Non-symmetric heart-shaped microreactor

Abstract

The utility model relates to an unsymmetrical heart-shaped microreactor. The non-symmetric heart-shaped microreactor comprises a plurality of non-symmetric heart-shaped reaction units; the left side and the right side of the baffle in the non-symmetric heart-shaped reaction unit are unequal in length; the symmetry of two adjacent non-symmetric heart-shaped reaction units in the non-symmetric heart-shaped microreactor is opposite. The research on the mixing strength shows that the mixing strength of the asymmetric micro-reactor is higher than that of a traditional counter-called heart-shaped micro-reactor, and the mixing strength is improved by 1.93%-9.44%. The numerical simulation analysis of Fischer-Tropsch synthesis is carried out in the asymmetric structure to prove the feasibility of the asymmetric structure in the aspect of improving the reaction effect. The net generation rate of the product in the non-symmetric heart-shaped microreactor is higher, the concentration of the product is higher at the same time, and as the Fischer-Tropsch synthesis is an exothermic reaction in which the total mole number of the gas is reduced, the pressure of the non-symmetric heart-shaped microreactor is smaller, and the enthalpy change is large; the advantage of the non-symmetric heart-shaped microreactor in the aspect of improving the reaction rate is further verified.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of continuous flow microchannel reactors in chemical industry production, especially, a kind of continuous flow microreactor of changing heart-shaped microreaction unit structure;Belong to asymmetric heart-shaped microreactor. BACKGROUND

[0002] In recent years, due to microfluidic technology can be in the condition of low cost high throughput, precise control microscale fluid, improve mass transfer and heat transfer efficiency, achieve better mixing effect and obtain the advantages such as more uniform particle size distribution of microparticle, more and more received the extensive attention of all circles in the world. Continuous flow reactor can realize continuous production, provide higher product yield and better product performance, and also has more excellent performance than traditional kettle type reactor in energy saving and emission reduction, so currently continuous flow reactor is gradually replacing kettle type reactor. Microfluidic technology is applied to continuous flow reactor and creates continuous flow microchannel reactor, which combines the advantages of microfluidic technology and continuous flow reactor, and realizes industrialization in the field of chemical engineering and pharmaceutical manufacturing, and shows bright prospect. American corning company has maturely used microfluidic technology in continuous flow reactor, and manufactured heart-shaped continuous flow microreactor, and corning microchannel continuous flow reactor is also called advanced flow reactor (AFR). AFR has been successfully used in material preparation, drug synthesis and fine chemical industry. The structure diagram of corning heart-shaped continuous flow microreactor is as shown in the accompanying Figure 1 Figure.

[0003] Microreactors can be divided into active and passive reactors according to whether external energy is required. Active microreactors require external energy, such as sound waves, piezoelectric micropumps, and magnetic field induction. Since external energy is required, higher energy consumption is a relatively obvious disadvantage. Passive microreactors do not require additional external energy fields. They improve mixing efficiency by changing the size, structure of the microchannel, and physical parameters of the fluid. Therefore, passive microreactors are more popular in the market. Common microchannel structures include T-shaped microchannel reactors, flow focusing microchannel reactors, and Y-shaped microchannel reactors. Compared with the above traditional continuous flow passive microreactors, the special structure of the heart-shaped passive microreactor can increase the gas-liquid two-phase interface area and the degree of turbulence, and make the fluid fully disturbed and mixed in the flow, thereby inhibiting the occurrence of "back mixing" and improving the mass transfer efficiency. The first 10,000-ton G5 microreactor device of Corning Corporation was completed in 2020 in cooperation with Zhejiang Weihua New Material Co., Ltd. and Shanghai Huihe Hede Biological Technology Co., Ltd. Corning G5 microchannel reactor successfully completed the full continuous production of a single set of 10,000-ton pesticide intermediates, and achieved stable operation. However, the completion of a reaction usually requires flowing through multiple microreaction units, and most of the ways to improve the capacity of continuous flow microchannel reactors in industry are to continuously stack microreactor modules, which will increase the floor area and industrial cost of the microreactor. SUMMARY

[0004] The purpose of the utility model is to change the structure of the heart-shaped microreactor, improve the mixing intensity and reaction rate, and thus enable the reactants to complete the reaction in fewer microreaction units, thereby reducing costs and industrial land.

[0005] The technical scheme of the utility model is as follows:

[0006] An asymmetric heart-shaped microreactor; the asymmetric heart-shaped microreactor contains multiple asymmetric heart-shaped reaction units; the lengths of the left and right sides of the baffle in the asymmetric heart-shaped reaction unit are not equal.

[0007] The asymmetric heart-shaped microreactor; the symmetry of the two adjacent asymmetric heart-shaped reaction units in the asymmetric heart-shaped microreactor is opposite.

[0008] Figure 1 is a three-dimensional schematic diagram of an asymmetric heart-shaped microreactor structure, and the gray area in the microreactor is the fluid flow area, and the blank area is the arc-shaped baffle. Figure 2 Figure 1 is a three-dimensional schematic diagram of an asymmetric heart-shaped microreactor structure, and the gray area in the microreactor is the fluid flow area, and the blank area is the arc-shaped baffle. Figure 3 (a) shows a two-dimensional planar top view of a symmetric heart-shaped microreactor, and Figure 3(b) shows the two-dimensional planar top view of the asymmetric heart-shaped microreactor. The difference between the two is that the length of the baffle on the left and right sides of the symmetric heart-shaped microreactor is equal, while the length of the baffle on the left and right sides of the asymmetric heart-shaped microreactor is not equal, and the symmetry of the two adjacent asymmetric heart-shaped reaction units in the asymmetric heart-shaped microreactor is opposite.

[0009] The mixing intensity of the asymmetric heart-shaped microreactor within the limited range is discussed. Compared with the traditional heart-shaped symmetric heart-shaped microreactor, the mixing intensity of the symmetric heart-shaped microreactor can be increased by 1.93% to 9.44% according to the different sizes of the baffle.

[0010] Through the study of the mixing intensity, it is found that the mixing intensity of the asymmetric microreactor is higher than that of the traditional symmetric heart-shaped microreactor, so the numerical simulation analysis of the Fischer-Tropsch synthesis in the asymmetric microreactor is carried out to prove the feasibility of the asymmetric structure in improving the reaction effect. The research results show that the net generation rate of the product in the asymmetric heart-shaped microreactor is greater, and the concentration of the product is greater at the same time. Since the Fischer-Tropsch synthesis is an exothermic reaction with a decrease in the total number of moles of gas, the pressure of the asymmetric heart-shaped microreactor is smaller, and the enthalpy change is greater, which further verifies the advantage of the asymmetric heart-shaped microreactor in improving the reaction rate. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is a schematic diagram of the structure of the Corning heart-shaped continuous flow microreactor.

[0012] Figure 2 It is a schematic diagram of the structure of the three-dimensional asymmetric heart-shaped microreactor.

[0013] Figure 3 It is a two-dimensional planar top view of the symmetric heart-shaped microreactor and the two-dimensional planar top view of the asymmetric heart-shaped microreactor.

[0014] Figure 4 It is a schematic diagram of the structure of the adjacent two asymmetric heart-shaped microreaction units.

[0015] Figure 5 It is a cross section for calculating the mixing intensity, that is, the median plane of the x-y plane in the z direction

[0016] Figure 6 It is a streamline distribution diagram in the symmetric heart-shaped microreactor and the asymmetric heart-shaped microreactor perpendicular to the flow direction.

[0017] Figure 7 It is a static pressure distribution cloud chart in the symmetric heart-shaped microreactor and the asymmetric heart-shaped microreactor.

[0018] Figure 8 It is a comparison cloud chart of the net generation rate of methane in the symmetric heart-shaped microreactor and the asymmetric heart-shaped microreactor.

[0019] Figure 9 The enthalpy distribution cloud diagram of the reaction process in the symmetric heart-shaped micro-reactor and the asymmetric heart-shaped micro-reactor.

[0020] Figure 10 The methane concentration distribution cloud diagram of different time in the symmetric heart-shaped micro-reactor and the asymmetric heart-shaped micro-reactor. DETAILED DESCRIPTION

[0021] The utility model makes further detailed description in combination with the drawings, the utility model only changes the length of the baffle in the heart-shaped micro-reactor, the rest structure size is same with the prior art continuous flow micro-channel reactor, and with the heart-shaped micro-reactor containing 4 heart-shaped micro-reaction units as an example, the characteristics are same with the above-mentioned if the heart-shaped micro-reactor contains more heart-shaped micro-reaction units.

[0022] In the utility model, L0 is the length of the shorter side of the baffle, and L is the length of the longer side of the baffle, as shown in the drawings. Figure 4 As shown in the drawings. Figure 4 It is the structure schematic diagram of two adjacent asymmetric heart-shaped micro-reaction units, and the symmetry of the two adjacent asymmetric heart-shaped micro-reaction units is opposite. The range of L0 in the asymmetric heart-shaped micro-reactor is 2.17-2.2mm, and the range of L is 2.5-2.83mm. In the symmetric heart-shaped micro-reactor selected as comparison in the utility model, L0=L=2.5mm.

[0023] When the Reynolds number Re=100, the mixing intensity of the asymmetric heart-shaped micro-reactor with L0=2.17mm and L=2.5mm is increased by 2.86%, the mixing intensity of the asymmetric heart-shaped micro-reactor with L0=2.2mm and L=2.5mm is increased by 1.93%. The mixing intensity of the asymmetric heart-shaped micro-reactor with L0=2.17mm and L=2.83mm is 53.86% when the Reynolds number Re=100, which is increased by 9.44% compared with the symmetric heart-shaped micro-reactor. The mixing intensity of the asymmetric heart-shaped micro-reactor with L0=2.2mm and L=2.83mm is increased by 8.67%. The mixing intensity of the asymmetric heart-shaped micro-reactor with L0=2.185mm and L=2.665mm is increased by 5.12%.

[0024] Through the research on the mixing intensity, the asymmetric micro-reactor has good mixing effect, so the numerical simulation analysis of the Fischer-Tropsch synthesis in the asymmetric micro-reactor is carried out to prove the feasibility of the asymmetric structure in improving the reaction effect. The research results show that the net generation rate of the product in the asymmetric heart-shaped micro-reactor is larger, and the product concentration is larger at the same time. Since the Fischer-Tropsch synthesis is an exothermic reaction of total gas molar number reduction, the pressure of the asymmetric heart-shaped micro-reactor is smaller, and the enthalpy change is larger, which further verifies the advantage of the asymmetric heart-shaped micro-reactor in improving the reaction rate.

[0025] The mixing effect of the reinforced fluid in the microchannel is the key to improve the reaction effect of the continuous flow microchannel reactor. First, the mixing characteristics of salt water and fresh water in the micro reactor are analyzed by numerical simulation. The mixing intensity needs to be evaluated by the mixing efficiency in the channel. The previous research mainly evaluates the numerical mixing intensity according to the variance of the component concentration of the channel cross section, that is, the mixing intensity index is defined as the variance index of the mixing intensity of different points in the same cross section, and the calculation formula is as follows:

[0026]

[0027]

[0028] In the formula, M (0≤M≤1) is the mixing intensity of the cross section of the channel, 0 represents that no mixing occurs between components, and 1 represents that the components are completely mixed; n is the number of sampling points of the cross section concentration; ω i is the component concentration of the sampling point on the cross section; ω ∞ is the component concentration of the mixed fluid in the channel when completely mixed; τ is the standard deviation of the component concentration of the cross section; τ max is the component concentration deviation of the cross section at the initial time without mixing.

[0029] The cross section used for calculating the mixing intensity selected by the utility model is the median surface of the x-y plane in the z direction, as shown in the drawing. Figure 5

[0030] Example 1: The size of the asymmetric heart-shaped reaction unit is L0=2.17mm, L=2.5mm, and the symmetry of the adjacent two asymmetric heart-shaped reaction units is opposite;

[0031] Example 2: The size of the asymmetric heart-shaped reaction unit is L0=2.2mm, L=2.5mm, and the symmetry of the adjacent two asymmetric heart-shaped reaction units is opposite;

[0032] Example 3: The size of the asymmetric heart-shaped reaction unit is L0=2.17mm, L=2.83mm, and the symmetry of the adjacent two asymmetric heart-shaped reaction units is opposite;

[0033] Example 4: The size of the asymmetric heart-shaped reaction unit is L0=2.2mm, L=2.83mm, and the symmetry of the adjacent two asymmetric heart-shaped reaction units is opposite;

[0034] Example 5: The size of the asymmetric heart-shaped reaction unit is L0=2.185mm, L=2.665mm, and the symmetry of the adjacent two asymmetric heart-shaped reaction units is opposite.

[0035] ​When the Reynolds number Re = 100, the mixing intensity of the asymmetric heart-shaped microreactor of Example 1 increased by 2.86%, and the mixing intensity of the asymmetric heart-shaped microreactor of Example 2 increased by 1.93%. The mixing intensity of the asymmetric heart-shaped microreactor of Example 3 was 53.86% at a Reynolds number Re = 100, which was 9.44% higher than that of the symmetric heart-shaped microreactor. The mixing intensity of the asymmetric heart-shaped microreactor of Example 4 increased by 8.67%. The mixing intensity of the asymmetric heart-shaped microreactor of Example 5 increased by 5.12%.

[0036] Through the study of mixing intensity, it was found that the mixing effect of asymmetric heart-shaped microreactors was better than that of symmetric heart-shaped microreactors. Among the asymmetric heart-shaped microreactors, the asymmetric microreactor with L0 = 2.17mm and L = 2.83mm had the best mixing effect. Therefore, numerical simulation analysis of Fischer-Tropsch synthesis was carried out in it to prove the feasibility of asymmetric structure in improving reaction effect. The reaction equation is as follows:

[0037] CO+3H2=CH4+H2O

[0038] The kinetic model parameters are shown in the following table:

[0039]

[0040] Attachment Figure 6 The streamline distribution diagrams perpendicular to the flow direction in the symmetrical heart-shaped microreactor and the asymmetrical heart-shaped microreactor are shown. The streamlines in the symmetrical heart-shaped microreactor are symmetrically distributed, while the streamlines in the asymmetrical heart-shaped microreactor are asymmetrically distributed. Figure 7 The static pressure distribution cloud diagrams of the symmetrical heart-shaped microreactor and the asymmetrical heart-shaped microreactor are shown. When the pressure changes from 0.4Pa to 0.8Pa, the color of the cloud diagram changes from blue to red. By comparing the colors, it is found that the pressure in the asymmetrical microreactor is lower than that in the symmetrical microreactor. Since the reactants and products in the reaction are both gaseous, and the reaction is a reaction in which the total molar number of gas decreases, it is proved that the content of the product in the asymmetrical microreactor is higher. Figure 8 The comparison of the net methane production rate in the symmetrical heart-shaped microreactor and the asymmetrical heart-shaped microreactor is shown in the cloud chart. The methane production rate ranges from 0 to 0.014 kg / (m 3 When the value of s) changes, the color of the cloud changes from blue to red. By comparing the colors, it is found that at the same time, the net methane production rate in the asymmetric microreactor is faster. Figure 9 The enthalpy change distribution cloud diagram of the reaction process in the symmetrical heart-shaped microreactor and the asymmetrical heart-shaped microreactor is shown. Since the reaction is an exothermic reaction, the enthalpy change value is negative, and the enthalpy change ranges from -5.5×10 6When the concentration of methane changes from 0 to 2 mol / m Figure 10 The concentration distribution cloud atlas of methane in the symmetric heart-shaped micro-reactor and the asymmetric heart-shaped micro-reactor is shown, and the concentration of methane changes from 0 to 2 mol / m 3 When the concentration of methane changes from 0 to 2 mol / m

[0041] The utility model discloses and the technical scheme that is proposed, and the person skilled in the art can realize through the reference of this article content, and the condition structure such as link is changed appropriately, although the technology of the utility model has been described through the preferred embodiment, the relevant technical personnel can obviously make the technology described in this article change or recombine in the utility model content, spirit and range without departing from, to realize the final preparation technology. It is particularly pointed out that all similar replacements and changes are obvious to the person skilled in the art, and they are regarded as including in the utility model spirit, range and content.

Claims

1. An asymmetric heart-shaped microreactor; characterized in that, The asymmetric heart-shaped micro-reactor contains multiple asymmetric heart-shaped reaction units; the lengths of the left and right sides of the baffle in the asymmetric heart-shaped reaction unit are different.

2. An asymmetric heart-shaped microreactor; characterized in that, The symmetry of the two adjacent asymmetric heart-shaped reaction units in the asymmetric heart-shaped micro-reactor is opposite.

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