CN115006864A - Production device and method of ultra-pure methanol - Google Patents

Abstract

The invention discloses a device and a method for producing ultra-pure methanol, which comprises a heater, a rectifying device, a first filtering membrane, a second filtering membrane and a third filtering membrane, wherein a first inlet of the first filtering membrane is connected with a first discharge port of the heater, and a first surplus side of the first filtering membrane is connected with a first inlet of the rectifying device; a second inlet of the second filtering membrane is connected with an outlet at the top of the rectifying device, and a second retentate side of the second filtering membrane is connected with a first inlet of the rectifying device; the second permeate side of the second filtration membrane is connected to the third inlet of the third filtration membrane and the retentate side of the third filtration membrane is connected to the second inlet of the second filtration membrane. The invention can further improve the low-purity methanol or the high-purity methanol to the ultra-high-purity methanol, and the ultra-high-purity methanol has high product purity.

Description

Device and method for producing ultra-pure methanol

Technical Field

The invention relates to the technical field of ultra-clean high-purity chemical reagents, in particular to a device and a method for producing ultra-pure methanol.

Background

The ultra-clean high-purity reagent is also called wet chemical or process chemical, is a key chemical in the manufacturing process of large-scale or ultra-large-scale integrated circuits and high-grade semiconductor devices, is mainly used in the procedures of cleaning, photoetching, corrosion and the like of silicon single chips, and has very important influence on the yield, the electrical property and the reliability of the integrated circuits due to the purity and the cleanliness. For a megabit scale device, a 0.10 μm particle may cause the device to fail. Submicron (4.0-35.0 um) devices require that the number of 0.1 um particles is less than 10, and various metal impurities such as Fe, Cu, Cr, Ni, Al, Na and the like are controlled below the detection lower limit (about 1 x 1010 atoms/cm 2) of the current analysis technology. The current international SEMI standardization organization divides ultra-clean high-purity reagents into 4 grades according to the application range: the SEMI-C1 standard (suitable for the manufacture of IC process technology with a diameter of 4.2 μm), the SEMI-C7 standard (suitable for the manufacture of IC process technology with a diameter of 0.8-4.2 μm), the SEMI-C8 standard (suitable for the manufacture of IC process technology with a diameter of 0.09-0.20 μm), and the SEMI-C12 standard (suitable for the manufacture of IC process technology with a diameter of 0.09-0.20 μm).

Through the existing production and preparation device and mode of ultra-high purity methanol, a certain amount of organic impurities and metal ions still exist in the finally extracted high-purity methanol, so that the purity of the finally extracted methanol is relatively low.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a device and a method for producing ultra-high-purity methanol, and the device and the method can further improve the product purity of the ultra-high-purity methanol.

The invention is realized by the following technical scheme:

the production device of the ultra-high purity methanol comprises a heater, a rectifying device, a first filtering membrane, a second filtering membrane and a third filtering membrane, wherein a first inlet of the first filtering membrane is connected with a first discharge port of the heater, and a first retentate side of the first filtering membrane is connected with a first inlet of the rectifying device; a second inlet of the second filtering membrane is connected with an outlet at the top of the rectifying device, and a second retentate side of the second filtering membrane is connected with a first inlet of the rectifying device; the second permeate side of the second filtration membrane is connected to the third inlet of the third filtration membrane, and the third retentate side of the third filtration membrane is connected to the second inlet of the second filtration membrane.

Further, the rectifying device comprises a light component removal tower and a heavy component removal tower, wherein a tower bottom outlet of the light component removal tower is connected with a second inlet of the heavy component removal tower, the light component removal tower is provided with the first inlet, and the heavy component removal tower is provided with the tower top outlet.

Further, the production apparatus further comprises a first condensing device, wherein the second inlet of the first condensing device is connected with the first permeate side of the first filtration membrane.

Further, the production apparatus further comprises a second condensing device disposed between the second filtering membrane and the third filtering membrane, a third inlet of the second condensing device is connected with the second permeate side of the second filtering membrane, and a third outlet of the second condensing device is connected with a third inlet of the third filtering membrane.

Further, the first filtering membrane is an organic composite membrane or an inorganic composite membrane or an organic-inorganic composite permeable membrane and is used for filtering water in the methanol.

Further, the second filtering membrane is an organic composite membrane, a supporting layer of the second filtering membrane is polytetrafluoroethylene, and a separating layer is a fluorine-containing polymer.

Further, the third filtering membrane is an organic composite membrane, a supporting layer of the third filtering membrane is polytetrafluoroethylene, and a separating layer is a fluorocarbon polymer chelating membrane.

Further, the preparation method of the fluorocarbon polymer chelating film comprises the following steps:

carrying out hydrophilic treatment on the porous PTFE membrane to obtain a hydrophilic base membrane;

the chelate resin is washed by hydrochloric acid solution, sodium hydroxide solution and deionized water in sequence and then is dried;

grinding and screening the washed and dried chelate resin to obtain powder;

mixing the powder with polyisobutylene and polyhexafluoroethylene emulsion, and defoaming in vacuum to form a coating solution;

coating the smearing liquid on a base membrane with hydrophilicity to prepare a chelating membrane;

the prepared chelate membrane is washed to be neutral by hydrochloric acid solution, sodium hydroxide solution and pure water in sequence, and then is dried and stored.

A method for producing ultra-high purity methanol, comprising the steps of:

heating low-purity methanol;

removing water content in the low-purity methanol;

removing organic impurities and most metal ions in the low-purity methanol;

further removing metal ions and particles in the low-purity methanol;

cooling the low-purity methanol;

and removing metal ions and particles in the low-purity methanol again.

Further, the steps of: removing organic impurities and most metal ions in low-purity methanol, and specifically comprising the following steps:

removing lighter organic impurities in the low-purity methanol;

most of metal ions and organic impurities with boiling points higher than that of the methanol in the low-purity methanol are removed.

Compared with the prior art, the invention has the advantages that:

1. the invention firstly uses the pervaporation permeable membrane to remove the water content in the methanol, compared with the dehydration treatment of a rectifying tower, the energy consumption is reduced by more than 50 percent, and the product yield is high.

2. The invention removes most metal ions and organic impurities lighter than methanol and higher than the boiling point of methanol by the light-weight removing rectifying tower and the heavy-weight removing rectifying tower.

3. According to the invention, metal ions are removed through the second filtering membrane and the electronic-grade pervaporation membrane which preferentially permeates methanol, and compared with the traditional multi-effect rectifying tower treatment, the energy consumption is reduced by more than 90%; the second filtering membrane is a compact membrane, and can remove particles at the same time, so that the product purity of the ultra-high-purity methanol is improved.

4. According to the invention, trace metal ions are removed by preparing an electronic-grade fluorocarbon polymer chelating membrane through reaction, the retentate side of the third filtering membrane returns to the second filtering membrane, the reaction removal effect is good, and the product yield can be improved; the membrane aperture is smaller, and simultaneously, the removal of particles can be carried out, thereby improving the product purity of the ultra-pure methanol.

Drawings

FIG. 1 is a schematic diagram showing the construction of an apparatus for producing ultra-high purity methanol according to an embodiment of the present invention;

FIG. 2 is a flow diagram of a process for the production of ultra-high purity methanol.

1. A heater; 10. a first access port; 11. a first discharge port; 2. a rectification device; 20. a light component removal tower; 200. a first rectification column; 201. a first total condensation tower; 202. a first reboiler; 203. a first inlet; 204. a bottom outlet; 21. a de-weighting tower; 210. a second rectification column; 211. a second total condensation tower; 212. a second reboiler; 213. a second inlet; 214. an outlet at the top of the tower; 3. a first filter membrane; 30. a first inlet; 31. a first retentate side; 32. a first permeate side; 4. a second filter membrane; 40. a second inlet; 41. a second retentate side; 42. a second permeate side; 5. a third filtration membrane; 50. a third inlet; 51. a third retentate side; 52. a third permeate side; 7. a first condensing device; 70. a first condenser; 700. a second access port; 701, performing heat treatment on the mixture; a second discharge port; 71. a first vacuum pump; 8. a second condensing device; 80. a second condenser; 800. a third inlet; 801. a third discharge port; 81. a second vacuum pump.

Detailed Description

The following non-limiting detailed description of the present invention is provided in connection with the preferred embodiments and accompanying drawings. In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

As shown in fig. 1, an apparatus for producing ultra-high purity methanol according to an embodiment of the present invention includes a heater 1, a rectifying apparatus 2, a first filtering membrane 3, a second filtering membrane 4, a third filtering membrane 5, a first condensing device 7, and a second condensing device 8.First filtrationThe first inlet 30 of the membrane 3 is connected to the first outlet 11 of the heater 1, a first filter membraneThe first retentate side 31 of the first filtration membrane 3 is connected to the first inlet 203 of the rectification apparatus 2 and the first permeate side 32 of the first filtration membrane 3 is connected to the second inlet 700 of the first condensation device 7; the second drain 701 of the first condensing device 7 is used to drain condensed wastewater. The second inlet 40 of the second filtering membrane 4 is connected with the top outlet 214 of the rectifying device 2, and the second retentate side 41 of the second filtering membrane 4 is connected with the first inlet 203 of the rectifying device 2; the second permeate side 42 of the second filtering membrane 4 is connected to the third inlet 50 of the third filtering membrane 5 and the second condensation device 8 is arranged between the second filtering membrane 4 and the third filtering membrane 5, in particular, the third inlet 800 of the second condensation device 8 is connected to the second permeate side 42 of the second filtering membrane 4, the third discharge 801 of the second condenser 8 is connected to the third inlet 50 of the third filtering membrane 5 and the third retentate side 51 of the third filtering membrane 5 is connected to the second inlet 40 of the second filtering membrane 4. The third permeate side 52 of the third filter membrane 5 is the final product.

The rectification device 2 comprises a light component removing tower 20 and a heavy component removing tower 21, wherein a tower bottom outlet 204 of the light component removing tower 20 is connected with a second inlet 213 of the heavy component removing tower 21, a first inlet 203 is arranged on the light component removing tower 20, and a tower top outlet 214 is arranged on the heavy component removing tower 21. By providing the rectifying apparatus 2, the rectifying apparatus 2 removes organic impurities lighter and higher boiling point than methanol and most of metal ions.

The lightness-removing column 20 includes a first rectification column 200, a first congealing column 201, and a first reboiler 202, the first congealing column 201 being disposed at the top of the first rectification column 200, and the first reboiler 202 being disposed at the bottom of the first rectification column 200.

The heavy component removal column 21 includes a second rectification column 210, a second congealing column 211, and a second reboiler 212, the second congealing column 211 is disposed at the top of the second rectification column 210, and the second reboiler 212 is disposed at the bottom of the second rectification column 210. The first inlet 203 of the first rectification column 200 is connected to the first retentate side 31 of the first filter membrane 3, the bottom outlet 204 of the first rectification column 200 is connected to the second inlet 213 of the second rectification column 210, and the top outlet 214 of the second rectification column 210 is connected to the second inlet 40 of the second filter membrane 4. Organic impurities lighter than methanol and higher in boiling point than methanol, most of metal ions are removed through the heavy component removal column 21 and the light component removal column 20.

The first condensing device 7 comprises a first condenser 70 and a first vacuum pump 71, the first condenser 70 is connected with the first vacuum pump 71, a second inlet 700 of the first condenser 70 is connected with the first permeation side 32 of the first filtering membrane 3, and a second outlet 701 of the first condenser 70 is used for discharging condensed wastewater. The first vacuum pump 71 pumps air in the first condenser 70, so as to avoid the pressure of the first condenser 70 from rising due to other non-condensable gases such as nitrogen and oxygen in the air.

The second condensation device 8 comprises a second condenser 80 and a second vacuum pump 81, the second condenser 80 is connected with the second vacuum pump 81, a third inlet 800 of the second condenser 80 is connected with the second permeate side 42 of the second filtration membrane 4, and a third outlet 81 of the second condenser 80 is connected with the third inlet 50 of the third filtration membrane 5. The function of the second vacuum pump 81 is similar to that of the first vacuum pump 71 and will not be described in detail here.

In this embodiment, the first filtering membrane 3 is an organic composite membrane, an inorganic composite membrane, or an organic-inorganic composite membrane, and is used for filtering water in methanol. The organic composite membrane can be a PVA/PVDF/PET material, the inorganic composite membrane can be a molecular sieve membrane/ceramic composite membrane, and the organic-inorganic composite membrane is a composite membrane integrating organic membrane and inorganic membrane technologies, such as an organic-inorganic composite hydrophobic membrane, and is not described herein for the prior art. The invention firstly uses the pervaporation permeable membrane to remove the water content in the methanol, and compared with the dehydration treatment of a rectifying tower, the energy consumption is reduced by more than 50 percent, and the product yield is high.

The second filtering membrane 4 is an organic composite membrane, a supporting layer of the second filtering membrane 4 is polytetrafluoroethylene, a separating layer is a fluorine-containing polymer, the methanol-containing composite membrane has preferential selectivity on methanol, and the components permeating through the membrane are in a gas phase state, so that the metal ions are well intercepted. The second filtering membrane 4 removes metal ions through an electronic-grade pervaporation membrane which preferentially permeates methanol, and compared with the traditional multi-effect rectifying tower treatment, the energy consumption is reduced by more than 90%; the second filtration membrane 4 is a dense membrane, and particulate matter removal is possible.

The third filtering membrane 5 is an organic composite membrane, the supporting layer of the third filtering membrane 5 is polytetrafluoroethylene, and the separating layer is a fluorocarbon polymer chelating membrane. The chelate film has an atom having an unbound lone pair of electrons, and the atom and the metal ion form a coordinate bond, thereby removing the metal ion. Trace metal ions are removed through the reaction of preparing an electronic-grade fluorocarbon polymer chelating membrane, the retentate side of the third filtering membrane 5 returns to the second filtering membrane 4, the reaction removal effect is good, and the product yield can be improved; the membrane aperture is smaller, and simultaneously, the removal of particles can be carried out.

The preparation method of the fluorocarbon polymer chelating film comprises the following steps:

the method comprises the following steps: carrying out hydrophilic treatment on the porous PTFE membrane to obtain a hydrophilic base membrane;

step two: the chelate resin is washed by hydrochloric acid solution, sodium hydroxide solution and deionized water in sequence and then dried;

step three: grinding and screening the washed and dried chelate resin to obtain powder;

step four: mixing the powder with polyisobutylene and polyhexafluoroethylene emulsion, and defoaming in vacuum to form a coating solution;

step five: coating the smearing liquid on a base membrane with hydrophilicity to prepare a chelating membrane;

step six: the prepared chelate membrane is washed to be neutral by hydrochloric acid solution, sodium hydroxide solution and pure water in sequence, and then is dried and stored.

The invention removes metal ions by two membrane technologies of a second filtering membrane 4 and a third filtering membrane 5, so that the metal ions meet the requirements of metal ions in the SEMI-C12 standard; the dissolution of the membrane materials of the two membranes is less, and the grade of a semiconductor is achieved; the two films can remove metal ions and particles at the same time, so that the product purity of the ultra-high-purity methanol is improved.

As shown in fig. 2, a method for producing ultra-high purity methanol includes the steps of:

s1, heating the low-purity methanol;

specifically, the low-purity methanol enters the heater 1 from the first inlet 10 and is heated to 50-100 ℃.

S2, removing the water content in the low-purity methanol;

specifically, the heated low-purity methanol enters from the first inlet 30 of the first filtering membrane 3, the absolute pressure of the first permeation side 32 of the first filtering membrane 3 is 1000-8000Pa, and the water content penetrating through the first permeation side 32 of the first filtering membrane 3 is condensed by the first condensing device 7 and then discharged.

S3, removing organic impurities and most metal ions in the low-purity methanol;

step S3 specifically includes:

s30, removing lighter organic impurities in the low-purity methanol;

specifically, after the low-purity methanol on the first retentate side 31 of the first filtering membrane 3 enters the lightness-removing column 20, organic impurities such as lighter alcohols, aldehydes, ketones, esters and the like in the methanol are removed; wherein the operation temperature of the lightness-removing column 20 is 40-70 ℃, the operation pressure is 0-50kPa, and the reflux ratio is 0.5-30.

S31, removing most of metal ions in the low-purity methanol and organic impurities with boiling points higher than that of the methanol.

The tower bottom component of the light component removal tower 20 enters the heavy component removal tower 21 again, and organic impurities such as alcohol, aldehyde, ketone, ester and the like with a boiling point higher than that of the methanol in the methanol and most of metal ions are removed. Wherein the operation temperature of the de-heavy tower 21 is 60-90 ℃, the operation pressure is 0-50kPa, and the reflux ratio is 0.5-30.

S4, further removing metal ions and particles in the low-purity methanol;

specifically, the low-purity methanol discharged from the outlet 214 of the second rectifying tower 210 enters the second filtering membrane 4 to further remove a part of metal ions and particulate matters; then, the raw material on the second retentate side 41 of the second filtration membrane 4 enters again from the first inlet 203 of the lightness-removing column 20, and step S3 is executed again. Wherein the operating temperature of S4 is 40-70 ℃, and the absolute pressure of the second permeate side 42 is 1000-8000 Pa.

S5, cooling the low-purity methanol.

In particular, the methanol coming out of the permeate side 42 of the second filtration membrane 4 enters the second condensation device 8 for cooling.

And S6, removing the metal ions and the particles in the low-purity methanol again.

Specifically, the methanol cooled by the second condensing device 8 enters the third filtering membrane 5 for treatment, so as to further remove metal ions and particulate matters; then, the raw material on the third retentate side 51 of the third filtration membrane 5 enters the second inlet 40 of the second filtration membrane 4 again, and step S4 is performed again, so that the third permeate side 52 of the third filtration membrane 5 is the final ultra-high purity methanol.

In order to better understand the present invention, the specific steps of a method for producing ultra-high purity methanol are further illustrated by two specific examples:

the first embodiment is as follows:

the method comprises the following steps: the low purity methanol was heated to 100 ℃.

Step two: methanol heated to 100 ℃ enters a molecular sieve membrane/ceramic composite membrane (first filtration membrane 3) and the absolute pressure of the permeation side of the membrane is 3000Pa, so that water in the methanol is removed.

Step three: the first retentate side 31 of the first filtering membrane 3 enters a first rectifying tower 200, the operation temperature of the top of the first rectifying tower 200 is 45 ℃, the operation temperature of the bottom of the tower is 70 ℃, the operation pressure of the top of the tower is 50kPa, the reflux ratio is 15, and light organic impurities such as alcohol, aldehyde, ketone, ester and the like are separated from the top of the tower.

The tower bottom components of the first rectifying tower 200 enter a second rectifying tower 210, the operation temperature of the top of the second rectifying tower 210 is 60 ℃, the operation temperature of the bottom of the tower is 80 ℃, the operation pressure of the top of the tower is 0kPa, and the reflux ratio is 20. Separating out the components of alcohol, aldehyde, ketone, ester and the like with boiling points higher than that of the methanol in the tower bottom and most of metal ions.

Step four: the tower top component of the second rectifying tower 210 enters a poly (sulfonated chloroethylene-based ether) polymer/PTFE membrane (a second filtering membrane 4) to further remove a part of metal ions and particulate matters. Wherein the operating temperature of step four is 50 ℃ and the absolute pressure of the second permeate side 42 is 3000 Pa.

Step five: the components of the second permeate side 42 of the second filtration membrane 4 enter the second condensation device 8 for cooling treatment; the components of the second retentate side 41 of the second filtration membrane 4 enter the first rectification column 200 again, and step three is performed again.

Step six: the components cooled by the second condensing device 8 enter a poly (sulfonated chloroethylene ether) -imine diacetic acid based chelating membrane/PTFE (third filtering membrane 5) to further remove metal ions and particulate matters. The third retentate side 51 of the third filter membrane 5 enters the second filter membrane 4 again and step four is performed again; the third permeate side 52 of the third filtration membrane 5 is the ultra-high purity methanol, and the analysis result of the ultra-high purity methanol is shown in table 1.

The second embodiment:

the method comprises the following steps: the low purity methanol was heated to 80 ℃.

Step two: methanol heated to 90 ℃ enters a PVA/PVDF/PET organic composite membrane (a first filtering membrane 3), the absolute pressure of the permeation side of the membrane is 3000Pa, and water in the methanol is removed.

Step three: the first permeation residue side 31 of the first filtering membrane 3 enters a first rectifying tower 200, the operation temperature of the top of the first rectifying tower 200 is 40 ℃, the operation temperature of the bottom of the tower is 70 ℃, the operation pressure of the top of the tower is 50kPa, and the reflux ratio is 15. The organic impurities such as lighter alcohol, aldehyde, ketone, ester and the like are separated from the tower top.

The tower bottom components of the first rectifying tower 200 enter a second rectifying tower 210, the operation temperature of the top of the second rectifying tower 210 is 60 ℃, the operation temperature of the bottom of the tower is 80 ℃, the operation pressure of the top of the tower is 0kPa, and the reflux ratio is 15. Separating out the components of alcohol, aldehyde, ketone, ester and the like with boiling points higher than that of the methanol in the tower bottom and most of metal ions.

Step four: the overhead component of the second rectification column 210 enters a polyhexafluoropropylene/PTFE membrane (second filtration membrane 4) to further remove a part of metal ions and particulate matter. Wherein the operating temperature of step four is 50 ℃ and the absolute pressure of the second permeate side 42 is 3000 Pa.

Step five: the components of the second permeate side 42 of the second filtration membrane 4 enter the second condensation device 8 for cooling treatment; the components of the second retentate side 41 of the second filtration membrane 4 enter the first rectification column 200 again, and step three is performed again.

Step six: the component cooled by the second condensing device 8 enters a polyhexafluoropropylene-imine diacetic acid radical chelating membrane/PTFE (third filtering membrane 5) to further remove metal ions and particulate matters. The third retentate side 51 of the third filter membrane 5 enters the second filter membrane 4 again and step four is performed again; the third permeate side 52 of the third filtration membrane 5 is the ultra-high purity methanol, and the analysis result of the ultra-high purity methanol is shown in table 1.

TABLE 1 analytical results

The above table is for explaining the components contained in the methanol raw material, the content of the components is greatly related to the source, but the applicability of the invention is not limited, and the methanol product produced by the production device and the method provided by the invention can reach the standard requirement of SEMI C12(G4) or above.

The invention removes metal ions by two membrane technologies of a second filtering membrane 4 and a third filtering membrane 5, so that the metal ions meet the requirements of metal ions in the SEMI-C12 standard; the dissolution of the membrane materials of the two membranes is less, and the grade of a semiconductor is achieved; the two films can remove metal ions and particles at the same time, so that the product purity of the ultra-high-purity methanol is improved.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. An ultra-high purity methanol production device is characterized by comprising a heater (1), a rectification device (2), a first filtering membrane (3), a second filtering membrane (4) and a third filtering membrane (5), wherein a first inlet (30) of the first filtering membrane (3) is connected with a first discharge port (11) of the heater (1), and a first retentate side (31) of the first filtering membrane (3) is connected with a first inlet (203) of the rectification device (2); the second inlet (40) of the second filtering membrane (4) is connected with the top outlet (214) of the rectifying device (2), and the second retentate side (41) of the second filtering membrane (4) is connected with the first inlet (203) of the rectifying device (2); the second permeate side (42) of the second filter membrane (4) is connected to the third inlet (50) of the third filter membrane (5), and the third retentate side (51) of the third filter membrane (5) is connected to the second inlet (40) of the second filter membrane (4).

2. Ultra high purity methanol production plant according to claim 1, wherein the rectification unit (2) comprises a light component removal column (20) and a heavy component removal column (21), wherein a bottom outlet (204) of the light component removal column (20) is connected to a second inlet (213) of the heavy component removal column (21), wherein the light component removal column (20) is provided with the first inlet (203), and wherein the heavy component removal column (21) is provided with the top outlet (214).

3. Ultra high purity methanol production plant according to claim 1, further comprising a first condensation device (7), wherein the second inlet port (700) of the first condensation device (7) is connected to the first permeate side (32) of the first filtration membrane (3).

4. Ultra-high purity methanol production plant according to claim 1, further comprising a second condensation device (8) arranged between the second filtration membrane (4) and a third filtration membrane (5), wherein a third inlet (800) of the second condensation device (8) is connected to the second permeate side (42) of the second filtration membrane (4), and wherein a third outlet (801) of the second condensation device (8) is connected to the third inlet (50) of the third filtration membrane (5).

5. The apparatus for producing ultra-high purity methanol according to claim 1, wherein the first filtration membrane (3) is an organic composite membrane or an inorganic composite membrane or an organic-inorganic composite water permeable membrane for filtering water in methanol.

6. The ultra-high purity methanol production apparatus according to claim 1, wherein the second filtration membrane (4) is an organic composite membrane, the support layer of the second filtration membrane (4) is polytetrafluoroethylene, and the separation layer is a fluoropolymer.

7. The apparatus for producing ultra-high purity methanol according to claim 1, wherein the third filtration membrane (5) is an organic composite membrane, the support layer of the third filtration membrane (5) is polytetrafluoroethylene, and the separation layer is a fluorocarbon polymer chelate membrane.

8. The apparatus for producing ultra-high-purity methanol according to claim 7, wherein the fluorocarbon polymer chelate film is prepared by the following method:

carrying out hydrophilic treatment on the porous PTFE membrane to obtain a hydrophilic base membrane;

the chelate resin is washed by hydrochloric acid solution, sodium hydroxide solution and deionized water in sequence and then dried;

grinding and screening the washed and dried chelate resin to obtain powder;

mixing the powder with polyisobutylene and polyhexafluoroethylene emulsion, and defoaming in vacuum to form a coating solution;

coating the smearing liquid on a base membrane with hydrophilicity to prepare a chelating membrane;

the prepared chelate membrane is washed to be neutral by hydrochloric acid solution, sodium hydroxide solution and pure water in sequence, and then is dried and stored.

9. A method for producing ultra-high purity methanol, which is characterized by comprising the following steps:

heating low-purity methanol;

removing water content in the low-purity methanol;

removing organic impurities and most metal ions in the low-purity methanol;

further removing metal ions and particles in the low-purity methanol;

cooling the low-purity methanol;

and removing metal ions and particles in the low-purity methanol again.

10. The method for producing ultra-high purity methanol according to claim 9, wherein the steps of: removing organic impurities and most metal ions in low-purity methanol, and specifically comprising the following steps:

removing lighter organic impurities in the low-purity methanol;

most of metal ions and organic impurities with boiling points higher than that of the methanol in the low-purity methanol are removed.

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