Apparatus and method for recycling acetonitrile mobile phase waste from liquid chromatography

Abstract

The present application relates to the field of chemical reagent waste liquid recovery, and discloses a device and method for recycling acetonitrile mobile phase waste liquid generated by liquid chromatography. The device is connected in series along the flow direction with: a chemical treatment unit for contacting the acetonitrile mobile phase waste liquid with a treatment agent, converting unsaturated organic matter in the acetonitrile mobile phase waste liquid into high-boiling-point impurities, converting proteins into precipitates, and performing neutralization treatment; an adsorption unit for removing organic impurities in the acetonitrile mobile phase waste liquid from the chemical treatment unit; and an extractive rectification unit for extractive rectification separation of acetonitrile, water and high-boiling-point impurities in the acetonitrile mobile phase waste liquid from the adsorption unit to obtain high-purity acetonitrile; wherein a filter is arranged on the flow channel between the chemical treatment unit and the adsorption unit for filtering solid impurities in the acetonitrile mobile phase waste liquid entering the adsorption unit. The present application can recycle and utilize acetonitrile in the acetonitrile mobile phase waste liquid, and can avoid resource waste.

Description

Technical Field

[0001] This invention relates to the field of chemical reagent waste liquid recovery, specifically to an apparatus and method for recovering acetonitrile mobile phase waste liquid generated by liquid chromatography. Background Technology

[0002] High-performance liquid chromatography (HPLC) has gradually become a mainstay of analytical methods due to its advantages such as high separation efficiency, good selectivity, high detection sensitivity, automated operation, and wide range of applications. The mobile phase plays a crucial role in liquid phase separation and is one of the core components of an HPLC column system. From a practical perspective, the selected mobile phase solvent should be inexpensive, readily available, safe to use, and of high purity. Commonly used organic solvents include methanol, acetonitrile, tetrahydrofuran, and isopropanol, which can be prepared by mixing them with ultrapure water in the correct proportions to obtain the mobile phase for the HPLC system. However, the mobile phase also generates a large amount of waste liquid containing the analyte after analysis.

[0003] The treatment of these mobile phase waste liquids is usually no different from that of general laboratory waste liquids, which is to mix them with other organic waste liquids for recycling and then burn them for discharge. However, since the mobile phase waste liquid itself is very pure and contains only a small amount of analytical impurities, it is a better treatment method to recover and recycle the organic phase portion than to burn it.

[0004] CN201820675654 discloses a continuous recovery device for refining and purifying crude acetonitrile, a byproduct of acrylonitrile production via the propylene ammoxidation process, to produce high-purity acetonitrile. The device mainly includes first, second, and third reaction towers and a reactor. Through continuous processes such as chemical treatment and distillation, it removes a large amount of water and trace impurities such as hydrogen cyanide, oxazole, and acetone from the crude acetonitrile to produce high-purity acetonitrile. However, this method mainly relies on distillation for purification, resulting in high energy consumption and equipment costs. Furthermore, the high-purity acetonitrile produced does not meet the requirements of HPLC.

[0005] CN201821820011 discloses a device for recovering high-purity acetonitrile in peptide synthesis, which mainly includes a conditioning tank, a first distillation column, an evaporator, a pervaporation separation unit, an adsorption column, and a second distillation column. However, this method is mainly for acetonitrile solutions with peptides as the main impurity, and its ability to recover and purify acetonitrile containing other small molecule impurities is very limited. At the same time, this process device requires multiple distillation and rectification operations, resulting in high energy consumption.

[0006] CN 109970290 A discloses a method and dedicated apparatus for zero-discharge treatment of high-salinity acetonitrile wastewater. The principle utilizes dual-membrane reverse osmosis desalination and biodegradation. The main equipment is a membrane aeration bioreactor system, which combines a membrane separator and a membrane aeration bioreactor, capable of separating and degrading acetonitrile in high-salinity acetonitrile wastewater. However, this method is designed for treating highly polluted, high-salinity acetonitrile wastewater systems, and the acetonitrile in the wastewater will be completely degraded and cannot be recycled. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of poor purification effect or capacity, high energy consumption and equipment costs in the existing technology, and to provide a device and method for recovering acetonitrile mobile phase waste liquid generated by liquid chromatography. It has integrated operation, high recovery rate, simple maintenance and good environmental and economic benefits.

[0008] To achieve the above objectives, the present invention provides a device for recovering acetonitrile mobile phase waste liquid generated by liquid chromatography, wherein the device comprises the following components connected in series along the material flow direction:

[0009] The chemical treatment unit is used to contact the acetonitrile mobile phase waste liquid with the treatment agent, so that the unsaturated organic matter in the acetonitrile mobile phase waste liquid is converted into high-boiling-point impurities, the protein is converted into precipitate, and neutralization treatment is performed.

[0010] An adsorption unit is used to remove organic impurities from the acetonitrile mobile phase waste liquid from the chemical treatment unit;

[0011] An extractive distillation unit is used to extract and distill acetonitrile, water and high-boiling-point impurities from the acetonitrile mobile phase waste liquid from the adsorption unit to obtain high-purity acetonitrile.

[0012] A filter element, disposed in the material channel between the chemical treatment unit and the adsorption unit, is used to filter solid impurities in the acetonitrile mobile phase waste liquid entering the adsorption unit. A second aspect of the present invention provides a method for recovering acetonitrile mobile phase waste liquid generated by liquid chromatography, performed in the apparatus described in the present invention, comprising the following steps:

[0013] 1) The acetonitrile mobile phase waste liquid and the treatment agent are contacted under contact conditions in the chemical treatment unit, so that the unsaturated organic matter in the acetonitrile mobile phase waste liquid is converted into high-boiling-point impurities, the protein is converted into precipitate, and neutralization treatment is carried out.

[0014] 2) The acetonitrile mobile phase waste liquid after the contact reaction in step 1) enters the adsorption unit for adsorption treatment to remove organic impurities; wherein, the solid impurities in the acetonitrile mobile phase waste liquid after the contact reaction are intercepted by the filter element.

[0015] 3) The acetonitrile mobile phase waste liquid after adsorption treatment in step 2) enters the extraction and distillation unit, where acetonitrile, water and high-boiling-point impurities in the acetonitrile mobile phase waste liquid are separated by extraction and distillation to obtain high-purity acetonitrile.

[0016] Compared with the prior art, the present invention has the following advantages through the above technical solution:

[0017] 1. This invention utilizes chemical treatment, adsorption, and extractive distillation techniques to separate the aqueous phase from acetonitrile in the acetonitrile mobile phase waste liquid generated by liquid chromatography, obtaining HPLC-grade acetonitrile that can be reused for preparing the mobile phase in high-performance liquid chromatography (HPLC). The effective recovery rate of acetonitrile is greater than 80%, the mass percentage of the recovered high-purity acetonitrile is ≥99.91%, the water content is less than 100 ppm, and the content of each organic impurity is less than 20 ppm. Preferably, the equipment of this invention is designed as an integrated unit, saving space, reducing energy and material consumption, and achieving full-process recovery of the mobile phase waste liquid generated by HPLC. No additional equipment is required, operation is simple, maintenance is convenient, and reliability is high.

[0018] 2. This invention recovers and utilizes the effective components of the mobile phase waste liquid generated by high performance liquid chromatography, which can avoid carbon emissions and resource waste caused by general laboratory waste liquid treatment methods, and achieve green recycling of resources. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the device for recovering acetonitrile mobile phase waste liquid generated by liquid chromatography in a specific embodiment of the present invention;

[0020] Figure 2 yes Figure 1 Schematic diagram of the structure of the intermediate reaction vessel;

[0021] Figure 3 yes Figure 1 Schematic diagram of the structure of a vortex adsorption column;

[0022] Figure 4 yes Figure 1 A schematic diagram of the structure of the central steam lifting column.

[0023] Explanation of reference numerals in the attached figures

[0024] 1. Reactor; 2. Outer shell; 3. Reaction chamber; 4. Stirring assembly; 5. Feed tank; 6. Stirring paddle; 7. Waste liquid outlet; 8. Cyclone adsorption column; 9. Adsorbent inlet; 10. Settling chamber; 11. Twin propellers; 12. Liquid phase outlet; 13. Stripping column; 14. Liquid tank; 15. Column; 16. Indicator section; 17. Water absorption section; 18. Top inlet / outlet; 19. Middle inlet / outlet; 20. Extractant inlet; 30. Shell. Detailed Implementation

[0025] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0026] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0027] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "left," and "right" generally refer to the upper, lower, left, and right positions shown in the accompanying drawings. "Inner" and "outer" refer to the inner and outer sides relative to the outline of each component or the inner and outer sides relative to the cavity. In this invention, unless otherwise specified, the "top" of the container refers to the position of the container from top to bottom at 0-10%; the "upper part" of the container refers to the position of the container from top to bottom at 0-33%; the "middle part" of the container refers to the position of the container from top to bottom at 33-66%; the "bottom" of the container refers to the position of the container from bottom to top at 0-10%; and the "lower part" of the container refers to the position of the container from bottom to top at 0-33%.

[0028] like Figures 1-4 As shown, one aspect of the present invention provides a device for recovering acetonitrile mobile phase waste liquid generated by liquid chromatography, wherein the device comprises, in series, the following components along the material flow direction:

[0029] The chemical treatment unit is used to contact the acetonitrile mobile phase waste liquid with the treatment agent, so that the unsaturated organic matter in the acetonitrile mobile phase waste liquid is converted into high-boiling-point impurities, the protein is converted into precipitate, and neutralization treatment is performed.

[0030] An adsorption unit is used to remove polar organic impurities and macromolecular organic impurities from the acetonitrile mobile phase waste liquid from the chemical treatment unit.

[0031] An extractive distillation unit is used to extract and distill acetonitrile, water and high-boiling-point impurities from the acetonitrile mobile phase waste liquid from the adsorption unit to obtain high-purity acetonitrile.

[0032] And a filter element, disposed in the material flow channel between the chemical treatment unit and the adsorption unit, for filtering solid impurities in the acetonitrile mobile phase waste liquid entering the adsorption unit.

[0033] The device of this invention combines a chemical treatment unit, an adsorption unit, and an extractive distillation unit to separate the aqueous phase from the acetonitrile mobile phase waste liquid generated by liquid chromatography using chemical treatment, adsorption, and extractive distillation techniques, obtaining HPLC-grade acetonitrile that can be reused for preparing the mobile phase of high-performance liquid chromatography. This method of recovering and reusing acetonitrile from the mobile phase waste liquid generated by liquid chromatography avoids the carbon emissions and resource waste caused by existing laboratory waste liquid treatment methods (i.e., mixing acetonitrile with other organic waste liquids for recovery and then burning it for emission), and achieves green recycling of resources. The effective recovery rate of acetonitrile is greater than 80%, the mass percentage of the recovered high-purity acetonitrile is ≥99.91%, the water content is less than 100 ppm, and the content of each organic impurity is less than 20 ppm.

[0034] According to a preferred embodiment of the present invention, such as Figure 1 As shown, the equipment also includes a housing 30, inside which are arranged a chemical treatment unit, an adsorption unit, and an extractive distillation unit; preferably, the chemical treatment unit is located above the adsorption unit, and the extractive distillation unit is located beside the adsorption unit. In this way, the acetonitrile waste liquid can flow downward under the action of gravity, and the entire equipment is integrated, which has the advantages of saving equipment space and reducing energy and material consumption.

[0035] In this invention, such as Figure 2 As shown, the chemical treatment unit is equipped with a reaction vessel 1 for chemical reactions and a feeding tank 5 for feeding the treatment agent, with the feeding tank 5 connected to the reaction vessel 1; the adsorption unit is equipped with a cyclone adsorption column 8 loaded with adsorbent; and the extractive distillation unit is equipped with a stripping column 13; wherein, the reaction vessel 1, the cyclone adsorption column 8, and the stripping column 13 are connected in series. Thus, acetonitrile waste liquid can be separated into high-purity acetonitrile through chemical treatment, filtration, adsorption, and extractive distillation.

[0036] In this invention, the reactor 1 includes an outer shell 2 and an inner frame nested within it. The outer shell 2 is provided with a heat exchanger for controlling the temperature of the inner frame. The heat exchanger can be a disc-shaped heating copper tube embedded in the shell wall of the outer shell 2 or a coil connected to the heat exchanger for circulating the heat exchange medium. The peripheral wall of the inner frame is surrounded by a reaction chamber 3 for chemical reactions to occur. The inner frame is provided with a waste liquid inlet and a waste liquid outlet 7.

[0037] In this invention, a waste liquid inlet penetrating the outer shell 2 is radially opened at the upper end of the inner frame of the vessel, and a waste liquid outlet 7 penetrating the outer shell 2 is opened at the bottom of the inner frame of the vessel; preferably, both the outer shell 2 and the inner frame of the vessel are cylindrical.

[0038] According to a preferred embodiment of the present invention, the diameter of the outer wall of the vessel shell 2 is 500-800 mm and the height is 400-800 mm.

[0039] According to a preferred embodiment of the present invention, the diameter of the inner wall of the inner frame of the vessel is 400-600 mm and the height is 300-600 mm.

[0040] According to a preferred embodiment of the present invention, the feeding tank 5 is an annular tank with its internal space divided into two independent chambers: a first feeding tank for storing acidic treatment agents and a second feeding tank for storing alkaline treatment agents. The first feeding tank is equipped with a first feeding pipe extending into the reaction chamber for feeding the acidic treatment agent into the reaction chamber 3; the second feeding tank is equipped with a second feeding pipe extending into the reaction chamber for feeding the alkaline treatment agent into the reaction chamber 3. The addition of either acidic or alkaline treatment agents to the feeding tank 5 is determined based on the pH value of the mobile phase waste liquid to achieve a neutral solution.

[0041] In this invention, such as Figure 2 As shown, the chemical treatment unit is equipped with a stirring assembly 4, which includes a drive motor and a stirring paddle 6 connected to the drive motor. The drive motor is located at the top of the inner frame of the reactor, and the stirring paddle 6 extends into the interior of the reaction chamber 3. Thus, the stirring paddle 6 can rotate under the drive of an electric stirrer to improve the reaction efficiency between the mobile phase waste liquid and the treatment agent. In this invention, the feeding tank 5 is located on the outer surface of the top wall of the inner frame of the reactor and is fitted around the drive motor of the stirring assembly 4. According to a preferred embodiment of the invention, as... Figure 3 As shown, the cyclone adsorption column 8 includes an adsorption section with an adsorption chamber and a settling section with a settling chamber 10. The adsorption chamber is connected to the settling chamber 10, allowing the adsorbent to accumulate in the settling chamber 10 after adsorption. A double propeller 11 is installed inside the adsorption chamber. When the double propeller 11 rotates at a low speed (e.g., 60-120 r / min), it can fully mix the mobile phase waste liquid with the adsorbent to improve the absorption efficiency. When the rotation speed is high (e.g., 360-480 r / min), centrifugal force is used to drive the adsorbent to slide quickly towards the wall and deposit in the settling chamber.

[0042] According to a preferred embodiment of the present invention, such as Figure 3 As shown, preferably, the adsorption chamber is a conical cavity that is larger at the top and smaller at the bottom. The top of the conical cavity is connected to the waste liquid outlet 7, and the bottom is connected to the settling chamber 10. In this way, the adsorbent adsorbed in the conical cavity slides rapidly towards the wall under the centrifugal force of the twin propellers 11 and slides into the settling chamber along the wall, avoiding the accumulation of adsorbent in the adsorption chamber.

[0043] In this invention, the adsorption section and the sedimentation section are detachably connected for quickly removing the adsorbent after adsorption.

[0044] According to a preferred embodiment of the present invention, more preferably, the diameter of the outer wall at the top of the conical cavity is the same as the diameter of the outer shell 2 of the vessel, and the diameter of the outer wall at the bottom is 100-200 mm; the height of the conical cavity is 400-600 mm.

[0045] According to a preferred embodiment of the present invention, the settling chamber 10 is a cylindrical cavity; more preferably, the diameter of the settling chamber 10 is the same as the bottom diameter of the conical cavity, and the height is 100-200 mm. In the present invention, the adsorbent inlet 9 is provided radially extending from the upper part of the adsorption chamber, and the liquid phase outlet 12 is provided radially extending from the lower part;

[0046] In this invention, a filter element is installed at the waste liquid outlet 7 to intercept various solid waste residues after chemical treatment; preferably, the filter element is at least one of a double-layer organic filter membrane, an inorganic ceramic membrane, an activated carbon filter element, or a stainless steel filter sheet; this invention is only illustrated by using a double-layer organic filter membrane as an example, but the invention is not limited thereto; more preferably, the organic filter membrane is at least one of polyethersulfone, polyvinyl chloride, polyacrylonitrile, or polytetrafluoroethylene.

[0047] According to a preferred embodiment of the present invention, such as Figure 4 As shown, the stripping column 13 includes a column 15 and a liquid tank 14 connected to the bottom of the column 15. The liquid tank 14 is equipped with a mechanism for adjusting the temperature inside the tank, such as embedding a heat exchange pipe or a heating copper pipe connected to a heat source in the tank wall. The liquid tank 14 is connected to the liquid phase outlet 12 and the extractant inlet 20, so that the adsorbed mobile phase waste liquid and the extractant come into contact and are distilled.

[0048] The top of the column 15 is provided with a top inlet / outlet 18 and a water absorption section 17. Acetonitrile is first distilled out in the liquid tank 14. After the water is removed by the water absorption section 17, high-purity acetonitrile is collected from the top inlet / outlet 18.

[0049] According to a preferred embodiment of the present invention, preferably, a distillation section and an indicator section 16 are arranged sequentially below the water absorption section 17. The distillation section is provided with a middle inlet and outlet 19. When the amount of water distilled from the liquid tank 14 gradually increases, the top inlet and outlet 18 is closed and the middle inlet and outlet 19 is opened according to the indication of the indicator section 16, so as to collect the distillate components. It should be noted that the distillate components are acetonitrile with a large water content that does not meet the HPLC grade standard.

[0050] In this invention, the tower column 15 is cylindrical; preferably, the tower column 15 has a height of 1000-1500mm and a diameter of 100-200mm.

[0051] According to a preferred embodiment of the present invention, the absorbent section 17 is provided with a first fixing member for fixing the absorbent; preferably, the first fixing member is an absorbent frame, more preferably, the height of the absorbent frame is 200-400mm.

[0052] According to a preferred embodiment of the present invention, the indicator segment 16 is provided with a second fastener for fixing the indicator; preferably, the second fastener is an indicator frame, and more preferably, the height of the indicator frame is 50-100mm.

[0053] According to a preferred embodiment of the present invention, the extractant inlet 20 is disposed in the column 15 located below the indicator section 16.

[0054] The device of this invention is an integrated unit that purifies acetonitrile mobile phase waste liquid through chemical treatment, filtration, adsorption, centrifugation, extraction and distillation to produce HPLC-grade acetonitrile suitable for high-performance liquid chromatography (HPLC). This achieves full-process recovery of mobile phase waste liquid generated by HPLC, while also exhibiting high effective component recovery rate, good reliability, no secondary pollution, no need for additional equipment, simple operation, convenient maintenance, and high reliability. The integrated design of the entire device saves space, energy, and material consumption.

[0055] A second aspect of the present invention provides a method for recovering acetonitrile mobile phase waste liquid generated by high performance liquid chromatography, the method being carried out in the apparatus of the present invention, comprising the following steps:

[0056] 1) The acetonitrile mobile phase waste liquid and the treatment agent are contacted under contact conditions in the chemical treatment unit, so that the unsaturated organic matter in the acetonitrile mobile phase waste liquid is converted into high-boiling-point impurities, the protein is converted into precipitate, and neutralization treatment is carried out.

[0057] 2) The acetonitrile mobile phase waste liquid after the contact reaction in step 1) is fed into the adsorption unit for adsorption treatment to remove organic impurities; wherein, solid impurities in the acetonitrile mobile phase waste liquid after the contact reaction are intercepted by the filter element.

[0058] 3. The acetonitrile mobile phase waste liquid after adsorption treatment in step 2 is fed into the extraction and distillation unit to separate the acetonitrile from water and high-boiling-point impurities in the acetonitrile mobile phase waste liquid by extraction and distillation to obtain high-purity acetonitrile.

[0059] This invention utilizes chemical treatment, adsorption, extraction, and distillation techniques to effectively separate the aqueous phase from acetonitrile in mobile phase waste liquid, recovering HPLC-grade acetonitrile that can be reused for high-performance liquid chromatography (HPLC) mobile phase preparation. The effective recovery rate of acetonitrile is greater than 80%, the mass percentage of the recovered high-purity acetonitrile is ≥99.91%, the water content is less than 100 ppm, and the content of each organic impurity is less than 20 ppm. This invention avoids the carbon emissions and resource waste caused by conventional laboratory waste liquid treatment methods in existing technologies, enabling green recycling of resources.

[0060] According to a preferred embodiment of the present invention, in step 1, acetonitrile waste liquid is fed through the waste liquid inlet, and a treatment agent is added through the feeding tank 5. The reaction is carried out in the reaction chamber 3 under the stirring of the stirring paddle 6, so that the unsaturated organic matter and protein in the acetonitrile waste liquid are converted and neutralized.

[0061] According to a preferred embodiment of the present invention, the contact reaction conditions preferably include: the rotation speed of the stirring paddle 6 is 60-180 r / min, the reaction temperature is 40-80℃, and the reaction time is 2-6 h;

[0062] According to a preferred embodiment of the present invention, the amount of treatment agent added to the reaction chamber 3 is 0.5%-2.5% of the total mass of the acetonitrile mobile phase waste liquid.

[0063] According to a preferred embodiment of the present invention, more preferably, the treatment agent includes an acidic treatment agent added through a first feeding tank and an alkaline treatment agent added through a second feeding tank.

[0064] According to a preferred embodiment of the present invention, it is further preferred that the acidic treatment agent includes an acid and / or an acidic oxidizing agent; even more preferably, the acid is selected from sulfuric acid and / or hypochlorous acid.

[0065] According to a preferred embodiment of the present invention, more preferably, the acidic oxide is selected from potassium permanganate and / or potassium dichromate.

[0066] According to a preferred embodiment of the present invention, it is further preferred that the alkaline treatment agent includes an alkali and / or an alkaline oxidant; even more preferably, the alkali is selected from potassium hydroxide and / or sodium hydroxide.

[0067] According to a preferred embodiment of the present invention, and further preferably, the alkaline oxide is selected from at least one of copper hydroxide, hydrogen peroxide, sodium hypochlorite, or sodium persulfate.

[0068] It should be noted that, in addition to converting proteins and unsaturated organic matter in the waste liquid, the treatment agent also has the function of adjusting the pH of the raw materials to neutral. Therefore, the amount of acid or alkali treatment agent to be added will be determined according to the pH value of the mobile phase waste liquid in order to achieve the purpose of neutralizing the solution.

[0069] For example, when the waste liquid contains citric acid, pepsin, etc., potassium hydroxide and hydrogen peroxide are added to adjust the pH from acidic to near neutral; when the waste liquid contains belladonna alkaloid, histone, etc., sulfuric acid and potassium dichromate are added to adjust the pH from alkaline to near neutral.

[0070] In this invention, in step 2, the adsorbent is introduced into the conical cavity of the cyclone adsorption column 8 through the adsorbent inlet 9; preferably, the adsorbent is brought into full contact with the acetonitrile waste liquid at the first rotation speed of the dual propeller 11 to remove polar organic impurities and macromolecular organic impurities; preferably, the adsorbent is rapidly slid towards the wall of the conical cavity and falls into the settling cavity 10 for deposition at the second rotation speed of the dual propeller 11; the adsorbed acetonitrile mobile phase waste liquid enters the liquid tank 14 from the liquid phase inlet 12.

[0071] In this invention, more preferably, the adsorbent is selected from one or more of granular activated carbon, activated alumina, polyacrylamide particles, and macroporous adsorption resin particles.

[0072] In this invention, the average particle size of the adsorbent is 2-4 mesh.

[0073] In this invention, the adsorption time is 1-2 hours.

[0074] In this invention, the first rotational speed is 60-120 r / min.

[0075] In this invention, the second rotational speed is 360-480 r / min.

[0076] According to a preferred embodiment of the present invention, in step 3, an extractant is added into the heating liquid tank 14 through the extractant inlet 20, and the acetonitrile waste liquid entering is distilled.

[0077] Acetonitrile is first distilled out from liquid tank 14, enters column 15, passes through indicator section 16 and distillation section, rises to water absorption section 17 to remove water, and is then collected from top inlet / outlet 18 to high-purity acetonitrile.

[0078] As the amount of water distilled from the liquid tank 14 gradually increases, the color-changing silica gel in the indicator section 16 gradually changes color. At this time, the top inlet / outlet 18 is closed and the middle inlet / outlet 19 is opened to collect the distillate containing acetonitrile. At this time, the water content in the distillate is relatively high, which does not meet the standard of HPLC grade acetonitrile. When there is no more gas phase distillation, heating is stopped and the extractant is recovered from the liquid tank 14.

[0079] According to a preferred embodiment of the present invention, preferably, the water-absorbing section 17 is loaded with a water-absorbing agent, which is selected from one or more of molecular sieves, phosphorus pentoxide, anhydrous calcium chloride and anhydrous magnesium sulfate.

[0080] According to a preferred embodiment of the present invention, preferably, the indicator segment 16 is loaded with an indicator, the indicator being color-changing silica gel.

[0081] According to a preferred embodiment of the present invention, the distillation conditions preferably include: a heating temperature of 100℃-140℃, a reflux ratio of 1-4 at the top of the column, a top discharge rate of 5-20 mL / min, and a discharge rate of 10-30 mL / min in the middle of the column.

[0082] According to a preferred embodiment of the present invention, preferably, the amount of extractant added is 10wt%-30wt% of the added mobile phase waste liquid.

[0083] In this invention, preferably, the extractant is selected from at least one of ethylene glycol, imidazole ionic liquids, and quaternary ammonium ionic liquids.

[0084] In this invention, more preferably, the imidazole ionic liquid is selected from 1-alkyl-3-methylimidazolium p-toluenesulfonate and / or 1-alkyl-2,3-dimethylimidazolium tetrafluoroborate.

[0085] In this invention, more preferably, the quaternary ammonium ionic liquid is selected from tributylmethylammonium chloride and / or tributylmethylammonium diimide salt.

[0086] In this invention, the acetonitrile waste liquid comprises, by mass fraction: acetonitrile 50-99%, water 1-50%, protein 0.5-1%, unsaturated organic impurities 0.05-0.2%, saturated organic impurities 0.05-0.1%, inorganic impurities 0.2-0.4%, and other solid substances <0.1%.

[0087] The present invention will be further described below with reference to embodiments, but the present invention is not limited thereto.

[0088] The following examples are in Figures 1-4 The process is carried out in the device shown, which includes a housing 30. Inside the housing 30, there is a chemical treatment unit, an adsorption unit, and an extractive distillation unit. The chemical treatment unit is located above the adsorption unit, and the extractive distillation unit is located beside the adsorption unit. The chemical treatment unit is equipped with a feeding tank 5 connected to the reaction vessel 1. The adsorption unit is equipped with a cyclone adsorption column 8 loaded with adsorbent. The extractive distillation unit is equipped with a stripping column 13. The reaction vessel 1, the cyclone adsorption column 8, and the stripping column 13 are connected in series.

[0089] The reaction vessel 1 includes a cylindrical outer shell 2 and a nested cylindrical inner frame. The outer shell 2 is equipped with a heating element. The peripheral wall of the inner frame forms a reaction chamber 3. A waste liquid inlet penetrating the outer shell 2 is radially opened at the upper end of the inner frame, and a waste liquid outlet 7 with a filter element penetrating the outer shell 2 is opened at the bottom of the inner frame. The chemical treatment unit is equipped with a stirring assembly 4, which includes a drive motor and a stirring paddle 6 connected to the drive motor. The drive motor is located at the top of the inner frame, and the stirring paddle 6 extends into the interior of the reaction chamber 3. A feeding tank 5 is located on the outer surface of the top wall of the inner frame and is fitted around the drive motor of the stirring assembly 4. The feeding tank 5 is an annular tank, and its internal space is divided into a first feeding tank for storing acidic treatment agents and a second feeding tank for storing alkaline treatment agents. The first feeding tank is equipped with a first feeding pipe extending into the interior of the reaction chamber, and the second feeding tank is equipped with a second feeding pipe extending into the interior of the reaction chamber.

[0090] The cyclone adsorption column 8 includes an adsorption section with an adsorption chamber and a settling section with a settling chamber 10 that are detachably connected. The adsorption chamber is connected to the settling chamber 10, and a double propeller 11 is provided inside the adsorption chamber. The adsorption chamber is a conical cavity that is larger at the top and smaller at the bottom. The top end is connected to the waste liquid outlet 7, and the bottom end is connected to the settling chamber 10. The settling chamber 10 is a cylindrical cavity. The adsorbent inlet 9 is radially extended from the upper part of the adsorption chamber, and the liquid phase outlet 12 is radially extended from the lower part.

[0091] The stripping column 13 includes a cylindrical column 15 and a liquid tank 14 connected to the bottom of the column 15. The liquid tank 14 is connected to the liquid phase inlet 12 and the extractant inlet 20. The top of the column 15 is provided with a top inlet / outlet 18. The column 15 is provided with an indicator section 16, a distillation section and a water absorption section 17 from bottom to top. The water absorption section 17 is provided with a water absorption frame for fixing the water absorption agent. The indicator section 16 is provided with an indicator frame for fixing the color-changing silica gel. The extractant inlet 20 is located in the column 15 below the indicator section 16.

[0092] The method for recovering acetonitrile mobile phase waste liquid generated by liquid chromatography includes the following steps:

[0093] 1) The acetonitrile mobile phase waste liquid and the treatment agent are reacted in the reaction chamber;

[0094] 2) The acetonitrile mobile phase waste liquid after the contact reaction in step 1) is fed into the cyclone adsorption column 8 for adsorption treatment;

[0095] 3) The acetonitrile mobile phase waste liquid after adsorption treatment in step 2) is fed into the liquid tank 14 for distillation separation, and high-purity acetonitrile is obtained at the top inlet / outlet 18.

[0096] The analytical methods for each technical indicator of this invention using chromatographically pure acetonitrile are based on the normative documents referenced in Q / SHAQ 02.28-2002 and SH / T1627.1-2014.

[0097] GB / T 6283-2008 Determination of moisture content in chemical products - Karl Fischer method (general method);

[0098] GB / T 9740-2008 General Method for Determination of Evaporation Residue of Chemical Reagents;

[0099] GB / T 611-2021 General Method for Determination of Density of Chemical Reagents;

[0100] GB / T 9736-2008 General methods for the determination of acidity and alkalinity of chemical reagents;

[0101] GB / T 9721-2006 General Rules for Molecular Absorption Spectrophotometry of Chemical Reagents (Ultraviolet and Visible Parts);

[0102] GB / T 9722-2006 General Rules for Gas Chromatography of Chemical Reagents

[0103]

Example 1

[0104] Adopting such Figure 1 The process shown has the following characteristics: the outer shell of the chemical reactor has a diameter of 600 mm and a height of 600 mm; the inner frame of the reactor has a diameter of 450 mm and a height of 400 mm; the main structure of the cyclone adsorption column has a bottom diameter of 150 mm and a height of 500 mm, a settling chamber height of 100 mm, a column height of 1200 mm and a diameter of 150 mm, a desiccant frame height of 300 mm, and an indicator frame height of 75 mm.

[0105] The composition of the mobile phase waste liquid (by mass percentage) is: acetonitrile 64%, water 35%, protein 0.6%, unsaturated organic impurities 0.08%, saturated organic impurities 0.1%, inorganic impurities 0.3%, and other solid impurities 0.07%. The mobile phase waste liquid enters the inner frame of the chemical treatment reactor. The feed tank contains hypochlorous acid, potassium permanganate, copper hydroxide, and hydrogen peroxide, with the added treatment agent accounting for 1% of the total mass of the mobile phase waste liquid. The reaction temperature is set at 60℃, the reaction time is 4 hours, and the stirring speed is 120 r / min. After the reaction is complete, the waste liquid enters a cyclone adsorption column, and the solid waste residue is retained in the inner frame of the reactor by a double-layer organic filter membrane made of polyethersulfone. After the waste liquid enters the cyclone adsorption column, polyacrylamide granules and macroporous adsorption resin with an average particle size of 3.5 mesh are added through the feed inlet. The dual propellers are adjusted to the first speed of 80 r / min to ensure sufficient contact between the waste liquid and the adsorbent, with an adsorption time of 1.5 h. After adsorption is complete, the dual propellers are adjusted to the second speed of 400 r / min, and the adsorbent subsequently settles in the settling chamber, while the waste liquid enters the liquid tank of the stripping column. The desiccant in the desiccant box is anhydrous magnesium sulfate. The extractant added to the liquid tank is ethylene glycol, accounting for 15% of the mass of the waste liquid in the liquid tank. The heating temperature is set to 120 degrees Celsius, the reflux ratio at the top of the column is 3, the discharge rate at the top of the column is controlled at 10 mL / min, and the discharge rate from the middle of the column is controlled at 20 mL / min. High-purity acetonitrile can be collected from the top inlet and outlet. After no more distillation occurs at the middle inlet and outlet, the extractant is recovered from the liquid tank.

[0106]

Example 2

[0107] Adopting such Figure 1The process shown has the following characteristics: the outer shell of the chemical reactor has a diameter of 700 mm and a height of 500 mm; the inner frame of the reactor has a diameter of 500 mm and a height of 500 mm; the main structure of the cyclone adsorption column has a bottom diameter of 180 mm and a height of 600 mm; the settling chamber has a height of 160 mm; the column height is 1400 mm and the diameter is 180 mm; the absorbent frame has a height of 350 mm; and the indicator frame has a height of 100 mm.

[0108] The composition of the mobile phase waste liquid (by mass percentage) is: acetonitrile 72%, water 27%, protein 0.8%, unsaturated organic impurities 0.12%, saturated organic impurities 0.08%, inorganic impurities 0.35%, and other solid impurities 0.08%. The mobile phase waste liquid enters the inner frame of the chemical treatment reactor. The feed tanks contain sulfuric acid, potassium dichromate, potassium hydroxide, and sodium hypochlorite. The added treatment agent is 1.5% of the total mass of the mobile phase waste liquid. The reaction temperature is set at 75℃, the reaction time is 6 hours, and the stirring speed is 160 r / min. After the reaction is complete, the waste liquid enters a cyclone adsorption column, and the solid waste residue is retained in the inner frame of the reactor by a double-layer organic filter membrane made of polytetrafluoroethylene. After the waste liquid enters the cyclone adsorption column, granular activated carbon and activated alumina are added through the feed inlet. The average particle size is 2.5 mesh. The dual propellers are adjusted to the first speed of 100 r / min to ensure sufficient contact between the waste liquid and the adsorbent. The adsorption time is 2 hours. After adsorption is complete, the dual propellers are adjusted to the second speed of 440 r / min, and the adsorbent is then deposited in the settling chamber. The waste liquid enters the liquid tank of the stripping column. The absorbent in the absorbent container is anhydrous calcium chloride. The extractant added to the liquid tank is 1-alkyl-2,3-dimethylimidazolium tetrafluoroborate, accounting for 20% of the waste liquid in the liquid tank by mass. The heating temperature is set to 135 degrees Celsius, the reflux ratio at the top of the column is 4, the discharge rate at the top of the column is controlled at 8 mL / min, and the discharge rate from the middle of the column is controlled at 15 mL / min. High-purity acetonitrile can be collected from the top inlet and outlet. After no more distillation occurs at the middle inlet and outlet, the extractant is recovered from the liquid tank.

[0109]

Example 3

[0110] Adopting such Figure 1 The process shown has the following characteristics: the outer shell of the chemical reactor has a diameter of 550 mm and a height of 450 mm; the inner frame of the reactor has a diameter of 450 mm and a height of 350 mm; the main structure of the cyclone adsorption column has a bottom diameter of 120 mm and a height of 450 mm; the settling chamber has a height of 120 mm; the column height is 1100 mm and the diameter is 120 mm; the absorbent frame has a height of 250 mm; and the indicator frame has a height of 60 mm.

[0111] The composition of the mobile phase waste liquid (by mass percentage) is: acetonitrile 65%, water 34%, protein 0.9%, unsaturated organic impurities 0.06%, saturated organic impurities 0.08%, inorganic impurities 0.4%, and other solid impurities 0.07%. The mobile phase waste liquid enters the inner frame of the chemical treatment reactor. The feeding tanks contain hypochlorous acid, potassium dichromate, copper hydroxide, and sodium persulfate. The mass of the treatment agent added is 1% of the total mass of the mobile phase waste liquid. The reaction temperature is set at 45℃, the reaction time is 2.5 h, and the stirring speed is 70 r / min. After the reaction is complete, the waste liquid enters the cyclone adsorption column, and the solid waste residue is retained in the inner frame of the reactor by a double-layer organic filter membrane made of polytetrafluoroethylene. After the waste liquid enters the cyclone adsorption column, activated alumina adsorbent with an average particle size of 4 mesh is added through the feed inlet. The dual propellers are adjusted to the first speed of 80 r / min to ensure sufficient contact between the waste liquid and the adsorbent, and the adsorption time is 1 hour. After adsorption is complete, the dual propellers are adjusted to the second speed of 360 r / min, and the adsorbent subsequently settles in the settling chamber, while the waste liquid enters the liquid tank of the stripping column. The absorbent in the absorbent container is a molecular sieve. The extractant added to the liquid tank is 1-alkyl-3-methylimidazolium p-toluenesulfonate, with a mass percentage of 12% of the waste liquid in the liquid tank. The heating temperature is set to 110 degrees Celsius, the top reflux ratio is 1.2, the top discharge rate is controlled at 15 mL / min, and the middle discharge rate is controlled at 20 mL / min. High-purity acetonitrile can be collected from the top inlet and outlet. After no more distillation occurs from the middle inlet and outlet, the extractant is recovered from the liquid tank.

[0112]

Example 4

[0113] Adopting such Figure 1 The process shown has the following characteristics: the outer shell of the chemical reactor has a diameter of 600 mm and a height of 700 mm; the inner frame of the reactor has a diameter of 500 mm and a height of 500 mm; the main structure of the cyclone adsorption column has a bottom diameter of 180 mm and a height of 550 mm; the settling chamber has a height of 150 mm; the column height is 1300 mm and the diameter is 150 mm; the absorbent frame has a height of 350 mm; and the indicator frame has a height of 90 mm.

[0114] The composition of the mobile phase waste liquid (by mass percentage) is: acetonitrile 70%, water 29%, protein 0.6%, unsaturated organic impurities 0.15%, saturated organic impurities 0.08%, inorganic impurities 0.3%, and other solid impurities 0.1%. The mobile phase waste liquid enters the inner frame of the chemical treatment reactor. The feed tank contains sulfuric acid, potassium permanganate, sodium hydroxide, and hydrogen peroxide. The added treatment agent accounts for 1.8% of the total mass of the mobile phase waste liquid. The reaction temperature is set at 70℃, the reaction time is 5 hours, and the stirring speed is 150 r / min. After the reaction is complete, the waste liquid enters the cyclone adsorption column through the outlet. The solid waste residue is retained in the inner frame of the reactor by a double-layer organic filter membrane made of polyvinyl chloride. After the waste liquid enters the cyclone adsorption column, granular activated carbon and macroporous adsorption resin with an average particle size of 3 mesh are added through the feed inlet. The dual propellers are adjusted to the first speed of 90 r / min to ensure sufficient contact between the waste liquid and the adsorbent, with an adsorption time of 1.6 h. After adsorption is complete, the dual propellers are adjusted to the second speed of 440 r / min, and the adsorbent subsequently settles in the settling chamber, while the waste liquid enters the liquid tank of the stripping column through the discharge outlet. The absorbent in the absorbent container is phosphorus pentoxide. The extractant added to the liquid tank is tributylmethylammonium chloride, with a mass percentage of 12% of the waste liquid in the liquid tank. The heating temperature is set to 130 degrees Celsius, the top reflux ratio is 2.5, the discharge rate at the top of the column is controlled at 8 mL / min, and the discharge rate from the middle of the column is controlled at 15 mL / min. High-purity acetonitrile can be collected from the top inlet and outlet. After no more distillation occurs at the middle inlet and outlet, the extractant is recovered from the liquid tank.

[0115] Comparative Example 1

[0116] Adopting such Figure 1 The process shown is excluding the chemical treatment unit. The main structure of the cyclone adsorption column has a bottom diameter of 650 mm, a height of 600 mm, a settling chamber height of 400 mm, a column height of 1250 mm, a diameter of 130 mm, a water absorbent frame height of 250 mm, and an indicator frame height of 60 mm.

[0117] The composition of the mobile phase waste liquid (by mass percentage) is: acetonitrile 77%, water 22%, protein 0.7%, unsaturated organic impurities 0.17%, saturated organic impurities 0.09%, inorganic impurities 0.35%, and other solid impurities 0.05%. The mobile phase waste liquid directly enters the cyclone adsorption column. After entering the column, activated alumina and macroporous adsorption resin with an average particle size of 2.5 mesh are added through the inlet. The dual propellers are adjusted to a first speed of 130 r / min to ensure sufficient contact between the waste liquid and the adsorbent, with an adsorption time of 1.8 h. After adsorption, the dual propellers are adjusted to a second speed of 430 r / min, and the adsorbent subsequently settles in the settling chamber, while the waste liquid enters the liquid tank of the stripping column. The desiccant in the desiccant frame is anhydrous calcium chloride. The extractant added to the liquid tank is tributylmethylammonium diimide salt, with a mass percentage of 15% of the waste liquid in the liquid tank. The heating temperature is set to 145 degrees Celsius, the reflux ratio at the top of the column is 2.8, the discharge rate at the top of the column is controlled at 16 mL / min, and the discharge rate in the middle of the column is controlled at 20 mL / min. High-purity acetonitrile can be collected from the top inlet and outlet. After the middle inlet and outlet stop distilling, the extractant is recovered from the liquid tank.

[0118] Comparative Example 2

[0119] Adopting such Figure 1 The process shown is excluding the adsorption unit. The outer shell of the chemical reactor has a diameter of 450 mm and a height of 350 mm; the inner frame has a diameter of 420 mm and a height of 520 mm; the column height is 1400 mm and the diameter is 175 mm; the height of the absorbent frame is 300 mm; and the height of the indicator frame is 80 mm.

[0120] The composition of the mobile phase waste liquid (by mass percentage) is: acetonitrile 52%, water 46%, protein 0.9%, unsaturated organic impurities 0.18%, saturated organic impurities 0.07%, inorganic impurities 0.35%, and other solid impurities 0.08%. The mobile phase waste liquid enters the inner frame of the chemical treatment reactor. The feeding tanks contain hypochlorous acid, potassium dichromate, potassium hydroxide, and sodium persulfate. The added treatment agent is 2% of the total mass of the mobile phase waste liquid. The reaction temperature is set at 65℃, the reaction time is 4 hours, and the stirring speed is 100 r / min. After the reaction is complete, the waste liquid is pumped directly from the outlet into the liquid tank of the stripping column. Solid waste residue is retained in the inner frame of the reactor by a double-layer organic filter membrane made of polyethersulfone. The absorbent in the absorbent container is anhydrous calcium chloride. The extractant added to the liquid tank is 1-alkyl-3-methylimidazolium p-toluenesulfonate, with a mass percentage of 17% of the waste liquid in the liquid tank. The heating temperature is set to 140 degrees Celsius, the reflux ratio at the top of the column is 2, the discharge rate at the top of the column is controlled at 15 mL / min, and the discharge rate in the middle of the column is controlled at 25 mL / min. High-purity acetonitrile can be collected from the top inlet and outlet. After the middle inlet and outlet stop distilling, the extractant is recovered from the liquid tank.

[0121] Comparative Example 3

[0122] Adopting such Figure 1 The process shown is excluding the extraction and distillation unit. The outer shell of the chemical reactor has a diameter of 500 mm and a height of 500 mm; the inner frame has a diameter of 450 mm and a height of 500 mm; the main structure of the cyclone adsorption column has a height of 500 mm, a bottom diameter of 160 mm, and a settling chamber height of 120 mm.

[0123] The composition of the mobile phase waste liquid (by mass percentage) is: acetonitrile 54%, water 45%, protein 0.8%, unsaturated organic impurities 0.18%, saturated organic impurities 0.07%, inorganic impurities 0.35%, and other solid impurities 0.05%. The mobile phase waste liquid enters the inner frame of the chemical treatment reactor. The feeding tanks contain hypochlorous acid, potassium dichromate, potassium hydroxide, and sodium persulfate, with the added treatment agent accounting for 1.2% of the total mobile phase waste liquid mass. The reaction temperature is set at 60℃, the reaction time at 4 hours, and the stirring speed at 80 r / min. After the reaction is complete, the waste liquid enters a cyclone adsorption column through the outlet. The solid waste residue is retained in the inner frame of the reactor by a double-layer organic filter membrane made of polyethersulfone. After the waste liquid enters the cyclone adsorption column, adsorbent polyacrylamide particles and activated alumina are added through the feed inlet. The average particle size of the particles is 3.5 mesh. The dual propellers are adjusted to the first speed of 120 r / min to ensure that the waste liquid and adsorbent are in full contact. The adsorption time is 1.6 h. After the adsorption is completed, the dual propellers are adjusted to the second speed of 420 r / min. The adsorbent then settles in the settling chamber. At the same time, the solution obtained from the discharge outlet is directly collected as acetonitrile product.

[0124] Performance testing comparison

[0125] Table 1: Report on the Detection Results of Chromatographic Grade Acetonitrile in Examples

[0126] Table 1

[0127]

[0128]

[0129] Table 2: Comparative Example Acetonitrile Test Results Report

[0130] Table 2

[0131]

[0132] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An apparatus for recycling acetonitrile mobile phase waste produced by liquid chromatography, characterized by, The device is connected in series along the flow direction, comprising: a chemical treatment unit for contacting acetonitrile mobile phase waste liquid with a treatment agent, converting unsaturated organic matter in the acetonitrile mobile phase waste liquid into high-boiling impurities, converting proteins into precipitates, and performing neutralization treatment; an adsorption unit for removing organic impurities in the acetonitrile mobile phase waste liquid from the chemical treatment unit; an extractive rectification unit for extractive rectification separation of acetonitrile, water and high-boiling impurities in the acetonitrile mobile phase waste liquid from the adsorption unit to obtain high-purity acetonitrile; and a filter arranged on the flow channel between the chemical treatment unit and the adsorption unit for filtering solid impurities in the acetonitrile mobile phase waste liquid entering the adsorption unit; The device further comprises a housing (30) internally provided with the chemical treatment unit, the adsorption unit and the extractive rectification unit; The chemical treatment unit is provided with a reaction kettle (1) for chemical reaction and a feeding tank (5) for feeding the treatment agent, and the feeding tank (5) is communicated with the reaction kettle (1); The adsorption unit is provided with a cyclone adsorption column (8) loaded with adsorbent; The extractive rectification unit is provided with a stripping column (13); Wherein, the reaction kettle (1), the cyclone adsorption column (8) and the stripping column (13) are communicated in series; the stripping column (13) comprises a tower column (15) and a liquid tank (14) communicated with the bottom end of the tower column (15), and the liquid tank (14) is communicated with a liquid phase pass-through port (12) and an extractant inlet (20), so that the adsorbed mobile phase waste liquid and the extractant are contacted and rectified; The top end of the tower column (15) is provided with a top inlet and outlet (18), and the tower column (15) is provided with a water absorption section (17) for removing water in the acetonitrile evaporated from the liquid tank (14); The bottom of the water absorption section (17) is sequentially provided with a distillation section and an indication section (16), and the distillation section is provided with a middle inlet and outlet (19); The indication section is used to indicate the closing of the top inlet and outlet (18) and the opening of the middle inlet and outlet (19); The distillation section is used to collect the acetonitrile-containing distillation components after the top inlet and outlet (18) is closed through the middle inlet and outlet (19).

2. The device according to claim 1, wherein The chemical treatment unit is arranged above the adsorption unit, and the adsorption unit is provided with the extractive rectification unit on the side; 3. The apparatus of claim 1, wherein, The reaction kettle (1) comprises a kettle shell (2) and an inner kettle frame, the kettle shell (2) is provided with a heat exchange member for controlling the temperature of the inner kettle frame; the peripheral wall of the inner kettle frame surrounds a reaction cavity (3) for chemical reaction, and the inner kettle frame is provided with a waste liquid inlet and a waste liquid outlet (7); And / or The feeding tank (5) is an annular tank, and the internal space is divided into a first feeding tank for storing acidic treatment agent and a second feeding tank for storing alkaline treatment agent.

4. The apparatus of claim 3, wherein, The kettle shell (2) and the inner kettle frame are both cylindrical.

5. The apparatus of claim 4, wherein, The chemical treatment unit is provided with a stirring assembly (4) comprising a driving motor and a stirring paddle (6) connected with the driving motor, the driving motor is arranged on the top of the inner frame of the kettle, and the stirring paddle (6) extends into the inside of the reaction cavity (3); And / or The diameter of the outer wall of the kettle shell (2) is 500-800mm, and the height is 400-800mm; And / or The diameter of the inner wall of the inner frame of the kettle is 400-600mm, and the height is 300-600mm; And / or A waste liquid inlet penetrating through the kettle shell (2) is radially arranged on the upper end of the inner frame of the kettle, and a waste liquid outlet (7) penetrating through the kettle shell (2) is arranged on the bottom of the inner frame of the kettle; And / or The heat exchange element is a heating element.

6. The apparatus of claim 5, wherein, The feeding groove (5) is arranged on the outer surface of the top wall of the inner frame of the kettle and is sleeved on the periphery of the driving motor of the stirring assembly (4).

7. The device according to claim 6, wherein, The first feeding groove is provided with a first feeding pipe extending into the inside of the reaction cavity for feeding the acidic treating agent into the reaction cavity (3); And / or The second feeding groove is provided with a second feeding pipe extending into the inside of the reaction cavity for feeding the alkaline treating agent into the reaction cavity (3).

8. The apparatus of claim 2, wherein, The cyclone adsorption column (8) comprises an adsorption section with an adsorption cavity and a sedimentation section with a sedimentation cavity (10), the adsorption cavity is communicated with the sedimentation cavity (10), so that the adsorbent after adsorption can be gathered in the sedimentation cavity (10), and double spiral paddles (11) are arranged in the adsorption cavity.

9. The device according to claim 8, wherein, The adsorption cavity is a tapered cavity with a large top and a small bottom, the top end of the tapered cavity is communicated with the waste liquid outlet (7), and the bottom end is communicated with the sedimentation cavity (10).

10. The device according to claim 9, wherein, The diameter of the bottom end outlet of the tapered cavity is 100-200mm, and the height of the tapered cavity is 400-600mm; And / or The sedimentation cavity (10) is a cylindrical cavity.

11. The device according to claim 10, wherein, The diameter of the sedimentation cavity (10) is the same as the diameter of the bottom of the tapered cavity, and the height is 100-200mm.

12. The apparatus of claim 9, wherein, The adsorption section and the sedimentation section are detachably connected; And / or An adsorbent feeding port (9) is radially arranged on the upper part of the adsorption cavity, and a liquid phase passing port (12) is radially arranged on the lower part of the adsorption cavity; And / or The filter element is arranged on the waste liquid outlet (7).

13. The device according to claim 12, wherein, The filter element is at least one of a double-layer organic filter membrane, an inorganic ceramic membrane, an activated carbon filter element and a stainless steel filter sheet.

14. The device according to claim 13, wherein, The material of the organic filter membrane is one of polyether sulfone, polyvinyl chloride, polyacrylonitrile or polytetrafluoroethylene.

15. The device according to claim 2, wherein, The tower column (15) is a cylindrical column.

16. The device according to claim 15, wherein, The height of the tower column (15) is 1000-1500mm, and the diameter is 100-200mm.

17. The apparatus of claim 2, wherein, The water absorption section (17) is provided with a first fixing member for fixing the water absorption agent.

18. The apparatus of claim 17, wherein, the first fixing member is a water absorption agent frame; and / or The indicating section (16) is provided with a second fixing member for fixing the indicator.

19. The apparatus of claim 18, wherein, the water absorption agent frame is 200-400 mm in height; and / or the second fixing member is an indicator frame; and / or The extractant inlet (20) is arranged at the column (15) below the indicating section (16).

20. The apparatus of claim 19, wherein, the indicator frame is 50-100 mm in height.

21. A method of recycling acetonitrile mobile phase waste produced by liquid chromatography, characterized by, The method is carried out in the apparatus of any one of claims 12-20, comprising the following steps: 1) contacting the acetonitrile mobile phase waste liquid and the treatment agent in the chemical treatment unit under contacting conditions, so that the unsaturated organic matter in the acetonitrile mobile phase waste liquid is converted into high-boiling impurities, the protein is converted into a precipitate, and neutralization treatment is performed; 2) the acetonitrile mobile phase waste liquid after the contacting reaction in step 1) enters the adsorption unit for adsorption treatment to remove organic impurities; wherein, the solid impurities in the acetonitrile mobile phase waste liquid after the contacting reaction are intercepted by the filter member; 3) the acetonitrile mobile phase waste liquid after the adsorption treatment in step 2) enters the extractive rectification unit, and acetonitrile in the acetonitrile mobile phase waste liquid is separated from water and high-boiling impurities by extractive rectification to obtain high-purity acetonitrile; In step 1), the acetonitrile waste liquid is fed through the waste liquid inlet, the treatment agent is added through the feeding groove (5), and the contacting reaction is carried out in the reaction cavity (3) under the stirring of the stirring paddle (6), so that the unsaturated organic matter and the protein in the acetonitrile waste liquid are converted and neutralization treatment is performed; In step 3), an extractant is added to the liquid tank (14) through the extractant inlet (20), and the entering acetonitrile waste liquid is rectified; The acetonitrile is first evaporated in the liquid tank (14), enters the column (15), passes through the indicating section (16) and the distillation section, and then rises to the water absorption section (17) to remove water, and high-purity acetonitrile is collected from the top inlet and outlet port (18); When the water content evaporated from the liquid tank (14) gradually increases, the color change silica gel of the indicating section (16) gradually changes color, at which time the top inlet and outlet port (18) is closed and the middle inlet and outlet port (19) is opened to collect the acetonitrile-containing distillate component; when there is no more gas phase evaporated, heating is stopped, and the extractant is recovered from the liquid tank (14).

22. The method of claim 21, wherein, the contacting reaction conditions include: the stirring paddle (6) rotates at a speed of 60-180 r / min, the reaction temperature is 40-80℃, and the reaction time is 2-6h; and / or The amount of the treatment agent added to the reaction cavity (3) is 0.5%-2.5% of the total mass of the acetonitrile mobile phase waste liquid.

23. The method of claim 22, wherein, the treatment agent includes an acidic treatment agent added through the first feeding groove and an alkaline treatment agent added through the second feeding groove.

24. The method of claim 23, wherein, the acidic treatment agent comprises an acid and an acidic oxidizing agent; and the basic treatment agent comprises a base and a basic oxidizing agent.

25. The method of claim 24, wherein, the acid is selected from sulfuric acid and / or hypochlorous acid; and / or the acidic oxidizing agent is selected from potassium permanganate and / or potassium dichromate; and / or the base is selected from potassium hydroxide and / or sodium hydroxide; and / or the basic oxidizing agent is selected from at least one of copper hydroxide, hydrogen peroxide, sodium hypochlorite or sodium persulfate.

26. The method of claim 22, wherein, In step 2), the adsorbent is fed into the conical cavity of the cyclone adsorption column (8) through the adsorbent feeding port (9).

27. The method of claim 26, wherein, the adsorbent is contacted with the acetonitrile waste liquid at the first rotational speed of the double propeller (11) to remove polar organic impurities and macromolecular organic impurities; and / or the adsorbent is rapidly slid to the conical cavity wall and falls into the sedimentation cavity (10) to deposit at the second rotational speed of the double propeller (11); the acetonitrile mobile phase waste liquid after adsorption enters the liquid tank (14) from the liquid phase outlet (12).

28. The method of claim 27, wherein the adsorbent is selected from one or more of granular activated carbon, activated alumina, polyacrylamide particles and macroporous adsorption resin particles; and / or the average particle size of the adsorbent is 2-4 mesh; and / or the adsorption time is 1-2 h; and / or the first rotational speed is 60-120 r / min; and / or the second rotational speed is 360-480 r / min.

29. The method of claim 22, wherein, the water absorption section (17) is loaded with a water absorption agent selected from one or more of molecular sieves, phosphorus pentoxide, anhydrous calcium chloride and anhydrous magnesium sulfate; and / or the indicator section (16) is loaded with an indicator, which is a color-changing silica gel; and / or the rectification conditions include a heating temperature of 100-140°C, a reflux ratio of 1-4 at the top of the column, and a top discharge rate of 5-20 mL / min and a middle column discharge rate of 10-30 mL / min; and / or the amount of the extractant added is 10wt%-30wt% of the added mobile phase waste liquid; and / or the extractant is selected from at least one of ethylene glycol, an imidazole-based ionic liquid and a quaternary ammonium-based ionic liquid.

30. The method of claim 29, wherein, the imidazole-based ionic liquid is selected from 1-alkyl-3-methyl imidazole p-toluene sulfonate and / or 1-alkyl-2,3-dimethyl imidazole tetrafluoroborate; and / or the quaternary ammonium-based ionic liquid is selected from tributylmethylammonium chloride and / or tributylmethylammonium bisimide.

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