Purification method of methanol

Abstract

The present invention relates to the technical field of fine chemical engineering, and particularly to a method for purifying methanol. The method for purifying methanol comprises the following steps: successively performing oxidation treatment, adsorption treatment and rectification treatment on a methanol raw material to obtain a methanol product; wherein, during the adsorption treatment, a composite material of nano titanium dioxide and graphene oxide is used to adsorb the methanol raw material after the oxidation treatment. The present invention uses the composite material of nano titanium dioxide and graphene oxide as an adsorbent for adsorption. The amount of the adsorbent used is small, and various organic impurities can be removed simultaneously, which is beneficial to reducing the experimental cost and process and saving the experimental time. After adsorption, rectification treatment is carried out again to further improve the purity of methanol, so that the obtained methanol product smoothly meets the mass spectrometry grade standard.

Description

Technical Field

[0001] The present invention relates to the technical field of fine chemicals, and particularly to a method for purifying methanol. Background Art

[0002] Currently, in the process of purifying methanol, modified activated carbon is mostly used as an adsorbent for adsorption. However, this method adds too much adsorbent for adsorption, and the surface of the activated carbon also needs to be modified, increasing the experimental cost and having too many experimental steps. It is very likely to introduce new impurities during the experimental process, and the obtained methanol product fails to meet the standard of methanol for liquid chromatography-mass spectrometry. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the related art. For this purpose, the present invention provides a method for purifying methanol, using a composite material of nano-titanium dioxide and graphene oxide as an adsorbent for adsorption. The amount of adsorbent used is small, and it can remove multiple organic impurities at the same time, which is beneficial to reducing the experimental cost and process and saving experimental time. After adsorption, rectification treatment is carried out to further improve the purity of methanol, so that the obtained methanol product can smoothly meet the mass spectrometry standard.

[0004] The present invention provides a method for purifying methanol, and the purification method includes the following steps:

[0005] Oxidize the methanol raw material, perform adsorption treatment and rectification treatment in sequence to obtain a methanol product;

[0006] Wherein, during the adsorption treatment process, a composite material of nano-titanium dioxide and graphene oxide is used to adsorb the methanol raw material after oxidation treatment.

[0007] Further, the preparation method of the composite material of nano-titanium dioxide and graphene oxide includes the following steps:

[0008] Mix nano-titanium dioxide and 3-aminopropyltriethoxysilane and react at a temperature of 70-90°C for 4-7 hours. Add water during the reaction process, and obtain functionalized titanium dioxide after the reaction ends;

[0009] Mix N,N-dimethylformamide and graphene oxide and disperse them by ultrasonic wave. Add the functionalized titanium dioxide to the mixture after the ultrasonic dispersion ends, and react at a temperature of 90-110°C for 6-8 hours to obtain the composite material of nano-titanium dioxide and graphene oxide.

[0010] Further, the mass ratio of the nano-titanium dioxide to the 3-aminopropyltriethoxysilane is 1:2-5;

[0011] The mass ratio of the graphene oxide to the functionalized titanium dioxide is 1:0.5-2.

[0012] Further, the mass ratio of the nano-titanium dioxide and graphene oxide composite material to the volume of the methanol raw material is (10-20) g: 1 L.

[0013] Further, the oxidation treatment includes: heating a mixture of the methanol raw material, potassium permanganate, and potassium hydroxide to 60-70°C and reacting for 5-8 h under the condition of condensation reflux.

[0014] Further, the mass of the potassium permanganate accounts for 0.5-1.5% of the mass of the methanol raw material;

[0015] The mass of the potassium hydroxide accounts for 0.4-0.6% of the mass of the methanol raw material.

[0016] Further, the adsorption treatment includes: performing primary adsorption and secondary adsorption on the methanol raw material after the oxidation treatment in sequence.

[0017] The primary adsorption includes using the nano-titanium dioxide and graphene oxide composite material to adsorb the methanol raw material after the oxidation treatment to obtain a first product;

[0018] The secondary adsorption includes using a molecular sieve to adsorb the first product to obtain a second product.

[0019] Further, the secondary batch distillation includes: performing primary batch distillation and secondary batch distillation on the second product in sequence.

[0020] Further, the primary batch distillation includes:

[0021] Performing total reflux on the second product in a distillation device for 1-3 h;

[0022] Setting the reflux ratio of the distillation device to 8:1-12:1, and collecting 4-6 segments of the distillate components.

[0023] Further, selecting at least part of the distillate components for the secondary batch distillation to obtain the methanol product;

[0024] Wherein, the operation steps of the secondary batch distillation are the same as those of the primary batch distillation.

[0025] Further, before performing the primary batch distillation, performing total reflux treatment on the distillation device using the methanol raw material.

[0026] One or more of the above technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0027] In the methanol purification method of the present invention, a composite material of nano-titanium dioxide and graphene oxide is used as an adsorbent for adsorption. The amount of the adsorbent used is small, and it can remove multiple organic impurities simultaneously, which is beneficial to reducing the experimental cost and process and saving experimental time. After the methanol raw material is adsorbed and treated, rectification treatment is carried out to further improve the purity of methanol, so that the obtained methanol product smoothly meets the mass spectrometry grade standard.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Detailed embodiments

[0029] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0030] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the embodiments of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0031] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0032] In the embodiments of the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than that of the second feature.

[0033] In the description of this specification, the description with reference to terms such as "an embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0034] The present invention provides a method for purifying methanol, and the purification method includes the following steps: successively performing oxidation treatment, adsorption treatment, and rectification treatment on a methanol raw material to obtain a methanol product; wherein, during the adsorption treatment, a composite material of nano-titanium dioxide and graphene oxide is used to adsorb the methanol raw material after the oxidation treatment.

[0035] In the method for purifying methanol of the present invention, a composite material of nano-titanium dioxide and graphene oxide is used as an adsorbent for adsorption. The amount of the adsorbent used is small, and it can remove multiple organic impurities at the same time, which is beneficial to reducing the experimental cost and process and saving the experimental time. After the adsorption treatment of the methanol raw material, rectification treatment is carried out again to further improve the purity of methanol, so that the obtained methanol product can smoothly meet the mass spectrometry grade standard.

[0036] The inventors of the present invention have found that the surface of nano-titanium dioxide (the particle size of nano-titanium dioxide is 0.1 - 100 nanometers) has hydroxyl groups, and the surface hydroxyl groups can bond with certain cations, thereby achieving an adsorption effect on metal ions or organic substances; in addition, nano-titanium dioxide has a huge specific surface area and has microporous channels with a network structure inside, which can adsorb organic substances and metal ions to the surface to the maximum extent. However, nano-titanium dioxide is prone to agglomeration and has relatively single functions. The surface of graphene oxide contains functional oxygen-containing functional groups such as hydroxyl groups, epoxy groups, carbonyl groups, and carboxyl groups. These active groups not only make it show good hydrophilicity but also can become active adsorbents to adsorb metal ions and organic substances. The inventors unexpectedly found that after grafting graphene oxide onto the surface of nano-titanium dioxide to form a nano-titanium dioxide and graphene oxide composite material, the advantages of both can be combined, agglomeration can be avoided, the specific surface area of the composite material is increased, and the material has higher adsorption capacity.

[0037] In some embodiments of the present invention, the preparation method of the nano-titanium dioxide and graphene oxide composite material includes the following steps: Mix nano-titanium dioxide and 3-aminopropyltriethoxysilane, and react at a temperature of 70 - 90 °C (for example, it can be 70 °C, 80 °C or 90 °C, etc.) for 4 - 7 h (for example, it can be 4 h, 5 h, 6 h or 7 h, etc.). During the reaction, add water, and after the reaction, obtain functionalized titanium dioxide; Mix N,N-dimethylformamide and graphene oxide and disperse them by ultrasonic wave. Add the functionalized titanium dioxide to the mixture after the ultrasonic dispersion ends, and react at a temperature of 90 - 110 °C (for example, it can be 90 °C, 100 °C or 110 °C, etc.) for 6 - 8 h (for example, it can be 6 h, 7 h or 8 h, etc.) to obtain the nano-titanium dioxide and graphene oxide composite material.

[0038] In some embodiments of the present invention, the mass ratio of the nano-titanium dioxide to the 3-aminopropyltriethoxysilane is 1:2 - 5; the mass ratio of the graphene oxide to the functionalized titanium dioxide is 1:0.5 - 2.

[0039] In some specific embodiments of the present invention, the preparation method of the nano-titanium dioxide and graphene oxide composite material includes the following steps:

[0040] 1. Add 200 mL of ethanol to a flask, add 1 g of nano-titanium dioxide, 10 g of 3-aminopropyltriethoxysilane, stir at 80 °C for 4 - 7 h, slowly add a small amount of deionized water during stirring, wash, filter and dry the product in the flask after the reaction to obtain functionalized titanium dioxide.

[0041] 2. Weigh 200 mL of N,N-dimethylformamide and 1 g of graphene oxide, add them to a flask, disperse them by ultrasonic treatment, then add 1 g of functionalized titanium dioxide, stir and heat to 100 °C for reaction for 6 - 8 h. After the reaction, wash, filter and dry the product in the flask to obtain a composite material of nano-titanium dioxide and graphene oxide.

[0042] In some embodiments of the present invention, the oxidation treatment includes: under the condition of condensation reflux, heating a mixture of methanol raw material, potassium permanganate and potassium hydroxide to 60 - 70 °C for reaction for 5 - 8 h. Thus, adding potassium permanganate can remove some double-bond organic substances in methanol, and adding potassium hydroxide can react with acidic impurities in the raw material to produce salt precipitates.

[0043] In some embodiments of the present invention, the mass of the potassium permanganate accounts for 0.5 - 1.5% of the mass of the methanol raw material; the mass of the potassium hydroxide accounts for 0.4 - 0.6% of the mass of the methanol raw material.

[0044] In some embodiments of the present invention, the adsorption treatment includes: successively performing primary adsorption and secondary adsorption on the methanol raw material after the oxidation treatment. The primary adsorption includes using the composite material of nano-titanium dioxide and graphene oxide to adsorb the methanol raw material after the oxidation treatment to obtain a first product; the secondary adsorption includes using molecular sieve to adsorb the first product to obtain a second product.

[0045] In some embodiments of the present invention, the mass ratio of the composite material of nano-titanium dioxide and graphene oxide to the volume of the methanol raw material is (10 - 20) g:1 L. Thus, the dosage of the composite material of nano-titanium dioxide and graphene oxide is small, and the adsorption effect is good, which can effectively remove aldehydes, ketones and esters in the methanol raw material.

[0046] In some specific embodiments of the present invention, the operation steps of the primary adsorption include: add about one-third of the height of the composite material of nano-titanium dioxide and graphene oxide in a 60 cm adsorption column, slowly pour the methanol raw material after the oxidation treatment into the adsorption column until it covers the adsorption material, open the outflow switch of the adsorption column, adjust the outflow rate to 1 drop / s, and connect a conical flask below to receive the first product obtained from the primary adsorption.

[0047] In some specific embodiments of the present invention, the operation steps of the secondary adsorption include: add 50 - 100 mesh 3A molecular sieve with a height of one-third in a 60 cm adsorption column, slowly pour the first product into the adsorption column until it covers the adsorption material, open the outflow switch of the adsorption column, adjust the outflow rate to 1 drop / s, and connect a conical flask below to receive the second product obtained from the secondary adsorption.

[0048] In some embodiments of the present invention, the secondary batch distillation includes: performing primary batch distillation and secondary batch distillation on the second product in sequence.

[0049] In some embodiments of the present invention, the primary batch distillation includes: performing total reflux in the distillation device using the second product for 1 - 3 h; setting the reflux ratio of the distillation device to 8:1 - 12:1, and collecting 4 - 6 sections of the distillate components.

[0050] In some embodiments of the present invention, at least a part of the distillate components is selected for the secondary batch distillation to obtain the methanol product; wherein, the operating steps of the secondary batch distillation are the same as those of the primary batch distillation.

[0051] In some specific embodiments of the present invention, one or two better sections of the distillate components among the 4 - 6 sections of the distillate components are selected for the secondary batch distillation.

[0052] In some embodiments of the present invention, before performing the primary batch distillation, the distillation device is subjected to total reflux treatment using the methanol raw material.

[0053] In some specific embodiments of the present invention, the purification method of methanol includes the following steps:

[0054] 1. Add 2 - 3 L of industrial - grade methanol raw material into a three - necked flask, and then add potassium permanganate accounting for 1% of the mass of the industrial - grade methanol raw material and potassium hydroxide accounting for 0.5%. Connect the condenser and thermometer, turn on the cooling water, temperature switch and stirring switch. When the thermometer rises to 65 °C, stop heating up, start timing, stop heating after reacting for 5 - 8 h, and take out the oxidized liquid after the device cools down.

[0055] 2. Filter the oxidized liquid by suction to remove the solid precipitate therein.

[0056] 3. Add the nano - titanium dioxide and graphene oxide composite material to about one - third of the height in a 60 - cm adsorption column, slowly pour the methanol raw material after suction filtration into the adsorption column until it covers the adsorption material, open the outflow switch of the adsorption column, adjust the outflow rate to 1 drop / s, and connect a conical flask below to receive the first product after adsorption.

[0057] 4. Then add 50 - 100 - mesh 3A molecular sieve to one - third of the height in a 60 - cm adsorption column, slowly pour the first product in step 3 into the adsorption column until it covers the adsorption material, open the outflow switch of the adsorption column, adjust the outflow rate to 1 drop / s, and connect a conical flask below to receive the second product after adsorption. Water can be removed through the molecular sieve.

[0058] 5. Assemble the experimental device, clean the tower body, condenser and kettle, etc., add stainless steel Raschig rings to the tower body, and seal each part well.

[0059] 6. Add raw material methanol to the three-necked flask (i.e., the kettle), perform total reflux for more than 2 hours, fully rinse the experimental device, and pour out the waste liquid after cooling.

[0060] 7. Add 2 L of the second product in Step 4 to the three-necked flask, turn on the cooling water, turn on the temperature switch to start heating up. When the thermometer rises to 65 °C, there is reflux liquid, stop heating up, maintain total reflux for 2 hours, and keep the system in the device stable. After 2 hours, turn on the reflux control switch, and set the reflux ratio to 8:1 - 12:1. Collect 5 fractions of the rectified liquid components, seal and leave for testing.

[0061] 8. Select 1 - 2 fractions with better test results in Step 7 for secondary batch rectification. The steps are the same as in Step 7, collect the rectified liquid components in segments, seal and leave for testing.

[0062] The present application will be further described below in conjunction with specific embodiments. It should be noted that the following embodiments are only used to explain the present application and should not be construed as a limitation to the present application.

[0063] Embodiment

[0064] Embodiment 1

[0065] The purification method of methanol includes the following steps:

[0066] 1. Add 3 L of industrial-grade methanol raw material to the three-necked flask, and then add 1% potassium permanganate and 0.5% potassium hydroxide based on the mass of the industrial-grade methanol raw material. Connect the condenser and thermometer, turn on the cooling water, temperature switch and stirring switch. When the thermometer rises to 65 °C, stop heating up, start timing, stop heating after reacting for 6 hours, and take out the oxidized liquid after the device cools down.

[0067] 2. Filter the oxidized liquid by suction to remove the solid precipitate therein.

[0068] 3. Add the composite material of titanium dioxide and graphene oxide (the mass of the composite material of titanium dioxide and graphene oxide is 30 g) to a 1 m adsorption column, slowly pour the filtered raw material into the adsorption column until it covers the adsorption material, turn on the outflow switch of the adsorption column, adjust the outflow rate to 1 drop / s, and connect the conical flask below to receive the first product after adsorption.

[0069] 4. Add 50-mesh 3A molecular sieve to one-third of the height of a 60 cm adsorption column, slowly pour the product in Step 3 into the adsorption column until it covers the adsorption material, turn on the outflow switch of the adsorption column, adjust the outflow rate to 1 drop / s, and connect the conical flask below to receive the second product after adsorption.

[0070] 5. Assemble the experimental device, clean the tower body, condenser, and still pot, etc., add stainless steel Raschig rings to the tower body, and seal each part well.

[0071] 6. Add raw material methanol to the three-necked flask (still pot), perform total reflux for more than 2 h, fully rinse the experimental device, and pour out the waste liquid after cooling.

[0072] 7. Add 2 L of the second product in Step 4 to the three-necked flask, turn on the cooling water, turn on the temperature switch to start heating. When the thermometer rises to 65 °C, there is reflux liquid, stop heating, maintain total reflux for 2 h, and keep the system in the device stable. After 2 h, turn on the reflux control switch, and set the reflux ratio to 8:1. Collect 5 segments of the rectified liquid components, and seal them for testing.

[0073] 8. Select 1 group of fractions with better test results in Step 7 for secondary batch rectification. The steps are the same as in Step 7. Collect the rectified liquid components in segments. After the rectified liquid is detected to be qualified, bottle and store it.

[0074] The conditions reached by each index in the methanol product and methanol raw material obtained in this example are shown in Table 1 below:

[0075] Table 1

[0076]

[0077] It should be noted that the specification column in Table 1 represents the standards that each index in methanol for liquid chromatography-mass spectrometry needs to reach, and the Example 1 column represents the specific conditions of each index of the methanol product purified by the purification method of Example 1.

[0078] As can be seen from Table 1, the methanol product for liquid chromatography-mass spectrometry prepared by the methanol purification method provided by the present invention has been significantly improved compared with the methanol raw material, and all indexes meet the requirements of the standards.

[0079] Example 2

[0080] The methanol purification method in this example is basically the same as that in Example 1, except that the mass of the nano-titanium dioxide and graphene oxide composite material in Step 3 is 40 g.

[0081] The conditions reached by each index in the methanol product and methanol raw material obtained in this example are shown in Table 2 below:

[0082] Table 2

[0083]

[0084] It should be noted that the specification column in Table 2 represents the standards that each index of methanol for liquid chromatography-mass spectrometry needs to meet, and the Example 2 column represents the specific conditions of each index of the methanol product purified by the purification method of Example 2.

[0085] Example 3

[0086] In this example, the purification method of methanol is basically the same as that of Example 1, except that the mass of the composite adsorbent material of nano-titanium dioxide and graphene oxide in step 3 is 45 g.

[0087] The conditions reached by each index in the methanol product and methanol raw material obtained in this example are shown in Table 3 below:

[0088] Table 3

[0089]

[0090] It should be noted that the specification column in Table 3 represents the standards that each index of methanol for liquid chromatography-mass spectrometry needs to meet, and the Example 3 column represents the specific conditions of each index of the methanol product purified by the purification method of Example 3.

[0091] Example 4

[0092] In this example, the purification method of methanol is basically the same as that of Example 1, except that the mass of the composite material of nano-titanium dioxide and graphene oxide in step 3 is 50 g.

[0093] The conditions reached by each index in the methanol product and methanol raw material obtained in this example are shown in Table 4 below:

[0094] Table 4

[0095]

[0096] It should be noted that the specification column in Table 4 represents the standards that each index of methanol for liquid chromatography-mass spectrometry needs to meet, and the Example 4 column represents the specific conditions of each index of the methanol product purified by the purification method of Example 4.

[0097] Example 5

[0098] In this example, the purification method of methanol is basically the same as that of Example 1, except that the mass of the composite material of nano-titanium dioxide and graphene oxide in step 3 is 60 g.

[0099] The conditions reached by each index in the methanol product and methanol raw material obtained in this example are shown in Table 5 below:

[0100] Table 5

[0101]

[0102] It should be noted that the specification column in Table 5 represents the standards that each index in methanol for liquid chromatography-mass spectrometry needs to meet, and the Example 5 column represents the specific conditions of each index of the methanol product purified by the purification method of Example 5.

[0103] Comparative Example 1

[0104] The purification method of methanol is the same as that in Example 1, except that the nano-titanium dioxide and graphene oxide composite material in Step 3 is replaced by modified activated carbon.

[0105] The conditions met by each index in the methanol product and methanol raw material obtained in this comparative example are shown in Table 6 below:

[0106] Table 6

[0107]

[0108] It should be noted that the specification column in Table 6 represents the standards that each index in methanol for liquid chromatography-mass spectrometry needs to meet, and the Comparative Example 1 column represents the specific conditions of each index of the methanol product purified by the purification method of Comparative Example 1.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for purifying methanol, characterized in that, The purification method includes the following steps: The methanol raw material is successively subjected to oxidation treatment, adsorption treatment, and rectification treatment to obtain a methanol product; Among them, during the adsorption treatment, a composite material of nano-titanium dioxide and graphene oxide is used to adsorb the methanol raw material after the oxidation treatment; The preparation method of the composite material of nano-titanium dioxide and graphene oxide includes the following steps: Mix nano-titanium dioxide and 3-aminopropyltriethoxysilane and react at a temperature of 70-90 °C for 4-7 h. Water is added during the reaction, and functionalized titanium dioxide is obtained after the reaction ends; Mix N,N-dimethylformamide and graphene oxide and disperse them by ultrasonic treatment. Add the functionalized titanium dioxide to the mixture after the ultrasonic dispersion ends, and react at a temperature of 90-110 °C for 6-8 h to obtain the composite material of nano-titanium dioxide and graphene oxide.

2. The purification method according to claim 1, characterized in that, The mass ratio of the nano-titanium dioxide to the 3-aminopropyltriethoxysilane is 1:2-5; The mass ratio of the graphene oxide to the functionalized titanium dioxide is 1:0.5-2.

3. The purification method according to any one of claims 1 to 2, characterized in that, The mass ratio of the composite material of nano-titanium dioxide and graphene oxide to the volume of the methanol raw material is (10-20) g:1 L.

4. The purification method according to claim 1, wherein The oxidation treatment includes: under the condition of condensation reflux, heating a mixture of the methanol raw material, potassium permanganate, and potassium hydroxide to 60-70 °C and reacting for 5-8 h.

5. The purification method according to claim 4, characterized in that The mass of the potassium permanganate accounts for 0.5-1.5% of the mass of the methanol raw material; The mass of the potassium hydroxide accounts for 0.4-0.6% of the mass of the methanol raw material.

6. The purification method according to claim 1, wherein The adsorption treatment includes: successively performing primary adsorption and secondary adsorption on the methanol raw material after the oxidation treatment, The primary adsorption includes using a composite material of nano-titanium dioxide and graphene oxide to adsorb the methanol raw material after the oxidation treatment to obtain a first product; The secondary adsorption includes using a molecular sieve to adsorb the first product to obtain a second product.

7. The purification method according to claim 6, characterized in that The rectification treatment includes primary batch rectification and secondary batch rectification. The second product is successively subjected to primary batch rectification and secondary batch rectification; The primary batch rectification includes: Performing total reflux on the second product in a rectification device for 1-3 h; Setting the reflux ratio of the rectification device to 8:1-12:1, and collecting 4-6 sections of rectified liquid components.

8. The purification method according to claim 7, characterized in that, Selecting at least part of the rectified liquid components for the secondary batch rectification to obtain the methanol product; Among them, the operating steps of the secondary batch rectification are the same as those of the primary batch rectification.

9. The purification method according to claim 7 or 8, characterized in that, Before performing the primary batch rectification, perform total reflux treatment on the rectification device using the methanol raw material.

Images