A process for separating methanol and dimethyl carbonate in a binary azeotrope
Patent Information
- Application Number
- CN202211542667.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-02
- Publication Date
- 2026-09-15
- Estimated Expiration
- 2042-12-02
AI Technical Summary
[0004]本申请提供了一种分离二元共沸物中甲醇和碳酸二甲酯的方法，以解决现有技术在分离二元共沸物中甲醇和碳酸二甲酯过程中分离效果不佳的同时分离的物料损失严重的技术问题
[0022] This application provides a method for separating methanol and dimethyl carbonate from a binary azeotrope. First, the binary azeotrope is heated to vaporization. Then, the vaporized binary azeotrope is introduced into an adsorption column packed with a solid metal salt using a preset space velocity. The flow rate of the vaporized binary azeotrope is controlled so that the solid metal salt undergoes a complexation reaction with the methanol in the binary azeotrope. Since this reaction is a non-catalytic chemical reaction and occurs at the solid-phase interface of the solid metal salt, the complexed product adheres to the surface of the solid metal salt, resulting in a heterogeneous phase. This achieves the separation of methanol and dimethyl carbonate from the binary azeotrope. Subsequent condensation yields pure dimethyl carbonate liquid, thus improving the separation effect. Moreover, this method only requires chemical adsorption, and the overall steps are simple and easy to operate, while also reducing material loss during the separation process.
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Abstract
Description
Technical Field
[0001] This application relates to the field of chemical separation and adsorption, and more particularly to a method for separating methanol and dimethyl carbonate from a binary azeotrope. Background Technology
[0002] Dimethyl carbonate is typically a colorless and transparent liquid under normal pressure and is currently one of the main raw materials for battery electrolyte production. Based on the concept of carbon neutrality, the transesterification process of ethylene carbonate and methanol is now widely used in industry to produce dimethyl carbonate. This process generates a binary azeotrope of dimethyl carbonate and methanol. The azeotropic temperature of this binary azeotrope is 63.75℃, and its azeotropic composition is 66.7% methanol and 33.3% dimethyl carbonate.
[0003] Currently, there are various methods for separating this binary azeotrope, including membrane separation, low-temperature crystallization, azeotropic distillation, extractive distillation, and pressure swing distillation. However, these methods suffer from low separation efficiency, high energy consumption, difficult operation, complex processes, and low product quality, resulting in poor separation effects and significant material loss. Therefore, providing a method for separating methanol and dimethyl carbonate from a binary azeotrope that improves separation efficiency while reducing material loss during the separation process is a pressing technical problem that needs to be solved. Summary of the Invention
[0004] This application provides a method for separating methanol and dimethyl carbonate in a binary azeotrope, to solve the technical problem that the existing technology has poor separation effect and serious material loss during the separation of methanol and dimethyl carbonate in a binary azeotrope.
[0005] In a first aspect, this application provides a method for separating methanol and dimethyl carbonate in a binary azeotrope, the method comprising:
[0006] Heating the binary azeotrope yields a vaporized azeotrope.
[0007] Under a preset space velocity, the vaporized azeotrope is introduced into the adsorption column for adsorption and then condensed to obtain dimethyl carbonate liquid.
[0008] The adsorption column is filled with a solid metal salt to enable the methanol in the vaporized azeotrope to undergo a complexation reaction with the solid metal salt.
[0009] The preset airspeed is 0.05 g / g·h to 0.15 g / g·h.
[0010] Optionally, the solid metal salt includes a metal chloride.
[0011] Optionally, the metal chloride includes at least one of magnesium chloride, calcium chloride, aluminum chloride, iron chloride, and zinc chloride.
[0012] Optionally, the average size of the solid metal salt is 10 mesh to 80 mesh.
[0013] Optionally, the heating may include heating in a vacuum environment.
[0014] Optionally, the vacuum level of the vacuum environment is 50 kPa to 70 kPa.
[0015] Optionally, the final temperature of the heating is 30°C to 50°C.
[0016] Optionally, the adsorption temperature is 30℃~50℃.
[0017] Optionally, the adsorption time is ≥1 hour.
[0018] Optionally, the method further includes:
[0019] The adsorption column after adsorption is regenerated and desorbed to obtain a regenerated adsorption column and methanol, respectively.
[0020] Under the preset space velocity, the vaporized azeotrope is introduced into the regeneration adsorption column for adsorption, so as to realize the regeneration and utilization of the solid metal salt in the adsorption column.
[0021] The technical solutions provided in this application have the following advantages compared with the prior art:
[0022] This application provides a method for separating methanol and dimethyl carbonate from a binary azeotrope. First, the binary azeotrope is heated to vaporization. Then, the vaporized binary azeotrope is introduced into an adsorption column packed with a solid metal salt using a preset space velocity. The flow rate of the vaporized binary azeotrope is controlled so that the solid metal salt undergoes a complexation reaction with the methanol in the binary azeotrope. Since this reaction is a non-catalytic chemical reaction and occurs at the solid-phase interface of the solid metal salt, the complexed product adheres to the surface of the solid metal salt, resulting in a heterogeneous phase. This achieves the separation of methanol and dimethyl carbonate from the binary azeotrope. Subsequent condensation yields pure dimethyl carbonate liquid, thus improving the separation effect. Moreover, this method only requires chemical adsorption, and the overall steps are simple and easy to operate, while also reducing material loss during the separation process. Attached Figure Description
[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 A flowchart illustrating the method provided in the embodiments of this application;
[0026] Figure 2 A detailed flowchart illustrating the method provided in the embodiments of this application;
[0027] Figure 3 This is a schematic diagram of the apparatus used in the method provided in the embodiments of this application. Detailed Implementation
[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0029] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.
[0030] The creative thinking behind this application is:
[0031] Current methods for separating binary azeotropes include membrane separation, low-temperature crystallization, azeotropic distillation, extractive distillation, and pressure swing distillation. However, these methods have the following drawbacks:
[0032] 1. Membrane separation is still in the laboratory stage. The membrane life is short, the processing capacity is small, the technology is not yet mature, and its industrialization has not yet been seen.
[0033] 2. The low-temperature crystallization method takes advantage of the fact that the freezing point of dimethyl carbonate (4℃) is higher than that of methanol (-97.8℃). However, the dimethyl carbonate-methanol azeotrope in the low-temperature crystallization method only crystallizes at -30℃ to -40℃ and a "eutectic" exists. This results in low separation efficiency, high energy consumption, difficult operation, and a complex process.
[0034] 3. Pressure distillation and extractive distillation are considered to be the most effective methods for separating azeotropes and are also commonly used in industry. Pressure distillation mainly changes the composition of azeotropes by increasing the pressure during distillation, thereby achieving effective separation of azeotropes. This process has high equipment investment and operating costs and also poses certain safety hazards.
[0035] 4. The selection of extractant is crucial in extractive distillation. A good extractant can significantly reduce separation energy consumption, but it also has disadvantages such as the need for secondary distillation (to recover the extractant) and lower product quality.
[0036] Meanwhile, due to their limitations, the above methods generally suffer from poor separation effects and significant material loss after separation. Therefore, how to provide a method for separating methanol and dimethyl carbonate in binary azeotropes to improve the separation effect while reducing material loss during the separation process is a technical problem that urgently needs to be solved.
[0037] To address the aforementioned technical problems, the inventors, through in-depth research, discovered that the complexation reaction between methanol and metal salts is a non-catalytic chemical reaction. The reaction occurs at the solid-phase interface of the metal salt, and the products also adhere to the surface of the metal salt, belonging to a heterogeneous phase. The equation for this complexation reaction is as follows:
[0038] A(s)CH3OHA·nCH2OH(s)
[0039] In the formula, A is a metal salt.
[0040] Therefore, chemical adsorption of methanol from binary azeotropes using solid metal salts can not only yield high-purity dimethyl carbonate with better separation efficiency, but also...
[0041] like Figure 1 As shown in the embodiments of this application, a method for separating methanol and dimethyl carbonate in a binary azeotrope is provided, the method comprising:
[0042] S1. Heating the binary azeotrope yields a vaporized azeotrope;
[0043] S2. Under a preset space velocity, the vaporized azeotrope is introduced into the adsorption column for adsorption and then condensed to obtain dimethyl carbonate liquid.
[0044] The adsorption column is filled with a solid metal salt to enable the methanol in the vaporized azeotrope to undergo a complexation reaction with the solid metal salt.
[0045] The preset airspeed is 0.05 g / g·h to 0.15 g / g·h.
[0046] In this embodiment, the positive effect of controlling the preset space velocity to 0.05 g / g·h to 0.15 g / g·h is that within this space velocity range, the preset space velocity is not only related to the throughput of the adsorption column, but also to the vacuum level of the vacuum environment during heating and the final temperature of heating. This ensures that the vaporized azeotrope is fully adsorbed by the adsorption column, allowing the methanol in the vaporized azeotrope and the solid metal salt in the adsorption column to react fully, thereby obtaining pure dimethyl carbonate gas, which facilitates subsequent condensation to obtain dimethyl carbonate liquid product.
[0047] A vaporization azeotrope refers to a mixture of methanol and dimethyl carbonate produced by heating a binary azeotrope. Since the vaporization azeotrope includes dimethyl carbonate with a mass fraction of 66.7% and 33.3%, the mass fraction parameters of the binary azeotrope are less affected by temperature when it vaporizes. Therefore, the mass fractions of methanol and dimethyl carbonate in the vaporization azeotrope remain within the above-mentioned data range.
[0048] In some alternative embodiments, the solid metal salt comprises a metal chloride.
[0049] In this embodiment of the application, by limiting the specific types of solid metal salts, since metal chlorides are widely distributed metal salt components, and in the subsequent desorption and regeneration stage, the introduction of other impurities or loss of solid metal salts can be avoided, thus ensuring the regeneration and utilization of solid metal salts.
[0050] In some alternative embodiments, the metal chloride includes at least one of magnesium chloride, calcium chloride, aluminum chloride, iron chloride, and zinc chloride.
[0051] In this embodiment, the specific type of metal chloride is defined to ensure its chemical adsorption of methanol in the gas azeotrope and to ensure the separation effect of dimethyl carbonate.
[0052] In some alternative embodiments, the average size of the solid metal salt is 10 mesh to 80 mesh.
[0053] In this embodiment of the application, the positive effect of controlling the average size of the solid metal salt to be 10 mesh to 80 mesh is that within this size range, it can ensure sufficient contact between the solid metal salt and the gas azeotrope, so that the methanol in the gas azeotrope can fully undergo a complexation reaction with the solid metal salt, thereby obtaining pure dimethyl carbonate and improving the separation effect.
[0054] In some alternative implementations, the heating includes heating in a vacuum environment.
[0055] In this embodiment, the positive effect of controlling heating in a vacuum environment is that it facilitates the conversion of binary azeotropes into gaseous states and the formation of vaporized azeotropes. At the same time, the vacuum environment can be used to control the preset space velocity of the vaporized azeotropes, ensuring the stability of the space velocity of the vaporized azeotropes and improving their separation effect.
[0056] In some alternative embodiments, the vacuum level of the vacuum environment is 50 kPa to 70 kPa.
[0057] In this embodiment, the positive effect of controlling the vacuum level of the vacuum environment to be 50 kPa to 70 kPa is that within this vacuum level range, the space velocity of the vaporized azeotrope after the conversion of the binary azeotrope can be controlled, thereby ensuring that the vaporized azeotrope enters the adsorption column at a preset space velocity and is adsorbed, thus obtaining pure dimethyl carbonate and improving the separation effect.
[0058] In some alternative embodiments, the endpoint temperature of the heating is 30°C to 50°C.
[0059] In this embodiment, controlling the final heating temperature to be between 30°C and 50°C has the positive effect of ensuring that the binary azeotrope is fully converted into a vaporized azeotrope within this temperature range. Since the heating temperature affects the diffusion of the vaporized azeotrope in a vacuum environment, controlling the heating temperature within this range can also provide a driving force for the vaporized azeotrope, thereby enabling the vaporized azeotrope to enter the adsorption column at a preset space velocity and be adsorbed, thus obtaining pure dimethyl carbonate and improving the separation effect.
[0060] In some alternative embodiments, the adsorption temperature is 30°C to 50°C.
[0061] In the embodiments of this application, the positive effect of controlling the adsorption temperature to be 30℃~50℃ is that within this temperature range, it can be ensured that after the vaporized azeotrope is adsorbed by the adsorption column, the methanol in the vaporized azeotrope has sufficient temperature to undergo a complexation reaction with the solid metal salt packing of the adsorption column, thereby completing the adsorption of methanol, obtaining pure dimethyl carbonate, and improving the separation effect.
[0062] In some alternative embodiments, the adsorption time is ≥1 hour.
[0063] In the embodiments of this application, the positive effect of controlling the adsorption time to ≥1h is that within this time range, the vaporized azeotrope has sufficient time to be adsorbed by the adsorption column, thereby ensuring that the reaction between the methanol in the vaporized azeotrope and the solid metal salt is sufficient, thus completing the adsorption of methanol, obtaining pure dimethyl carbonate, and improving the separation effect.
[0064] In some optional implementations, the method further includes:
[0065] S3. The adsorption column after adsorption is subjected to regeneration and desorption treatment to obtain a regenerated adsorption column and methanol, respectively;
[0066] S4. Under the preset space velocity, the vaporized azeotrope is introduced into the regeneration adsorption column for adsorption, so as to realize the regeneration and utilization of the solid metal salt in the adsorption column.
[0067] In this embodiment, by regenerating and desorbing the adsorption column, not only can the adsorption column be regenerated, but the methanol adsorbed by chemisorption in the adsorption column can also be removed, thereby obtaining a pure methanol product and further improving the separation effect of binary azeotropes.
[0068] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional conditions, or conditions recommended by the manufacturer are followed.
[0069] The following examples all use 50g of solid metal salt as a reference.
[0070] Example 1
[0071] like Figure 2 As shown, a method for separating methanol and dimethyl carbonate in a binary azeotrope is provided, which, in the case of... Figure 3 The following operate within the illustrated device:
[0072] S1. Heating the binary azeotrope yields a vaporized azeotrope;
[0073] S2. Under a preset space velocity, a vaporized azeotrope is introduced into the adsorption column for adsorption and then condensed to obtain dimethyl carbonate liquid.
[0074] S3. The adsorption column after adsorption is regenerated and desorbed to obtain a regenerated adsorption column and methanol, respectively;
[0075] S4. Under a preset space velocity, a vaporized azeotrope is introduced into the regeneration adsorption column for adsorption, so as to realize the regeneration and utilization of solid metal salts in the adsorption column.
[0076] The adsorption column is filled with a solid metal salt to enable the methanol in the vaporized azeotrope to undergo a complexation reaction with the solid metal salt.
[0077] The preset air velocity is 0.05 g / g·h.
[0078] The solid metal salt is a magnesium chloride.
[0079] The average size of the solid metal salt is 20 mesh to 40 mesh.
[0080] Heating includes heating in a vacuum environment.
[0081] The vacuum level of the vacuum environment is 60 kPa.
[0082] The final heating temperature is 30℃.
[0083] The adsorption temperature is 30℃.
[0084] The adsorption time was 1 hour.
[0085] Example 2
[0086] Comparing Example 2 with Example 1, the difference between Example 2 and Example 1 is as follows:
[0087] The preset air velocity is 0.1 g / g·h.
[0088] The solid metal salt is a calcium chloride.
[0089] The average size of the solid metal salt is 30 mesh to 50 mesh.
[0090] The vacuum level of the vacuum environment is 60 kPa.
[0091] The final heating temperature is 30℃.
[0092] The adsorption temperature is 30℃.
[0093] Example 3
[0094] Comparing Example 3 with Example 1, the difference between Example 3 and Example 1 is as follows:
[0095] The preset air velocity is 0.15 g / g·h.
[0096] The solid metal salt is a calcium chloride.
[0097] The average size of the solid metal salt is 30 mesh to 50 mesh.
[0098] The vacuum level of the vacuum environment is 50 kPa.
[0099] The final heating temperature is 40℃.
[0100] The adsorption temperature is 40℃.
[0101] Example 4
[0102] Comparing Example 4 with Example 1, the difference between Example 4 and Example 1 is as follows:
[0103] The preset air velocity is 0.1 g / g·h.
[0104] The solid metal salt is a magnesium chloride.
[0105] The average size of the solid metal salt is 10 mesh to 20 mesh.
[0106] The vacuum level of the vacuum environment is 50 kPa.
[0107] The final heating temperature is 30℃.
[0108] The adsorption temperature is 30℃.
[0109] Example 5
[0110] Comparing Example 5 with Example 1, the difference between Example 5 and Example 1 is as follows:
[0111] The preset air velocity is 0.1 g / g·h.
[0112] The solid metal salt is a calcium chloride.
[0113] The average size of the solid metal salt is 60-80 mesh.
[0114] The vacuum level of the vacuum environment is 50 kPa.
[0115] The final heating temperature is 30℃.
[0116] The adsorption temperature is 30℃.
[0117] Example 6
[0118] Comparing Example 6 with Example 1, the difference between Example 6 and Example 1 is as follows:
[0119] The preset air velocity is 0.1 g / g·h.
[0120] The solid metal salt is a calcium chloride.
[0121] The average size of the solid metal salt is 20 mesh to 40 mesh.
[0122] The vacuum level of the vacuum environment is 60 kPa.
[0123] The final heating temperature is 40℃.
[0124] The adsorption temperature is 40℃.
[0125] Example 7
[0126] Comparing Example 7 with Example 1, the difference between Example 7 and Example 1 is as follows:
[0127] The preset air velocity is 0.1 g / g·h.
[0128] The solid metal salt is a magnesium chloride.
[0129] The average size of the solid metal salt is 20 mesh to 40 mesh.
[0130] The vacuum level of the vacuum environment is 60 kPa.
[0131] The final heating temperature is 50℃.
[0132] The adsorption temperature is 50℃.
[0133] Example 8
[0134] Comparing Example 8 with Example 1, the difference between Example 8 and Example 1 is as follows:
[0135] The preset air velocity is 0.1 g / g·h.
[0136] The solid metal salt is FeCl3.
[0137] The average size of the solid metal salt is 20 mesh to 40 mesh.
[0138] The vacuum level of the vacuum environment is 60 kPa.
[0139] The final heating temperature is 30℃.
[0140] The adsorption temperature is 30℃.
[0141] Example 9
[0142] Comparing Example 9 with Example 1, the difference between Example 9 and Example 1 is as follows:
[0143] The preset air velocity is 0.1 g / g·h.
[0144] The solid metal salt is AlCl3.
[0145] The average size of the solid metal salt is 20 mesh to 40 mesh.
[0146] The vacuum level of the vacuum environment is 50 kPa to 60 kPa.
[0147] The final heating temperature is 30℃.
[0148] The adsorption temperature is 30℃.
[0149] Example 10
[0150] Comparing Example 10 with Example 1, the difference between Example 10 and Example 1 is as follows:
[0151] The preset air velocity is 0.1 g / g·h.
[0152] The solid metal salt is ZnCl2.
[0153] The average size of the solid metal salt is 20 mesh to 40 mesh.
[0154] The vacuum level of the vacuum environment is 60 kPa.
[0155] The final heating temperature is 30℃.
[0156] The adsorption temperature is 30℃.
[0157] Relevant experimental and effect data:
[0158] The dimethyl carbonate liquids obtained in each embodiment and comparative example were measured to determine the content of the active ingredients, and the results are shown in Table 1.
[0159] The detection method for dimethyl carbonate is gas chromatography.
[0160] Table 1. Content of dimethyl carbonate in liquid dimethyl carbonate
[0161]
[0162] Detailed analysis of Table 1:
[0163] The DMC content after separation refers to the content of dimethyl carbonate in the dimethyl carbonate liquid separated from the binary azeotrope. The higher the content, the higher the purity of the separated dimethyl carbonate, which means the better the separation effect.
[0164] Data from Examples 1-10 show that: the binary azeotrope is first heated to vaporization, and then the vaporized binary azeotrope is introduced into an adsorption column filled with solid metal salt through a preset space velocity. The flow rate of the vaporized binary azeotrope is controlled so that the solid metal salt can undergo a complexation reaction with methanol in the binary azeotrope. Since this reaction is a non-catalytic chemical reaction and occurs at the solid-phase interface of the solid metal salt, the complexed product adheres to the surface of the solid metal salt, resulting in a heterogeneous phase. This achieves the separation of methanol and dimethyl carbonate in the binary azeotrope. After condensation, pure dimethyl carbonate liquid can be obtained, thereby improving the separation effect. Moreover, this method only requires chemical adsorption, and the overall steps are simple and easy to operate, which can also reduce material loss during the separation process.
[0165] One or more technical solutions in the embodiments of this application have at least the following technical effects or advantages:
[0166] (1) The present application provides a method for separating methanol and dimethyl carbonate in a binary azeotrope. The binary azeotrope is first heated to vaporization, and then the vaporized binary azeotrope is introduced into an adsorption column filled with solid metal salt through a preset space velocity. The flow rate of the vaporized binary azeotrope is controlled so that the solid metal salt can undergo a complexation reaction with methanol in the binary azeotrope. After condensation, pure dimethyl carbonate liquid can be obtained, thereby improving the separation effect. Moreover, the method only requires chemical adsorption. The steps of the whole method are simple and easy to operate. At the same time, it can also reduce the material loss in the separation process.
[0167] (2) The method for separating methanol and dimethyl carbonate in a binary azeotrope provided in this application uses a solid metal salt to chemically adsorb the binary azeotrope, which can obtain a high-purity dimethyl carbonate liquid product. Furthermore, the solid metal salt can be regenerated and desorbed in the later stage to obtain methanol with a purity of not less than 99.5%. The regenerated solid metal salt can be recycled without generating waste liquid or waste gas, which is environmentally friendly.
[0168] (3) The method for separating methanol and dimethyl carbonate in a binary azeotrope provided in this application is simple because it only requires three steps: heating, chemical adsorption and condensation. Therefore, it has the advantages of simple production process and equipment, low operating cost and environmental friendliness.
[0169] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.
[0170] In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the orientation shown in the accompanying drawings. Furthermore, in the description of this application, the terms "comprising," "including," etc., mean "including but not limited to."
[0171] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any actual relationship or order between these entities or operations. In this document, "and / or" describes the association between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. A and B can be singular or plural. In this document, "at least one" means one or more, and "more than" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c," or "at least one of a, b, and c," can both represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.
[0172] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.
Claims
1. A method for separating methanol and dimethyl carbonate from a binary azeotrope, characterized in that, The method includes: Heating the binary azeotrope yields a vaporized azeotrope. Under a preset space velocity, the vaporized azeotrope is introduced into the adsorption column for adsorption and then condensed to obtain dimethyl carbonate liquid. The adsorption column is filled with a solid metal salt to enable the methanol in the vaporized azeotrope to undergo a complexation reaction with the solid metal salt. The preset air velocity is 0.05 g / g•h to 0.15 g / g•h; The solid metal salt is magnesium chloride or calcium chloride.
2. The method according to claim 1, characterized in that, The average size of the solid metal salt is 10 mesh to 80 mesh.
3. The method according to claim 1, characterized in that, The heating includes heating in a vacuum environment.
4. The method according to claim 3, characterized in that, The vacuum level of the vacuum environment is 50 kPa to 70 kPa.
5. The method according to claim 1, characterized in that, The final temperature of the heating is 30℃~50℃.
6. The method according to claim 1, characterized in that, The adsorption temperature is 30℃~50℃.
7. The method according to claim 1, characterized in that, The adsorption time is ≥1 hour.
8. The method according to claim 1, characterized in that, The method further includes: The adsorption column after adsorption is regenerated and desorbed to obtain a regenerated adsorption column and methanol, respectively. Under the preset space velocity, the vaporized azeotrope is introduced into the regeneration adsorption column for adsorption, so as to realize the regeneration and utilization of the solid metal salt in the adsorption column.