Triphenylphosphine solvent removal system and method

Abstract

The invention provides an efficient triphenylphosphine solvent removal system and method. The system integrates a quenching liquid storage tank, a film evaporator, a heat tracing conveying pipeline, a distillation crystallization kettle, a gas phase switching valve group, a methanol high-level tank and a chlorobenzene and methanol recovery device. Wherein the film evaporator is used for preliminarily separating chlorobenzene; the distillation crystallization kettle is provided with a jacket and is in switchable connection with the cooling water circulation system and the heating system through a temperature sensor, accurate temperature control is achieved, and the heating system provides the temperature needed by distillation and maintains the molten state of triphenylphosphine before methanol is dropwise added. The gas phase switching valve group is connected with a chlorobenzene and methanol recovery device, and methanol recovery liquid flows back to the distillation crystallization kettle. According to the system, two steps of chlorobenzene removal through secondary rectification and recrystallization purification are continuously completed in the same kettle, so that a chlorobenzene solvent is efficiently and economically removed from quenching liquid, and a high-purity triphenylphosphine product is obtained.

Description

Technical Field

[0001] This application belongs to the field of chemical product separation technology, and specifically relates to a triphenylphosphine solvent removal system and method. Background Technology

[0002] Triphenylphosphine (PPh), an important organophosphorus compound, has wide applications in pharmaceuticals, pesticides, polymer materials, and fine chemicals. With the rapid development of downstream industries, the demand for high-purity triphenylphosphine products is increasing daily.

[0003] Currently, the typical industrial process for producing triphenylphosphine involves the reaction of phosphorus trichloride with chlorobenzene under the action of a catalyst. However, this reaction system is complex. While the target product, triphenylphosphine, is generated, a large amount of byproducts and unreacted chlorobenzene solvent are often produced, forming a complex quenching solution containing triphenylphosphine, chlorobenzene, and small amounts of impurities. Existing solvent removal processes require multi-step separation and multiple recrystallization purification of the quenching solution. The entire process is time-consuming, and the recovery rate of triphenylphosphine is low, leading to increased production costs and energy consumption, and reduced production efficiency.

[0004] Therefore, how to efficiently and economically remove chlorobenzene solvent from the quenching solution to obtain high-purity triphenylphosphine products is a technical problem that urgently needs to be solved in current industrial production. Summary of the Invention

[0005] The purpose of this application is to provide a triphenylphosphine solvent removal system and method that can efficiently and economically remove chlorobenzene solvent from quenching fluid to obtain high-purity triphenylphosphine products.

[0006] To achieve the above-mentioned technical effects, this application provides a method for removing triphenylphosphine solvent, comprising the following steps:

[0007] S1, chlorobenzene is removed by a single distillation step;

[0008] S2, secondary distillation to remove chlorobenzene;

[0009] S3, recrystallization and separation yielded triphenylphosphine;

[0010] S2 and S3 are carried out in the same reactor. After S2 is completed, heating of the reactor is stopped. When the temperature inside the reactor is not lower than 80°C, methanol is continuously added dropwise to the reactor until the temperature inside the reactor is lower than 65°C. When the temperature inside the reactor drops to below 25°C, the recrystallized triphenylphosphine is separated.

[0011] In this scheme, by completing the two steps of secondary distillation to remove chlorobenzene and recrystallization purification in the same reactor, the time delay, material loss, and contamination risks associated with traditional multi-equipment transfers are avoided, significantly improving production efficiency and reducing energy consumption. Utilizing the physical property that triphenylphosphine is molten above 80℃, methanol is directly added dropwise to the molten triphenylphosphine. The methanol rapidly dissolves the molten triphenylphosphine and simultaneously evaporates endothermally, achieving a stable and uniform cooling process. This avoids localized overheating or oxidation, promotes the regular precipitation of crystals, and yields a high-purity triphenylphosphine product.

[0012] To achieve the above-mentioned technical effects, this application also provides a triphenylphosphine solvent removal system, comprising: a quenching liquid storage tank, a thin-film evaporator connected to the outlet of the quenching liquid storage tank, a chlorobenzene recovery device connected to the upper steam outlet of the thin-film evaporator, a conveying pipeline connected to the bottom concentrate outlet of the thin-film evaporator, a distillation crystallizer connected to the outlet of the conveying pipeline, a gas phase switching valve group connected to the top exhaust port of the distillation crystallizer, and a methanol high-level tank connected to the top liquid inlet of the distillation crystallizer. The gas phase switching valve group is respectively connected to the chlorobenzene recovery device and the methanol recovery device. The outlet of the methanol recovery device is connected to the reflux liquid inlet of the distillation crystallizer. The outer periphery of the distillation crystallizer is wrapped with a jacket. The jacket is switchably connected to a cooling water circulation system and a heating system. The heating system is used to provide the temperature required for the distillation of the triphenylphosphine mixture and to maintain the triphenylphosphine in the distillation crystallizer in a molten state before adding methanol.

[0013] Furthermore, a flow control valve is connected between the outlet of the methanol high-level tank and the inlet at the top of the distillation crystallization vessel to control the rate at which methanol is added dropwise to the molten triphenylphosphine.

[0014] Furthermore, the delivery pipeline is a heat-traced delivery pipeline, the inner layer of which forms a delivery channel for the triphenylphosphine mixture, and the outer layer forms a jacket space for heat exchange.

[0015] Furthermore, the chlorobenzene recovery device includes a chlorobenzene condenser and a chlorobenzene storage tank connected to the condensate outlet at the bottom of the chlorobenzene condenser.

[0016] Furthermore, the methanol recovery device includes a methanol condenser, with an inlet at the top of the methanol condenser connected to the gas phase switching valve assembly, and a liquid outlet at the bottom of the methanol condenser.

[0017] Furthermore, a methanol reflux pump is connected between the liquid outlet and the reflux inlet of the distillation crystallizer.

[0018] Furthermore, the outlet of the quenching liquid storage tank is connected to the inlet of the thin film evaporator via a metering pump.

[0019] Furthermore, the bottom of the distillation crystallization vessel is also provided with an inert gas inlet.

[0020] Furthermore, the above-mentioned triphenylphosphine solvent removal system also includes a vacuum assembly connected to the chlorobenzene recovery device and / or the methanol recovery device.

[0021] The beneficial effects of this application are as follows:

[0022] 1. This application provides a method for solvent removal of triphenylphosphine, which completes two steps—secondary distillation to remove chlorobenzene and recrystallization purification—in the same reactor. This avoids the time delays, material losses, and contamination risks associated with traditional multi-equipment transfers, significantly improving production efficiency and reducing energy consumption. Utilizing the physical property that triphenylphosphine is molten above 80°C, methanol is directly added dropwise to the molten triphenylphosphine. The methanol rapidly dissolves the molten triphenylphosphine and simultaneously evaporates, absorbing heat and achieving a stable and uniform cooling process. This avoids localized overheating or oxidation, promotes the regular precipitation of crystals, and yields a high-purity triphenylphosphine product.

[0023] 2. This application provides a triphenylphosphine solvent removal system that achieves the evaporation and recovery of chlorobenzene and methanol within a distillation crystallization vessel by utilizing a gas-phase switching valve assembly and a high-level methanol tank. Furthermore, by recrystallizing molten triphenylphosphine using methanol feedstock and reflux methanol within the distillation crystallization vessel, the efficiency and purity of triphenylphosphine recovery are improved. Precise jacket temperature control ensures efficient recrystallization of triphenylphosphine in its molten state, thereby optimizing the chlorobenzene recovery and triphenylphosphine purification process and effectively solving the problems of cumbersome, time-consuming, and energy-intensive processes inherent in traditional methods. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a triphenylphosphine solvent removal system in an embodiment of this application.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1. Quenching liquid storage tank; 2. Thin-film evaporator; 21. Steam outlet; 3. Chlorobenzene recovery unit; 31. Chlorobenzene condenser; 32. Chlorobenzene storage tank; 4. Heat tracing pipeline; 5. Distillation crystallizer; 51. Exhaust port; 52. Liquid inlet; 53. Inert gas inlet; 6. Gas phase switching valve group; 7. Methanol high-level tank; 71. Flow control valve; 8. Methanol recovery unit; 81. Methanol condenser; 82. Methanol reflux pump. Detailed Implementation

[0027] The embodiments of the technical solution of this application will be described in detail below. The following embodiments are only used to illustrate the technical solution of this application more clearly, and are therefore only examples, and should not be used to limit the scope of protection of this application.

[0028] Example 1

[0029] Figure 1 A schematic diagram of a triphenylphosphine solvent removal system according to an embodiment of this application is shown. This application provides a triphenylphosphine solvent removal system, such as... Figure 1 As shown, the apparatus includes: a quenching liquid storage tank 1; a thin-film evaporator 2 connected to the outlet of the quenching liquid storage tank 1; a chlorobenzene recovery device 3 connected to the upper steam outlet 21 of the thin-film evaporator 2; a conveying pipeline 4 connected to the bottom concentrate outlet 22 of the thin-film evaporator 2; a distillation crystallizer 5 connected to the outlet of the conveying pipeline 4; a gas phase switching valve group 6 connected to the top exhaust port 51 of the distillation crystallizer 5; and a methanol high-level tank 7 connected to the top liquid inlet 52 of the distillation crystallizer 5. The gas phase switching valve group 6 is connected to the chlorobenzene recovery device 3 and the methanol recovery device 8, respectively. The outlet of the methanol recovery device 8 is connected to the reflux liquid inlet of the distillation crystallizer 5. The distillation crystallizer 5 is surrounded by a jacket. The jacket is switchably connected to a cooling water circulation system and a heating system via a temperature sensor. The heating system is used to provide the temperature required for the distillation of the triphenylphosphine mixture and to maintain the triphenylphosphine in the distillation crystallizer 5 in a molten state before adding methanol.

[0030] Specifically, the quenching liquid storage tank 1 is used to store the triphenylphosphine quenching liquid obtained in the quenching process. The thin film evaporator 2 is preferably a scraped thin film evaporator. The quenching liquid in the quenching liquid storage tank 1 enters the feed port of the thin film evaporator 2 through the pipeline. Under the action of gravity, a liquid film is formed along the inner wall of the heating cylinder, and the film is forced to form by the high-speed rotating scraper for preliminary solvent evaporation.

[0031] Optionally, the outlet of the quenching liquid storage tank 1 is connected to the inlet of the thin-film evaporator 2 via a metering pump to transport the quenching liquid from the storage tank to the thin-film evaporator 2. The metering pump can be a corrosion-resistant pump with adjustable flow rate, such as a gear pump or a screw pump.

[0032] The high-concentration triphenylphosphine solution at the bottom of the thin-film evaporator 2 is transported to the distillation crystallizer 5 via the delivery pipeline 4. The delivery pipeline 4 is preferably a heated delivery pipeline with a double-layer structure. The inner layer forms a delivery channel for the triphenylphosphine mixture, and the outer layer forms a jacketed space for heat exchange. The inner layer wall can be made of corrosion-resistant materials such as stainless steel or enamel to accommodate any residual solvent or the corrosiveness of triphenylphosphine. The jacketed space is filled with a heat transfer medium, such as heat transfer oil, steam, or other suitable heating fluid.

[0033] The distillation crystallization vessel 5 is a jacketed reactor with a stirrer connected to the top. The jacket surrounding the distillation crystallization vessel 5 is switchably connected to a cooling water circulation system and a heating system via a temperature sensor. The heating system provides the temperature required for the distillation of the triphenylphosphine mixture and maintains the triphenylphosphine in a molten state within the distillation crystallization vessel 5 before the addition of methanol. Initially, as methanol is added dropwise from the methanol high-level tank 7 to the molten triphenylphosphine, some of the methanol evaporates and is condensed and recovered by the methanol recovery unit 8. After evaporation, it flows back into the distillation crystallization vessel 5. The cooling water circulation system is used to cool the distillation crystallization vessel 5 after the triphenylphosphine has fully dissolved in the methanol, recrystallizing the molten triphenylphosphine to obtain a high-purity product.

[0034] The gas phase switching valve assembly 6 switches the steam flow direction according to different stages of the distillation and crystallization process. In the initial stage of distillation, mainly chlorobenzene vapor is discharged. The gas phase switching valve assembly 6 connects the exhaust port 51 to the chlorobenzene recovery device 3, allowing the chlorobenzene vapor to enter the chlorobenzene recovery device 3 for recovery. After the addition of methanol, the discharged steam is mainly methanol vapor. The gas phase switching valve assembly 6 connects the exhaust port 51 to the methanol recovery device 8 to achieve methanol recovery.

[0035] In one implementation, a flow control valve 71 is connected between the outlet of the methanol high-level tank 7 and the inlet 52 at the top of the distillation crystallizer 5 to control the rate at which methanol is added dropwise to molten triphenylphosphine. The flow control valve 71 can be a high-precision proportional regulating valve, which can accurately control the rate at which methanol is added to molten triphenylphosphine to ensure the smooth progress of the recrystallization process and the good morphology of the product crystals.

[0036] Preferably, the chlorobenzene recovery device 3 includes a chlorobenzene condenser 31 and a chlorobenzene storage tank 32 connected to the condensate outlet at the bottom of the chlorobenzene condenser 31.

[0037] Preferably, the methanol recovery device 8 includes a methanol condenser 81, with an air inlet at the top of the methanol condenser 81 connected to the gas phase switching valve group 6, and a liquid outlet at the bottom of the methanol condenser 81.

[0038] Optionally, a methanol reflux pump 82 is connected between the liquid outlet and the reflux inlet of the distillation crystallizer 5. This pump is used to pump the condensed methanol liquid back to the distillation crystallizer 5, thereby realizing the recycling of methanol.

[0039] Preferably, the system also includes a vacuum assembly connected to the chlorobenzene recovery unit 3 and / or the methanol recovery unit 8. The vacuum assembly can reduce the pressure within the system, allowing chlorobenzene to evaporate at a lower temperature, reducing the possibility of triphenylphosphine undergoing side reactions due to high temperatures, while simultaneously improving the evaporation rate and recovery efficiency of chlorobenzene.

[0040] In one implementation, the bottom of the distillation crystallization vessel 5 is further provided with an inert gas inlet 53. The inert gas is preferably nitrogen. During the distillation and crystallization process of triphenylphosphine, a small amount of inert gas can be periodically or continuously introduced into the vessel to form an inert atmosphere, effectively removing any residual oxygen in the vessel, preventing the triphenylphosphine from being oxidized at high temperatures, ensuring product purity, and improving operational safety.

[0041] The method for solvent removal of triphenylphosphine using the above-mentioned solvent removal system includes the following steps:

[0042] S1, Primary distillation to remove chlorobenzene: The quenching solution is fed from the quenching solution storage tank 1 into the thin-film evaporator 2 to evaporate the chlorobenzene solvent. The evaporated chlorobenzene vapor enters the chlorobenzene recovery unit 3 for condensation and recovery. The preliminarily concentrated triphenylphosphine solution is discharged from the concentrate outlet 22 at the bottom of the thin-film evaporator 2.

[0043] S2, Secondary distillation to remove chlorobenzene: The pre-concentrated triphenylphosphine solution discharged from the bottom of the thin-film evaporator 2 is transported to the distillation crystallizer 5 via a heated pipeline 4, with the heating temperature of the pipeline 4 not lower than 90℃. The distillation crystallizer 5 is stirred and heated to reach a temperature of 110±5℃ to further evaporate residual chlorobenzene. The gas phase switching valve group 6 is operated to connect the exhaust port 51 of the distillation crystallizer 5 to the chlorobenzene recovery unit 3, closing the passage to the methanol recovery unit 8. The chlorobenzene vapor evaporated in the vessel enters the chlorobenzene condenser 31 of the chlorobenzene recovery unit 3, and is condensed and recovered to the chlorobenzene storage tank 32. When the chlorobenzene in the vessel is almost completely evaporated, heating is stopped, and the temperature inside the distillation crystallizer 5 is maintained at not lower than 80±5℃ by the heating system, keeping the triphenylphosphine in a molten state to prepare for subsequent recrystallization purification.

[0044] S3, recrystallization separation to obtain triphenylphosphine: Operate the gas phase switching valve group 6 to switch it to the methanol recovery unit 8, while simultaneously closing the passage to the chlorobenzene recovery unit 3, and stop heating the jacket of the distillation crystallizer 5. Methanol is slowly added dropwise from the methanol high-level tank 7 to the molten triphenylphosphine through the top inlet 52 of the distillation crystallizer 5. As methanol continues to be added, the triphenylphosphine gradually dissolves, and the temperature of the vessel gradually decreases due to the evaporation of methanol carrying away some heat. During this process, the evaporated methanol vapor enters the methanol recovery unit 8 through the gas phase switching valve group 6, where it is condensed into liquid methanol by the methanol condenser and returned to the distillation crystallizer 5 through the reflux inlet connected to the outlet of the methanol recovery unit 8, realizing the recycling of methanol. When the vessel temperature drops below 65±2℃, the addition and reflux of methanol are stopped. Switch the jacket of the distillation crystallizer 5 from the heating system to the cooling water circulation system to cool the temperature of the material inside the vessel to 25±2℃. Triphenylphosphine dissolved in methanol will precipitate crystals, and recrystallization and purification will be completed to obtain the triphenylphosphine product.

[0045] Based on the embodiments provided in this application, some specific experiments have been conducted, which can be referred to in the following examples, and comparative examples are also given. From these examples and comparative examples, it can be seen that the solution provided in this application achieves good results. It should be noted that the following examples are only used to illustrate the present invention in detail and do not limit the scope of protection of the invention in any way.

[0046] The initial component content (mass percentage) of the quenching fluid used in the following examples and comparative examples is: triphenylphosphine 35%, chlorobenzene 60%, and by-products and impurities 5%.

[0047] Example 2

[0048] This embodiment provides a system for the removal of triphenylphosphine solvent, employing... Figure 1 The system structure shown is used for solvent removal of triphenylphosphine from the quenching solution. The method steps include S1, S2, and S3 as described in Example 1.

[0049] Example 3

[0050] This embodiment provides a system for removing triphenylphosphine solvent. The difference from Embodiment 2 is that the thin-film evaporator 2 and the distillation crystallizer 5 are connected by a pipeline without heating function; otherwise, they are the same as in Embodiment 2. The method steps also include S1, S2, and S3 as described in Embodiment 1.

[0051] Comparative Example 1

[0052] This embodiment provides a system for solvent removal of triphenylphosphine. The difference from Embodiment 2 is that the methanol recovery device 8 is not set up and the gas phase switching valve group 6 is replaced with an exhaust valve. The operation steps are adapted. In step S2, when the chlorobenzene in the vessel is basically evaporated, the heating is stopped and the jacket of the distillation crystallization vessel 5 is switched from the heating system to the cooling water circulation system to cool the temperature of the material in the vessel and obtain crude triphenylphosphine. In step S3, methanol is added from the methanol high-level tank 7 through the liquid inlet 52 at the top of the distillation crystallization vessel 5 to the cooled crude triphenylphosphine to dissolve and recrystallize it, instead of adding it dropwise to the molten triphenylphosphine. The rest is the same as in Embodiment 2.

[0053] The purity of the triphenylphosphine products obtained in Examples 2-3 and Comparative Example 1 was determined by high performance liquid chromatography (HPLC). The recovery rate of triphenylphosphine was calculated using the following formula (1), where η is the recovery rate of triphenylphosphine, and m out For the quality of dried products, m in C represents the total mass of the quenching fluid. in The values ​​represent the mass percentage of triphenylphosphine. The test results are shown in Table 1 below.

[0054]

[0055] Table 1. Experimental data on solvent removal of triphenylphosphine from Examples 2-3 and Comparative Example 1.

[0056] Example 2 Example 3 Comparative Example 1 Triphenylphosphine purity (%) 96.2 95.4 95.5 Triphenylphosphine recovery rate (%) 93.5 89.7 85.3 Single batch processing time (h) 4.5 5.8 7.2 Total energy consumption (kWh / kg) 14.6 17.9 22.4

[0057] Experimental conclusion:

[0058] The purity differences of the triphenylphosphine obtained in Examples 2, 3, and Comparative Example 1 are small, indicating that the triphenylphosphine solvent removal system of this application, which recrystallizes molten triphenylphosphine with methanol, has less impact on the purity of triphenylphosphine compared to the prior art method of recrystallizing cooled triphenylphosphine with methanol. Although the purity of Comparative Example 1 was close to or even slightly higher than that of Example 3 in this experiment, its single-batch processing time and total processing energy consumption were significantly higher than those of Examples 2 and 3.

[0059] Example 2 achieved a triphenylphosphine recovery rate of 93.5%, significantly better than Example 3 and Comparative Example 1. This demonstrates that the heated delivery pipeline effectively avoids cooling crystallization and adhesion loss of triphenylphosphine during transportation. Furthermore, the effective recovery and recycling of methanol further reduces the risk of solvent carrying away the product, thereby maximizing the recovery efficiency of triphenylphosphine. Therefore, the triphenylphosphine solvent removal system of this application exhibits significant comprehensive advantages in terms of product purity, recovery rate, single-batch processing time, and total energy consumption, further validating the beneficial effects of this application.

[0060] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

[0061] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for removing triphenylphosphine solvent, comprising the following steps: S1, chlorobenzene is removed by a single distillation; S2, secondary distillation to remove chlorobenzene; S3, recrystallization and separation yielded triphenylphosphine; The feature is that: S2 and S3 are carried out in the same reactor. After S2 is completed, the reactor is stopped from heating. When the temperature inside the reactor is not lower than 80°C, methanol is continuously added dropwise to the reactor until the temperature inside the reactor is lower than 65°C. When the temperature inside the reactor drops to below 25°C, the recrystallized triphenylphosphine is separated.

2. A triphenylphosphine solvent removal system, characterized in that, include: Quenching liquid storage tank (1), thin-film evaporator (2) connected to the outlet of the quenching liquid storage tank (1), chlorobenzene recovery device (3) connected to the upper steam outlet (21) of the thin-film evaporator (2), conveying pipeline (4) connected to the bottom concentrate outlet (22) of the thin-film evaporator (2), distillation crystallizer (5) connected to the outlet of the conveying pipeline (4), gas phase switching valve group (6) connected to the top exhaust port (51) of the distillation crystallizer (5), and liquid inlet (52) connected to the top of the distillation crystallizer (5). The methanol high-level tank (7) is connected to the chlorobenzene recovery device (3) and the methanol recovery device (8) respectively. The outlet of the methanol recovery device (8) is connected to the reflux inlet of the distillation crystallizer (5). The outer periphery of the distillation crystallizer (5) is wrapped with a jacket. The jacket is switchably connected to the cooling water circulation system and the heating system. The heating system is used to provide the temperature required for the distillation of the triphenylphosphine mixture and to maintain the triphenylphosphine in the distillation crystallizer (5) in a molten state before adding methanol.

3. The triphenylphosphine solvent removal system as described in claim 2, characterized in that, A flow control valve (71) is connected between the outlet of the methanol high-level tank (7) and the top inlet (52) of the distillation crystallizer (5) to control the rate at which methanol is added to the molten triphenylphosphine.

4. The triphenylphosphine solvent removal system as described in claim 2, characterized in that, The delivery pipeline (4) is a heat-traced delivery pipeline. The inner layer of the heat-traced delivery pipeline forms a delivery channel for the triphenylphosphine mixture, and its outer layer forms a jacket space for heat exchange.

5. The triphenylphosphine solvent removal system as described in claim 2, characterized in that, The chlorobenzene recovery device (3) includes a chlorobenzene condenser (31) and a chlorobenzene storage tank (32) connected to the condensate outlet at the bottom of the chlorobenzene condenser (31).

6. The triphenylphosphine solvent removal system as described in claim 2, characterized in that, The methanol recovery device (8) includes a methanol condenser (81), the top of which has an air inlet connected to the gas phase switching valve group (6), and the liquid outlet is located at the bottom of the methanol condenser (81).

7. The triphenylphosphine solvent removal system as described in claim 6, characterized in that, A methanol reflux pump (82) is connected between the liquid outlet and the reflux inlet of the distillation crystallizer (5).

8. The triphenylphosphine solvent removal system as described in claim 2, characterized in that, The outlet of the quenching liquid storage tank (1) is connected to the inlet of the thin film evaporator (2) via a metering pump.

9. The triphenylphosphine solvent removal system as described in claim 2, characterized in that, The bottom of the distillation crystallizer (5) is also provided with an inert gas inlet (53).

10. The triphenylphosphine solvent removal system as described in claim 2, characterized in that, It also includes a vacuum assembly connected to the chlorobenzene recovery unit (3) and / or the methanol recovery unit (8).

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