Microchannel Device and Its Applications

Abstract

The present invention discloses a microchannel device and its application, which adopts a device including a micromixer (a) and a microreactor (b), wherein the outlet of the micromixer is connected to the inlet of the microreactor through a connecting pipeline (7). In this device, a mixing reaction coupling strengthening process of various heterogeneous systems can be carried out. The heterogeneous raw materials respectively enter the micromixer through a preheater for mixing and contact, and a reaction separation coupling process is carried out in the microreactor. The heat transfer, mass transfer and reaction processes are strengthened through microscale sieve holes and microscale annular gap spaces, so as to realize the efficient progress of complex heterogeneous reaction processes, and it can be used in the field of microchannel technology process strengthening.

Description

Technical Field

[0001] The present invention belongs to the field of microchannel devices. Background Art

[0002] Microchannel reaction technology refers to a new type of process intensification technology for carrying out chemical reactions, heat transfer, mixing, separation, and control in a three-dimensional structural process fluid channel with a characteristic size of 10 - 1000 μm. It can significantly improve the heat and mass transfer efficiency and space utilization rate, achieve precise control of reaction temperature, reaction time, and material ratio, and has inherent safety. In recent years, microchannel reaction technology has achieved rapid development in the fields of fine chemical industry and pharmaceutical chemical industry.

[0003] Due to the characteristics of high-efficiency conversion and continuous production that can be achieved by microchannel reaction technology, it has a very broad application prospect in the field of fine chemical synthesis.

[0004] Chinese Patent CN201610932204 discloses a microchannel reactor with a column arrangement structure. In the fine chemical industry, there are many heterogeneous reaction processes with complex processes. The production processes of many high-value-added fine chemical products include multiple processes such as heat transfer, mixing, reaction, and separation. Therefore, it is very difficult to achieve precise control of the product production process in a traditional batch reactor, and there are no very mature commercial products and process routes for the multi-process coupling of the existing microchannel technology in a heterogeneous system. Summary of the Invention

[0005] One of the technical problems to be solved by the present invention is to provide a microchannel device.

[0006] Another technical problem to be solved by the present invention is to provide a method for strengthening the mixing reaction coupling process based on microchannel technology.

[0007] The third technical problem to be solved by the present invention is to provide a microchannel method for synthesizing ε-caprolactone.

[0008] A microchannel device includes (a) a micromixer and (b) a microreactor, wherein the outlet of the micromixer is connected to the inlet of the microreactor through a connecting pipeline (7); the micromixer includes an aqueous phase raw material inlet (1), an oil phase raw material inlet (2), a mixing channel (3), a folded micro sieve hole (4), a mixer sleeve (5), and a mixer nozzle (6). The micromixer (a) is located at symmetric positions on both sides of the microreactor (b), and the included angle between the central axis of the micromixer and the central axis of the microreactor is 30 - 150°, preferably 60 - 120°. The mixing channel (3) in the micromixer is an annular space I with an annular gap distance of 10 - 2000 microns formed between the mixer sleeve (5) and the mixer nozzle (6), the annular gap distance is preferably 50 - 1000 microns, and more preferably 400 - 600 microns; the folded micro sieve holes (4) are distributed on the side surface of the columnar body of the mixer nozzle (6), with a hydraulic diameter of 10 - 1000 microns, preferably 50 - 150 microns, a hole pitch of 50 - 5000 microns, preferably 100 - 1000 microns, and a folded angle of 20 - 160°, preferably 60 - 120°; the microreactor includes a gas phase product outlet (8), a liquid phase raw material inlet (9), a reactor outer wall (10), a reaction channel (11), a heating pipe wall (12), a liquid phase product outlet (13), a gas phase raw material inlet (14), and a heating medium inlet (15). The liquid phase raw material inlet (9) of the microreactor is an annular gap with a characteristic size of 100 - 500 microns, preferably 200 - 300 microns, and the reaction channel (11) is an annular space II with an annular gap distance of 500 - 5000 microns formed between the heating pipe wall (12) and the reactor outer wall (10), preferably 1000 - 4000 microns, and more preferably 2000 - 3000 microns.

[0009] A method for intensifying the mixing reaction coupling process based on microchannel technology uses a microchannel device and includes the following steps:

[0010] (1) The mixing process of the aqueous phase raw material and the oil phase raw material is carried out in the micromixer (a). The mixing process is that the aqueous phase raw material enters the mixer (a) from the aqueous phase raw material inlet (1), is mixed and dispersed, and then contacts the oil phase raw material entering from the oil phase raw material inlet (2).

[0011] The micromixer (a) includes: an aqueous phase raw material inlet (1), an oil phase raw material inlet (2), a mixing channel (3), a folded micro sieve hole (4), a mixer sleeve (5), and a mixer nozzle (6);

[0012] (2) The liquid obtained at the outlet of the micromixer (a) enters the microreactor (b) through the connecting pipeline (7) as its liquid phase raw material.

[0013] The microreactor includes: a gas-phase product outlet (8), a liquid-phase raw material inlet (9), a reactor outer wall (10), a reaction channel (11), a heating pipe wall (12), a liquid-phase product outlet (13), a gas-phase raw material inlet (14), and a heating medium inlet (15);

[0014] (3) The reaction process of the liquid-phase raw material and the gas-phase raw material in the microreactor (b) is that the liquid-phase raw material enters from the liquid-phase raw material inlet (9) and countercurrently contacts the gas-phase raw material entering from the gas-phase raw material inlet (14) in the reaction channel (11). The heat required for the reaction is provided by the heating medium in the heating pipe wall (12). The gas-phase product of the reaction process is discharged from the gas-phase product outlet (8), and the liquid-phase product is discharged from the liquid-phase product outlet (8).

[0015] A microchannel method for synthesizing ε-caprolactone using a microchannel device includes the following steps:

[0016] (1) The aqueous-phase raw material contains a homogeneous catalyst and an oxidant, and the oxidant is selected from hydrogen peroxide, tert-butyl hydroperoxide, peracetic acid, and perpropionic acid; preferably hydrogen peroxide and perpropionic acid; more preferably hydrogen peroxide;

[0017] (2) The oil-phase raw material contains cyclohexanone and a water-carrying agent, and the water-carrying agent is selected from benzene, toluene, ethyl propionate, ethyl acetate, carbon tetrachloride, or dichloroethane; preferably toluene and ethyl propionate;

[0018] (3) The aqueous-phase raw material and the oil-phase raw material are preheated by a preheater and then enter a micromixer for a mixing process. The mixing process is that the aqueous-phase raw material enters the mixer nozzle (6) from the aqueous-phase raw material inlet (1), is dispersed through the folded micro-sieve holes (4), and contacts the oil-phase raw material entering from the oil-phase raw material inlet (2) in the mixing channel (3). The preheating temperature of the preheating process is 40-60°C;

[0019] (4) The liquid obtained at the outlet of the micromixer (a) contains cyclohexanone, an oxidant, water, a homogeneous catalyst, and a water-carrying agent, and enters the microreactor (b) through the connecting pipeline (7) as its liquid-phase raw material;

[0020] (5) The liquid-phase raw material (containing cyclohexanone, an oxidant, water, a homogeneous catalyst, and a water-carrying agent) and the gas-phase raw material (selected from air, nitrogen, helium, and argon; preferably nitrogen and helium) undergo a reaction process in the microreactor (b). The reaction process is that the liquid-phase raw material enters from the liquid-phase raw material inlet (9) and countercurrently contacts the gas-phase raw material entering from the gas-phase raw material inlet (14) in the reaction channel (11). The heat required for the reaction is provided by the heating medium in the heating pipe wall (12);

[0021] (6) The liquid-phase product of the microreactor (b) (including ε-caprolactone, cyclohexanone, homogeneous catalyst, and water-carrying agent) is discharged as the target product from the liquid-phase product outlet (13). The gas-phase product carries the water-carrying agent and moisture and is discharged from the gas-phase product outlet (8). After cooling, the water-carrying agent is recovered and recycled through oil-water separation.

[0022] The microchannel method for synthesizing ε-caprolactone uses a microchannel device including (a) a micromixer and (b) a microreactor, where the outlet of the micromixer is connected to the inlet of the microreactor through a connecting pipeline (7). The micromixer includes: an aqueous raw material inlet (1), an oil-phase raw material inlet (2), a mixing channel (3), a folded micro-sieve hole (4), a mixer sleeve (5), and a mixer nozzle (6). The microreactor includes: a gas-phase product outlet (8), a liquid-phase raw material inlet (9), a reactor outer wall (10), a reaction channel (11), a heating pipe wall (12), a liquid-phase product outlet (13), a gas-phase raw material inlet (14), and a heating medium inlet (15). During the reaction process, the gas-liquid volume ratio is (1 - 30):1, the temperature is 50 - 150 °C, the pressure is -0.1 - 0.1 MPa, and the residence time is 0.5 - 30 min; the mass fraction of the oxidant in the aqueous raw material is 10% - 70%, preferably 20% - 50%, and the molar ratio of the oxidant to cyclohexanone is 1.0 - 4.5, preferably 3.0 - 4.0; the homogeneous catalyst is a coordination compound of tungstate and oxalic acid, and the mass fraction of the catalyst in the aqueous raw material is 0.1% - 5.0%, and the molar ratio of oxalic acid to sodium tungstate is 1.0 - 2.0; the mass fraction of the water-carrying agent in the oil-phase raw material is 20% - 80%.

[0023] The beneficial effects of the ε-caprolactone microchannel device and method provided by the present invention are as follows:

[0024] The ε-caprolactone microchannel device and method provided by the present invention use a low-concentration oxidant to oxidize cyclohexanone to synthesize ε-caprolactone in one step, greatly simplifying the process flow. At the same time, it also avoids using peroxy acids with great potential safety hazards during the process, ensuring good safety throughout the process flow.

[0025] The method for strengthening the mixing reaction coupling process based on microchannel technology provided by the present invention has good applicability and is suitable for the continuous production of the Baeyer-Villiger reaction process of various different reaction substrates. Especially for the process of oxidizing cyclohexanone to synthesize ε-caprolactone, the effect is more obvious.

[0026] The microchannel method for synthesizing ε-caprolactone provided by the present invention realizes the continuous production of ε-caprolactone. Through the microscale effect to strengthen the efficient mixing of the heterogeneous liquid-liquid system, a relatively high conversion rate of cyclohexanone is achieved, which can reach more than 85%. Also, through the confinement effect of the microscale structure, the reaction fluid in the device flows in a plug flow mode, so that the reaction residence time can be accurately controlled, and a relatively high selectivity of ε-caprolactone is achieved. At the same time, a reaction dehydration coupling process is constructed based on the microchannel technology, and the water content in the ε-caprolactone synthesis system is reduced by an effective on-line separation means, avoiding the decrease in product yield caused by the hydrolysis of ε-caprolactone. It belongs to a low-carbon, environmentally friendly, energy-saving and emission-reducing process route. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic structural diagram of a microscale porous nozzle mixer and a microscale coaxial annular tube falling film reactor provided by the present invention.

[0028] In the figure: (a) Micro mixer: aqueous phase raw material inlet (1); oil phase raw material inlet (2); mixing channel (3); folded micro sieve holes (4); mixer casing (5); mixer nozzle (6) (b) Micro reactor: gas phase product outlet (8); liquid phase raw material inlet (9); reactor outer wall (10); reaction channel (11); heating tube wall (12); liquid phase product outlet (13); gas phase raw material inlet (14); heat transfer oil inlet (15); connecting pipeline (7).

[0029] Figure 2 It is a schematic diagram of the micro sieve hole structure in the micro mixer of the present invention

[0030] In the figure: (c) Folded micro sieve holes; (d) Ladder-shaped micro sieve holes; (e) Z-shaped micro sieve holes. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The present invention will be further described below by way of examples, but the content of the present invention is not limited thereby.

[0032] The following examples are carried out in a micro reactor according to the requirements of the method of the present invention.

[0033]

Example 1

[0034] (1) Device construction: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micro mixer and the central axis of the micro reactor is 45°. The hydraulic diameter of the folded micro sieve hole structure on the mixer nozzle is 100 microns, the hole spacing is 500 microns, the folded angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the micro reactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1Build a device for synthesizing ε-caprolactone using the microchannel technology according to the schematic diagram of the device shown. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator. The crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0035] (2) Synthesis of ε-caprolactone: Use a metering pump to transport the aqueous phase raw material containing the catalyst, and select hydrogen peroxide as the oxidant, where the mass fraction of hydrogen peroxide is 30%, the mass fraction of the catalyst is 2%, and the molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0; use a metering pump to transport the oil phase raw material containing the water-carrying agent, where the mass fraction of the water-carrying agent toluene is 50%. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated by a preheater and fully mixed at 50 °C in the micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid phase raw material through a connecting pipeline, enters the microreactor through the liquid phase raw material inlet, and contacts countercurrently with the air entering from the lower gas inlet to carry out the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, the reaction pressure is atmospheric pressure, the residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet, and the gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet, and is recycled after cooling through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 85.2%, and the selectivity of ε-caprolactone is 95.1%.

[0036]

Example 2

[0037] (1) Device construction: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 60°. The hydraulic diameter of the water-retaining micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folding angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 Build a device for synthesizing ε-caprolactone using the microchannel technology according to the schematic diagram of the device shown. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator. The crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0038] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated by a preheater and fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid-phase raw material through a connecting pipeline and enters the microreactor through the liquid-phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet. The gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet, and after cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 82.1% and the selectivity of ε-caprolactone is 94.6%.

[0039]

Example 3

[0040] (1) Setup of the device: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 120°. The hydraulic diameter of the water-retaining micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folding angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology-based ε-caprolactone synthesis device. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0041] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst, and hydrogen peroxide is selected as the oxidant, with the mass fraction of hydrogen peroxide being 30% and the mass fraction of the catalyst being 2%. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, with the mass fraction of the water-carrying agent toluene being 50%. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid phase raw material through a connecting pipeline and enters the microreactor through the liquid phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet, and the gas phase product carrying the water-carrying agent and water is discharged from the gas phase product outlet, and after cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 84.6% and the selectivity of ε-caprolactone is 93.1%.

[0042]

Example 4

[0043] (1) Setup of the device: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining micro-sieve hole structure on the nozzle of the mixer is 300 microns, the hole pitch is 500 microns, the folding angle is 90°, the annular gap distance of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap distance of the reaction channel is 2500 microns. Refer to Figure 1 the device schematic diagram shown to set up the microchannel technology-based ε-caprolactone synthesis device. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0044] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30%, and the catalyst mass fraction is 2%. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil-phase raw material containing the water-carrying agent, where the mass fraction of the water-carrying agent toluene is 50%. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid-phase raw material. It enters the microreactor through the liquid-phase raw material inlet and contacts countercurrently with the air entering from the lower gas inlet to carry out the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel. The gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet. The gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 83.2%, and the selectivity of ε-caprolactone is 94.8%.

[0045]

Example 5

[0046] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 50 microns, the hole spacing is 500 microns, the folding angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator. The crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0047] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid phase raw material. It enters the microreactor through the liquid phase raw material inlet and contacts the air entering from the lower gas inlet countercurrently to carry out the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel. The gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet. The gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 85.5%, and the selectivity of ε-caprolactone is 94.8%.

[0048]

Example 6

[0049] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining micro-screen hole structure on the nozzle of the mixer is 100 microns, the hole pitch is 800 microns, the folding angle is 90°, the annular gap distance of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap distance of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the device for synthesizing ε-caprolactone by microchannel technology. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator. The crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0050] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid phase raw material, and enters the microreactor through the liquid phase raw material inlet, where it contacts countercurrently with the air entering from the lower gas inlet and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet, and the gas phase product carrying the water-carrying agent and water is discharged from the gas phase product outlet, and is recycled after cooling through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 83.6%, and the selectivity of ε-caprolactone is 94.2%.

[0051]

Example 7

[0052] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 300 microns, the folded angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the device schematic diagram shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0053] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil-phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated by a preheater and fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid-phase raw material through a connecting pipeline and enters the microreactor through the liquid-phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel. The gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet. The gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet, and after cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 86.0% and the selectivity of ε-caprolactone is 95.3%.

[0054] Table 1

[0055]

[0056]

[0057]

Example 8

[0058] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole pitch is 500 microns, the folding angle is 30°, the annular gap distance of the mixing channel is 500 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap distance of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0059] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The two streams of materials are preheated separately through a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid phase raw material through a connecting pipeline, and enters the microreactor through the liquid phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel. The gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet. The gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet, and is recycled after cooling through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 82.1% and the selectivity of ε-caprolactone is 92.2%.

[0060]

Example 9

[0061] (1) Setup of the device: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folding angle is 60°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0062] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30%, and the catalyst mass fraction is 2%. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil phase raw material containing the water-carrying agent, where the mass fraction of the water-carrying agent toluene is 50%. The two streams of materials are preheated by a preheater and fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid phase raw material through a connecting pipeline, and enters the microreactor through the liquid phase raw material inlet, where it contacts the air entering from the lower gas phase inlet in a countercurrent manner and undergoes the cyclohexanone oxidation reaction. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel. The gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet, and the gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 84.3%, and the selectivity of ε-caprolactone is 93.8%.

[0063]

Example 10

[0064] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining structure with a folded shape on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folded angle is 120°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the device schematic diagram shown to set up the ε-caprolactone synthesis device using microchannel technology. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0065] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous raw material containing the catalyst, and hydrogen peroxide is selected as the oxidant, with the mass fraction of hydrogen peroxide being 30% and the mass fraction of the catalyst being 2%. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, with the mass fraction of the water-carrying agent toluene being 50%. The two streams of materials are preheated by a preheater and fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid-phase raw material through a connecting pipeline, and enters the microreactor through the liquid-phase raw material inlet, where it contacts the air entering from the lower gas-phase inlet in a countercurrent manner and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, the reaction pressure is at atmospheric pressure, the residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet, and the gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet, and is recycled after cooling through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 84.7% and the selectivity of ε-caprolactone is 94.6%.

[0066]

Example 11

[0067] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole pitch is 500 microns, the folding angle is 150°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the device for synthesizing ε-caprolactone by the microchannel technology. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0068] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous-phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil-phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid-phase raw material, and enters the microreactor through the liquid-phase raw material inlet, where it contacts the air entering from the lower gas-phase inlet in a countercurrent manner and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel. The gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, which is the crude product of the target product ε-caprolactone, is discharged from the liquid-phase product outlet. The gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 83.3%, and the selectivity of ε-caprolactone is 93.5%.

[0069]

Example 12

[0070] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining micro-screen hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folding angle is 90°, the annular gap spacing of the mixing channel is 1000 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the device schematic diagram shown to set up the microchannel technology synthesis device for ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0071] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid-phase raw material, and enters the microreactor through the liquid-phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet, and the gas-phase product carrying the water-carrying agent and water is discharged from the gas-phase product outlet, and is recycled after cooling through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 82.1% and the selectivity of ε-caprolactone is 94.2%.

[0072]

Example 13

[0073] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining agent nozzle with a folded micro-sieve hole structure on the micromixer is 100 microns, the hole pitch is 500 microns, the folded angle is 90°, the annular gap distance of the mixing channel is 500 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 500 microns, and the annular gap distance of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0074] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30%, and the mass fraction of the catalyst is 2%. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil phase raw material containing the water-carrying agent, where the mass fraction of the water-carrying agent toluene is 50%. The two streams of materials are preheated by a preheater and fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid phase raw material, and enters the microreactor through the liquid phase raw material inlet to contact countercurrently with the air entering from the lower gas inlet and carry out the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel. The gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet, and the gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet, and is recycled after cooling through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 84.2%, and the selectivity of ε-caprolactone is 91.6%.

[0075]

Example 14

[0076] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole pitch is 500 microns, the folded angle is 90°, the annular gap distance of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap distance of the reaction channel is 4000 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology synthesis device for ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0077] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The two streams of materials are preheated by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid-phase raw material through a connecting pipeline and enters the microreactor through the liquid-phase raw material inlet, where it contacts the air entering from the lower gas-phase inlet in a countercurrent manner and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel. The gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet. The gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 80.2%, and the selectivity of ε-caprolactone is 91.8%.

[0078] Table 2

[0079]

[0080]

[0081]

Example 15

[0082] (1) Setup of the device: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining micro-sieve hole structure on the nozzle of the mixer is 40 microns, the hole pitch is 500 microns, the folding angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0083] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30%, and the mass fraction of the catalyst is 2%. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, where the mass fraction of the water-carrying agent toluene is 50%. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid phase raw material, and enters the microreactor through the liquid phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet, and the gas phase product carrying the water-carrying agent and water is discharged from the gas phase product outlet, and is recycled after cooling through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 85.6%, and the selectivity of ε-caprolactone is 94.2%.

[0084]

Example 16

[0085] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 150 microns, the hole spacing is 500 microns, the folding angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the device schematic diagram shown to set up the microchannel technology synthesis device for ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0086] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst, and hydrogen peroxide is selected as the oxidant, with the mass fraction of hydrogen peroxide being 30% and the mass fraction of the catalyst being 2%. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil phase raw material containing the water-carrying agent, with the mass fraction of the water-carrying agent toluene being 50%. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated by a preheater and fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid phase raw material, and enters the microreactor through the liquid phase raw material inlet, where it contacts countercurrently with the air entering from the lower gas inlet and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet, and the gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet, and is recovered and recycled through oil-water separation after cooling. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 84.1% and the selectivity of ε-caprolactone is 94.4%.

[0087]

Example 17

[0088] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 100 microns, the folded angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the device for synthesizing ε-caprolactone by microchannel technology. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0089] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid phase raw material through a connecting pipeline and enters the microreactor through the liquid phase raw material inlet, where it contacts countercurrently with the air entering through the lower gas inlet and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet, and the gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 83.1%, and the selectivity of ε-caprolactone is 93.2%.

[0090]

Example 18

[0091] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole pitch is 1000 microns, the folded angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the device schematic diagram shown to set up the microchannel technology-based ε-caprolactone synthesis device. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0092] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil-phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated by a preheater and fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid-phase raw material through a connecting pipeline, and enters the microreactor through the liquid-phase raw material inlet, where it contacts countercurrently with the air entering through the lower gas inlet and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet, and the gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet, and is recycled after cooling through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 84.8% and the selectivity of ε-caprolactone is 93.6%.

[0093]

Example 19

[0094] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folded angle is 90°, the annular gap spacing of the mixing channel is 400 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round pipe. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0095] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst, and hydrogen peroxide is selected as the oxidant, with the mass fraction of hydrogen peroxide being 30% and the mass fraction of the catalyst being 2%. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil phase raw material containing the water-carrying agent, with the mass fraction of the water-carrying agent toluene being 50%. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated by a preheater and fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid phase raw material, and enters the microreactor through the liquid phase raw material inlet to contact countercurrently with the air entering from the lower gas inlet and carry out the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet, and the gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet, and is recycled after cooling through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 85.4% and the selectivity of ε-caprolactone is 93.6%.

[0096]

Example 20

[0097] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folded angle is 90°, the annular gap spacing of the mixing channel is 600 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0098] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30%, and the mass fraction of the catalyst is 2%. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil-phase raw material containing the water-carrying agent, where the mass fraction of the water-carrying agent toluene is 50%. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid-phase raw material, and enters the microreactor through the liquid-phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet, and the gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 84.5%, and the selectivity of ε-caprolactone is 92.6%.

[0099]

Example 21

[0100] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining folded micro-screen hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folding angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2000 microns. Refer to Figure 1 the device schematic diagram shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0101] (2) Synthesis of ε-caprolactone: A metering pump is used to deliver the aqueous phase raw material containing the catalyst, and hydrogen peroxide is selected as the oxidant, wherein the mass fraction of hydrogen peroxide is 30%, the mass fraction of the catalyst is 2%, and the molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0; a metering pump is used to deliver the oil phase raw material containing the water-carrying agent, wherein the mass fraction of the water-carrying agent toluene is 50%. The molar ratio of the oxidant to cyclohexanone is 3.5, and the two streams of materials are preheated by a preheater and fully mixed in a micro mixer at 50°C. The liquid at the outlet of the micro mixer passes through a connecting pipeline and enters the micro reactor as a liquid phase raw material. It enters the micro reactor through the liquid phase raw material inlet and contacts with the air entering from the lower gas phase inlet in countercurrent to carry out the cyclohexanone oxidation reaction. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature of the reaction channel is controlled at 90°C by heating the heat transfer oil in the tube wall, the reaction pressure is normal pressure, the residence time of the reaction materials is controlled to be 10 minutes by adjusting the flow of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled to be 10:1 by adjusting the gas mass flowmeter. The liquid product of the microreactor is discharged from the outlet of the liquid product as the target product crude ε-caprolactone, and the gas product is discharged from the outlet of the gas product with the water agent and water, and is recovered and recycled by oil-water separation after cooling. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 82.2%, and the selectivity of ε-caprolactone is 94.1%.

[0102] Table 2

[0103]

[0104]

[0105] [Example 22]

[0106] (1) Device construction: The main body of the microchannel device is made of stainless steel 316L. The angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded microsieve structure on the mixer nozzle is 100 μm, the hole spacing is 500 μm, the folding angle is 90°, the annular gap spacing of the mixing channel is 500 μm, the liquid phase raw material inlet of the microreactor is an annular gap of 250 μm, and the annular gap spacing of the reaction channel is 2500 μm. Figure 1 The schematic diagram of the device shown is a device for synthesizing ε-caprolactone using microchannel technology. The micromixer and the microreactor are connected by a stainless steel round tube. The temperature of the above device is controlled by an all-in-one cooling and heating machine. The crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0107] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous-phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 5% for the catalyst. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil-phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid-phase raw material through a connecting pipeline and enters the microreactor through the liquid-phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet. The gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 88.2%, and the selectivity of ε-caprolactone is 89.8%.

[0108]

Example 23

[0109] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folded angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0110] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 20%, and the mass fraction of the catalyst is 2%. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, where the mass fraction of the water-carrying agent toluene is 50%. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid-phase raw material, and enters the microreactor through the liquid-phase raw material inlet, where it contacts the air entering from the lower gas-phase inlet in a countercurrent manner and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet, and the gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 79.8%, and the selectivity of ε-caprolactone is 90.2%.

[0111]

Example 24

[0112] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folding angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0113] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, with a mass fraction of 30% for the water-carrying agent toluene. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid phase raw material, and enters the microreactor through the liquid phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet. The gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet, and after cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 85.9% and the selectivity of ε-caprolactone is 91.3%.

[0114]

Example 25

[0115] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folded angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0116] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous-phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil-phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated by a preheater and fully mixed at 70 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid-phase raw material, and enters the microreactor through the liquid-phase raw material inlet to contact countercurrently with the air entering from the lower gas inlet and carry out the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet. The gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet, and is recycled after cooling through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 85.8% and the selectivity of ε-caprolactone is 92.6%.

[0117]

Example 26

[0118] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole pitch is 500 microns, the folded angle is 90°, the annular gap distance of the mixing channel is 500 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap distance of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the device for synthesizing ε-caprolactone by microchannel technology. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0119] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30%, and the mass fraction of the catalyst is 2%. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil-phase raw material containing the water-carrying agent, where the mass fraction of the water-carrying agent toluene is 50%. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated by a preheater and fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid-phase raw material through a connecting pipeline and enters the microreactor through the liquid-phase raw material inlet, where it contacts countercurrently with the air entering from the lower gas inlet and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 120 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet, and the gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 87.4%, and the selectivity of ε-caprolactone is 90.1%.

[0120]

Example 27

[0121] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folded angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0122] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst, and hydrogen peroxide is selected as the oxidant, with the mass fraction of hydrogen peroxide being 30% and the mass fraction of the catalyst being 2%. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, with the mass fraction of the water-carrying agent toluene being 50%. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated by a preheater and fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid phase raw material through a connecting pipeline and enters the microreactor through the liquid phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is atmospheric pressure. The residence time of the reaction materials is controlled at 5 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet, and the gas phase product carrying the water-carrying agent and water is discharged from the gas phase product outlet, and after cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 81.2% and the selectivity of ε-caprolactone is 88.6%.

[0123]

Example 28

[0124] (1) Setup of the device: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folded angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing ε-caprolactone. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0125] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous raw material containing the catalyst, where the mass fraction of hydrogen peroxide is 30% and the mass fraction of the catalyst is 2%. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, where the mass fraction of the water-carrying agent toluene is 50%. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated by a preheater and fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid phase raw material through a connecting pipeline and enters the microreactor through the liquid phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel. The gas-liquid ratio in the reaction channel is controlled at 5:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet. The gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 84.9% and the selectivity of ε-caprolactone is 91.5%.

[0126] Table 2

[0127] Example 22 23 24 25 26 27 28 Mass fraction of catalyst in aqueous raw material / % 5 2 2 2 2 2 2 Mass fraction of oxidant in aqueous raw material / % 30 20 30 30 30 30 30 Mass fraction of water-carrying agent in oil-phase raw material / % 50 50 30 50 50 50 50 Molar ratio of oxidant to cyclohexanone dosage 3.5 3.5 3.5 3.5 3.5 3.5 3.5 Temperature during mixing process / °C 50 50 50 70 50 50 50 Temperature during reaction process / °C 90 90 90 90 120 90 90 Reaction residence time / min 10 10 10 10 10 5 10 Gas-liquid ratio (volume ratio) of reaction system 10 10 10 10 10 10 5 Conversion rate of cyclohexanone / % 88.2 79.8 85.9 85.8 87.4 81.2 84.9 Selectivity of ε-caprolactone / % 89.8 90.2 91.3 92.6 90.1 88.6 91.5

[0128]

Example 29

[0129] (1) Setup of the device: The main body of the microchannel device is made of stainless steel 316L. The angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole pitch is 500 microns, the folded angle is 90°, the annular gap distance of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap distance of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the device for synthesizing ε-caprolactone by microchannel technology. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid phase outlet of the microreactor.

[0130] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous-phase raw material containing the catalyst. Peroxypropionic acid is selected as the oxidant, with a mass fraction of 15% for peroxypropionic acid and 2% for the catalyst. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the oil-phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The molar ratio of the oxidant to cyclohexanone is 3.5. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid-phase raw material, and enters the microreactor through the liquid-phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat-conducting oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid-phase product outlet, and the gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet, and is recycled after cooling through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 86.2%, and the selectivity of ε-caprolactone is 93.3%.

[0131]

Example 30

[0132] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining microporous structure on the folded nozzle of the mixer is 100 microns, the pore spacing is 500 microns, the folded angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid-phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the device schematic diagram shown to set up the ε-caprolactone synthesis device by microchannel technology. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude ε-caprolactone can be collected from the liquid-phase outlet of the microreactor.

[0133] (2) Synthesis of ε-caprolactone: A metering pump is used to transport the aqueous phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 30% for hydrogen peroxide and 2% for the catalyst. The molar ratio of oxalic acid to sodium tungstate in the catalyst is 1.0. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, with a mass fraction of 50% for the water-carrying agent toluene. The molar ratio of the oxidant to cyclohexanone is 4.0. The two streams of materials are preheated separately by a preheater and then fully mixed at 50 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor through a connecting pipeline as the liquid phase raw material, and enters the microreactor through the liquid phase raw material inlet, where it contacts the air entering from the lower gas phase inlet in a countercurrent manner and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 90 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude ε-caprolactone as the target product, is discharged from the liquid phase product outlet. The gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet, and is recycled after cooling through oil-water separation. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 88.2% and the selectivity of ε-caprolactone is 94.3%.

[0134]

Example 30

[0135] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole pitch is 500 microns, the folded angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the device schematic diagram shown to set up the microchannel technology for synthesizing peracetic acid. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude peracetic acid can be collected from the liquid phase outlet of the microreactor.

[0136] (2) Synthesis of peracetic acid: A metering pump is used to transport the aqueous phase raw material containing the catalyst, and hydrogen peroxide is selected as the oxidant, with the mass fraction of hydrogen peroxide being 50% and the mass fraction of the catalyst being 0.2%. The catalyst is 98% concentrated sulfuric acid. A metering pump is used to transport the oil phase raw material acetic acid containing the water-carrying agent, with the mass fraction of the water-carrying agent cyclohexane being 50%. The molar ratio of the oxidant to acetic acid is 0.5. The two streams of materials are preheated by a preheater and fully mixed at 20 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid phase raw material through a connecting pipeline and enters the microreactor through the liquid phase raw material inlet, where it contacts the air entering from the lower gas phase inlet in a countercurrent manner and undergoes the acetic acid peroxidation reaction. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 60 °C by the heat-conducting oil in the heating tube wall, the reaction pressure is atmospheric pressure, the residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 50:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude peracetic acid as the target product, is discharged from the liquid phase product outlet, and the gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude peracetic acid show that the conversion rate of hydrogen peroxide in this process is 99.6% and the selectivity of ε-caprolactone is 98.2%.

[0137]

Example 31

[0138] (1) Setup of the device: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the water-retaining micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole spacing is 500 microns, the folding angle is 90°, the annular gap spacing of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap spacing of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the microchannel technology for synthesizing peroxypropionic acid. The micromixer and the microreactor are connected by a stainless steel round tube. The above device is temperature-controlled by a thermostatic bath circulator, and the crude peroxypropionic acid can be collected from the liquid phase outlet of the microreactor.

[0139] (2) Synthesis of peroxypropionic acid: A metering pump is used to transport the aqueous phase raw material containing the catalyst. Hydrogen peroxide is selected as the oxidant, with a mass fraction of 50%, and the catalyst mass fraction is 0.1%. The catalyst is 98% concentrated sulfuric acid. A metering pump is used to transport the organic phase raw material containing the water-carrying agent, where the mass fraction of the water-carrying agent ethyl propionate is 50%. The molar ratio of the oxidant to propionic acid is 0.5. The two streams of materials are preheated separately through a preheater and then fully mixed at 30 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid phase raw material through a connecting pipeline, and enters the microreactor through the liquid phase raw material inlet, where it contacts the air entering from the lower gas phase inlet in a countercurrent manner and undergoes the peroxygenation reaction of propionic acid. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 60 °C by the heat transfer oil in the heating tube wall, and the reaction pressure is at atmospheric pressure. The residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid phase product of the microreactor, the crude peroxypropionic acid as the target product, is discharged from the liquid phase product outlet. The gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet, and after cooling, it is recycled through oil-water separation. The analysis results of the crude peroxypropionic acid show that the conversion rate of hydrogen peroxide in this process is 95.2%, and the selectivity of peroxypropionic acid is 97.7%.

[0140]

Example 32

[0141] (1) Device setup: The main body of the microchannel device is made of stainless steel 316L. The included angle between the central axis of the micromixer and the central axis of the microreactor is 45°. The hydraulic diameter of the folded micro-sieve hole structure on the nozzle of the mixer is 100 microns, the hole pitch is 500 microns, the folded angle is 90°, the annular gap distance of the mixing channel is 500 microns, the annular gap of the liquid phase raw material inlet of the microreactor is 250 microns, and the annular gap distance of the reaction channel is 2500 microns. Refer to Figure 1 the schematic diagram of the device shown to set up the device for synthesizing m-chloroperoxybenzoic acid by microchannel technology. The micromixer and the microreactor are connected by a stainless steel round pipe. The above device is temperature-controlled by a thermostatic bath circulator. The crude m-chloroperoxybenzoic acid can be collected from the liquid phase outlet of the microreactor.

[0142] (2) Synthesis of m-chloroperbenzoic acid: A metering pump is used to transport the aqueous-phase raw material containing the catalyst, and hydrogen peroxide is selected as the oxidant, with the mass fraction of hydrogen peroxide being 50%; a metering pump is used to transport the organic-phase raw material containing the water-carrying agent, and dichloromethane is selected as the water-carrying agent, with the mass fraction of dichloromethane being 50%. The two streams of materials are preheated by a preheater and then fully mixed at 30 °C in a micromixer. The liquid at the outlet of the micromixer enters the microreactor as the liquid-phase raw material through a connecting pipeline, and enters the microreactor through the liquid-phase raw material inlet, where it contacts the air entering from the lower gas inlet countercurrently and undergoes the oxidation reaction of cyclohexanone. The heat required for the reaction is provided by the heating medium in the heating tube wall. The temperature inside the reaction channel is controlled at 60 °C by the heat-conducting oil in the heating tube wall, the reaction pressure is atmospheric pressure, the residence time of the reaction materials is controlled at 10 min by adjusting the flow rate of the metering pump and the length of the reaction channel, and the gas-liquid ratio in the reaction channel is controlled at 10:1 by adjusting the gas mass flowmeter. The liquid-phase product of the microreactor, the crude m-chloroperbenzoic acid as the target product, is discharged from the liquid-phase product outlet, and the gas-phase product carries the water-carrying agent and water and is discharged from the gas-phase product outlet. After cooling, it is recycled through oil-water separation. The analysis results of the crude m-chloroperbenzoic acid show that the conversion rate of cyclohexanone in this process is 89.2%, and the selectivity of m-chloroperbenzoic acid is 93.1%.

[0143]

Comparative Example 1

[0144] (1) Setup of the device: A Parr 4566 bench-top reactor produced by Parr Company of the United States is used as the reaction device. The main body is made of stainless steel 316L. The volume of the reactor is 300 ml, the inner diameter is 2.5 inches, and the inner depth is 4.0 inches. The above device uses an electric heating method for temperature control, with an internal stirring paddle for mixing the reaction materials, and an external condenser-fractionation device for removing the water in the system and refluxing the water-carrying agent.

[0145] (2) Synthesis of ε-caprolactone: 100 ml of aqueous-phase raw material is added, and hydrogen peroxide is selected as the oxidant, with the mass fraction of hydrogen peroxide being 30% and the mass fraction of the catalyst being 2%. The molar ratio of the amounts of oxalic acid and sodium tungstate in the catalyst is 1.0; 60 ml of organic-phase raw material containing the water-carrying agent is added, and toluene is selected as the water-carrying agent, with the mass fraction of toluene being 50%. After the reaction materials are fully mixed in the reactor by the internal stirring paddle, the temperature of the reactor is controlled at 90 °C by electric heating, the reaction pressure is atmospheric pressure, and the water generated during the reaction is continuously removed by the water-carrying agent. After reacting for 100 min, the heating is stopped and the target product is collected. The analysis results of the crude ε-caprolactone show that the conversion rate of cyclohexanone in this process is 85.6%, and the selectivity of ε-caprolactone is 92.5%.

[0146] As can be seen from Table 1, the reaction residence time of Example 1 is much shorter than that of Comparative Example 1. Compared with Comparative Example 1, the reaction time of Example 1 is only 10% of it, indicating that the method described in the present invention can greatly improve the device productivity.

[0147] [Comparative Example 2] The synthesis of ε-caprolactone was carried out by a two-step method in a microchannel reactor

[0148] (1) Device setup: Two sets of G1 microchannel reaction devices from Corning, USA were connected in series. The characteristic size of the channels was 300 microns, and the main body was made of special borosilicate glass. The liquid holdup of the reactor was 8.2 ml, and the above device was temperature-controlled by means of heat transfer oil.

[0149] (2) Preparation of peroxyacid: 70% hydrogen peroxide was used as the oxidant, and the flow rate ratio of acetic anhydride to hydrogen peroxide was controlled at 1.4:1. After the two streams of materials were fully preheated, they entered the reaction zone of the microchannel reactor for mixing reaction. The reaction temperature was set at 40 °C, and the residence time of the reaction materials was controlled at 180 s by adjusting the flow rate of the metering pump and the length of the microchannel. The materials were collected from the outlet of the microchannel reaction system, and the obtained peracetic acid had a mass fraction of 21.1%.

[0150] (3) Preparation of ε-caprolactone: The peroxyacid solution prepared above and the raw material cyclohexanone were respectively fed into the preheating zone of the device by metering pumps. After the two streams of materials were fully preheated, they entered the reaction zone for mixing reaction. The mixing reaction was carried out at a set temperature of 80 °C, and the molar ratio of peroxyacid to cyclohexanone was 1.3:1. The residence time of the reaction materials was controlled at 400 s by adjusting the flow rate of the pump. The oxidation product was continuously discharged from the outlet and collected in a product collector. The product was analyzed by GC, and the conversion rate of the raw material cyclohexanone was 85.4%, and the selectivity of ε-caprolactone was 92.2%.

[0151] As can be seen from Table 1, the concentration of hydrogen peroxide used as the oxidant in Example 1 is much lower than that in Comparative Example 2, and at the same time the process is greatly simplified. Compared with Comparative Example 2, it has great advantages in terms of process simplicity and process safety.

Claims

1. A method for synthesizing ε-caprolactone using a microchannel device, wherein the microchannel device includes a micromixer (a) and a microreactor (b), and The outlet of the micro mixer is connected to the side inlet of the micro reactor through a connecting pipeline (7). The micro mixer includes: an aqueous phase raw material inlet (1), an oil phase raw material inlet (2), a mixing channel (3), a micro sieve hole (4), a mixer sleeve (5), and a mixer nozzle (6). The micro reactor includes: a gas phase product outlet (8), a liquid phase raw material inlet (9), a reactor outer wall (10), a reaction channel (11), a heating pipe wall (12), a liquid phase product outlet (13), a gas phase raw material inlet (14), and a heating medium inlet (15). The number of the micro mixers (a) is greater than or equal to 2; the micro mixers (a) are located at symmetrical positions on both sides of the micro reactor (b), and the included angle between the central axis of the micro mixer and the central axis of the micro reactor is 30 - 150°. The method includes the following steps: 1) The aqueous phase raw material and the oil phase raw material are preheated by a preheater, and the preheating temperature is 40 - 60°C. The aqueous phase raw material includes a homogeneous catalyst and an oxidant, and the oil phase raw material includes cyclohexanone and a water-carrying agent. 2) The homogeneous catalyst and the oxidant enter the mixer nozzle (6) through the aqueous phase raw material inlet (1), are dispersed through the micro sieve hole (4), and contact with cyclohexanone and the water-carrying agent entering from the oil phase raw material inlet (2) in the mixing channel (3). The oxidant is selected from hydrogen peroxide, tert-butyl hydroperoxide, peracetic acid, and perpropionic acid; the water-carrying agent is selected from benzene, toluene, ethyl propionate, ethyl acetate, carbon tetrachloride, or dichloroethane. 3) The liquid phase raw material obtained at the outlet of the micro mixer (a) contains cyclohexanone, an oxidant, a homogeneous catalyst, and a water-carrying agent; the liquid phase raw material enters the micro reactor (b) through the connecting pipeline (7) from the liquid phase raw material inlet (9), and the liquid phase raw material contacts the gas phase raw material entering from the gas phase raw material inlet (14) countercurrently in the reaction channel (11), and the heat required for the reaction is provided by the heating medium in the heating pipe wall (12); the gas phase raw material is selected from air, nitrogen, helium, and argon. 4) The liquid phase product of the micro reactor (b) is discharged from the liquid phase product outlet (13). The liquid phase product contains ε-caprolactone, cyclohexanone, a homogeneous catalyst, and a water-carrying agent. The gas phase product carries the water-carrying agent and water and is discharged from the gas phase product outlet (8), and after cooling, the water-carrying agent is recovered through oil-water separation and recycled. The homogeneous catalyst is selected from the coordination compound of tungstate and oxalic acid. The micro sieve hole (4) is selected from a folded micro sieve hole, a ladder-shaped micro sieve hole, and a Z-shaped micro sieve hole.

2. The method according to claim 1, wherein, The included angle between the central axis of the micro mixer and the central axis of the micro reactor is 60 - 120°.

3. The method according to claim 1, wherein, The mixing channel (3) in the micro mixer (a) is an annular space I with an annular gap distance of 10 - 1000 microns formed between the mixer sleeve (5) and the mixer nozzle (6).

4. The method according to claim 3, wherein, The annular gap distance is 50 - 750 microns.

5. The method according to claim 4, wherein The annular gap distance is 400 - 600 microns.

6. The method according to claim 1, wherein The folded micro sieve holes (4) are distributed on the side surface of the columnar body of the mixer nozzle (6), the hydraulic diameter is 5 - 500 microns, the hole spacing is 50 - 5000 microns, and the folded angle is 20 - 160°.

7. The method according to claim 1, wherein The hydraulic diameter of the folded micro sieve holes (4) is 20 to 200 microns, the hole pitch is 100 to 1000 microns, and the folding angle is 60 to 120°.

8. The method according to claim 1, wherein, The liquid-phase raw material inlet (9) of the microreactor is a folded baffle with an inclination angle of 5 to 45°. An annular gap space II with an annular gap distance of 100 to 500 microns is formed between the end of the folded baffle and the outer wall (10) of the microreactor. The reaction channel (11) is an annular gap space III with an annular gap distance of 500 to 5000 microns formed between the heating tube wall (12) and the outer wall (10) of the reactor.

9. The method according to claim 8, wherein An annular gap space II with an annular gap distance of 200 to 300 microns is formed between the end of the folded baffle and the outer wall (10) of the microreactor. The reaction channel (11) is an annular gap space III with an annular gap distance of 1000 to 4000 microns formed between the heating tube wall (12) and the outer wall (10) of the reactor.

10. The method according to claim 8, wherein, The reaction channel (11) is an annular gap space III with an annular gap distance of 2000 to 3000 microns formed between the heating tube wall (12) and the outer wall (10) of the reactor.

11. The method according to claim 1, wherein, The oxidant is selected from hydrogen peroxide and peroxypropionic acid.

12. The method according to claim 11, wherein The oxidant is selected from hydrogen peroxide.

13. The method according to claim 1, wherein The water-carrying agent is selected from toluene and ethyl propionate.

14. The method according to claim 1, wherein The gas-phase raw material is selected from nitrogen and helium.

15. The method according to claim 1, wherein, During the reaction, the volume ratio of the gas-phase raw material to the liquid-phase raw material is (1 to 30):1, the reaction temperature is 50 to 150 °C, the reaction pressure is -0.1 to 0.1 MPa, and the residence time is 0.5 to 30 min.

16. The method according to claim 1, wherein, Calculated by mass percentage, the content of the oxidant in the aqueous-phase raw material is 10% to 70%.

17. The method according to claim 16, wherein, Calculated by mass percentage, the content of the oxidant in the aqueous-phase raw material is 20% to 50%.

18. The method according to claim 1, wherein The mass percentage content of the catalyst in the aqueous-phase raw material is 0.1 to 5.0%, and the molar ratio of oxalic acid to sodium tungstate is 1.0 to 2.

0.

19. According to the method described in claim 1, the mass percentage content of the water-carrying agent in the oil-phase raw material is 20 to 80%.

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