Continuous deep dehydration method of anisole for boron isotope separation

Abstract

The invention provides a continuous deep dehydration method of anisole for boron isotope separation, which comprises the following steps: firstly, limiting anisole subjected to silica gel primary dehydration to meet the conditions that the purity is greater than or equal to 99.5 wt% and the water content is 80-120ppm, then, carrying out silica gel primary dehydration, so that water in the anisole is primarily adsorbed by silica gel particles, and the water content of the anisole obtained by silica gel primary dehydration is less than or equal to 50ppm; and deeply dehydrating the anisole containing trace water by using a molecular sieve, so that the trace water is further fully dehydrated by the molecular sieve, thereby obtaining the anisole for boron isotope separation, and the water content is less than or equal to 10ppm. The continuous deep dehydration method disclosed by the invention is simple to operate and high in safety, can further reduce the production cost by virtue of regeneration of silica gel particles and molecular sieve particles, and is convenient for industrial popularization and application.

Description

Technical Field

[0001] The invention relates to the technical field of boron isotope separation, in particular to a complexing agent anisole used for boron isotope separation, and in particular to a continuous deep dehydration method of anisole used for boron isotope separation. Background Art

[0002] Stable isotope boron-10 ( 10 B) Due to its unique neutron absorption characteristics, it is increasingly used in modern nuclear industry, military equipment and medicine. 10 B products include boron-10 acid, boron-10 powder, boron carbide, boron nitride and other products with different abundance requirements. The industrial chain is long and the product application fields are wide, especially playing an important role in alleviating the global petrochemical energy shortage. The application of such products in the nuclear energy field makes it possible to widely develop and apply economic, safe and clean nuclear energy resources.

[0003] Since the isotope boron-10 has a much larger thermal neutron capture area than boron-11, it is widely used in the nuclear industry to manufacture thermal neutron counters, reactor control rods and thermal neutron shielding materials, especially in boron neutron cancer treatment methods (BNCT). The abundance of boron-10 in nature is only 19-20%, so it is necessary to enrich and purify the boron-10 isotope.

[0004] The chemical exchange distillation method of boron trifluoride anisole is a process technology first invented in the United States. It started in the mid-1970s and reached full production in 1977 with a production scale of 2 tons / year, and the boron-10 abundance can reach 92%. This process technology has advantages because it operates under normal temperature and pressure conditions and has a higher separation coefficient. Although the process of preparing anisole complex from raw materials is slightly longer than that of methyl and ethyl ether complex materials, its basic material anisole is recycled in the whole process of the production system, and the final product is enriched boron trifluoride-10 ( 10 BF3) and boron trifluoride-11( 11 BF3), both of which are high value-added terminal technology products. In terms of cost and benefit accounting, they have obvious advantages over the methyl and ethyl ether methods, making the production cost much lower. Currently, the United States and Georgia both use this process technology route.

[0005] Anisole is widely used in the fields of drug synthesis, dye synthesis, spice blending as an important raw material, intermediate and solvent. The water content of anisole of technical grade is relatively low, generally at several hundred ppm, or even lower. However, when anisole is used for the chemical exchange rectification method of boron trifluoride anisole to realize boron isotope separation, further dehydration is required. As separated object, the raw material boron trifluoride gas of isotope boron-10 and isotope boron-11 is very easy to react with water, and the hydrofluoric acid produced has extremely strong corrosiveness, and violent heat release, and by-products are also easy to block pipelines, reduce heat exchange efficiency and conveying efficiency, therefore need anisole to carry out deep dehydration, it is generally believed that water content needs to be reduced to below 30ppm, even to below 10ppm, thereby ensuring production safety, extending equipment service life, reducing the generation of by-products, and improving production efficiency.

[0006] At present, commonly used anisole dehydration methods include physical adsorption method and chemical reaction method. The molecular sieve drying method in the physical adsorption method, such as the preparation method of a super dry organic solvent disclosed in CN 112479797 A, needs to be carried out in a glove box and in a nitrogen atmosphere, and the reaction conditions are harsh, and it is not suitable for industrialized continuous scale production. The water gas reaction method in the chemical reaction method, such as the boron isotope separation complexing agent anisole refining and purification method disclosed in CN 107573224 A, uses CO to react with the water in anisole under catalytic conditions to remove trace water, although the reaction has a large dehydration depth, it needs to be carried out under high temperature and high pressure conditions, not only additional reaction equipment is required, but also the reaction conditions are relatively harsh, in addition, the raw material used in the reaction system is CO and one of the products is H2, not only flammable and explosive, but also highly toxic, and has high requirements for the operating environment.

[0007] In summary, it is necessary to provide a simple continuous deep dehydration method for anisole suitable for boron isotope separation. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a continuous deep dehydration method for anisole for boron isotope separation, comprising sequentially performing silica gel primary dehydration and molecular sieve deep dehydration, based on a two-step dehydration process, so as to obtain anisole for boron isotope separation with a water content of ≤10ppm; the continuous deep dehydration method of the present invention is not only simple to operate and highly safe, but also can further reduce production costs by means of the regeneration of silica gel particles and molecular sieve particles, and is convenient for industrial promotion and use.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] The object of the present invention is to provide a continuous deep dehydration method of anisole for boron isotope separation, and the continuous deep dehydration method comprises the following contents:

[0011] Anisole with a purity of ≥99.5wt% and a water content of 80-120ppm is first subjected to primary dehydration using silica gel to obtain anisole with a water content of ≤50ppm, and then subjected to deep dehydration using molecular sieves to obtain anisole for boron isotope separation with a water content of ≤10ppm.

[0012] The continuous deep dehydration method of the present invention first limits the anisole for silica gel initial dehydration to meet the conditions of purity ≥99.5wt% and water content of 80-120ppm, then silica gel initial dehydration is performed, so that the water in the anisole is preliminarily adsorbed by silica gel particles, the water content of the anisole obtained by the silica gel initial dehydration is ≤50ppm, then the anisole containing trace water is subjected to molecular sieve deep dehydration, so that the trace water is further fully dehydrated by the molecular sieve, thereby obtaining anisole for boron isotope separation and the water content is ≤10ppm. The continuous deep dehydration method of the present invention is not only simple to operate, but also highly safe, and can further reduce production costs by means of the regeneration of silica gel particles and molecular sieve particles, and is convenient for industrial promotion and use.

[0013] As a preferred technical solution of the present invention, the anisole with a purity of ≥99.5wt% and a water content of 80-120ppm comprises: anisole obtained by distilling industrial anisole.

[0014] As a preferred technical solution of the present invention, the purity of the industrial anisole is 94.5-99.5wt%, for example, 94.5wt%, 95wt%, 96wt%, 97wt%, 98wt%, 99wt%, or 99.5wt%, and the water content is 0.8-1.2wt%, for example, 0.8wt%, 0.9wt%, 1wt%, 1.1wt% or 1.2wt%, etc.

[0015] And / or, the distillation temperature is 150-155°C, that is, the temperature is controlled at about the boiling point of anisole, such as 150°C, 151°C, 152°C, 153°C, 154°C or 155°C.

[0016] And / or, the distillation pressure is 120-140 Pa / m, for example, 120 Pa / m, 125 Pa / m, 130 Pa / m, 135 Pa / m or 140 Pa / m.

[0017] As a preferred technical solution of the present invention, the continuous deep dehydration method also includes: reacting the anisole obtained by deep dehydration of the molecular sieve with CO gas in a fixed bed under the action of a catalyst to perform ultra-deep dehydration to obtain anisole for boron isotope separation with a water content of 1 to 3 ppm, for example, 1 ppm, 1.5 ppm, 2 ppm, 2.5 ppm or 3 ppm.

[0018] It should be noted that whether to perform ultra-deep water removal on the anisole obtained by deep water removal with molecular sieve to further reduce the water content of anisole can be selected by those skilled in the art according to actual needs.

[0019] As a preferred technical solution of the present invention, the reaction temperature of the ultra-deep water removal is 150-200°C, for example, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C or 200°C, etc., the reaction CO pressure is 1.0-5.0MPa, for example, 1.0MPa, 1.5MPa, 2.0MPa, 2.5MPa, 3.0MPa, 3.5MPa, 4.0MPa, 4.5MPa or 5.0MPa, etc., and the reaction time is 3-5h, for example, 3h, 3.5h, 4h, 4.5h or 5h, etc.

[0020] And / or, the catalyst is a copper-based catalyst.

[0021] As a preferred technical solution of the present invention, the silica gel initial water removal uses silica gel particles of 100 to 400 meshes, such as 100 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, 350 mesh or 400 mesh.

[0022] Preferably, the method for regenerating the silica gel particles comprises: drying at 130-150° C. for 2-4 hours, and / or, drying by purging with dry nitrogen.

[0023] In the present invention, the silica gel particles can be regenerated by drying at 130-150°C for 2-4 hours. The drying temperature is 130-150°C, such as 130°C, 135°C, 140°C, 145°C or 150°C, and the drying time is 2-4 hours, such as 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours.

[0024] As a preferred technical solution of the present invention, the anisole flow rate of the silica gel for initial water removal is 50-100 mL / min, for example, 50 mL / min, 60 mL / min, 70 mL / min, 80 mL / min, 90 mL / min or 100 mL / min.

[0025] As a preferred technical solution of the present invention, the molecular sieve deep water removal uses molecular sieve particles of 100 to 400 meshes, such as 100 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, 350 mesh or 400 mesh.

[0026] And / or, the molecular sieve deep water removal uses molecular sieve particles of any one type among 3A, 4A, 5A or 13X.

[0027] As a preferred technical solution of the present invention, the regeneration method of the molecular sieve particles includes: drying at 220-300° C. for 4-6 hours, and / or, drying by purging with dry nitrogen.

[0028] In the present invention, the molecular sieve particles can be regenerated by drying at 220-300°C for 4-6 hours. The drying temperature is 220-300°C, such as 220°C, 240°C, 260°C, 280°C or 3000°C, and the drying time is 4-6 hours, such as 4h, 4.5h, 5h, 5.5h or 6h.

[0029] As a preferred technical solution of the present invention, the flow rate of anisole for deep water removal by the molecular sieve is 50-100 mL / min, for example, 50 mL / min, 60 mL / min, 70 mL / min, 80 mL / min, 90 mL / min or 100 mL / min.

[0030] Compared with the prior art solutions, the present invention has at least the following beneficial effects:

[0031] (1) The continuous deep dehydration method of the present invention comprises the following steps: firstly, the anisole subjected to the initial dehydration of silica gel satisfies the conditions that the purity is ≥99.5wt% and the water content is 80-120ppm; then, the silica gel is initially dehydrated so that the water in the anisole is preliminarily adsorbed by the silica gel particles; the water content of the anisole obtained by the initial dehydration of silica gel is ≤50ppm; then, the anisole containing trace water is subjected to deep dehydration by molecular sieve so that the trace water is further fully dehydrated by the molecular sieve, thereby obtaining anisole for boron isotope separation with a water content of ≤10ppm;

[0032] (2) The continuous deep dehydration method of the present invention is not only simple to operate and highly safe, but also can further reduce production costs by regenerating silica gel particles and molecular sieve particles, making it easier to promote and use in industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of a continuous deep dehydration device for anisole used for boron isotope separation in Example 3 of the present invention;

[0034] In the figure: 1-distillation tower; 2-silica gel primary water removal drying tower; 3-molecular sieve deep water removal drying tower; 4-first anisole storage tank; 5-chemical drying tower; 6-second anisole storage tank; 7-online moisture detector; 8-switching valve. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0036] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0037] Example 1

[0038] This embodiment provides a continuous deep dehydration method of anisole for boron isotope separation, and the continuous deep dehydration method comprises the following contents:

[0039] The purity of the anisole to be dehydrated is 99.7wt% and the water content is 100ppm, which meets the requirements of purity ≥99.5wt% and water content of 80-120ppm. The product has high purity and does not need to be distilled, and can be directly subjected to silica gel primary water removal.

[0040] The initial dehydration of silica gel is carried out using a fixed bed, the fixed bed is filled with 100 mesh silica gel particles, the bed height is 50 cm, the inner diameter is 10 cm, the anisole flow rate of the initial dehydration of silica gel is 50 mL / min, and the water content of the obtained anisole satisfies ≤50 ppm;

[0041] The deep water removal by molecular sieve was carried out using a fixed bed, which was filled with 100-mesh 4A molecular sieve particles. The bed height was 50 cm and the inner diameter was 10 cm. The flow rate of anisole for deep water removal by molecular sieve was 50 mL / min. The initial water content of anisole at the outlet was 8 ppm. After 200 min, the water content of anisole at the outlet was 10 ppm.

[0042] Example 2

[0043] This embodiment provides a continuous deep dehydration method of anisole for boron isotope separation, and the continuous deep dehydration method comprises the following contents:

[0044] Adopt common anisole industrial product, purity is 95.0wt%, water content is 1wt%, does not meet the requirement that purity is ≥99.5wt%, water content is 80~120ppm, needs to carry out rectification treatment, control the target temperature of rectification to be 155 ℃, the target pressure of rectification is 130Pa / m, the purity of anisole is increased to 99.6wt%, and water content is reduced to 80ppm;

[0045] The anisole after rectification is subjected to initial dehydration on silica gel, wherein the initial dehydration on silica gel is carried out using a fixed bed, wherein the fixed bed is filled with 200-mesh silica gel particles, the bed height is 30 cm, the inner diameter is 6 cm, the flow rate of the anisole in the initial dehydration on silica gel is 50 mL / min, and the water content of the obtained anisole satisfies ≤50 ppm;

[0046] The deep water removal by molecular sieve was carried out using a fixed bed, which was filled with 200-mesh 5A molecular sieve particles. The bed height was 50 cm and the inner diameter was 10 cm. The flow rate of anisole for deep water removal by molecular sieve was 100 mL / min. The initial water content of anisole at the outlet was 7 ppm. After about 100 minutes, the moisture detector at the outlet of the initial water removal drying tower detected that the water content exceeded 50 ppm. The switching valve was used to switch to the spare tower. After a total water removal of 200 minutes, the water content of anisole at the outlet was 9 ppm.

[0047] Example 3

[0048] This embodiment provides a method for continuous deep dehydration of anisole for boron isotope separation, and the continuous deep dehydration device of anisole for boron isotope separation is used. Figure 1 As shown, the continuous deep dehydration device comprises a rectifying tower 1, a silica gel primary dehydration drying tower 2, a molecular sieve deep dehydration drying tower 3, a first anisole storage tank 4, a chemical drying tower 5, and a second anisole storage tank 6 connected in series; two silica gel primary dehydration drying towers 2 are arranged in parallel between the rectifying tower 1 and the molecular sieve deep dehydration drying tower 3, a switching valve 8 is arranged on the upstream main pipeline, and a moisture online detector 7 is arranged on the downstream main pipeline, and the switching valve 8 and the moisture online detector 7 are respectively electrically connected to a controller (not shown in the figure), so that the controller can be set based on the water content of the moisture online detector 7, and the switching valve 8 is switched to ensure that the water content of the anisole obtained by the initial dehydration of the silica gel satisfies ≤50ppm; a cooler is arranged between the chemical drying tower 5 and the second anisole storage tank 6; the top portion of the rectifying tower 1, the silica gel primary dehydration drying tower 2, the molecular sieve deep dehydration drying tower 3, and the first anisole storage tank 4 The anisole inlet is separately provided and the anisole outlet is respectively provided at the bottom, the chemical drying tower 5 is a fixed bed reactor, the upper part provides a chemical drying anisole inlet for feeding anisole from the first anisole storage tank 4, the lower part provides a CO gas inlet for feeding the CO gas required for the chemical reaction, the middle part is fixedly provided with a catalyst for catalyzing the water gas reaction in the chemical drying tower, the top provides a chemical drying waste gas outlet for discharging the waste gas generated by the water gas reaction, the bottom provides a chemical drying anisole outlet for discharging anisole for boron isotope separation with a water content of 1 to 3ppm, and storing it in the second anisole storage tank 6; the bottom of the silica gel primary dehydration drying tower 2 provides a primary dehydrated anisole outlet, and an online moisture detector 7 is provided at the primary dehydrated anisole outlet for online monitoring whether the water content of the anisole discharged from the primary dehydrated anisole outlet is ≤50ppm;

[0049] The continuous deep dehydration method comprises the following contents:

[0050] Adopt common anisole industrial product, purity is 95.0wt%, water content is 1wt%, do not meet the requirement that purity ≥99.5wt%, water content is 80~120ppm, need to enter rectifying tower 1 and carry out rectification treatment, control the target temperature of rectification to be 155 ℃, the target pressure of rectification is 130Pa / m, the purity of anisole is increased to 99.6wt%, and water content is reduced to 80ppm;

[0051] The anisole after the rectification enters the silica gel initial water removal drying tower 2 to carry out the silica gel initial water removal, the silica gel initial water removal drying tower 2 adopts a fixed bed to carry out, the fixed bed is filled with 400 mesh silica gel particles, the bed height is 40cm, the internal diameter is 10cm, the anisole flow rate of the silica gel initial water removal is 50mL / min, and the water content of the anisole obtained meets≤50ppm;

[0052] The anisole completing the initial dewatering of silica gel enters the deep dewatering drying tower 3 of molecular sieve and carries out the deep dewatering of molecular sieve, the deep dewatering drying tower 3 of molecular sieve adopts fixed bed to carry out, and fixed bed is filled with 400 purpose 13X molecular sieve particles, and bed height is 30cm, and internal diameter is 15cm, and the anisole flow velocity of the deep dewatering of molecular sieve is 60mL / min, the water content initial concentration 8ppm of the flow outlet anisole, after about 100min, the outlet moisture detector of the initial dewatering drying tower detects that water content exceeds 50ppm, utilizes switching valve 8 to switch to standby tower, and after total dewatering 200min, the flow outlet anisole water content is 10ppm; The anisole completing the deep dewatering of molecular sieve enters the first anisole storage tank 4 to store, for balancing and stabilizing pipeline pressure;

[0053] Anisole from the first anisole storage tank 4 enters a chemical drying tower 5, which is a fixed reaction bed. A catalyst is loaded in the tower. Anisole is pumped into the tower from the top with a constant flow pump at a flow rate of 20 mL / min, and CO is pumped into the tower from the bottom with a pressure pump at a flow rate of 10 mL / min. Ultra-deep water removal is carried out under the action of a catalyst. The reaction temperature is controlled to be 200 ° C, the reaction pressure is 1.0 MPa, and the reaction time is 4 h. Reaction waste gas is removed from the top of the tower, and anisole is removed from the bottom of the tower and then cooled. The tower enters the second anisole storage tank 6 to obtain anisole for boron isotope separation and the water content is reduced to 1 ppm.

[0054] This embodiment adopts Figure 1The invention discloses a continuous deep dehydration device for anisole used for boron isotope separation, which reduces the water content of anisole step by step. First, the anisole having a water content of 1wt% is passed through a rectifying tower under normal pressure to remove most of the water and impurities. Then, the anisole is passed through a silica gel primary dehydration drying tower equipped with silica gel particles, and after sufficient mixing, water is preliminarily adsorbed, and the water content can be reduced to about 50ppm. The anisole containing trace water is further fully dehydrated through a molecular sieve deep dehydration drying tower equipped with a molecular sieve, and the water content can be reduced to about 10ppm. Storage tanks can be installed between the towers for balancing and stabilizing pipeline pressure, and an online moisture detector is installed at the water outlet of the primary dehydration drying tower for monitoring the running state of the drying tower. When the water content of anisole is required to be more stringent, the anisole can be further subjected to ultra-dehydration by a chemical reaction method, that is, water gas reaction is carried out through a chemical drying tower, and the water content can be reduced to 1-3ppm.

[0055] Comparative Example 1

[0056] This comparative example provides a continuous deep dehydration method for anisole for boron isotope separation. Compared with Example 1, the only difference is that the silica gel particles and the molecular sieve particles are mixed and then loaded into a fixed bed, that is, the initial dehydration of silica gel and the deep dehydration of molecular sieve are combined into a one-step dehydration process; the specific contents are as follows:

[0057] The purity of the anisole to be dehydrated is 99.7wt% and the water content is 100ppm, which meets the requirements of purity ≥99.5wt% and water content of 80-120ppm. The product has high purity and does not need to be distilled, and can be directly subjected to silica gel primary water removal.

[0058] The fixed bed is filled with a mixture of 100-mesh silica gel particles and 100-mesh 4A molecular sieve particles. The bed height is 100 cm, the inner diameter is 10 cm, the anisole flow rate is 50 mL / min, and the initial water content of anisole at the outlet is 8 ppm. After about 120 minutes, the water content of anisole at the outlet exceeds 10 ppm, which does not meet the requirement of water content ≤ 10 ppm, and it is necessary to switch to another continuous deep dehydration process production line.

[0059] In this comparative example, silica gel and molecular sieve are both mainly dehumidified by physical adsorption, the pores of silica gel are not uniform, and there is no selectivity to adsorbate, so the water absorption is large (can reach 200% of deadweight), but the water absorption capacity (referring to the removal capacity of low concentration water) is low, the pores of molecular sieve are uniform, and only have adsorption capacity to molecules smaller than pore size, so the extremely small amount of water in anisole can be selectively removed, but the adsorption capacity is smaller (less than 20%). Therefore, if mixed, molecular sieve will soon reach saturation under high concentration water, and then lose the ability of deep dehydration.

[0060] It should be noted that, when the continuous deep dehydration method of the present invention is used, the continuous deep dehydration is carried out for 200 minutes, and the water content of anisole at the outlet meets the corresponding requirements, the production line is switched to another continuous deep dehydration process production line. That is, except for emergencies, the switching of the continuous deep dehydration process production line is based on whether the continuous operation reaches 200 minutes.

[0061] In summary, the present invention provides a kind of continuous deep dehydration method of anisole for boron isotope separation, first limit the anisole that carries out silica gel initial dehydration to meet the conditions of purity ≥99.5wt%, water content is 80~120ppm, then silica gel initial dehydration is carried out, so that the water in anisole is preliminarily adsorbed by silica gel particles, the water content of anisole obtained by silica gel initial dehydration is ≤50ppm, then the anisole containing trace water is subjected to molecular sieve deep dehydration, so that trace water is further fully dehydrated by molecular sieve, thereby obtaining anisole for boron isotope separation and water content ≤10ppm. The continuous deep dehydration method of the present invention is not only simple to operate, high in safety, but also can further reduce production costs with the help of silica gel particles and molecular sieve particles regeneration, and is convenient for industrial promotion and use.

[0062] The present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0063] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0064] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0065] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A continuous deep dehydration method for anisole for boron isotope separation, characterized in that: The continuous deep dehydration method comprises the following contents: Anisole with a purity of ≥99.5wt% and a water content of 80-120ppm is first subjected to primary dehydration using silica gel to obtain anisole with a water content of ≤50ppm, and then subjected to deep dehydration using molecular sieves to obtain anisole for boron isotope separation with a water content of ≤10ppm.

2. The continuous deep dehydration method according to claim 1, characterized in that: The anisole with a purity of ≥99.5wt% and a water content of 80-120ppm comprises: anisole obtained by distilling industrial anisole.

3. The continuous deep dehydration method according to claim 2, characterized in that: The industrial anisole has a purity of 94.5-99.5 wt % and a water content of 0.8-1.2 wt %; And / or, the distillation temperature is 150-155°C; And / or, the distillation pressure is 120-140 Pa / m.

4. The continuous deep dehydration method according to claim 1 or 2, characterized in that: The continuous deep dehydration method also includes: reacting the anisole obtained by deep dehydration of the molecular sieve with CO gas in a fixed bed under the action of a catalyst to perform ultra-deep dehydration to obtain anisole for boron isotope separation with a water content of 1 to 3 ppm.

5. The continuous deep dehydration method according to claim 4, characterized in that: The reaction temperature of the ultra-deep water removal is 150-200°C, the reaction CO pressure is 1.0-5.0MPa, and the reaction time is 3-5h; And / or, the catalyst is a copper-based catalyst.

6. The continuous deep dehydration method according to any one of claims 1, 2 or 4, characterized in that: The silica gel is used for initial water removal using silica gel particles of 100 to 400 meshes; Preferably, the method for regenerating the silica gel particles comprises: drying at 130-150° C. for 2-4 hours, and / or, drying by purging with dry nitrogen.

7. The continuous deep dehydration method according to claim 6, characterized in that: The anisole flow rate of the silica gel for initial water removal is 50-100 mL / min.

8. The continuous deep dehydration method according to any one of claims 1, 2 or 4, characterized in that: The molecular sieve deep water removal adopts 100-400 mesh molecular sieve particles; And / or, the molecular sieve deep water removal uses molecular sieve particles of any one type among 3A, 4A, 5A or 13X.

9. The continuous deep dehydration method according to claim 8, characterized in that: The molecular sieve particle regeneration method comprises: drying at 220-300° C. for 4-6 hours, and / or, drying by purging with dry nitrogen.

10. The continuous deep dehydration method according to claim 8, characterized in that: The anisole flow rate for deep water removal by the molecular sieve is 50-100 mL / min.

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