System and method for producing hydroxyl deuterated straight-chain alcohol

Abstract

The invention discloses a system and a method for producing hydroxyl deuterated straight-chain alcohol. The system comprises a tank reactor, a rectifying tower, a primary condenser, a first receiving tank, a second receiving tank and a switching type valve pipe group device, wherein the top of the tank reactor is connected to the bottom of the rectifying tower, and the top of the rectifying tower is connected to a gas phase inlet of the primary condenser; the first receiving tank and the second receiving tank are selectively communicated with the feeding hole of the reaction kettle or the liquid phase outlet of the primary condenser through the switching type valve pipe group device. According to the method, azeotropic limitation can be thoroughly broken, sufficient conversion of reactants is realized, and meanwhile, high yield and efficient continuous production are taken into account.

Description

Technical Field

[0001] This invention belongs to the field of deuterated reagent production, specifically relating to a system and method for producing hydroxydeuterated straight-chain alcohols. Background Technology

[0002] Hydroxydeuterated methanol (CH3OD) and hydroxydeuterated ethanol (CH3CH2OD) are deuterated compounds formed by isotopic deuteration of methanol and ethanol, respectively. They have special physicochemical properties and are widely used in materials synthesis, pharmaceutical research and development and other fields, and the demand is increasing day by day.

[0003] In the preparation of hydroxydeuterated straight-chain alcohols, existing technologies typically face challenges such as difficulties in separating and purifying byproducts, complex reaction systems, and the inability to simultaneously achieve high product yield and deuteration degree. Chinese patent application CN115572211A discloses a method for preparing monodeuterated ethanol by reacting ethyl formate, ethyl acetate, or sodium ethoxide as substrates with heavy water. However, this method has significant drawbacks: when using ester substrates such as ethyl formate or ethyl acetate, the reaction produces organic acids such as formic acid and acetic acid, or their salts, which not only increases the difficulty of subsequent separation and purification, leading to a decrease in yield, but also causes the solid salt byproducts to easily encapsulate heavy water, resulting in thickening of the reaction system, decreased mass transfer efficiency, and a slower reaction rate. When using alkoxides such as sodium ethoxide as substrates, the strongly alkaline byproducts such as sodium hydroxide generated in the reaction continue to catalyze the reaction, leading to intense exothermic reactions, increased viscosity, and introducing uncontrollable safety risks, which also greatly complicates product separation.

[0004] To overcome the aforementioned problems, Chinese patent application CN117645527B discloses a method using carbonate as a substrate and reacting it with heavy water under an alkaline catalyst. The only byproduct is carbon dioxide gas, which can be promptly removed from the reaction system. This ensures that the crude product contains no byproducts other than the raw materials (carbonate, heavy water, and alkaline catalyst) and the deuterated product, significantly reducing the difficulty of subsequent purification. This not only guarantees the deuteration degree of the product but also improves the yield. However, this method still has inherent drawbacks in terms of reaction kinetics and process efficiency. Since carbonate, heavy water, and the generated hydroxydeuterated alcohol form an azeotrope, if these azeotropes are directly collected as products during the reaction, it will lead to incomplete conversion of the reactants, making it difficult to further improve the deuteration degree of the product. Furthermore, the presence of azeotropes still poses a technical bottleneck for the efficient separation and purification of the final product, restricting further improvements in production efficiency and product quality.

[0005] Therefore, there is an urgent need in the field for a method and system that can completely break the azeotropic limitation, achieve full conversion of reactants, and simultaneously achieve high yield and efficient continuous production of hydroxydeuterated straight-chain alcohols. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method and system for the continuous production of hydroxy deuterated straight-chain alcohols that can completely break the azeotropic limitation, achieve full conversion of reactants, and simultaneously achieve high yield and high efficiency.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A system for producing hydroxydeuterated straight-chain alcohols includes a batch reactor, a distillation column, a primary condenser, a first receiving tank, a second receiving tank, and a switching valve assembly.

[0009] The top of the batch reactor is connected to the bottom of the distillation column, and the top of the distillation column is connected to the gas phase inlet of the first-stage condenser.

[0010] The first receiving tank and the second receiving tank can be selectively connected to the feed inlet of the reactor or the liquid phase outlet of the first-stage condenser through the switching valve assembly, so as to realize the switching between the feeding function and the receiving function.

[0011] This invention employs an innovative dual-receiving tank switching design to recycle azeotropic materials, which may contain unreacted dialkyl carbonate, heavy water, and products after initial condensation, back into the reactor for further reaction. This "reaction-condensation-reuse-re-reaction" cyclical model ensures that the reactants in the azeotrope are continuously consumed until the reaction is nearly complete, thus fundamentally solving the conversion bottleneck caused by azeotropes.

[0012] Preferably, the switching valve assembly includes a first discharge pipe and a second discharge pipe connecting the liquid phase outlet of the primary condenser to the first receiving tank and the second receiving tank, respectively; and a first feed pipe and a second feed pipe connecting the batch reactor to the first receiving tank and the second receiving tank, respectively. Valves are installed on the first discharge pipe, the second discharge pipe, the first feed pipe, and the second feed pipe. A secondary condensation device is provided at the top of the first receiving tank and the second receiving tank. The secondary condensation device includes several secondary condensers, which are respectively installed on the first discharge pipe, the second discharge pipe, and the vent of the first receiving tank and the second receiving tank. These condensers are used to deeply condense the material from the primary condenser and discharge the non-condensable byproduct carbon dioxide gas from the system. Furthermore, the secondary condensers are arranged in parallel to jointly condense the material entering the first receiving tank or the second receiving tank, reducing the loss of volatile materials carried by non-condensable carbon dioxide gas.

[0013] Preferably, the first and second feed pipes are connected to the rear half of the batch reactor and merged into a main feed pipe, which is inserted from the top of the batch reactor and extends its outlet to the liquid phase region of the batch reactor. Furthermore, the outlet of the feed pipe extends into the bottom of the batch reactor to prevent material loss caused by the added material being carried away from the reaction system by steam.

[0014] The present invention also provides a method for producing hydroxydeuterated straight-chain alcohols, comprising the following steps:

[0015] Step S10: The carbonate catalyst and heavy water are mixed in a batch reactor to form a catalytic system, and the dialkyl carbonate material is placed in the first receiving tank;

[0016] Step S20: Heat the batch reactor to the reaction temperature, continuously add the dialkyl carbonate material from the first receiving tank to the batch reactor for reaction, and simultaneously condense the gaseous material containing hydroxy deuterated straight-chain alcohol generated by the reaction after separation by the distillation column and collect it in the second receiving tank.

[0017] Step S30: When the material in the first receiving tank is completely transported, it is switched from the feeding state to the receiving state. At the same time, the second receiving tank is switched from the receiving state to the feeding state. The intermediate material containing hydroxy deuterated straight-chain alcohol that it received is added to the batch reactor. The material containing hydroxy deuterated straight-chain alcohol generated in the subsequent reaction is condensed and collected in the first receiving tank.

[0018] Step S40: Repeat step S30 at least once until a qualified hydroxydeuterated straight-chain alcohol product is obtained. Then, the crude product in the final receiving tank is purified by distillation to obtain the hydroxydeuterated straight-chain alcohol product.

[0019] In step S10, the carbonate catalyst is selected from at least one of lithium carbonate, potassium carbonate, sodium carbonate, and cesium carbonate;

[0020] In step S10, the alkyl group in the dialkyl carbonate is a C1-C3 alkyl group, and further, the dialkyl carbonate is selected from dimethyl carbonate or diethyl carbonate;

[0021] In step S10, the amount of the carbonate catalyst is calculated based on the total mass of the dialkyl carbonate and heavy water, and is 1-5 wt%. More preferably, the amount of the carbonate catalyst is 2-3 wt%.

[0022] In step S10, the molar ratio of the dialkyl carbonate to the heavy water is 1:(1~10), and more preferably, the molar ratio of the dialkyl carbonate to the heavy water is 1:(2~3).

[0023] The method of the present invention allows the reaction to be carried out at a higher temperature; in step S20, the reaction temperature is 85~95°C.

[0024] In step S20, the specific temperature control parameters of the distillation column are: bottom temperature of 65℃~70℃ and top temperature of 58℃~62℃.

[0025] In step S20, the distillation column has 10-20 theoretical plates and a reflux ratio of 0.2-0.5.

[0026] In step S20, the condensation includes primary condensation and secondary condensation. The primary condensation uses a primary condenser to perform initial condensation on the gaseous material output from the top of the distillation column. The secondary condensation uses a secondary condenser to perform deep condensation on the gaseous material after primary condensation, and discharges the uncondensed by-product carbon dioxide gas from the top of the secondary condenser.

[0027] In step S20, the temperature of the primary condenser is -5 to 0°C, and the temperature of the secondary condenser is -15 to -10°C.

[0028] Step S40 further includes a batch feeding step. After the current batch reaction is completed and the qualified product is removed, the moisture content of the qualified product is detected, the consumed heavy water and the heavy water carried out by the product are replenished to the batch reactor, and dialkyl carbonate is added to the receiving tank that is currently in the feeding standby state, so as to start the next batch reaction and realize semi-continuous production.

[0029] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0030] 1. Significantly improved reaction kinetics: By employing a feeding method that slowly adds dialkyl carbonate to excess heavy water in a receiving tank, a locally high-concentration reaction environment is achieved. Simultaneously, the circulation mode enriches high-boiling-point heavy water in the batch reactor, overcoming the azeotropic limitation and allowing the reaction to proceed at higher temperatures. The dual optimization and synergistic effect of temperature and concentration significantly improves the reaction rate and production efficiency.

[0031] 2. This invention breaks the limitations imposed by azeotropes on the reaction process, achieving near-complete conversion of reactants and improving product yield. Through an innovative dual-receiving tank switching design, the azeotropic material, which may contain unreacted dialkyl carbonate, heavy water, and products after initial condensation, is reintroduced as feed into the reactor for further reaction. This "reaction-condensation-reuse-re-reaction" cyclical model ensures that reactants in the azeotrope are continuously consumed until the reaction approaches completion, thus fundamentally solving the conversion bottleneck caused by azeotropes. Simultaneously, the systematic closed-loop circulation and efficient two-stage condensation recovery design minimize the loss of volatile materials, ensuring a stable product yield of over 98.0%.

[0032] 3. This invention achieves semi-continuous and automated production, significantly improving production efficiency. Utilizing a switching valve assembly, it enables seamless and synchronous switching between the "feeding" and "receiving" functions of the first and second receiving tanks. This allows preparation for the next batch to begin before the previous batch reaction is fully completed, facilitating the transition from intermittent to semi-continuous production. This greatly shortens the production cycle and improves equipment utilization and production efficiency.

[0033] 4. Highly efficient byproduct treatment and simplified separation and purification process. This invention employs a two-stage condenser integrated at the rear end of the switching valve assembly to deeply condense the gaseous material from the first-stage condenser, significantly reducing the entrainment loss of volatile products with the non-condensable carbon dioxide byproduct. The entire reaction process leaves no byproducts other than carbon dioxide, resulting in extremely high-purity crude product. Subsequent simple distillation purification is sufficient to obtain a high-purity product, greatly simplifying the purification process and reducing energy consumption and production costs. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the switching receiving system and method for producing hydroxydeuterated straight-chain alcohols according to the present invention.

[0035] Figure 2 This is a gas phase detection spectrum of the product in the receiving tank after the first switch in Example 1.

[0036] Figure 3 This is the gas phase detection spectrum of the product in the receiving tank after the fourth switch in Example 1.

[0037] Figure 4 The image shows the 1H NMR spectrum of the product hydroxydeuterated methanol prepared in Example 1.

[0038] Figure 5 The image shows the 1H NMR spectrum of the product hydroxydeuterated ethanol prepared in Example 5.

[0039] 1-Stirred reactor, 2-Distillation column, 3-First stage condenser, 4-Reflux ratio controller, 5-Second stage condenser, 6-First receiving tank, 7-Second receiving tank, 8-Switching valve assembly, 81-First discharge pipeline, 82-Second discharge pipeline, 83-First feed pipeline, 84-Second feed pipeline. Detailed Implementation

[0040] Example 1:

[0041] Step S10: Mix 2.17 kg of potassium carbonate catalyst with 22.24 kg of heavy water in a batch reactor to form a catalytic system, and place 50 kg of dimethyl carbonate in the first receiving tank;

[0042] Step S20: Heat the batch reactor to 90°C and control the distillation column connected to the batch reactor to establish a temperature gradient from top to bottom, with the bottom temperature at 65°C and the top temperature at 60°C. Continuously add dimethyl carbonate from the first receiving tank to the batch reactor for reaction. Simultaneously, the gaseous material containing hydroxy-deuterated methanol generated by the reaction is separated and condensed in the distillation column. Control the reflux ratio of the distillation column to 0.3, the temperature of the first-stage condenser to 0°C, and the temperature of the second-stage condenser to -10°C. The condensed material is collected in the second receiving tank.

[0043] Step S30: When the dimethyl carbonate in the first receiving tank is completely delivered, it is switched from the feeding state to the receiving state. At the same time, the second receiving tank is switched from the receiving state to the feeding state. The intermediate material containing hydroxy deuterated methanol that it received is added to the batch reactor. The material containing hydroxy deuterated methanol generated in the subsequent reaction is condensed and collected in the first receiving tank.

[0044] Step S40: After repeating step S30 once, take a sample from the sampling port of the second receiving tank for gas phase detection. The detection data shows that the content of hydroxydeuterated methanol is 37.50%, the content of dimethyl carbonate is 62.50%, and the moisture content is 5.66%. The gas phase detection spectrum is as follows. Figure 2 As shown, after repeating step S30 three times, a sample was taken for gas chromatography analysis. The analysis data showed that the content of hydroxydeuterated methanol was 98.18%, the content of dimethyl carbonate was 1.82%, and the water content was 2.38%. The gas chromatography spectrum is shown below. Figure 3 As shown, the crude hydroxydeuterated methanol was then discharged from the second receiving tank and fed into a distillation column for distillation to obtain 36.25 kg of refined hydroxydeuterated methanol (molar yield 98.8%, purity >99%, water content 171.9 ppm). 1 The degree of deuteration of hydroxydeuterated methanol was 99.68% as determined by 1H NMR. The 1H NMR spectrum is shown below. Figure 4 As shown, the 1H NMR data are 1H NMR (400MHz, CH3OD) 3.31 (s, 3H), 4.84 (q, 0.0032H, J = 4.0Hz), deuterium single-round yield 49.4%.

[0045] Example 2:

[0046] This embodiment is basically the same as Embodiment 1, except that the amount of heavy water added in the batch reactor is 33.35 kg and the amount of potassium carbonate catalyst added is 2.50 kg.

[0047] Example 3:

[0048] This embodiment is basically the same as Embodiment 1, except that the carbonate catalyst is cesium carbonate and the amount added is 1.44 kg.

[0049] Example 4:

[0050] This embodiment is basically the same as Embodiment 1, except that: the amount of heavy water added in the batch reactor is 111.18 kg, the amount of potassium carbonate catalyst added is 4.84 kg, the batch reactor is heated to 95°C, the bottom temperature of the distillation column is 70°C, and the top temperature of the column is 62°C.

[0051] Example 5:

[0052] This embodiment is basically the same as Embodiment 1, except that: 50 kg of diethyl carbonate is placed in the first receiving tank, the amount of heavy water added to the batch reactor is 16.96 kg, the amount of potassium carbonate catalyst added is 2.01 kg, the batch reactor is heated to 95°C, the bottom temperature of the distillation column is 68°C, and the top temperature of the column is 60°C. 1 The degree of deuteration of hydroxydeuterated ethanol was determined to be 98.55% by 1H NMR. The 1H NMR spectrum is shown below. Figure 4 As shown, the 1H NMR data are 1 H NMR (400MHz, DMSO-d6) 1.05 (t, 3H, J = 7.0Hz), 3.43 (d, 1.9885H, J = 7.0Hz), 4.39 (s, 0.0145H).

[0053] Example 6:

[0054] This embodiment is basically the same as embodiment 5, except that the carbonate catalyst is sodium carbonate and the amount added is 3.35 kg.

[0055] Example 7:

[0056] This embodiment is basically the same as embodiment 5, except that: the amount of heavy water added in the batch reactor is 63.58 kg, the carbonate catalyst is cesium carbonate and the amount added is 2.84 kg, the bottom temperature of the distillation column is 70°C, and the top temperature of the column is 62°C.

[0057] Example 8:

[0058] This embodiment is basically the same as embodiment 5, except that: the carbonate catalyst is potassium carbonate and the amount added is 3.35 kg, the bottom temperature of the distillation column is 65°C and the top temperature is 60°C.

[0059] Example 9:

[0060] This embodiment is basically the same as Embodiment 1, except that: while discharging crude hydroxydeuterated methanol from the second receiving tank, 50 kg of dimethyl carbonate is added to the first receiving tank, and 12.02 kg of heavy water is added to the batch reactor. After receiving the feed, steps S10 to S40 are repeated.

[0061] Example 10:

[0062] This embodiment is basically the same as Embodiment 1, except that: a reaction device of the same scale is used, the amount of heavy water added in the batch reactor is 22.24g, the amount of potassium carbonate catalyst added is 3.17g, and the amount of potassium carbonate added in the first receiving tank is 50g.

[0063] Comparative Example 1:

[0064] This comparative example is basically the same as Example 5, except that: ethyl formate is used instead of diethyl carbonate, the amount of heavy water added in the batch reactor is 27.04 kg, and the amount of potassium carbonate catalyst added is 48.95 kg, to obtain hydroxydeuterated ethanol, with deuterated formic acid-d1 as a byproduct.

[0065] Comparative Example 2:

[0066] This comparative example is basically the same as Example 5, except that sodium ethoxide is used instead of diethyl carbonate, the amount of heavy water added in the batch reactor is 37.08 kg, potassium carbonate catalyst is not added, hydroxydeuterated ethanol is obtained, and sodium deuterium oxide is the byproduct.

[0067] Comparative Example 3:

[0068] This comparative example is basically the same as comparative example 2, except that the amount of heavy water added in the batch reactor is 113.41 kg.

[0069] Comparative Example 4:

[0070] 22.24g of heavy water and 2.17g of potassium carbonate catalyst were mixed and added to a 150ml three-necked flask equipped with a reflux condenser. Then, 50g of dimethyl carbonate was added dropwise. The reaction temperature was controlled at 90℃. After the reaction was completed, hydroxydeuterated methanol was obtained by distillation.

[0071] Comparative Example 5:

[0072] 22.24 kg of heavy water and 2.17 kg of potassium carbonate catalyst were mixed and added to a 100 L batch reactor equipped with a reflux condenser. Then, 50 kg of dimethyl carbonate was added dropwise. The reaction temperature was controlled at 90 °C. After the reaction was completed, hydroxydeuterated methanol was obtained by distillation.

[0073] The reaction process parameters and reaction data of Examples 2 to Comparative Examples 5 are summarized in Table 1.

[0074] Table 1 Summary of reaction process parameters and reaction data from Examples 2 to Comparative Examples 5

[0075]

[0076] Note that the formula for calculating the deuterium yield per round in the table is n. 重水 *2 / n 产品

[0077] As can be seen from Table 1:

[0078] In Comparative Example 1, ethyl formate was used as the substrate to generate formic acid-d1 as a byproduct. This byproduct reacted with potassium carbonate, resulting in the consumption of 0.5 equivalents of potassium carbonate catalyst. If an additional 0.5 equivalents of potassium carbonate were not added based on Example 1, the reaction would terminate prematurely due to catalyst deactivation. However, when an additional 0.5 equivalents of potassium carbonate was added based on Example 1, the excessive solid material in the system made stirring difficult, and the reaction was forced to stop after two switching operations, ultimately leading to a decrease in product yield and degree of deuteration. In addition, the formic acid-d1 byproduct also consumed deuterium atoms in heavy water, resulting in a decrease in the utilization rate of high-value deuterium sources, with a single-round deuterium yield of only 16.4%.

[0079] In Comparative Example 2, sodium ethoxide was used as the substrate to generate 1 equivalent of sodium deuterium oxide as a byproduct. The gradual accumulation of this byproduct led to a continuous increase in system viscosity, causing the intermediate and target products to be encapsulated, thus affecting the yield and product purity. Simultaneously, the generation of sodium deuterium oxide consumed deuterium in heavy water, resulting in a decrease in deuterium utilization; the single-round deuterium yield was 17.2%.

[0080] In Comparative Example 3, sodium ethoxide was still used as the substrate, and the reaction produced 1 equivalent of sodium deuterium oxide. To avoid product encapsulation loss due to excessive viscosity of the system, the amount of heavy water was increased to dilute the reaction system, maintaining the final concentration of sodium deuterium oxide at approximately 40 wt%. However, the excessive use of heavy water resulted in a significant loss of deuterium atoms, with a single-round deuterium yield of only 7.9%, significantly reducing the deuterium atom economy of the reaction.

[0081] Comparative Example 4 used a small-batch, single-feed reaction, while Comparative Example 5 used a large-batch, single-feed reaction. The results from Comparative Examples 4 and 5 show that under small-batch, single-feed conditions, the azeotropic effect within the reaction system has virtually no impact on the reaction process or product quality. However, under large-batch, single-feed conditions, the azeotropic phenomenon leads to insufficient deuteration degree, decreased purity, and reduced product yield in the final product. The traditional single-feed model has an inherent "scaling-up bottleneck" during production scale-up. Specifically, as the scale of a single batch increases, the negative impact of the low-boiling-point azeotrope composed of carbonate, heavy water, and the generated hydroxy-deuterated alcohol on the reaction intensifies, restricting the process stability and product quality of large-scale production.

Claims

1. A system for producing a hydroxyl deuterated straight-chain alcohol, characterized by, Includes a batch reactor, a distillation column, a primary condenser, a first receiving tank, a second receiving tank, and a switching valve assembly; The top of the batch reactor is connected to the bottom of the distillation column, and the top of the distillation column is connected to the gas phase inlet of the first-stage condenser. The first and second receiving tanks can be selectively connected to the feed inlet of the reactor or the liquid phase outlet of the primary condenser via the switching valve assembly.

2. The system for producing a hydroxyl deuterated straight-chain alcohol according to claim 1, characterized by, The switching valve assembly includes a first discharge pipe and a second discharge pipe that connect the liquid phase outlet of the primary condenser to the first receiving tank and the second receiving tank, respectively; and a first feed pipe and a second feed pipe that connect the batch reactor to the first receiving tank and the second receiving tank, respectively. Valves are installed on the first discharge pipe, the second discharge pipe, the first feed pipe, and the second feed pipe. A secondary condensation device is provided at the top of the first receiving tank and the second receiving tank. The secondary condensation device includes several secondary condensers, which are respectively installed on the first discharge pipe, the second discharge pipe, and the vent outlets of the first receiving tank and the second receiving tank.

3. The system for producing a hydroxyl deuterated straight-chain alcohol according to claim 1, wherein, The first feed pipe and the second feed pipe are connected to the rear half of the batch reactor and merged into a main feed pipe. The main feed pipe is inserted from the top of the batch reactor and its outlet extends to the liquid phase region of the batch reactor.

4. A method for producing a hydroxyl deuterated linear alcohol using the system according to any one of claims 1 to 3, characterized in that, Includes the following steps: step S10: The carbonate catalyst is mixed with heavy water in a batch reactor to form a catalytic system, and the dialkyl carbonate material is placed in the first receiving tank; Step S20: Heat the batch reactor to the reaction temperature, continuously add the dialkyl carbonate material from the first receiving tank to the batch reactor for reaction, and simultaneously condense the gaseous material containing hydroxy deuterated straight-chain alcohol generated by the reaction after separation by the distillation column and collect it in the second receiving tank. Step S30: When the material in the first receiving tank is completely transported, it is switched from the feeding state to the receiving state. At the same time, the second receiving tank is switched from the receiving state to the feeding state. The intermediate material containing hydroxy deuterated straight-chain alcohol that it received is added to the batch reactor. The material containing hydroxy deuterated straight-chain alcohol generated in the subsequent reaction is condensed and collected in the first receiving tank. Step S40: Repeat step S30 at least once until a qualified hydroxydeuterated straight-chain alcohol product is obtained. Then, the crude product in the final receiving tank is purified by distillation to obtain the hydroxydeuterated straight-chain alcohol product.

5. The method of claim 4, wherein, In step S10, the carbonate catalyst is selected from at least one of lithium carbonate, potassium carbonate, sodium carbonate, and cesium carbonate; In step S10, the amount of the carbonate catalyst is 1 to 5 wt% of the total mass of the dialkyl carbonate and heavy water.

6. The method of claim 4, wherein, In step S10, the dialkyl carbonate is selected from dimethyl carbonate or diethyl carbonate; In step S10, the molar ratio of the dialkyl carbonate to the heavy water is 1:(1~10).

7. The method of claim 4, wherein, In step S20, the reaction temperature is 85~95℃; In step S20, the specific temperature control parameters of the distillation column are: bottom temperature of 65℃~70℃ and top temperature of 58℃~62℃.

8. The method according to claim 7, characterized in that, In step S20, the distillation column has 10-20 theoretical plates and a reflux ratio of 0.2-0.

5.

9. The method according to claim 4, characterized in that, In step S20, the condensation includes primary condensation and secondary condensation; The primary condenser performs initial condensation on the gaseous material output from the top of the distillation column through a primary condenser. The secondary condenser performs deep condensation on the material after primary condensation through a secondary condenser device, and discharges the uncondensed by-product carbon dioxide gas from the top of the secondary condenser. In step S20, the temperature of the primary condenser is -5 to 0°C, and the temperature of the secondary condenser is -15 to -10°C.

10. The method according to claim 4, characterized in that, Step S40 is executed 2 to 5 times; Step S40 also includes a batch replenishment step: After the current batch reaction is completed and the qualified product is removed, the moisture content of the qualified product is tested, the consumed heavy water and the heavy water carried out by the product are replenished into the batch reactor, and dialkyl carbonate is added to the receiving tank that is currently in the feeding standby state to start the next batch reaction.

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