent is distilled out from the top of the column, and the material after solvent removal is distilled out from the bottom of the column. The material after solvent removal continuously enters the scraping evaporator (pressure 0.15 MPaA, heating temperature 140°C, distillation temperature after gas phase condensation 110°C). The removed tar is discharged from the bottom, and the product is distilled out from the top (99.6 kg / h). The composition is analyzed by gas chromatography after sampling (β-ionone 98.37 wt%, isomers 1.63 wt%), and the overall process yield of β-ionone is calculated to be 96.62%.

[0081]

Comparative Example

[0082] β-ionone was continuously synthesized using a common tubular reactor with an inner diameter of the circular tube of 2 mm:

[0083] A 15 wt% pseudoionone solution was prepared with dichloroethane as the solvent. The pseudoionone solution and 95 wt% sulfuric acid were continuously fed into the microchannel reaction equipment at 316.0 kg / h and 99.8 kg / h respectively. The residence times t 1 and t 2 in the low-temperature pipe section and the high-temperature pipe section were 2 s and 15 s respectively, and the reaction temperatures were 0°C and 40°C respectively. The discharged material from the microchannel reaction equipment and the quenching water (400 kg / h) were continuously fed into the quenching kettle, maintaining the liquid hold-up in the quenching kettle at 1223 kg, adjusting the material balance of the inlet and outlet of the quenching kettle, and ensuring the residence time t 3 of the quenching reaction was 90 min, and the temperature inside the quenching kettle was adjusted to 40°C. The discharged material from the quenching kettle was continuously fed into the phase separator I, maintaining the liquid hold-up in the phase separator I at 1223 kg, adjusting the material balance of the inlet and outlet of the phase separator I, and ensuring the phase separation time t 4 was 90 min, and the temperature inside the phase separator I was adjusted to 40°C. The oil phase I (316 kg / h) coming out after the phase separator I has separated the water phase was sampled and analyzed by gas chromatography for its composition (β-ionone 10.80 wt%, isomers 1.73 wt%, tar 2.55 wt%, and the rest being the solvent), and the reaction yield of β-ionone was calculated to be 71.94%.

[0084] The oil phase I and the 5 wt% aqueous potassium bicarbonate solution of the deacidifying agent (52.8 kg / h) were continuously fed into the deacidification kettle, maintaining the liquid hold-up in the deacidification kettle at 553 kg, adjusting the material balance of the inlet and outlet of the deacidification kettle, and ensuring the residence time t 5It is 90 min, and the temperature inside the deacidification kettle is adjusted to 40°C. The discharged material from the deacidification kettle is continuously fed into the phase separator II, maintaining the liquid hold-up in the phase separator II at 553 kg, adjusting the material balance of the inlet and outlet of the phase separator II, and ensuring the phase separation time t 6 is 90 min, and the temperature inside the phase separator II is adjusted to 40°C. The oil phase II coming out after the phase separator II has separated the deacidifying agent phase continuously enters the desolventizing rectification column (10 rectification trays, rectification column pressure 4 kPaA, bottom temperature of the column 125°C, top temperature of the column 20°C). The solvent is distilled out from the top of the column, and the material after desolventizing is distilled out from the bottom of the column. The material after desolventizing continuously enters the scraper evaporator (pressure 0.15 MPaA, heating temperature 140°C, distillation temperature after gas phase condensation 110°C). The removed tar is discharged from the bottom, and the product is distilled out from the top (39.2 kg / h). The composition is analyzed by gas chromatography after sampling (β-ionone 86.04 wt%, isomer 13.96 wt%). The overall process yield of β-ionone is calculated to be 71.13%.

[0085] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the method of the present invention, several improvements and supplements can be made, and these improvements and supplements should also be regarded as the protection scope of the present invention.

Claims

1. A microchannel reaction device, characterized in that: It comprises a low-temperature pipe section and a high-temperature pipe section connected to the end of the low-temperature pipe section; the low-temperature pipe section and the high-temperature pipe section respectively comprise two wave-shaped reaction tubes arranged in a staggered manner; The two reaction tubes of the low temperature tube section follow the cosine function curve along the axial extension direction: Low temperature reaction tube 1: Low temperature reaction tube 2: Among them, x1 is the axial displacement of the low-temperature reaction tube, f 11 (x1) and f 12 (x1) is the longitudinal displacement of the low-temperature reaction tube corresponding to the axial displacement x1; A1 is the amplitude of the cosine function, which is 3-20 times, preferably 5-10 times, the inner diameter of the low-temperature reaction tube; T h1 is the half period of the cosine function, and its value is 3-20 times, preferably 5-10 times, the inner diameter of the low-temperature reaction tube; The two reaction tubes of the high-temperature tube section follow the sine function curve along the axial extension direction: High temperature reaction tube 1: High temperature reaction tube 2: Among them, x2 is the axial displacement of the high temperature reaction tube, f 21 (x2) and f 22 (x2) is the longitudinal displacement of the high temperature reaction tube when the axial displacement is x2; A2 is the amplitude of the sine function, which is 1-20 times of A1, preferably 3-10 times; T h2 is the half period of the sine function, and its value is T h1 1-20 times, preferably 3-10 times.

2. The microchannel reaction device according to claim 1, characterized in that: The inner diameter of the low temperature reaction tube and the inner diameter of the high temperature reaction tube are independently 0.2-10 mm, preferably 2-6 mm.

3. The microchannel reaction device according to claim 1 or 2, characterized in that: A plurality of collision contact elements are arranged in the low temperature reaction tube and the high temperature reaction tube; Preferably, the collision contact element is spherical, and the diameter of the spherical element is 0.4-0.8 times the inner diameter of the reaction tube where the spherical element is located.

4. A method for continuously synthesizing β-ionone, characterized in that: The microchannel reaction device according to any one of claims 1 to 3 is used to react with a pseudoionone solution and an acid material as raw materials to continuously synthesize β-ionone.

5. The method for continuous synthesis of β-ionone according to claim 4, characterized in that: The acid material is concentrated sulfuric acid, preferably 85-98wt% sulfuric acid, more preferably 90-95wt% sulfuric acid; Preferably, the amount of the raw material is calculated as the mass ratio of pseudoionone to the acid in the acid material, which is 1:(1-6); Preferably, the solvent used in the pseudoionone solution is selected from alkanes, chloroalkanes, benzene series, preferably one or more of n-hexane, n-heptane, dichloromethane, dichloroethane, and toluene.

6. The method for continuous synthesis of β-ionone according to claim 4, characterized in that: The reaction temperature in the low temperature section is -30°C to 10°C, preferably -20°C to 0°C; Preferably, the reaction temperature in the high temperature section is 20-50°C, preferably 30-40°C.

7. The method for continuous synthesis of β-ionone according to any one of claims 4 to 6, characterized in that: The reaction residence time in the low temperature section is 1-20s, preferably 2-10s; Preferably, the reaction residence time in the high temperature pipe section is 10-40 s, preferably 15-25 s.

8. The method for continuous synthesis of β-ionone according to any one of claims 4 to 7, characterized in that: The pseudoionone solution and the acid material are fed into two reaction tubes of the low-temperature tube section respectively, firstly continuously mixed and reacted in the low-temperature tube section, and then flow into the high-temperature tube section to continue mixing and reacting.

9. The method for continuously synthesizing β-ionone according to any one of claims 4 to 8, characterized in that: After the reaction is completed, the oil phase is obtained by quenching, phase separation and deacidification, and then purified, and then the light components and heavy components in the oil phase are removed to obtain the product β-ionone.

10. The method for continuous synthesis of β-ionone according to claim 9, characterized in that: The deacidifying agent used for the deacidification is selected from an inorganic weak base and / or an organic base, preferably one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, monoethanolamine, diethanolamine, triethanolamine, mono-n-propanolamine, di-n-propanolamine, tri-n-propanolamine, monoisopropanolamine, diisopropanolamine, and triisopropanolamine.

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