A method and system for testing liquid-liquid mixing performance of a reactor

Abstract

The application provides a kind of reactor liquid-liquid mixing performance test method and system, and the system is widely applicable, and high sensitivity.The main reactant acetylsalicylic acid in the application can be dissolved in organic solvent, used to characterize liquid-liquid mixing process, at the same time, since the main reaction of acetylsalicylic acid and sodium hydroxide is instantaneous reaction, the side reaction is fast reaction with similar intrinsic reaction time and molecular mixing characteristic time, thus it has high sensitivity to molecular mixing efficiency in reactor.Acetylsalicylic acid and sodium hydroxide mainly used in the application are common basic chemicals in industry and society, and the price is low.The whole operation process and analysis process are simple, and it is easy to popularize, all raw material liquids in the application can be simply dissolved after weighing during configuration, and the operation process does not need to be isolated from air, and can be suitable for reactors under various working conditions such as intermittent, semi-continuous and continuous operation.

Description

Technical Field

[0001] The present invention relates to the field of chemical engineering technology, and more specifically, to a method and system for testing liquid-liquid mixing performance of a reactor. Background Art

[0002] Reactions between liquids are widely present in the chemical industry, such as esterification, saponification, nitration, neutralization, metathesis, alkylation and other reactions. Since these reactions often have side reactions that compete with the main reaction, two or more streams of liquid materials need to achieve a good molecular mixing state in the reactor to avoid excessive local material concentration, which makes side reactions more likely to occur. When developing and comparing reactors, it is necessary to quantitatively characterize their molecular mixing properties. There are currently three main means to characterize the molecular mixing performance of reactors: optical methods, CFD simulations, and chemical probes. Compared with optical methods that rely heavily on high-precision equipment and CFD simulation methods that require a lot of computing resources, chemical probes have the advantages of being simple, fast and direct. The so-called chemical probe method is a method of forming a "memory" of the molecular mixing state in the reactor through the selectivity of a special test reaction, and then quantitatively characterizing the mixing performance of the reactor. The reaction systems used in the chemical probe method can be divided into two categories, namely competitive series systems and parallel competitive systems:

[0003]

[0004]

[0005] In practice, equal amounts of substance A and substance B are fed as two liquid streams. If the two liquid streams quickly achieve molecular-level uniform mixing in the reactor, reactant B is completely consumed by reactant A to produce the main product R. Otherwise, a side reaction will react with the local excess of substance B produced by the uneven mixing to produce a byproduct S. The selectivity of S is usually defined by a parameter X. S (dissociation index), which ranges from 0 to 1, with smaller values ​​corresponding to better mixing. Of course, not all competing reactions can be used as probe systems. The primary reaction must be quasi-instantaneous, and the side reaction should also be a rapid reaction, with a characteristic time less than or equal to the characteristic time of molecular mixing within the reactor, to sensitively characterize the reactor's mixing performance. Summary of the Invention

[0006] In order to solve the problem that the classic chemical probe system cannot be applied to liquid-liquid heterogeneous processes and there is no new mature chemical probe system that can be used for liquid-liquid heterogeneous mixing processes, the present invention proposes a new chemical probe system that can be used to characterize the mixing efficiency of liquid-liquid homogeneous and heterogeneous mixing processes.

[0007] To solve at least one of the above problems, in a first aspect, the present application provides a method for testing liquid-liquid mixing performance of a reactor, comprising:

[0008] dissolving acetylsalicylic acid in an organic solvent to form an acetylsalicylic acid organic mixture;

[0009] passing the acetylsalicylic acid organic mixture and a sodium hydroxide solution into a reactor to be tested for liquid-liquid mixing;

[0010] detecting a reaction product obtained by reacting the acetylsalicylic acid organic mixture and the sodium hydroxide solution to determine a segregation index of the reaction product, and further determining the mixing performance of the reactor.

[0011] Preferably, the step of dissolving acetylsalicylic acid in an organic solvent to form an acetylsalicylic acid organic mixture comprises:

[0012] dissolving the acetylsalicylic acid in a small-molecule alcohol organic solvent to form an acetylsalicylic acid organic alcohol solution, or

[0013] dissolving the acetylsalicylic acid in an oily long-chain alcohol organic solvent to form an acetylsalicylic acid oily alcohol solution;

[0014] wherein the acetylsalicylic acid organic alcohol solution can be used to detect the liquid-liquid homogeneous mixing performance of the reactor to be tested, and the acetylsalicylic acid oily alcohol solution can be used to detect the liquid-liquid heterogeneous mixing performance of the reactor to be tested.

[0015] Preferably, the acetylsalicylic acid organic mixture and the sodium hydroxide solution undergo a neutralization reaction to obtain a reaction product, acetylsalicylic acid sodium;

[0016] the acetylsalicylic acid sodium and the acetylsalicylic acid organic mixture undergo a side reaction to obtain by-products, sodium salicylate and sodium acetate.

[0017] Preferably, the step of detecting the reaction product obtained by reacting the acetylsalicylic acid organic mixture and the sodium hydroxide solution to determine the segregation index of the reaction product, and further determining the mixing performance of the reactor comprises:

[0018] adjusting the pH value of the reaction product to weakly acidic, and adding a ferric chloride solution to the reaction product;

[0019] if the reaction product turns purple, the reaction product contains the by-products, and the acetylsalicylic acid organic mixture and the sodium hydroxide solution undergo a side reaction;

[0020] determining the segregation index of the by-products according to the absorbance of the reaction product, and further determining the mixing performance of the reactor according to the segregation index.

[0021] Preferably, the absorbance of the reactant can be determined by a liquid chromatograph or a spectrophotometer.

[0022] In a second aspect, the application provides a system for testing liquid-liquid mixing performance of a reactor, comprising:

[0023] a mixing assembly for dissolving acetylsalicylic acid in an organic solvent to form an acetylsalicylic acid organic mixture;

[0024] a reactor to be tested, wherein a liquid inlet of the reactor to be tested is connected to a liquid outlet of the mixing assembly, and the acetylsalicylic acid organic mixture and a sodium hydroxide solution are introduced into the reactor to be tested for liquid-liquid mixing;

[0025] a detection assembly for detecting a reactant obtained by reacting the acetylsalicylic acid organic mixture and the sodium hydroxide solution to determine a segregation index of the reactant, and further determining the mixing performance of the reactor.

[0026] Preferably, the mixing assembly comprises two mixing cavities, one of which is connected to the acetylsalicylic acid and a small-molecule alcohol organic solvent, and the other of which is connected to the acetylsalicylic acid and an oily long-chain alcohol organic solvent.

[0027] Preferably, the detection assembly comprises two liquid inlets, one of which can add a pH adjuster, and the other of which can add a ferric chloride solution.

[0028] Preferably, the detection assembly further comprises a liquid chromatograph or a spectrophotometer.

[0029] Advantages of the invention

[0030] The application provides a testing method and system for liquid-liquid mixing performance of a reactor, which has a wide application range and high sensitivity. In the application, acetylsalicylic acid, a main reactant, can be dissolved in an organic solvent to characterize the liquid-liquid mixing process. Since the main reaction between acetylsalicylic acid and sodium hydroxide is an instantaneous reaction, and the side reaction is a fast reaction with a similar intrinsic reaction time and molecular mixing characteristic time, the system has high sensitivity to the molecular mixing efficiency in the reactor. Acetylsalicylic acid and sodium hydroxide used in the application are common basic chemicals in industry and society, and are low in price. The whole operation and analysis process is simple and convenient for popularization. When all raw materials are configured, they can be simply dissolved after weighing, and the operation process does not need to be isolated from air, and can be applied to reactors under various working conditions such as intermittent, semi-continuous and continuous operation. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and all of the other drawings can be obtained by those of ordinary skill in the art without any creative effort based on these drawings.

[0032] Figure 1 A flowchart of a test method for liquid-liquid mixing performance of a reactor in the embodiments of the present application is shown in the figure.

[0033] Figure 2 A schematic diagram of a reaction system of acetylsalicylic acid and sodium hydroxide in the embodiments of the present application is shown in the figure.

[0034] Figure 3 A flowchart of a test system for liquid-liquid mixing performance of a reactor in the embodiments of the present application is shown in the figure. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only represent some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those of ordinary skill in the art without any creative effort fall within the scope of protection of the present application.

[0036] For the convenience of description, the description of "first", "second" and the like in the present application is only set for the purpose of description, and cannot be understood as indicating or implying the relative importance of the technical features indicated or the number of the technical features indicated. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the fact that the technical solutions can be realized by those of ordinary skill in the art. When the combination of technical solutions appears to be contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection required by the present application.

[0037] The most commonly used chemical probe system at present is iodide-iodate system and diazonium salt system. Although these two systems have been widely used, there are still some defects in operation, such as the requirement of freshly preparing the raw material liquid, the interference of oxygen in the air on the reaction, etc. More importantly, the development of the current reaction intensifier for liquid-liquid heterogeneous (i.e. usually called oil-water two-phase) mixing process is endless, and these classic chemical probe systems cannot be applied to oil-water two-phase. The chemical probe system for liquid-liquid heterogeneous mixing process at present cannot be widely applied due to the theoretical defects.

[0038] To solve the problem that the classical chemical probe system cannot be applied to liquid-liquid heterogeneous process and there is no new mature chemical probe system available for liquid-liquid heterogeneous mixing process, the present application provides a kind of reactor liquid-liquid mixing performance test method, as shown in Figure 1 , comprising:

[0039] Step S100: dissolve acetylsalicylic acid in an organic solvent to form an acetylsalicylic acid organic mixture;

[0040] Step S101: pass the acetylsalicylic acid organic mixture and sodium hydroxide solution into the reactor to be tested for liquid-liquid mixing;

[0041] Step S102: detecting the reaction product obtained by the reaction of the acetylsalicylic acid organic mixture and the sodium hydroxide solution to determine the segregation index of the reaction product, and then judging the mixing performance of the reactor.

[0042] As shown in Figure 2 , the present application develops the basic hydrolysis reaction of acetylsalicylic acid (commonly known as aspirin) as a new type of chemical probe system. The main reaction is the neutralization reaction of the carboxyl group of acetylsalicylic acid with sodium hydroxide, and the tandem competitive side reaction is the basic hydrolysis process of the acetyl group of acetylsalicylic acid. Since the neutralization reaction is extremely fast and is generally considered to be an instantaneous reaction, if the two liquid streams in the reactor achieve uniform mixing on a molecular scale, the sodium hydroxide will be completely neutralized. When the mixing is not ideal, the local excess sodium hydroxide will continue to react with the neutralization product acetylsalicylic acid sodium, causing it to hydrolyze to form byproducts sodium salicylate and sodium acetate. Moreover, the basic hydrolysis of the acetyl group is a fast reaction, and the intrinsic reaction time is similar to the molecular mixing time, which can sensitively characterize the mixing efficiency.

[0043] Acetylsalicylic acid has good solubility in organic solvents. Therefore, acetylsalicylic acid can be dissolved in an organic solvent or a mixture thereof with water to form a water-soluble acetylsalicylic acid solution, which can be mixed with a sodium hydroxide aqueous solution to characterize the liquid-liquid mixing process.

[0044] In the test method described in the present application, the detection of byproducts can use high performance liquid chromatography, visible light colorimetric analysis, acid-base titration, etc., to determine the byproduct concentration and then determine the segregation index.

[0045] From the above description, the application provides a test method for liquid-liquid mixing performance of a reactor. The system has wide application range and high sensitivity. In the application, acetylsalicylic acid, the main reactant, is soluble in an organic solvent and is used to characterize the liquid-liquid mixing process. In addition, the main reaction between acetylsalicylic acid and sodium hydroxide is a fast reaction with a reaction time close to the intrinsic reaction time and molecular mixing characteristic time, so the system has high sensitivity to the molecular mixing efficiency in the reactor. Acetylsalicylic acid and sodium hydroxide used in the application are common basic chemicals in industry and society, and are low in price. The whole operation process and analysis process are simple and convenient for popularization. All raw materials in the application can be simply dissolved after weighing during preparation, and the operation process does not need to be isolated from air, so the system can be applied to reactors under various working conditions such as intermittent, semi-continuous and continuous operation. In addition, the by-product detection of the system can be carried out through a visible light color reaction, and the reaction can be directly measured under a spectrophotometer without the need of precise analysis equipment. At the same time, the color depth of the by-product can be compared by naked eyes to obtain a rough evaluation of the mixing performance of the reactor on site.

[0046] In some embodiments, the acetylsalicylic acid is dissolved in an organic solvent to form an acetylsalicylic acid organic mixed solution, including:

[0047] The acetylsalicylic acid is dissolved in a small-molecule alcohol organic solvent to form an acetylsalicylic acid organic alcohol solution, or

[0048] The acetylsalicylic acid is dissolved in an oily long-chain alcohol organic solvent to form an acetylsalicylic acid oily alcohol solution.

[0049] The acetylsalicylic acid organic alcohol solution can be used to detect the liquid-liquid homogeneous mixing performance of the reactor to be tested, and the acetylsalicylic acid oily alcohol solution can be used to detect the liquid-liquid heterogeneous mixing performance of the reactor to be tested.

[0050] It can be understood that acetylsalicylic acid is slightly soluble in water and has good solubility in alcohol solvents. Therefore, in actual operation, acetylsalicylic acid can be dissolved in ethanol, methanol or other small-molecule alcohols or mixtures thereof to form a water-soluble acetylsalicylic acid solution, which can be mixed with a sodium hydroxide aqueous solution to characterize the liquid-liquid homogeneous mixing process. At the same time, acetylsalicylic acid can also be dissolved in butanol, amyl alcohol or other oily long-chain alcohols, which can be mixed with a sodium hydroxide aqueous solution to characterize the liquid-liquid heterogeneous mixing process.

[0051] In some embodiments, the reaction between the acetylsalicylic acid organic mixed solution and the sodium hydroxide solution is detected to determine the segregation index of the reaction, and then the mixing performance of the reactor is judged, including:

[0052] The pH value of the reaction is adjusted to weak acidity, and an iron chloride solution is added to the reaction.

[0053] If the reactant becomes purple, the reactant contains the by-product, and the acetylsalicylic acid organic mixture solution reacts with the sodium hydroxide solution to produce a by-product;

[0054] According to the absorbance of the reactant, the segregation index of the by-product is determined, and then the mixing performance of the reactor is determined according to the segregation index.

[0055] In this embodiment, visible light colorimetric analysis is preferably used, which has the advantages of being simple and fast. Phenolic hydroxyl and iron ions can form a stable purple complex under weak acidic conditions, and the color depth is proportional to the concentration. After the completion of the mixing experiment, part of the sample solution is taken out, the ph value is adjusted to weak acidity with dilute hydrochloric acid, then a small amount of ferric chloride solution is added, and the sample solution is shaken to form a stable magenta purple color. Then the absorbance is measured in a spectrophotometer to determine the concentration of the by-product and the segregation index.

[0056] The present application also provides a test system for the liquid-liquid mixing performance of a reactor, comprising:

[0057] A mixing assembly is used to dissolve acetylsalicylic acid in an organic solvent to form an acetylsalicylic acid organic mixture solution.

[0058] A reactor under test is connected to the liquid outlet of the mixing assembly, and the acetylsalicylic acid organic mixture solution and sodium hydroxide solution are introduced into the reactor under test for liquid-liquid mixing.

[0059] A detection assembly is used to detect the reactant obtained by the reaction of the acetylsalicylic acid organic mixture solution and the sodium hydroxide solution to determine the segregation index of the reactant, and then the mixing performance of the reactor is determined.

[0060] Acetylsalicylic acid dissolved in small molecular alcohol such as ethanol, methanol or a mixture thereof with water forms a water-soluble acetylsalicylic acid solution, which is mixed with sodium hydroxide aqueous solution to characterize the liquid-liquid homogeneous mixing process. Acetylsalicylic acid dissolved in oily long-chain alcohol such as butanol, pentanol, etc. is mixed with sodium hydroxide aqueous solution to characterize the liquid-liquid heterogeneous mixing process. The mixing assembly can introduce acetylsalicylic acid, alcohol organic solvent or oily long-chain alcohol solvent to obtain an acetylsalicylic acid organic mixture solution. The acetylsalicylic acid organic mixture solution and sodium hydroxide solution are introduced into the reactor under test, and the detection assembly detects the reactant produced by the reaction of the acetylsalicylic acid organic mixture solution and the sodium hydroxide solution in the reactor under test to determine the mixing performance of the reactor.

[0061] In some other embodiments, the mixing assembly includes two mixing cavities, one of which introduces the acetylsalicylic acid and small molecular alcohol organic solvent, and the other of which introduces the acetylsalicylic acid and oily long-chain alcohol organic solvent.

[0062] In some other embodiments, the detection assembly comprises two liquid inlets, one of which can add a pH adjuster and the other of which can add a ferric chloride solution.

[0063] In the present application, the detection of the byproduct can employ high performance liquid chromatography, visible light colorimetric analysis, acid-base neutralization titration, etc. The present application recommends using visible light colorimetric analysis because of its advantages of simplicity and speed. Phenolic hydroxyl and iron ions can form a stable purple complex under weakly acidic conditions, and the color depth is proportional to the concentration. After the completion of the mixing experiment, part of the sample is taken out into the detection assembly, dilute hydrochloric acid is introduced into the detection assembly to adjust the pH value to weakly acidic, and then a small amount of ferric chloride solution is introduced, and the sample solution is shaken to see that it becomes a stable magenta purple color. Then the absorbance is measured in a spectrophotometer to determine the byproduct concentration and thus the segregation index.

[0064] The system for characterizing the liquid-liquid mixing efficiency of a reactor provided by the present application is specifically described below in combination with specific examples.

[0065] In stating the examples, for the sake of simplicity, the reaction process shown in the accompanying drawings is written as: Figure 1

[0066]

[0067] The segregation index is defined as:

[0068]

[0069] Figure 3 A flow chart showing that the probe system described in the present application is used to characterize the liquid-liquid mixing efficiency of a reactor.

[0070] Example 1

[0071] The standard stirred tank liquid-liquid homogeneous mixing efficiency is tested by using the present system. 54 grams of acetylsalicylic acid is weighed and dissolved in 500 milliliters of ethanol, and deionized water is added to make up to 3 liters to prepare 3 liters of 0.1 mol / L acetylsalicylic acid solution A. 40g of sodium hydroxide solid is weighed and dissolved in 1 liter of deionized water to prepare 1 liter of 1 mol / L sodium hydroxide solution B. Solution A is added to a stirred tank with four baffles, the stirring paddle is turned on, and the speed is adjusted to stabilize at 300 rpm. Then solution B is slowly injected into the outer edge of the stirring paddle, and after the injection is completed, 10 milliliters of sample solution is randomly taken from the tank with a pipette, and analyzed by the method shown in the accompanying drawings to calculate the segregation index X Figure 2 S is 0.38.

[0072] Examples 1-1 to 1-5

[0073] ​​The same experimental procedure as in Example 1 was used, at the same room temperature and water temperature, the only difference being the stirring tank speed, and the results are shown in the following table:

[0074] Example 1-1 1-2 1-3 1-4 1-5 Rotational speed / rpm 400 500 600 700 800 X S ]]> 0.31 0.26 0.23 0.21 0.19

[0075] Example 2

[0076] The liquid-liquid non-homogeneous mixing efficiency of the system was tested using a standard stirring tank. 54 grams of acetylsalicylic acid was dissolved in 500 milliliters of butanol, and butanol was added to make up to 3 L, to obtain 3 liters of 0.1 mol / L acetylsalicylic acid butanol solution A. 40 g of sodium hydroxide solid was dissolved in 1 liter of deionized water, to obtain 1 liter of 1 mol / L sodium hydroxide solution B. Solution A was added to a stirring tank with four baffles, the stirring paddle was turned on, and the speed was adjusted to stabilize at 300 rpm. Then solution B was slowly injected into the outer edge of the stirring paddle, after injection was completed, 10 milliliters of sample solution was randomly taken from the tank, then 10 milliliters of ethanol and 10 milliliters of deionized water were added to make it homogeneous, then the same method as in Example 1 was used for analysis, and the collection index X S was calculated to be 0.59.

[0077] Examples 2-1 to 2-5

[0078] The same experimental procedure as in Example 2 was used, at the same room temperature and water temperature, the only difference being the stirring tank speed, and the results are shown in the following table:

[0079] Example 2-1 2-2 2-3 2-4 2-5 Rotational speed / rpm 400 500 600 700 800 X S ]]> 0.48 0.4 0.35 0.31 0.29

[0080] Example 3

[0081] The liquid-liquid homogeneous mixing efficiency of the system was tested using a high gravity reactor. 18 grams of acetylsalicylic acid was dissolved in 500 milliliters of ethanol, and deionized water was added to make up to 1 L, to obtain 1 liter of 0.1 mol / L acetylsalicylic acid solution A. 4 g of sodium hydroxide solid was dissolved in 1 liter of deionized water, to obtain 1 liter of 0.1 mol / L sodium hydroxide solution B. The high gravity reactor was turned on and stabilized at a speed of 300 rpm. Then solution A and solution B were simultaneously pumped into the high gravity reactor, and the flow rate of both was controlled at 500 ml / min. 10 milliliters of liquid was taken from the outlet of the high gravity reactor, and the method shown in the following table was used for analysis, and the collection index X Figure 2 was calculated to be 0.15. S

[0082] Examples 3-1 to 3-5

[0083] The same experimental procedure as in Example 3 was used, at the same room temperature and water temperature, the only difference being the high gravity speed, and the results are shown in the following table: ​

[0084] Example 3-1 3-2 3-3 3-4 3-5 Rotational speed / rpm 400 500 600 700 800 X S ]]> 0.11 0.06 0.03 0.02 0.01

[0085] Example 4

[0086] The liquid-liquid heterogeneous mixing efficiency of the supergravity reactor was tested using the system. First, 18 g of acetylsalicylic acid was dissolved in 500 ml of butanol, and butanol was added to 1 L to prepare 1 L of 0.1 mol / L acetylsalicylic acid butanol solution A. 4 g of sodium hydroxide solid was dissolved in 1 L of deionized water to prepare 1 L of 0.1 mol / L sodium hydroxide solution B. The supergravity reactor was started and stabilized at 300 rpm. Then, solution A and solution B were pumped into the supergravity reactor at a flow rate of 500 ml / min. 10 ml of liquid was taken at the outlet of the supergravity reactor, and then 10 ml of ethanol and 10 ml of deionized water were added to the sample to make it homogeneous. Then, the same method as in Example 3 was used for analysis, and the collection index X was calculated to be 0.31. S

[0087] Examples 4-1 to 4-5

[0088] The same experimental operation as in Example 2 was used, and the same room temperature and water temperature were used, except that the rotation speed of the supergravity was different. The results are shown in the following table:

[0089] Example 4-1 4-2 4-3 4-4 4-5 Rotational speed / rpm 400 500 600 700 800 X S ]] 0.22 0.15 0.10 0.08 0.07

[0090] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the embodiments of the present specification. Illustrative expressions of the above terms in the present specification do not necessarily refer to the same embodiment or example.

[0091] In addition, the different embodiments or examples described in the present specification and the features of the different embodiments or examples can be combined and combined by those skilled in the art without contradiction. The above is only an embodiment of the embodiments of the present specification and is not intended to limit the embodiments of the present specification. The embodiments of the present specification can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the embodiments of the present specification shall be included in the scope of the claims of the embodiments of the present specification.​

Claims

1. A method for testing the liquid-liquid mixing performance of a reactor, characterized in that: include: dissolving acetylsalicylic acid in an organic solvent to form an acetylsalicylic acid organic mixed solution; Passing the acetylsalicylic acid organic mixed solution and the sodium hydroxide solution into the reactor to be tested for liquid-liquid mixing; The reactant obtained by the reaction of the acetylsalicylic acid organic mixture and the sodium hydroxide solution is detected to determine the dissociation index of the reactant, thereby judging the mixing performance of the reactor; the acetylsalicylic acid organic mixture and the sodium hydroxide solution undergo a neutralization reaction to obtain sodium acetylsalicylate as a reactant; The sodium acetylsalicylate reacts with the organic mixture of acetylsalicylic acid to produce byproducts of sodium salicylate and sodium acetate; the reactants obtained by the reaction of the organic mixture of acetylsalicylic acid and the sodium hydroxide solution are detected to determine the dissociation index of the reactants, thereby judging the mixing performance of the reactor, including: adjusting the pH value of the reactant to weak acidity, and adding ferric chloride solution to the reactant; If the reactant turns purple, the reactant contains the by-product, and the acetylsalicylic acid organic mixture reacts with the sodium hydroxide solution; The separation index of the by-product is determined according to the absorbance of the reactant, and the mixing performance of the reactor is further judged according to the separation index.

2. The testing method according to claim 1, wherein: The step of dissolving acetylsalicylic acid in an organic solvent to form an acetylsalicylic acid organic mixed solution comprises: dissolving the acetylsalicylic acid in a small molecule alcohol organic solvent to form an acetylsalicylic acid organic alcohol solution, or, dissolving the acetylsalicylic acid in an oily long-chain alcohol organic solvent to form an acetylsalicylic acid oily alcohol solution; The organic alcohol solution of acetylsalicylic acid can be used to detect the liquid-liquid homogeneous mixing performance of the reactor to be tested, and the oily alcohol solution of acetylsalicylic acid can be used to detect the liquid-liquid heterogeneous mixing performance of the reactor to be tested.

3. The testing method according to claim 1, wherein: The absorbance of the reactants can be measured using a liquid chromatograph or a spectrophotometer.

4. A test system for liquid-liquid mixing performance of a reactor, characterized in that: include: A mixing component is used to dissolve acetylsalicylic acid in an organic solvent to form an acetylsalicylic acid organic mixed solution; A reactor to be tested, wherein the liquid inlet of the reactor to be tested is connected to the liquid outlet of the mixing component, and the acetylsalicylic acid organic mixed liquid and the sodium hydroxide solution are introduced into the reactor to be tested for liquid-liquid mixing; a detection component for detecting a reactant obtained by reacting the acetylsalicylic acid organic mixture with the sodium hydroxide solution to determine an isolation index of the reactant, thereby judging the mixing performance of the reactor; the acetylsalicylic acid organic mixture undergoes a neutralization reaction with the sodium hydroxide solution to obtain sodium acetylsalicylate as a reactant; The sodium acetylsalicylate reacts with the organic mixture of acetylsalicylic acid to produce byproducts of sodium salicylate and sodium acetate; the reactants obtained by the reaction of the organic mixture of acetylsalicylic acid and the sodium hydroxide solution are detected to determine the dissociation index of the reactants, thereby judging the mixing performance of the reactor, including: adjusting the pH value of the reactant to weak acidity, and adding ferric chloride solution to the reactant; If the reactant turns purple, the reactant contains the by-product, and the acetylsalicylic acid organic mixture reacts with the sodium hydroxide solution; Determining the separation index of the byproduct according to the absorbance of the reactant, and then judging the mixing performance of the reactor according to the separation index; The detection component includes two liquid inlets, one of which is used to add a pH adjuster, and the other is used to add a ferric chloride solution.

5. The test system according to claim 4, characterized in that: The mixing component includes two mixing chambers, wherein the acetylsalicylic acid and a small molecule alcohol organic solvent are introduced into one of the mixing chambers, and the acetylsalicylic acid and an oily long-chain alcohol organic solvent are introduced into the other mixing chamber.

6. The test system according to claim 5, characterized in that: The detection component also includes: a liquid chromatograph or a spectrophotometer.

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