Efficient concentration and dehydration process for triphenylphosphine crude product

Abstract

An efficient concentration and dehydration process for a triphenylphosphine crude product belongs to the field of triphenylphosphine dehydration, and comprises the following steps: S1, adding an entrainer into the triphenylphosphine crude product, the weight ratio of the entrainer to the triphenylphosphine crude product being (1-2): 1, and the entrainer being formed by mixing normal hexane and toluene according to 1: 1; s2, putting the mixture obtained in the step S1 into a distillation kettle, and heating until the azeotropic temperature is 70-85 DEG C; s3, controlling the distillation pressure to be normal pressure, azeotropic for 1-2 hours, and boiling off the entrainer and water to obtain a triphenylphosphine solution; s4, enabling the triphenylphosphine solution subjected to azeotropic dehydration to pass through a dynamic adsorption device, and filling an adsorption tower of the dynamic adsorption device with a modified molecular sieve as an adsorbent; through a combined process of azeotropic distillation, dynamic adsorption and short-path molecular distillation, the water content in the triphenylphosphine crude product can be remarkably reduced, the purity is improved, and the quality of the final product is ensured to reach a high standard.

Description

Technical Field

[0001] The invention relates to the field of triphenylphosphine dehydration, and more specifically to a high-efficiency concentration and dehydration process for crude triphenylphosphine. Background Art

[0002] At present, in the pharmaceutical industry and fine chemical industry, triphenylphosphine is widely used as an important raw material or reagent. However, due to the limitation of production technology, what is usually obtained is a crude triphenylphosphine containing a large amount of moisture and other impurities. In order to meet the needs of subsequent applications, it must be purified. As an important organophosphorus compound, triphenylphosphine has a wide range of applications in industries such as medicine, pesticides and fine chemicals. However, due to its complex production process, low yield, and a large amount of moisture and other impurities in the crude product, the purity and quality of the final product are seriously affected. At present, common concentration and dehydration methods mainly include distillation, vacuum drying and adsorbent dehumidification.

[0003] The invention patent with publication number CN110343133A discloses a method for producing triphenylphosphine by reduction, which relates to the field of triphenylphosphine production. The steps include dripping trichlorosilane after dehydrating triphenylphosphine oxide and solvent toluene, reducing triphenylphosphine oxide to triphenylphosphine, dripping into a hydrolysis kettle, using chloromethyl ether to recover the tail gas HCL as a by-product hydrochloric acid by using a falling film absorption device, separating the water phase to filter out silicon dioxide, washing the organic phase with water and stratifying it, and then putting it into a distillation kettle to recover toluene, toluene reuse, material desolvation solution and methanol dissolution stirring evenly, cooling crystallization, methanol is applied several times and then distilled and reused, and the crystallized material is centrifuged and then vacuum dried and packaged to obtain the product triphenylphosphine. The beneficial effect is that the present invention produces triphenylphosphine by reduction method, which is environmentally friendly and does not produce three wastes, and saves costs. However, the process flow of the scheme is long, and the crude product contains a large amount of water and other impurities, which affects the quality of the final product. Summary of the invention

[0004] To address this problem, this scheme proposes a highly efficient concentration and dehydration process for crude triphenylphosphine.

[0005] This scheme designs a highly efficient concentration and dehydration process for crude triphenylphosphine, comprising the following steps: S1. Adding an entrainer to the crude triphenylphosphine, the ratio of the weight of the entrainer to the weight of the crude triphenylphosphine is 1-2:1, and the entrainer is a mixture of n-hexane and toluene in a ratio of 1:1; the low boiling point of n-hexane ensures that water is quickly taken away, shortening the dehydration time, and the higher boiling point of toluene extends the efficient dehydration stage of azeotropic distillation, thereby improving the final dehydration depth; n-hexane effectively reduces the risk of high-temperature decomposition and protects the structure of triphenylphosphine, and toluene has a good dissolving and carrying-out effect on polar impurities, thereby further improving the purity of the product; the combination of the two solvents reduces the demand for a single solvent, and both n-hexane and toluene can be recycled and reused by distillation; toluene is a weakly polar solvent, has a certain scavenging effect on polar impurities, and is more conducive to improving the purity of triphenylphosphine.

[0006] S2, placing the mixture obtained in S1 in a distillation kettle, and heating to an azeotropic temperature of 70-85°C; S3, controlling the distillation pressure to normal pressure, azeotroping for 1-2 hours, the entrainer and water are boiled away, and a triphenylphosphine solution is obtained; The purpose is to quickly remove most of the water in the crude product and reduce the burden of subsequent dehydration.

[0007] S4, passing the triphenylphosphine solution after azeotropic dehydration through a dynamic adsorption device, using a modified molecular sieve as an adsorbent, and loading it into an adsorption tower of the dynamic adsorption device; S5. Control the material flow rate to 1-2 cm / s, adsorb for 0.5-1 hour, ensure that the material is fully in contact with the adsorbent, and obtain the material after adsorption and dehydration; The purpose is to further remove residual moisture and some polar impurities, including oxides and esters.

[0008] S6, sending the material after adsorption and dehydration in S5 to a short-range molecular distillation device, setting the distillation temperature to 150-180°C, the ambient pressure to 0.01-0.1 mbar, and distilling for 30-60 minutes; S7. Triphenylphosphine is separated and condensed in the form of vapor, and non-volatile impurities remain in the short-range molecular distillation device. The condensed product is collected to ensure that no impurities remain.

[0009] The purpose is to remove non-volatile impurities and ensure that the purity of triphenylphosphine products meets industry requirements.

[0010] Preferably, the steam after boiling the azeotropic agent and water in S3 is condensed and then separated into layers, and the azeotropic agent is recovered for recycling.

[0011] Preferably, the distillation kettle in S2-S3 maintains good sealing performance to reduce the volatilization loss of the entrainer.

[0012] Preferably, the dynamic adsorption device in S4 is selected according to the scale of the enterprise. For large-scale dehydration treatment, an industrialized continuous flow adsorption tower system is selected, and for small and medium-scale dehydration treatment, a multifunctional fixed bed adsorption device is selected.

[0013] Preferably, after the adsorption in S5 is completed, the adsorbent is regenerated every 5-7 days, the regeneration process includes heating and vacuum treatment, and the adsorption tower is cleaned every 5-7 days to prevent clogging.

[0014] Preferably, the residues in the short-range molecular distillation device in S7 should be cleaned up in time.

[0015] Preferably, the weight ratio of the entrainer to the crude triphenylphosphine is 1.2-1.8:1.

[0016] Preferably, the weight ratio of the entrainer to the crude triphenylphosphine is 1.5:1.

[0017] Compared with the prior art, the advantages of the present invention are: (1) The present invention can significantly reduce the water content in the crude triphenylphosphine product and improve the purity at the same time through the combined process of azeotropic distillation, dynamic adsorption and short-range molecular distillation, thereby ensuring that the quality of the final product reaches a high standard.

[0018] (2) The present invention uses n-hexane and toluene as azeotropes. The low boiling point of n-hexane ensures that water is quickly removed, shortening the dehydration time. The higher boiling point of toluene prolongs the efficient dehydration stage of azeotropic distillation, thereby increasing the final dehydration depth. n-hexane effectively reduces the risk of high-temperature decomposition and protects the structure of triphenylphosphine. Toluene has a good dissolving and removing effect on polar impurities, further improving the purity of the product. The combination of the two solvents reduces the demand for a single solvent, and both n-hexane and toluene can be recycled and reused by distillation. Toluene is a weakly polar solvent and has a certain scavenging effect on polar impurities, which is more helpful to improve the purity of triphenylphosphine. (3) The azeotropic agent and the adsorbent of the present invention can be recycled, thereby reducing solvent consumption and waste discharge. At the same time, the yield of triphenylphosphine is increased by optimizing the separation technology, thereby achieving efficient resource utilization and environmental friendliness. DETAILED DESCRIPTION

[0019] The present application is further described in detail below in conjunction with examples, comparative examples and performance testing experiments. These examples should not be construed as limiting the scope of protection claimed in the present application.

[0020] Examples 1-5 Embodiment 1: A process for efficiently concentrating and dehydrating crude triphenylphosphine, comprising the following steps: S1, to the crude triphenylphosphine, an entrainer is added, the ratio of the weight of the entrainer to the weight of the crude triphenylphosphine is 1.5:1, and the entrainer is formed by mixing normal hexane and toluene in a ratio of 1:1; S2, placing the mixture obtained in S1 in a distillation kettle and heating it to an azeotropic temperature of 78°C; S3, controlling the distillation pressure to normal pressure, azeotroping for 2 hours, the entrainer and water boil away, and a triphenylphosphine solution is obtained; S4, passing the triphenylphosphine solution after azeotropic dehydration through a dynamic adsorption device, using a modified molecular sieve as an adsorbent, and loading it into an adsorption tower of the dynamic adsorption device; S5. Control the material flow rate to 1 cm / s and adsorb for 1 hour to ensure that the material is in full contact with the adsorbent to obtain the material after adsorption and dehydration; S6, sending the material after adsorption and dehydration in S5 to a short-range molecular distillation device, setting the distillation temperature to 170°C, the ambient pressure to 0.05 mbar, and distilling for 60 minutes; S7. Triphenylphosphine is separated and condensed in the form of vapor, and non-volatile impurities remain in the short-range molecular distillation device. The condensed product is collected to ensure that no impurities remain.

[0021] Embodiment 2: A process for efficiently concentrating and dehydrating a crude triphenylphosphine product, comprising the following steps: S1, adding an azeotropic agent to the crude triphenylphosphine product, wherein the ratio of the weight of the azeotropic agent to the weight of the crude triphenylphosphine product is 1:1, and the azeotropic agent is a mixture of n-hexane and toluene in a ratio of 1:1; S2, placing the mixture obtained in S1 in a distillation kettle, and heating it to an azeotropic temperature of 78°C; S3, controlling the distillation pressure to be normal pressure, azeotroping for 2 hours, and the azeotropic agent and water are boiled away to obtain a triphenylphosphine solution; S4, passing the triphenylphosphine solution after azeotropic dehydration through a dynamic adsorption device, using a modified molecular sieve as an adsorbent, and loading it into an adsorption tower of the dynamic adsorption device; S5. Control the material flow rate to 1 cm / s and adsorb for 1 hour to ensure that the material is in full contact with the adsorbent to obtain the material after adsorption and dehydration; S6, sending the material after adsorption and dehydration in S5 to a short-range molecular distillation device, setting the distillation temperature to 170°C, the ambient pressure to 0.05 mbar, and distilling for 60 minutes; S7, triphenylphosphine is separated and condensed in the form of vapor, non-volatile impurities remain in the short-range molecular distillation device, and the condensed product is collected to ensure that no impurities remain; Example 3: A process for efficiently concentrating and dehydrating a crude triphenylphosphine product, comprising the following steps: S1, adding an azeotropic agent to the crude triphenylphosphine product, wherein the weight ratio of the azeotropic agent to the weight of the crude triphenylphosphine product is 2:1, and the azeotropic agent is a mixture of n-hexane and toluene in a ratio of 1:1; S2, placing the mixture obtained in S1 in a distillation kettle, and heating it to an azeotropic temperature of 78°C; S3, controlling the distillation pressure to normal pressure, azeotroping for 2 hours, the entrainer and water boil away, and a triphenylphosphine solution is obtained; S4, passing the triphenylphosphine solution after azeotropic dehydration through a dynamic adsorption device, using a modified molecular sieve as an adsorbent, and loading it into an adsorption tower of the dynamic adsorption device; S5. Control the material flow rate to 1 cm / s and adsorb for 1 hour to ensure that the material is in full contact with the adsorbent to obtain the material after adsorption and dehydration; S6, sending the material after adsorption and dehydration in S5 to a short-range molecular distillation device, setting the distillation temperature to 170°C, the ambient pressure to 0.05 mbar, and distilling for 60 minutes; S7, triphenylphosphine is separated and condensed in the form of vapor, non-volatile impurities remain in the short-range molecular distillation device, and the condensed product is collected to ensure that no impurities remain; Example 4: A process for efficiently concentrating and dehydrating a crude triphenylphosphine product, comprising the following steps: S1, adding an azeotropic agent to the crude triphenylphosphine product, wherein the ratio of the weight of the azeotropic agent to the weight of the crude triphenylphosphine product is 1.2:1, and the azeotropic agent is a mixture of n-hexane and toluene in a ratio of 1:1; S2, placing the mixture obtained in S1 in a distillation kettle, and heating it to an azeotropic temperature of 78°C; S3, controlling the distillation pressure to normal pressure, azeotroping for 2 hours, the entrainer and water boil away, and a triphenylphosphine solution is obtained; S4, passing the triphenylphosphine solution after azeotropic dehydration through a dynamic adsorption device, using a modified molecular sieve as an adsorbent, and loading it into an adsorption tower of the dynamic adsorption device; S5. Control the material flow rate to 1 cm / s and adsorb for 1 hour to ensure that the material is in full contact with the adsorbent to obtain the material after adsorption and dehydration; S6, sending the material after adsorption and dehydration in S5 to a short-range molecular distillation device, setting the distillation temperature to 170°C, the ambient pressure to 0.05 mbar, and distilling for 60 minutes; S7, triphenylphosphine is separated and condensed in the form of vapor, non-volatile impurities remain in the short-range molecular distillation device, and the condensed product is collected to ensure that no impurities remain; Example 5: A process for efficiently concentrating and dehydrating a crude triphenylphosphine product, comprising the following steps: S1, adding an azeotropic agent to the crude triphenylphosphine product, wherein the ratio of the weight of the azeotropic agent to the weight of the crude triphenylphosphine product is 1.8:1, and the azeotropic agent is a mixture of n-hexane and toluene in a ratio of 1:1; S2, placing the mixture obtained in S1 in a distillation kettle, and heating it to an azeotropic temperature of 78°C; S3, controlling the distillation pressure to normal pressure, azeotroping for 2 hours, the entrainer and water boil away, and a triphenylphosphine solution is obtained; S4, passing the triphenylphosphine solution after azeotropic dehydration through a dynamic adsorption device, using a modified molecular sieve as an adsorbent, and loading it into an adsorption tower of the dynamic adsorption device; S5. Control the material flow rate to 1 cm / s and adsorb for 1 hour to ensure that the material is in full contact with the adsorbent to obtain the material after adsorption and dehydration; S6, sending the material after adsorption and dehydration in S5 to a short-range molecular distillation device, setting the distillation temperature to 170°C, the ambient pressure to 0.05 mbar, and distilling for 60 minutes; S7, triphenylphosphine is separated and condensed in the form of vapor, non-volatile impurities remain in the short-range molecular distillation device, and the condensed product is collected to ensure that no impurities remain; Embodiment 6-7 Embodiment 6: A process for efficiently concentrating and dehydrating crude triphenylphosphine, comprising the following steps: S1, to the crude triphenylphosphine, an entrainer is added, the ratio of the weight of the entrainer to the weight of the crude triphenylphosphine is 1.5:1, and the entrainer is formed by mixing normal hexane and toluene in a ratio of 1:1; S2, placing the mixture obtained in S1 in a distillation kettle and heating it to an azeotropic temperature of 78°C; S3, controlling the distillation pressure to normal pressure, azeotroping for 2 hours, the entrainer and water boil away, and a triphenylphosphine solution is obtained; S4, passing the triphenylphosphine solution after azeotropic dehydration through a dynamic adsorption device, using a modified molecular sieve as an adsorbent, and loading it into an adsorption tower of the dynamic adsorption device; S5. Control the material flow rate to 2 cm / s and adsorb for 0.5 hours to ensure that the material is in full contact with the adsorbent to obtain the material after adsorption and dehydration; S6, sending the material after adsorption and dehydration in S5 to a short-range molecular distillation device, setting the distillation temperature to 170°C, the ambient pressure to 0.05 mbar, and distilling for 60 minutes; S7. Triphenylphosphine is separated and condensed in the form of vapor, and non-volatile impurities remain in the short-range molecular distillation device. The condensed product is collected to ensure that no impurities remain.

[0022] Embodiment 7: A process for efficiently concentrating and dehydrating crude triphenylphosphine, comprising the following steps: S1, to the crude triphenylphosphine, an entrainer is added, the ratio of the weight of the entrainer to the weight of the crude triphenylphosphine is 1.5:1, and the entrainer is formed by mixing normal hexane and toluene in a ratio of 1:1; S2, placing the mixture obtained in S1 in a distillation kettle and heating it to an azeotropic temperature of 78°C; S3, controlling the distillation pressure to normal pressure, azeotroping for 2 hours, the entrainer and water boil away, and a triphenylphosphine solution is obtained; S4, passing the triphenylphosphine solution after azeotropic dehydration through a dynamic adsorption device, using a modified molecular sieve as an adsorbent, and loading it into an adsorption tower of the dynamic adsorption device; S5. Control the material flow rate to 1.5 cm / s and adsorb for 0.7 hours to ensure that the material is in full contact with the adsorbent to obtain the material after adsorption and dehydration; S6, sending the material after adsorption and dehydration in S5 to a short-range molecular distillation device, setting the distillation temperature to 170°C, the ambient pressure to 0.05 mbar, and distilling for 60 minutes; S7. Triphenylphosphine is separated and condensed in the form of vapor, and non-volatile impurities remain in the short-range molecular distillation device. The condensed product is collected to ensure that no impurities remain.

[0023] Embodiment 8-9 Embodiment 8: A process for efficiently concentrating and dehydrating crude triphenylphosphine, comprising the following steps: S1, to the crude triphenylphosphine, an entrainer is added, the ratio of the weight of the entrainer to the weight of the crude triphenylphosphine is 1.5:1, and the entrainer is formed by mixing normal hexane and toluene in a ratio of 1:1; S2, placing the mixture obtained in S1 in a distillation kettle and heating it to an azeotropic temperature of 78°C; S3, controlling the distillation pressure to normal pressure, azeotroping for 2 hours, the entrainer and water boil away, and a triphenylphosphine solution is obtained; S4, passing the triphenylphosphine solution after azeotropic dehydration through a dynamic adsorption device, using a modified molecular sieve as an adsorbent, and loading it into an adsorption tower of the dynamic adsorption device; S5. Control the material flow rate to 1 cm / s and adsorb for 1 hour to ensure that the material is in full contact with the adsorbent to obtain the material after adsorption and dehydration; S6, sending the material after adsorption and dehydration in S5 to a short-range molecular distillation device, setting the distillation temperature to 170°C, the ambient pressure to 0.1 mbar, and distilling for 60 minutes; S7. Triphenylphosphine is separated and condensed in the form of vapor, and non-volatile impurities remain in the short-range molecular distillation device. The condensed product is collected to ensure that no impurities remain.

[0024] Embodiment 9: A process for efficiently concentrating and dehydrating crude triphenylphosphine, comprising the following steps: S1, to the crude triphenylphosphine, an entrainer is added, the ratio of the weight of the entrainer to the weight of the crude triphenylphosphine is 1.5:1, and the entrainer is formed by mixing normal hexane and toluene in a ratio of 1:1; S2, placing the mixture obtained in S1 in a distillation kettle and heating it to an azeotropic temperature of 78°C; S3, controlling the distillation pressure to normal pressure, azeotroping for 2 hours, the entrainer and water boil away, and a triphenylphosphine solution is obtained; S4, passing the triphenylphosphine solution after azeotropic dehydration through a dynamic adsorption device, using a modified molecular sieve as an adsorbent, and loading it into an adsorption tower of the dynamic adsorption device; S5. Control the material flow rate to 1 cm / s and adsorb for 1 hour to ensure that the material is in full contact with the adsorbent to obtain the material after adsorption and dehydration; S6, sending the material after adsorption and dehydration in S5 to a short-range molecular distillation device, setting the distillation temperature to 170°C, the ambient pressure to 0.01 mbar, and distilling for 60 minutes; S7. Triphenylphosphine is separated and condensed in the form of vapor, and non-volatile impurities remain in the short-range molecular distillation device. The condensed product is collected to ensure that no impurities remain.

[0025] Comparative Example Comparative Example 1: The difference from Example 1 is that only n-hexane is selected as the azeotropic agent; Comparative Example 2: The difference from Example 1 is that only toluene is selected as the azeotropic agent; Comparative Example 3: The difference from Example 1 is that the adsorbent is activated alumina; Comparative Example 4: The difference from Example 1 is that S1-S3 are missing; Examples 1-9 and Comparative Examples 1-4 were subjected to comparative experiments under the following conditions: Step 1, select the same crude triphenylphosphine, water content 7%, the crude triphenylphosphine is subjected to standard operation according to the above-mentioned embodiment and comparative example operation steps, and then the triphenylphosphine sample obtained by condensation is sealed and stored for subsequent detection; Step 2: Measure the water content of the triphenylphosphine sample by Karl Fischer volumetric method, calibrate and preheat the equipment with a Karl Fischer moisture meter, accurately weigh 0.2 g of the triphenylphosphine sample and put it into a sample bottle, add an appropriate amount of anhydrous methanol to dissolve the sample, start the titrator, record the titration consumption, calculate the final water content according to the titration solution consumption, repeat 3 times and take the average value; Step 3: Use gas chromatography to detect the purity of the triphenylphosphine sample. Configure a calibration curve for the internal standard method. Accurately weigh 0.5 g of the sample and dissolve it in n-hexane. Inject the sample into a gas chromatograph. Select a starting temperature of 80°C and a heating rate of 5°C / min. Record the chromatographic peak area and calculate the purity of the triphenylphosphine.

[0026] The data obtained are shown in Table 1: Table 1 Result analysis: Effect of azeotropic agent selection: n-hexane + toluene mixed azeotropic agent (Examples 1-9) is significantly better than a single azeotropic agent (Comparative Example 1, Comparative Example 2). The dehydration efficiency of a single azeotropic agent is low, resulting in a higher water content and reduced purity.

[0027] Influence of adsorbent: The adsorption effect of modified molecular sieve is better than that of activated alumina (Comparative Example 3). Although activated alumina can dehydrate, its adsorption capacity is weak, resulting in slightly lower moisture content and purity.

[0028] Effect of process optimization: Properly increasing the adsorption linear velocity (such as Examples 6 and 7) or adjusting the ratio (such as Examples 3, 5, and 9) can further optimize the effect.

[0029] A high proportion of entrainer can significantly reduce the water content to 0.02-0.03% and increase the purity to 99.9%. However, too high a proportion will reduce the effect and increase the process cost.

[0030] Comparison of the process without azeotropes: In the absence of S1-S3 (Comparative Example 4), the moisture content is the highest and the purity is the lowest, indicating that azeotropic dehydration is a key step.

[0031] Comparison of Comparative Example 3 with Example 1 is shown in Table 2 Table 2 For high-precision, high-purity dehydration requirements, modified molecular sieves are more suitable and can provide better dehydration effects and impurity removal. If there are higher requirements for cost and ease of operation, and lower precision requirements, activated alumina is a more economical and practical choice.

[0032] Comparative Example 1, Comparative Example 2 and Example 1, the properties of n-hexane and toluene are shown in Table 3: characteristic n-Hexane Toluene Azeotropic temperature (with water) 69℃ 84.1℃ Boiling Point 68.7℃ 110.6℃ Water Solubility Almost insoluble Almost insoluble polarity Non-polar Weak polarity Table 3 The low boiling point of n-hexane ensures that water is quickly taken away and the dehydration time is shortened. The higher boiling point of toluene prolongs the efficient dehydration stage of azeotropic distillation and increases the final dehydration depth. n-hexane effectively reduces the risk of high-temperature decomposition and protects the structure of triphenylphosphine. Toluene has a good dissolving and removing effect on polar impurities, further improving the purity of the product. The combination of the two solvents reduces the demand for a single solvent, and both n-hexane and toluene can be recovered and reused by distillation. Toluene is a weakly polar solvent and has a certain scavenging effect on polar impurities, which is more helpful to improve the purity of triphenylphosphine.

[0033] The basic principles, main features and advantages of the present invention are shown and described above; those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected; the scope of protection claimed by the present invention is determined by the attached claims and their effects.

Claims

1. A process for efficiently concentrating and dehydrating crude triphenylphosphine, characterized in that: The following steps are involved: S1, to the crude triphenylphosphine, an entrainer is added, the ratio of the weight of the entrainer to the weight of the crude triphenylphosphine is 1-2:1, and the entrainer is a mixture of n-hexane and toluene in a ratio of 1:1; S2, placing the mixture obtained in S1 in a distillation kettle, and heating it to an azeotropic temperature of 70-85°C; S3, controlling the distillation pressure to normal pressure, azeotroping for 1-2 hours, the entrainer and water are boiled away, and a triphenylphosphine solution is obtained; S4, passing the triphenylphosphine solution after azeotropic dehydration through a dynamic adsorption device, using a modified molecular sieve as an adsorbent, and loading it into an adsorption tower of the dynamic adsorption device; S5. Control the material flow rate to 1-2 cm / s, adsorb for 0.5-1 hour, ensure that the material is fully in contact with the adsorbent, and obtain the material after adsorption and dehydration; S6, sending the material after adsorption and dehydration in S5 to a short-range molecular distillation device, setting the distillation temperature to 150-180°C, the ambient pressure to 0.01-0.1 mbar, and distilling for 30-60 minutes; S7. Triphenylphosphine is separated and condensed in the form of vapor, and non-volatile impurities remain in the short-range molecular distillation device. The condensed product is collected to ensure that no impurities remain.

2. A triphenylphosphine crude product efficient concentration and dehydration process according to claim 1, characterized in that: The steam after boiling of the azeotropic agent and water in S3 is condensed and separated into layers, and the azeotropic agent is recovered for recycling.

3. A triphenylphosphine crude product efficient concentration and dehydration process according to claim 1, characterized in that: The distillation kettle in S2-S3 maintains good sealing performance, thereby reducing the volatilization loss of the entrainer.

4. A triphenylphosphine crude product efficient concentration and dehydration process according to claim 1, characterized in that: The dynamic adsorption device in S4 is selected according to the scale of the enterprise. For large-scale dehydration treatment, an industrial continuous flow adsorption tower system is selected, and for small and medium-scale dehydration treatment, a multifunctional fixed bed adsorption device is selected.

5. A triphenylphosphine crude product efficient concentration and dehydration process according to claim 1, characterized in that: After the adsorption in S5 is completed, the adsorbent is regenerated every 5-7 days, wherein the regeneration process includes heating and vacuum treatment, and the adsorption tower is cleaned every 5-7 days to prevent blockage.

6. A triphenylphosphine crude product efficient concentration and dehydration process according to claim 1, characterized in that: The residues in the short-range molecular distillation device in S7 should be cleaned up in time.

7. A process for efficiently concentrating and dehydrating crude triphenylphosphine according to claim 1, characterized in that: The ratio of the weight of the entrainer to the weight of the crude triphenylphosphine is 1.2-1.8:

1.

8. A process for efficient concentration and dehydration of crude triphenylphosphine according to claim 7, characterized in that: The ratio of the weight of the entrainer to the weight of the crude triphenylphosphine is 1.5:1.

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