Micro-channel reaction device and system and application thereof

Abstract

The invention relates to the field of chemical equipment, in particular to a microchannel reaction device and system and application thereof. The reaction device comprises a reaction unit, the reaction unit comprises a first feeding main pipe, a second feeding main pipe, a discharging main pipe and at least two snakelike reaction pipes located between the first feeding main pipe and the discharging main pipe, a feeding end and a discharging end are formed at the two ends of each snakelike reaction pipe respectively, and the first feeding main pipe and the second feeding main pipe are communicated with each other. The discharging end of each S-shaped reaction pipe is communicated with the discharging main pipe, the feeding end of each S-shaped reaction pipe extends to the first feeding main pipe to form a first feeding branch pipe, the included angle between the axes of the first feeding branch pipes of any two S-shaped reaction pipes is not smaller than 20 degrees, and the included angle between the axes of the second feeding branch pipes of any two S-shaped reaction pipes is not smaller than 20 degrees. Any first feeding branch pipe is communicated with a second feeding branch pipe extending out of the second feeding main pipe. According to the device structure, reaction materials can be fully mixed, the intersolubility of the reaction materials is enhanced, and the reaction efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of chemical equipment, and particularly to a microchannel reaction device and system and their applications. Background Art

[0002] The olefin hydration reaction is a common process for preparing alcohols from olefins in industry. However, since olefins are non-polar compounds and water is a strongly polar compound, the mutual solubility between the two is small, resulting in a low conversion rate of olefins. In industry, the pressure required for the olefin hydration reaction usually reaches above 6 MPa, aiming to increase the solubility of olefins in water. In the prior art, olefins and water enter a tower reactor through a conventional mixing method and pass through multiple non-fixed catalyst beds filled with resin. The single-pass conversion rate of olefins is low. For example, the single-pass conversion rate of butene is generally 6-10%. To increase the total conversion rate of olefins, a large amount of olefins usually needs to be recycled, resulting in high energy consumption and material consumption of the device, and ultimately affecting the economy of the product. In addition, since the catalyst is in a moving state, the catalyst is easily damaged, affecting the service life of the catalyst, and at the same time, it is easy to block the water caps in the reaction tower, increasing the pressure drop of the tower.

[0003] CN114425286A discloses an olefin hydration reaction system and method. Two streams of materials containing olefins and water are cut by a number of microchannels composed of lipophilic fiber filaments and hydrophilic fiber filaments, then subjected to impinging mixing, and then introduced into a four-stage tubular reactor for hydration reaction. In this invention, water and olefins are respectively atomized into micron-sized small droplets, and the dispersion is relatively uniform. The single-pass conversion rate of C4 olefins > 63%. However, with the increase of the residence time, a certain degree of stratification phenomenon will inevitably still occur between the water phase and the oil phase.

[0004] CN114505017A discloses an olefin hydration reaction device and hydration method. Two streams of materials with different water-olefin ratios enter a tower reactor respectively after being cut by a number of microchannels composed of lipophilic fiber filaments and hydrophilic fiber filaments. The reactor is filled with four catalyst beds. The single-pass conversion rate of propylene is about 94%, the single-pass conversion rate of n-butene is about 50%, and the single-pass conversion rate of isobutene is about 98%.

[0005] CN114471378A discloses that olefins and water are mixed and enter a tower reactor filled with fiber filaments with different characteristics. The hydration reaction is promoted by strengthening the mixing and multi-stage water replenishment. The single-pass conversion rate of propylene > 88%, the single-pass conversion rate of n-butene > 32%, and the single-pass conversion rate of isobutene > 94%.

[0006] It can be seen that by enhancing the solubility of olefins in water, the progress of the reaction can be effectively promoted. However, the above reaction process is still relatively complex, and the miscibility of olefins and water will inevitably show different degrees of stratification as the disturbance decreases and the residence time is too long, resulting in a certain limitation on the hydration conversion rate of olefins.

[0007] CN101402549B discloses that on the basis of the existing process for directly hydrating lower olefins to produce lower alcohols, polyethylene glycol accounting for 0.5-5% of the mass of olefins is added to the reaction water as a reaction aid, and a single-stage or two-stage fixed-bed reactor is used, so that the olefin conversion rate is increased by 1.5-3.5%, but the capacity is limited. Summary of the Invention

[0008] The object of the present invention is to overcome the problem of low raw material conversion rate caused by insufficient mixing of microchannel reaction materials in the prior art, and to provide a microchannel reaction device and system and their applications. The device has the characteristics of being able to fully mix reaction materials and enhance the miscibility of reaction materials. At the same time, the volume of the reactor is reduced, the circulation amount of raw materials and the material and energy consumption of the whole process are greatly reduced, and the production efficiency is improved.

[0009] To achieve the above object, in the first aspect of the present invention, a microchannel reaction device is provided. The reaction device includes: a reaction unit, including a first feed main pipe, a second feed main pipe and a discharge main pipe, and a serpentine reaction pipe located between the first feed main pipe and the discharge main pipe. There are at least two serpentine reaction pipes, and both ends of each serpentine reaction pipe are respectively formed into a feed end and a discharge end. Among them, the discharge end of each serpentine reaction pipe is communicated with the discharge main pipe, and the feed end of each serpentine reaction pipe extends to the first feed main pipe to form a first feed branch pipe. Among them, the included angle between the axes of the first feed branch pipes of any two serpentine reaction pipes is not less than 20°, and a second feed branch pipe extending from the second feed main pipe is communicated on any first feed branch pipe.

[0010] In the second aspect of the present invention, a microchannel reaction system is provided. The system includes: at least one stage of microchannel reaction devices connected in an alternating manner and a product collection unit; a first feed unit, communicating with the first feed main pipe of the first microchannel reaction device; a second feed unit, communicating with the second feed main pipe of any microchannel reaction device; the product collection unit is communicated with the discharge main pipe of the microchannel reaction device, and is provided with an organic phase discharge port and an aqueous phase discharge port. Optionally, the organic phase discharge port is communicated with the first feed main pipe of the next-stage microchannel reaction device; among them, the microchannel reaction device is the microchannel reaction device described in the first aspect.

[0011] In the third aspect of the present invention, an application of the described device and the described system in the olefin hydration reaction is provided.

[0012] Through the above technical solutions, the present invention has the following advantages:

[0013] The device structure of the present invention enables the reaction materials to be fully mixed, enhances the mutual solubility of the reaction materials, improves the reaction efficiency, reduces the volume of the reactor at the same time, greatly reduces the recycle amount of raw materials and the material and energy consumption of the entire process, and improves the production efficiency; effectively reduces the reaction pressure, is simple to operate, safe to use, and suitable for industrial production.

[0014] Applying the device of the present invention to the olefin hydration reaction effectively enhances the mutual solubility of olefins and water, makes the olefins and water present an emulsified state, and greatly improves the single-pass conversion rate of olefins. Description of the Drawings

[0015] Figure 1 is a schematic diagram of a microchannel reaction system and process according to a preferred embodiment of the present invention;

[0016] Figure 2 is a schematic diagram of the internal structure of a microchannel reactor according to a preferred embodiment of the present invention.

[0017] Description of the Reference Numerals

[0018] 1 - First raw material tank, 2 - Second raw material tank, 3 - Microchannel reactor, 4 - First product collection tank, 5 - First metering pump, 6 - Second metering pump, 7 - Heating layer, 8 - Insulation layer, 9 - Olefin, 10 - Aqueous solution of auxiliary agent, 11 - First reaction product, 12 - First organic phase, 13 - First aqueous phase, 14 - Catalyst. Detailed Embodiments

[0019] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0020] The present invention provides a microchannel reaction device, which comprises: a reaction unit including a first main feed pipe, a second main feed pipe, a discharge main pipe, and a serpentine reaction pipe located between the first main feed pipe and the discharge main pipe. At least two serpentine reaction pipes are provided, and both ends of each serpentine reaction pipe are respectively formed into a feed end and a discharge end. Among them, the discharge end of each serpentine reaction pipe is communicated with the discharge main pipe, and the feed end of each serpentine reaction pipe extends to the first main feed pipe to form a first feed branch pipe. Among them, the included angle between the axes of the first feed branch pipes of any two serpentine reaction pipes is not less than 20°, and a second feed branch pipe extending from the second main feed pipe is communicated on any first feed branch pipe.

[0021] The device structure of the present invention can enable the reaction materials to be fully mixed, enhance the mutual solubility of the reaction materials, improve the reaction efficiency, reduce the volume of the reactor at the same time, greatly reduce the circulation amount of raw materials and the material and energy consumption of the whole process, and improve the production efficiency.

[0022] According to a preferred embodiment of the present invention, along the extending direction, the included angle between the axes of the first feed branch pipes of any two serpentine reaction pipes can be, for example, 20°, 30°, 45°, 60°, 75°, 90°, 120°, preferably 30 - 120°.

[0023] According to a preferred embodiment of the present invention, 2 - 4 serpentine reaction pipes are provided.

[0024] According to a preferred embodiment of the present invention, along the material flow direction, the included angle between the axis of the second main feed pipe and the axis of the first main feed pipe is not greater than 90°, and can be, for example, 30°, 45°, 60°, 75°, 90°, preferably 45° - 90°, more preferably 90°. By adopting the foregoing preferred scheme, the full mixing of raw materials can be further realized and the reaction efficiency can be improved.

[0025] According to a preferred embodiment of the present invention, any arc of any serpentine reaction pipe is a short arc intercepted by the corresponding circle at the diameter wherein. By adopting the foregoing preferred scheme, the full mixing of raw materials can be further realized and the reaction efficiency can be improved.

[0026] According to a preferred embodiment of the present invention, any arc of each serpentine reaction pipe is the same, and preferably any arc of each serpentine reaction pipe is the same.

[0027] According to a preferred embodiment of the present invention, the diameter of the circle corresponding to any arc of any serpentine reaction pipe is twice the equivalent diameter of the serpentine reaction pipe.

[0028] According to a preferred embodiment of the present invention, the short arcs on any of the serpentine reaction tubes are tangentially connected in a peak-valley shape, and the number of short arcs ≥ 3. By adopting the foregoing preferred solution, the sufficient mixing of raw materials can be further achieved, and the reaction efficiency can be improved.

[0029] According to a preferred embodiment of the present invention, the equivalent diameter of the first main feed pipe is 1-8 mm.

[0030] According to a preferred embodiment of the present invention, the equivalent diameter of the first feed branch pipe is 0.5-4 mm.

[0031] According to a preferred embodiment of the present invention, the equivalent diameter of the serpentine reaction tube is 0.8-5 mm.

[0032] According to a preferred embodiment of the present invention, the equivalent diameter of the discharge main pipe is 2-10 mm.

[0033] According to a preferred embodiment of the present invention, the equivalent diameter of the second main feed pipe is 1-8 mm.

[0034] According to a preferred embodiment of the present invention, the equivalent diameter of the second feed branch pipe is 0.5-3 mm.

[0035] According to a preferred embodiment of the present invention, the reaction unit further includes: a heating unit, which is arranged to wrap the reaction unit and is used to provide heat for the reaction unit. Heat is conducted between the inner wall of the reaction unit and the outer wall of the serpentine reaction tube through a heat-conducting medium, and the heat-conducting medium can be water or water vapor or heat-conducting oil.

[0036] According to a preferred embodiment of the present invention, the reaction unit further includes: a heat-insulating unit, which is arranged closely to the heating unit and is used to prevent heat dissipation in the device.

[0037] According to a preferred embodiment of the present invention, the inner wall of any reaction tube is coated with a solid catalyst. By adopting the foregoing preferred solution, the distance for the raw materials to enter the catalyst bed layer can be shortened, and sufficient mixing and in-situ reaction can be achieved.

[0038] In the present invention, the coating method can be a conventional method in the art. For example, the method is to grind the solid catalyst into powder with a certain particle size, suspend it in a liquid-phase solvent to form a catalyst slurry, and pass it through a microchannel reactor at a certain temperature to immobilize it on the inner wall of the reaction zone, and repeat at least 3 times. Subsequently, it is washed with water to remove the catalyst particles that are not firmly immobilized. In the present invention, the thickness of the catalyst coating layer is not higher than the equivalent diameter of the reaction zone of the microchannel reactor.

[0039] According to a preferred embodiment of the present invention, the solid catalyst is selected from one or two of strongly acidic cation exchange resins and solid acids, such as sulfonic acid resin and HZSM-5 catalyst.

[0040] According to a preferred embodiment of the present invention, the particle size of the solid catalyst is 200-300 mesh.

[0041] The present invention provides a microchannel reaction system, which includes: at least one stage, preferably 1-4 stages of alternately connected microchannel reaction devices and a product collection unit; a first feed unit connected to the first main feed pipe of the first microchannel reaction device; a second feed unit connected to the second main feed pipe of any one of the microchannel reaction devices; the product collection unit is connected to the discharge main pipe of the microchannel reaction device and is provided with an organic phase discharge port and an aqueous phase discharge port. Optionally, the organic phase discharge port is connected to the first main feed pipe of the next-stage microchannel reaction device; wherein, the microchannel reaction device is the microchannel reaction device of the present invention.

[0042] According to a preferred embodiment of the present invention, the organic phase discharge port of the product collection unit of the last stage is connected to a distillation device to obtain an organic phase recycle material and part of the product.

[0043] According to a preferred embodiment of the present invention, the aqueous phase discharge port of the product collection unit of any stage is connected to a distillation device to obtain a recycle material and part of the product.

[0044] The present invention provides an application of the described device and the described system in the olefin hydration reaction.

[0045] Using the device of the present invention in the olefin hydration reaction effectively enhances the mutual solubility of olefins and water, makes the olefins and water present an emulsified state, and greatly improves the single-pass conversion rate of olefins.

[0046] The present invention provides an olefin hydration method, which is carried out in the device of the present invention and includes: an olefin raw material is introduced into a serpentine reaction tube through a first main feed pipe and contacts with an aqueous phase containing an auxiliary agent from a second main feed pipe in the serpentine reaction tube for a hydration reaction; the auxiliary agent includes an emulsifier with an HLB value of 10-20 and optionally a water-soluble diol reagent with a carbon number ≥4.

[0047] In the method of the present invention, using an emulsifier with an HLB value of 10-20 can achieve more prominent reaction effects compared with the traditional use of a water-soluble diol reagent with a carbon number ≥4 due to its unique action mode.

[0048] According to a preferred embodiment of the present invention, the emulsifier is selected from at least one of Tween, nonylphenol polyoxyethylene ether compounds, and alkylphenol polyoxyethylene ether compounds, preferably at least one of Tween 20, Tween 40, Tween 60, Tween 80, nonylphenol polyoxyethylene ether - 10, nonylphenol polyoxyethylene ether - 15, and alkylphenol polyoxyethylene ether - 10.

[0049] According to a preferred embodiment of the present invention, the water - soluble diol reagent with a carbon number ≥ 4 is selected from at least one of diethylene glycol, triethylene glycol, polyethylene glycol 400, and polyethylene glycol 600.

[0050] As Figure 1 shown, it is a schematic diagram of the microchannel reaction system and process of a preferred embodiment of the present invention. The reaction system includes:

[0051] A microchannel reactor 3, and a first raw material tank 1 connected to the first main feed pipe of the microchannel reactor 3, with a first metering pump 5 arranged on the connecting pipeline; a second raw material tank 2 connected to the second main feed pipe of the microchannel reactor 3, with a second metering pump 6 arranged on the connecting pipeline; and a first product collection tank 4 connected to the discharge main pipe of the microchannel reactor 3.

[0052] The reaction process includes: The first raw material (olefin 9) is injected into the microchannel reactor 3 from the first raw material tank 1, and the second raw material (auxiliary aqueous solution 10) is injected into the microchannel reactor 3 from the second raw material tank 2. The two raw materials collide, mix, and react to obtain a first reaction product 11, which is sent to the first product collection tank 4 for oil - water two - phase separation to obtain a first aqueous phase 13 and a first organic phase 12.

[0053] As Figure 2 described, it is a schematic diagram of the internal structure of a microchannel reactor of a preferred embodiment of the present invention. The main feed inlet of the microchannel reactor is connected to multiple feed branch pipes. The internal channel is a circular channel. The two feed branch pipes form a certain angle along the direction of liquid flow. The liquid inlet is distributed in an umbrella shape and is divided into 2 paths. Two vertical (radial) feed inlets are arranged at the end of the liquid distribution area (the ends of the two feed branch pipes). The reaction area is serpentine, and the inner wall of the reaction tube is coated with a catalyst 14. The diameter of the axial inlet flow channel of the microchannel reactor is 1 - 8 mm, the diameter of the axial umbrella - shaped distribution flow channel is 0.5 - 4 mm, the diameter of the serpentine reaction channel is 0.8 - 5 mm, the diameter of the axial outlet flow channel is 2 - 10 mm, and the diameter of the radial flow channel is 0.5 - 3 mm. The short arc of the serpentine reaction area is the short arc intercepted at the diameter of a circle with a diameter of 1.6 - 10 mm. The number of short arcs is not less than 3, and they are connected in a peak - valley shape. The inner wall of any reaction tube is coated with a solid catalyst. A heating layer 7 is closely attached to the outside of the microchannel reactor, and a heat - insulating layer 8 is closely attached to the heating layer. The short arc is the short arc intercepted at the diameter of a circle with a diameter of 1.6 - 10 mm. The number of short arcs is not less than 3 and they are connected in a peak - valley shape. The inner wall of any reaction tube is coated with a solid catalyst. A heating layer 7 is closely attached to the outside of the microchannel reactor, and a heat - insulating layer 8 is closely attached to the heating layer.

[0054] The present invention will be described in detail below through examples. In the following examples, the contents of olefins and alcohol products are measured by gas chromatography, and the corresponding conversion rates and selectivities are obtained by stoichiometry; unless otherwise specified, the raw materials are all commercially available products.

[0055] Example 1

[0056] exist Figure 1 , Figure 2 The device shown in the figure is carried out. The microchannel reactor used in this embodiment has two feed main pipes, the internal channel is a circular channel, the first feed main pipe is connected to two umbrella-shaped feed branches, the angle between the two feed branches is 90°, and a vertical (radial) feed port is set at the end of the liquid distribution area, that is, the branch extending from the second feed main pipe, the two feed main pipe flow channels present a 90° angle, the reaction zone is serpentine, and the inner wall of the reaction tube is coated with a high temperature resistant sulfonic acid resin (the coating thickness is not higher than the equivalent diameter of the reaction zone of the microchannel reactor). The microchannel reactor has an axial (first) feed main pipe with an equivalent diameter of 5 mm, an umbrella-shaped distribution channel (first feed branch) with an equivalent diameter of 2.5 mm, a serpentine reaction channel with an equivalent diameter of 4 mm, an axial outlet channel (discharge main pipe) with an equivalent diameter of 7 mm, a second feed main pipe inlet channel with a diameter of 5 mm, and a (second) feed branch channel with an equivalent diameter of 2 mm. The short arc of the serpentine reaction zone is equivalent to a circle with a diameter of 8 mm. The short arcs intercepted at the equivalent diameter are 6 in number and are tangentially connected in a peak-to-valley shape. The olefin hydration reactor of the present invention is applied to the hydration reaction of n-butene.

[0057] The process includes: a C4 raw material containing n-butene is fed into the first feed main pipe in the microchannel reactor through a metering pump, and an aqueous solution containing 3wt% Tween 80 enters the radial channel in the microchannel reactor. The two streams collide and quickly enter the reaction zone coated with a catalyst for hydration reaction, and then converge at the outlet and enter the first collection tank for stratification, wherein the upper layer is an olefin organic phase and the lower layer is an aqueous phase. The upper organic phase then enters the next-stage microchannel reactor to repeat the two-stage hydration reaction.

[0058] The conditions included: the molar ratio of water to butene was 2.5:1 in the first-stage microchannel reaction system and 2.4:1 in the second-stage microchannel reaction system, the hydration reaction temperature was 150°C, the pressure was 6 MPa, and the feed space velocity (based on the volume of the supported catalyst) was 1.5 h -1 The reaction results are shown in Table 1.

[0059] Example 2

[0060] The microchannel reactor used in this embodiment has a total of two main feed inlets. The internal channel is a circular channel. The first main feed inlet is connected to 3 feed branches distributed in an umbrella shape, and the included angle between two adjacent feed branches is 45°. A vertical feed inlet, that is, a branch pipe extended from the second main feed inlet, is respectively arranged at the end of the liquid distribution area. The flow channels of the two main feed inlets present an included angle of 60°. The reaction area is serpentine, and the inner wall of the reaction tube is coated with high-temperature resistant sulfonic acid resin. The equivalent diameter of the axial (first) main feed inlet of the microchannel reactor is 5 mm, the equivalent diameter of the umbrella-shaped distributed flow channel (the first feed branch) is 2.8 mm, the equivalent diameter of the serpentine reaction channel is 4.2 mm, the equivalent diameter of the axial outlet flow channel (the discharge main pipe) is 7 mm, the diameter of the inlet flow channel of the second main feed inlet is 5 mm, and the equivalent diameter of the flow channel of the (second) feed branch is 2.5 mm. The short arc of the serpentine reaction area is the short arc intercepted at the 1 / 7 equivalent diameter of the circle with an equivalent diameter of 8.4 mm. The number of short arcs is 6, and they are tangent-connected in a peak-valley shape. The olefin hydration reactor of the present invention is applied to the n-butene hydration reaction.

[0061] The reaction process and reaction conditions are the same as those in Example 1. The reaction results are shown in Table 1.

[0062] Example 3

[0063] The microchannel reactor used in this embodiment has a total of two main feed inlets. The internal channel is a circular channel. The first main feed inlet is connected to 4 feed branches distributed in an umbrella shape, and the included angle between two adjacent feed branches is 30°. A vertical feed inlet, that is, a branch pipe extended from the second main feed inlet, is respectively arranged at the end of the liquid distribution area. The flow channels of the two main feed inlets present an included angle of 45°. The reaction area is serpentine, and the inner wall of the reaction tube is coated with high-temperature resistant sulfonic acid resin. The equivalent diameter of the axial (first) main feed inlet of the microchannel reactor is 4 mm, the equivalent diameter of the umbrella-shaped distributed flow channel (the first feed branch) is 2.4 mm, the equivalent diameter of the serpentine reaction channel is 4 mm, the equivalent diameter of the axial outlet flow channel (the discharge main pipe) is 6 mm, the diameter of the inlet flow channel of the second main feed inlet is 4 mm, and the equivalent diameter of the flow channel of the (second) feed branch is 2 mm. The short arc of the serpentine reaction area is the short arc intercepted at the 1 / 5 diameter of the circle with an equivalent diameter of 8 mm. The number of short arcs is 6, and they are tangent-connected in a peak-valley shape. The olefin hydration reactor of the present invention is applied to the n-butene hydration reaction.

[0064] The reaction process and reaction conditions are the same as those in Example 1. The reaction results are shown in Table 1.

[0065] Example 4

[0066] The microchannel reactor used in this embodiment is the same as that in Example 1, except that the included angle between two adjacent feed branches is 20°.

[0067] The reaction process and reaction conditions are the same as those in Example 1. The reaction results are shown in Table 1.

[0068] Example 5

[0069] The microchannel reactor used in this example is the same as that in Example 1, except that the short circular arc in the serpentine reaction zone is the short circular arc intercepted at 1 / 15 of the diameter of a circle with an equivalent diameter of 8 mm.

[0070] The reaction process and reaction conditions are the same as those in Example 1. The reaction results are shown in Table 1.

[0071] Example 6

[0072] The microchannel reactor used in this example is the same as that in Example 1. The difference is that the olefin is propylene, the aqueous phase is an aqueous solution containing 2 wt% Tween 60, and the reaction conditions are that the molar ratio of water to propylene is 6:1 in the first-stage microchannel reaction system and 5.8:1 in the second-stage microchannel reaction system, the hydration reaction temperature is 140 °C, the pressure is 6 MPa, and the feed space velocity (based on the volume of the supported catalyst) is 0.5 h -1 . The reaction results are shown in Table 1. The reaction results are shown in Table 1.

[0073] Example 7

[0074] The microchannel reactor used in this example is the same as that in Example 1. The difference is that the olefin is isobutene, the aqueous phase is an aqueous solution containing 2 wt% Tween 60, and the reaction conditions are that the molar ratio of water to isobutene is 1.6:1 in the first-stage microchannel reaction system and 1.4:1 in the second-stage microchannel reaction system, the hydration reaction temperature is 90 °C, the pressure is 3 MPa, and the feed space velocity (based on the volume of the supported catalyst) is 2 h -1 . The reaction results are shown in Table 1. The reaction results are shown in Table 1.

[0075] Comparative Example 1

[0076] The microchannel reactor used in this comparative example is the same as that in Example 1, except that the first feed main pipe does not have feed branch pipes and is directly connected to a serpentine pipe.

[0077] The reaction process and reaction conditions are the same as those in Example 1. The reaction results are shown in Table 1.

[0078] Comparative Example 2

[0079] The microchannel reactor used in this comparative example is the same as that in Example 1, except that the second feed main pipe is not provided, and the olefin phase and the aqueous phase enter the first feed main pipe simultaneously.

[0080] The reaction process and reaction conditions are the same as those in Example 1. The reaction results are shown in Table 1.

[0081] Comparative Example 3

[0082] The microchannel reactor used in this comparative example is the same as that in Example 1, except that the reaction zone is linear.

[0083] The reaction process and reaction conditions are the same as those in Example 1. The reaction results are shown in Table 1.

[0084] Table 1 Olefin hydration reaction results of each example and comparative example

[0085] Olefin molar conversion rate (%) Alcohol selectivity (%) Example 1 88.52 97.61 Example 2 85.74 97.92 Example 3 86.06 97.64 Example 4 85.11 97.55 Example 5 83.23 97.43 Example 6 98.47 99.81 Example 7 95.54 97.32 Comparative Example 1 78.41 97.38 Comparative Example 2 71.89 97.59 Comparative Example 3 65.94 97.48

[0086] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the technical concept scope of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A microchannel reaction device, characterized in that, the reaction device comprises: a reaction unit, including a first main feed pipe, a second main feed pipe, a discharge main pipe, and a serpentine reaction pipe located between the first main feed pipe and the discharge main pipe. There are at least two serpentine reaction pipes. The two ends of each serpentine reaction pipe are respectively formed into a feed end and a discharge end. Among them, the discharge end of each serpentine reaction pipe is communicated with the discharge main pipe, and the feed end of each serpentine reaction pipe extends to the first main feed pipe to form a first feed branch pipe. Among them, the included angle between the axes of the first feed branch pipes of any two serpentine reaction pipes is not less than 20°, and a second feed branch pipe extending from the second main feed pipe is communicated on any first feed branch pipe.

2. The device according to claim 1, wherein, there are 2 - 4 serpentine reaction pipes; and / or the included angle between the axes of the first feed branch pipes of any two serpentine reaction pipes is 30° - 120°; and / or the included angle between the axis of the second main feed pipe and the axis of the first main feed pipe is not greater than 90°, preferably 45° - 90°.

3. The device according to claim 1 or 2, wherein, Any radian of any of the serpentine reaction tubes is the short circular arc intercepted by the corresponding circle at the diameter at the place; preferably, any radian of each serpentine reaction pipe is the same, and more preferably any radian of each serpentine reaction pipe is the same.

4. The device according to any one of claims 1 - 3, wherein, the diameter of the circle corresponding to any radian of any serpentine reaction pipe is twice the equivalent diameter of the serpentine reaction pipe; the short circular arcs on any serpentine reaction pipe are connected in a peak-valley tangential manner, and the number of short circular arcs ≥ 3.

5. The device according to any one of claims 1 - 4, wherein, the equivalent diameter of the first main feed pipe is 1 - 8 mm; and / or the equivalent diameter of the first feed branch pipe is 0.5 - 4 mm; and / or the equivalent diameter of the serpentine reaction pipe is 0.8 - 5 mm; and / or the equivalent diameter of the discharge main pipe is 2 - 10 mm; and / or the equivalent diameter of the second main feed pipe is 1 - 8 mm; and / or the equivalent diameter of the second feed branch pipe is 0.5 - 3 mm.

6. The device according to any one of claims 1 - 5, wherein, the reaction unit further comprises: a heating unit, which is arranged to wrap the reaction unit and is used to provide heat for the reaction unit; a heat preservation unit, which is arranged closely to the heating unit and is used to prevent heat dissipation in the device.

7. The device according to any one of claims 1 - 6, wherein, the inner wall of any reaction pipe is coated with a solid catalyst; preferably, the solid catalyst is selected from one or two of strongly acidic cation resin and solid acid; more preferably, the particle size of the solid catalyst is 200 - 300 mesh.

8. A microchannel reaction system, characterized in that, the system comprises: at least one stage of microchannel reaction devices and a product collection unit arranged in an alternately connected manner; a first feed unit, which is connected to the first main feed pipe of the first microchannel reaction device; a second feed unit, which is connected to the second main feed pipe of any microchannel reaction device; The product collection unit is connected to the main discharge pipe of the microchannel reaction device, and is provided with an organic phase discharge port and an aqueous phase discharge port. Optionally, the organic phase discharge port is connected to the first main feed pipe of the next-stage microchannel reaction device; Wherein, the microchannel reaction device is the microchannel reaction device described in any one of claims 1-7.

9. The system according to claim 8, Wherein, The organic phase discharge port of the product collection unit of the last stage is connected to the distillation device to obtain organic phase recycled materials and part of the product; and / or The aqueous phase discharge port of any stage of the product collection unit is connected to the distillation device to obtain aqueous phase recycled materials and part of the product.

10. Use of the device according to any one of claims 1-7 and the system according to claim 8 or 9 in the olefin hydration reaction.

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