Semiconductor-grade PGMEA purification system and purification method

Abstract

The invention belongs to the technical field of semiconductor-grade PGMEA purification, and particularly relates to a semiconductor-grade PGMEA purification system and method, and the semiconductor-grade PGMEA purification system comprises a metal ion adsorption unit, a primary separation rectification unit, an azeotropic rectification unit, a phase separation unit, an n-butyl alcohol raw material unit, a solvent recovery rectification unit, and a metal ion removal rectification unit. The yield of rectifying tower top wastewater generated by azeotropy of PGMEA / water is reduced in a four-tower rectification mode, energy consumption caused by dehydration is reduced by adopting n-butyl alcohol as an entrainer, and semiconductor-grade PGMEA is obtained through the metal ion adsorption unit, the primary separation rectification unit, the azeotropic rectification unit, the phase separation unit, the solvent recovery rectification unit and the metal ion removal rectification unit. The yield of the ultrapure PGMEA is high, the selectivity is high when the n-butyl alcohol is used as the entrainer, the energy consumption is low, and the final wastewater amount is low.

Description

Technical Field

[0001] The invention relates to the technical field of semiconductor-grade PGMEA purification, and in particular to a semiconductor-grade PGMEA purification system and a purification method, which adopts industrial-grade PGMEA as a raw material to produce a PGMEA liquid with a purity of not less than 99.99%. Background Art

[0002] Propylene glycol methyl ether acetate (PGMEA) has ether, carbonyl and alkyl groups, so that there are both non-polar and polar parts in the same molecule. These two functional groups are mutually restrained and repelled, and each of them is inherent, which makes it have a wide range of solubility. Therefore, PGMEA is known as a universal solvent. PGMEA has the following characteristics: first, it can dissolve many different types of substances, such as ink, paint, ink, textile dyes and textile oils; second, it has good volatility and may form explosive steam / air mixtures at temperatures above 42°C, so it should be sealed when used; in addition, it has a colorless and transparent appearance and will not stain the cleaned objects when used as a cleaning agent; finally, it has low toxicity and environmental protection, and is friendly to the environment and human body during use. High-purity propylene glycol methyl ether acetate (PGMEA) is currently a commonly used photoresist stirring solvent. High-purity PGMEA evenly spreads the photoresist on the surface of the silicon wafer, so that the photoresist and the silicon wafer surface are effectively bonded together. In addition, after photolithography is completed, PGMEA can also be used as a cleaning agent to thoroughly clean the photoresist and silicon wafer surface.

[0003] The raw material composition of industrial PGMEA is about 95%, H2O accounts for about 4%, and the rest are metal ions and their anions. Therefore, the purification of PGMEA must consider both the purity of PGMEA and the removal of metal ions. Most of the impurities in PGMEA are H2O, and H2O and PGMEA form an azeotrope with an azeotropic temperature of 96.62°C and an azeotropic composition of 44.95% PGMEA and 55.05% H2O. Direct distillation will produce a large amount of PGMEA-H2O azeotropic wastewater, which is difficult to treat. The removal of metal ions must consider both the removal of solvent metal ions and the avoidance of metal ions in the purified solvent.

[0004] Patent CN108299202B uses "normal pressure extraction distillation + vacuum distillation process" to process PGMEA / water solution to recover high-purity PGMEA. Its extraction distillation uses ethyl benzyl ether as an extractant, and the amount of ethyl benzyl ether used is 2-10 times that of PGMEA. The top of the extraction tower is 86.5% H2O, 0.05% PGMEA, and 13.45% of ethyl benzyl ether. The phase separation tank separates water and ethyl benzyl ether, and the bottom of the tower is 11.8% PGMEA and 88.2% ethyl benzyl ether for vacuum distillation tower treatment. However, since the density of ethyl benzyl ether is 0.949, which is very close to 1, the phase separation tank cycle of water and ethyl benzyl ether is long and the separation effect is low. Secondly, the amount of extractant is 2-10 times that of PGMEA, which is large, resulting in high energy consumption of the bottom of the vacuum distillation tower.

[0005] Patent CN116239469 A uses "esterification preparation + ordinary distillation + vacuum distillation process" to prepare high-purity PGMEA. The prepared PGMEA / water solution is subjected to ordinary distillation to remove light components, and the tower bottom is subjected to vacuum distillation to remove heavy components and metal ions. Since 44.95% PGMEA and 55.05% H2O form a 96.62℃ azeotropic mixture, a large amount of PGMEA wastewater will be generated at the top of the ordinary distillation tower and needs to be treated. In addition, the purity of PGMEA in this system is only 99.992%.

[0006] Patent CN104370742B uses "sedimentation + distillation + rectification process" to treat PGMEA waste liquid. It also does not take into account that 44.95% PGMEA and 55.05% H2O form a 96.62°C azeotropic mixture. Therefore, after multiple distillations, the purity is only 95%, and the highest is 99%.

[0007] Patent CN114702385B adopts "two-stage distillation + microfiltration + dehydration + nanofiltration" to prepare high-purity PGMEA using industrial PGMEA as raw material. It also does not take into account that 44.95% PGMEA and 55.05% H2O form a 96.62°C azeotropic mixture, resulting in a large amount of PGMEA wastewater generated at the top of the distillation tower that needs to be treated. Summary of the invention

[0008] The prior art has its own advantages, but still has certain disadvantages. The purpose of the present invention is to make up for the shortcomings of the prior art, reduce the output of distillation tower top wastewater generated by PGMEA / water azeotropy by a four-tower distillation method, and use n-butanol as an azeotropic agent to reduce the energy consumption caused by dehydration; through a metal ion adsorption unit, a primary distillation unit, a n-butanol azeotropic distillation tower unit, a phase separation unit, a solvent recovery distillation tower unit, and a metal ion removal distillation unit to obtain a semiconductor-grade PGMEA process.

[0009] The present invention is achieved through the following technical solutions:

[0010] The present invention provides a semiconductor-grade PGMEA purification system, comprising a metal ion adsorption unit, a primary fractionation distillation unit, an azeotropic distillation unit, a phase separation unit, a n-butanol raw material unit, a solvent recovery distillation unit, and a metal ion removal distillation unit;

[0011] The metal ion adsorption unit is used to receive industrial PGMEA raw materials and remove some metal ions;

[0012] The primary fractionation and rectification unit is connected to the metal ion adsorption unit, and is used to receive the PGMEA raw material sent by the metal ion adsorption unit, and perform preliminary rectification on the PGMEA raw material;

[0013] The azeotropic distillation unit is connected to the primary distillation unit, and is used to receive the PGMEA-H2O azeotrope distilled by the primary distillation unit, and perform azeotropic treatment on the PGMEA-H2O azeotrope;

[0014] The phase separation unit and the n-butanol raw material unit are respectively connected to the azeotropic distillation unit. The phase separation unit is used to receive the top component sent by the azeotropic distillation unit, the light component and the heavy component formed by layering, and the light component is mixed with the n-butanol sent by the n-butanol raw material unit and sent to the azeotropic distillation unit for recycling;

[0015] The solvent recovery distillation unit is respectively connected to the azeotropic distillation unit, the n-butanol raw material unit, and the metal ion removal distillation tower, and is used to receive the bottom components sent by the azeotropic distillation unit and perform distillation again. The n-butanol distilled from the top of the tower is returned to the n-butanol raw material tank, and the high-purity PGMEA distilled from the bottom of the tower enters the metal ion removal distillation tower;

[0016] The metal ion removal distillation unit is connected to the primary distillation unit and the solvent recovery distillation unit, and is used to receive the high-purity PGMEA distilled from the primary distillation unit and the solvent recovery distillation unit, and distill the high-purity PGMEA again to form semiconductor-grade PGMEA.

[0017] Specifically, the metal ion adsorption unit includes at least two sets of metal ion adsorbers arranged in series or in parallel, the inlet end of the metal ion adsorption unit is provided with a first precision filter, and the outlet end of the metal ion adsorption unit is provided with a second precision filter;

[0018] Furthermore, the metal ion adsorber is made of 316L material, and the interior is EP electropolished with a roughness of ≤0.25μm to reduce the residue on the inner surface of the adsorber and the precipitation of metal ions. The preferred operating temperature is 20-50°C, and the operating pressure is 1-3barg. The chelated adsorbent used is preferably styrene macroporous iminodiacetic acid chelated resin, the pore size of the primary chelated adsorbent resin is 0.1-0.3μm, and the pore size of the secondary chelated adsorbent resin is 0.05-0.5μm. The two-stage adsorber can be connected in series or in parallel, and is regenerated offline. The height-to-diameter ratio of the adsorber is 10-20, preferably 15; the first front precision filter uses a 0.5μm filter with a perfluorinated skeleton and filter element, and the second rear precision filter uses a 0.1μm filter with a perfluorinated skeleton and filter element.

[0019] Specifically, the primary fractionation unit includes a primary fractionation tower, a first filter disposed at the top of the primary fractionation tower, and a second filter disposed at the bottom of the primary fractionation tower;

[0020] Furthermore, the primary distillation tower is made of 316L material, and the interior is EP electrolytic polished with a roughness of ≤0.25μm to reduce the residue on the inner surface of the primary distillation tower and the precipitation of metal ions. The primary distillation tower has a tower section height of 1.5 to 3m, and a liquid collecting redistributor is provided to reduce the influence of wall flow, wherein electrolytically treated plate corrugated packing is used; the theoretical number of plates is 30 to 100, preferably 55 to 60; the reflux ratio is 0.5 to 10, preferably 1.5 to 2; the operating pressure is 5 to 100 kpaG, preferably 5 to 10 kpaG; the tower top operating temperature is 96 to 116°C, preferably 96 to 100°C; the tower bottom operating temperature is 146 to 177°C, preferably 146 to 150°C; when the theoretical number of plates is 60, the feed position is the 20th to 40th, preferably 28th to 32nd.

[0021] Specifically, the azeotropic distillation unit includes an azeotropic distillation tower, a third filter disposed at the top of the azeotropic distillation tower, and a fourth filter disposed at the bottom of the azeotropic distillation tower;

[0022] Furthermore, the azeotropic distillation tower is made of 316L material, and the interior is EP electrolytically polished with a roughness of ≤0.25μm to reduce the residue on the inner surface of the azeotropic distillation tower and the precipitation of metal ions. The distillation tower has a tower section height of 1.5 to 3m, and a liquid collector redistributor is provided to reduce the influence of wall flow, wherein electrolytically treated plate corrugated packing is used; the azeotropic agent used is n-butanol, which forms an azeotrope of 92.67°C with 44.46% H2O, which is much lower than the boiling point of PGMEA 154.8°C; The theoretical plate number is 20 to 80, preferably 50 to 60; the reflux ratio is 0.1 to 5, preferably 0.1 to 0.5; the operating pressure is 5 to 100 kpaG, preferably 5 to 10 kpaG; the tower top operating temperature is 92 to 112°C, preferably 92 to 96°C; the tower bottom operating temperature is 130 to 150°C, preferably 130 to 134°C; when the theoretical plate number is 60, the feed position is the 20th to 40th, preferably the 28th to 32nd; the n-butanol solvent feed plate position is the 2nd to 10th, preferably the 4th to 6th.

[0023] Specifically, the solvent recovery distillation unit includes a solvent recovery distillation tower, a fifth filter disposed at the top of the solvent recovery distillation tower, and a sixth filter disposed at the bottom of the solvent recovery distillation tower;

[0024] Furthermore, the solvent recovery distillation tower is made of 316L material, and the interior is EP electrolytic polished with a roughness of ≤0.25μm to reduce the residue on the inner surface of the solvent recovery distillation tower and the precipitation of metal ions. The solvent recovery distillation tower has a tower section height of 1.5 to 2.5m, and a liquid collecting redistributor is provided to reduce the influence of wall flow, wherein electrolytically treated random packing is used; the theoretical plate number is 30 to 100, preferably 50 to 60 blocks; the reflux ratio is 4 to 10, preferably 4 to 6; the operating pressure is 5 to 100 kpaG, preferably 5 to 10 kpaG; the tower top operating temperature is 117 to 137°C, preferably 117 to 121°C; the tower bottom operating temperature is 146 to 166°C, preferably 146 to 150°C; when the theoretical plate number is 60, the feed position is 20 to 40, preferably 28 to 32 blocks.

[0025] Specifically, the demetallization ion distillation unit includes a demetallization ion distillation tower and a third precision filter arranged at the inlet end of the demetallization ion distillation tower, a seventh filter arranged at the top of the demetallization ion distillation tower, an eighth filter arranged at the bottom of the demetallization ion distillation tower, and a fourth precision filter arranged at the outlet end of the seventh filter;

[0026] Furthermore, the demetallization distillation tower is made of 316L material, and the interior is EP electrolytic polished with a roughness of ≤0.25μm to reduce the residue on the inner surface of the demetallization distillation tower and the precipitation of metal ions; the number of theoretical plates is 10 to 40, preferably 20 to 30; the reflux ratio is 1 to 6, preferably 2 to 3; the operating pressure is 5 to 100kpaG, preferably 5 to 10kpaG; the top operating temperature is 146 to 150°C; the bottom operating temperature is 146 to 150°C; when the number of theoretical plates is 30, the feed position is 15 to 20, preferably 15 to 18; the front third precision filter adopts a 0.1μm filter with a perfluorinated framework and filter element, and the rear fourth precision filter adopts a 0.05μm ultra-precision filter with a perfluorinated framework and filter element.

[0027] Specifically, the phase separation tank of the phase separation unit is made of 316L material, and the interior is EP electrolytic polished with a roughness of ≤0.25μm to reduce the residue on the inner surface of the phase separation tank and the precipitation of metal ions. The phase separation tank adopts a horizontal structure and is provided with an interface agent; the density of n-butanol is 0.81, and it is easier to separate from water; the phase separation time is 0.5 to 1h, preferably 45Min, and the phase separation temperature is 70 to 92°C, preferably 80°C.

[0028] The present invention also provides a semiconductor-grade PGMEA purification method, based on the semiconductor-grade PGMEA purification system, comprising the following steps:

[0029] (1) The industrial PGMEA raw materials are filtered and then enter the metal ion adsorption unit to remove some metal ions;

[0030] (2) The industrial PGMEA raw material after the removal of some metal ions enters the primary fractionation unit for preliminary distillation. After the preliminary distillation, the PGMEA-H2O azeotrope at the top of the tower enters the azeotropic distillation unit, and the high-purity PGMEA at the bottom of the tower enters the metal ion removal distillation unit;

[0031] (3) the azeotropic distillation unit azeotropes the PGMEA-H2O azeotrope, and the components at the top of the tower after azeotropy enter the phase separation unit, and the components at the bottom of the tower enter the solvent recovery distillation unit;

[0032] (4) The phase separation unit separates the components at the top of the tower after azeotropy into light components and heavy components, and the light components are mixed with the n-butanol sent from the n-butanol feed unit and sent to the azeotropic distillation unit for recycling;

[0033] (5) The solvent recovery distillation unit distills the components at the bottom of the tower again after azeotropy, and the n-butanol distilled from the top of the tower is returned to the n-butanol raw material unit, and the high-purity PGMEA distilled from the bottom of the tower enters the metal ion removal distillation unit;

[0034] (6) The metal ion removal distillation unit further distills the high-purity PGMEA to form semiconductor-grade PGMEA.

[0035] The beneficial effects of the present invention are as follows: the present invention uses a four-tower distillation method to reduce the output of distillation tower top wastewater generated by PGMEA / water azeotropy, uses n-butanol as an azeotropic agent to reduce the energy consumption caused by dehydration, and obtains semiconductor-grade PGMEA through a metal ion adsorption unit, a primary fractionation distillation unit, an azeotropic distillation unit, a phase separation unit, a solvent recovery distillation unit, and a metal ion removal distillation unit. The yield of ultrapure PGMEA is high, n-butanol as an azeotropic agent has high selectivity, low energy consumption, and low final wastewater volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural diagram of the semiconductor-grade PGMEA purification system of the present invention. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0038] like Figure 1 A semiconductor-grade PGMEA purification system is shown, comprising a metal ion adsorption unit, a primary fractionation distillation unit, an azeotropic distillation unit, a phase separation unit, a n-butanol raw material unit, a solvent recovery distillation unit, and a metal ion removal distillation unit;

[0039] The metal ion adsorption unit comprises at least two sets of metal ion adsorbers 2 and 3 connected in series or in parallel, a first precision filter 1 is provided at the inlet end of the metal ion adsorption unit, and a second precision filter 4 is provided at the outlet end of the metal ion adsorption unit;

[0040] The primary fractionation and rectification unit comprises a primary fractionation and rectification tower 6, a first filter 7 arranged at the top of the primary fractionation and rectification tower 6, a second filter 9 arranged at the bottom of the primary fractionation and rectification tower 6, and a reflux / extraction control module 8 arranged behind the first filter 7;

[0041] The azeotropic distillation unit includes an azeotropic distillation tower 10, a third filter 11 disposed at the top of the azeotropic distillation tower 10, and a fourth filter 13 disposed at the bottom of the azeotropic distillation tower 10. A reflux / extraction control module 12 is disposed after the third filter 11.

[0042] The solvent recovery distillation unit includes a solvent recovery distillation tower 15, a fifth filter 16 disposed at the top of the solvent recovery distillation tower 15, and a sixth filter 18 disposed at the bottom of the solvent recovery distillation tower 15. A reflux / extraction control module 17 is disposed after the fifth filter 16.

[0043] The demetallization ion distillation unit comprises a demetallization ion distillation tower 20 and a third precision filter 19 arranged at the inlet end of the demetallization ion distillation tower 20, a seventh filter 21 arranged at the top of the demetallization ion distillation tower 20, an eighth filter 23 arranged at the bottom of the demetallization ion distillation tower 20, and a fourth precision filter 24 arranged at the outlet end of the seventh filter 21, and a reflux / extraction control module 22 is arranged after the seventh filter 21;

[0044] The phase separation unit includes a phase separation tank 14 ; the n-butanol raw material unit includes an n-butanol raw material tank 5 .

[0045] Industrial PGMEA raw material a enters the first precision filter 1 for filtration to obtain industrial PGMEA raw material b, which enters the metal ion adsorber 2 and the metal ion adsorber 3 to remove some metal ions;

[0046] The industrial PGMEA raw material c after removing some metal ions enters the second precision filter 4 for filtration to obtain the industrial PGMEA raw material d, and enters the primary fractionation distillation tower 6 for preliminary distillation. After the preliminary distillation, the PGMEA-H2O azeotrope e at the top of the tower enters the azeotropic distillation tower 10 through the first filters 7 and 8, and the high-purity PGMEA f at the bottom of the tower is filtered through the second filter 9 and the third precision filter 19 to obtain high-purity PGMEA, which enters the metal ion removal distillation tower 20;

[0047] The azeotropic distillation tower 10 azeotropes the PGMEA-H2O azeotrope, and the component h at the top of the tower after azeotropy enters the phase separation tank 14 through the third filter 11, and the component g at the bottom of the tower enters the solvent recovery distillation tower 15 through the fourth filter 13;

[0048] The phase separation tank 14 separates the component h at the top of the tower after azeotropy into light component i and heavy component l, and the light component i is mixed with the n-butanol k sent from the n-butanol raw material tank 5 and sent to the azeotropic distillation tower 10 for recycling, and the heavy component l is discharged and collected as a small amount of waste water;

[0049] The solvent recovery distillation tower 15 distills the component g at the bottom of the tower again after azeotropy, and the n-butanol m distilled from the top of the tower returns to the n-butanol raw material tank 5 through the fifth filter 16 and 17, and the high-purity PGMEA n distilled from the bottom of the tower passes through the sixth filter 18 and the third precision filter 19 to obtain high-purity PGMEA, and enters the metal ion removal distillation tower 20;

[0050] The metal ion removal distillation tower 20 distills the high-purity PGMEA again to form semiconductor-grade PGMEA, and obtains semiconductor-grade PGMEA p through the seventh filter 21, and then obtains PGMEA liquid q with a concentration of not less than 99.99% through the fourth precision filter 24. The waste liquid r is filtered through the eighth filter 23 and discharged.

[0051] The following example is used to explain this in detail.

[0052] Example 1

[0053] 100kg / h of industrial 95% PGMEA is used as raw material. After pre-removal of particulate matter through a 10-inch 0.5μm perfluorinated filter, it enters a DN200×3000mm two-stage metal ion adsorption column to remove particulate matter. The pore size of the first-stage chelating agent resin is 0.2μm, and the pore size of the second-stage chelating agent resin is 0.25μm. Then it enters a 10-inch 0.1μm perfluorinated filter to remove particulate matter precipitated from the filler, and then enters an electrolytically polished primary distillation tower. The size of the primary distillation tower is DN125, the height of the corrugated packing is 14.5m, the number of theoretical plates is 60, the feed is the 30th plate, the reflux ratio is 0.5, the top extraction rate is 0.1, the operating pressure is normal pressure, the top temperature is 96.23℃, the bottom temperature is 145.56℃, 10kg / h 50% PGMEA and 49.9% H2O azeotrope is extracted from the top of the tower, and the azeotropic distillation unit is removed. The bottom of the tower is 90kg / h 99.99% or more PGMEA, but it contains a certain amount of metal ions. The PGMEA at the bottom of the tower is removed by the metal ion removal distillation unit.

[0054] The azeotropic distillation tower processes 10kg / h of 50% PGMEA and 49.9% H2O azeotropes. The size of the electrolytically polished azeotropic distillation tower is DN100. The height of the corrugated packing used is 14.5m, the number of theoretical plates is 60, the feed is the 30th plate, the entrainer and the fresh entrainer enter the 4th plate, the entrainer is n-butanol, the reflux ratio is 0.1, the top recovery rate is 0.8, the operating pressure is atmospheric pressure, the top temperature is 92.22℃, and the bottom temperature is 129.97℃. The top of the azeotropic distillation tower produces 23.34 kg / h of 38.75% H2O, 61.21% n-butanol, and 2.87*10^-8 PGMEA. After phase separation, the heavy phase produced is 5.67 kg / h of 88.25% H2O, 11.74% n-butanol, and 2.2*10^-9 PGMEA, which is discharged from the system to the wastewater treatment system; the light components produced by phase separation are 17.67 kg / h 22.87% H2O, 77.12% n-butanol, and 3.74*10^-8 PGMEA, which are returned to the azeotropic distillation tower for recycling; the fresh n-butanol is supplemented at 1.5 kg / h; the phase separation time is 25 minutes. The bottom of the azeotropic distillation tower produces 5.83 kg / h of 85.7% PGMEA, 14.30% n-butanol, and 0% H2O mixed solution, which enters the solvent recovery distillation unit.

[0055] The solvent recovery distillation tower processes 5.83kg / h of 85.7% PGMEA, 14.30% n-butanol, and 0% H2O mixed solution. The size of the electrolytically polished azeotropic distillation tower is DN32, the height of the random packing used is 4.5m, the number of theoretical plates is 60, the feed is the 30th tower plate, the reflux ratio is 4, the top recovery rate is 0.15, the operating pressure is atmospheric pressure, the top temperature is 117.42℃, and the bottom temperature is 145.56℃. The top of the solvent recovery distillation tower produces 0.88kg / h 4.65% PGMEA and 95.34% n-butanol, which can be recycled. The bottom of the solvent recovery distillation tower produces 4.96kg / h PGMEA above 99.99%, and n-butanol is ppt grade, which enters the metal ion removal distillation unit.

[0056] The metal removal distillation tower treats 90kg / h of PGMEA at the bottom of the primary distillation tower and 4.96kg / h of PGMEA at the bottom of the solvent recovery distillation unit. The size of the metal removal distillation tower is DN125, the height of the corrugated packing is 14.5m high, the number of theoretical plates is 60, the feed is the 30th tower plate, the reflux ratio is 0.5, the top recovery rate is 0.99, the operating pressure is atmospheric pressure, the top temperature is 145.52℃, and the bottom temperature is 145.56℃. 94.01kg / h of 99.99% PGMEA is produced at the top of the tower, and the rest is intermittently discharged from the bottom of the tower. The overall yield of PGMEA is 98.95%. The amount of wastewater produced accounts for 5.67% of the raw material processing volume, and the composition is 88.25% H2O, 11.74% n-butanol. PGMEA is PPb grade, which greatly improves the availability of PGMEA.

[0057] Example 2

[0058] The same as Example 1, but without the azeotropic distillation unit and the solvent recovery distillation unit, with 100kg / h of industrial 95% PGMEA as the raw material, after pre-removing part of the particulate matter through a 10-inch 0.5μm perfluorinated filter, enter the DN200×3000mm 2-stage metal ion adsorption column to remove part of the metal ions, wherein the pore size of the primary chelating agent resin is 0.2μm, and the pore size of the secondary chelating agent resin is 0.25μm. Then enter the 10-inch 0.1μm perfluorinated filter to remove the particulate matter precipitated from the filler, and then enter the electrolytic polishing primary fractionation distillation tower. The size of the primary distillation tower is DN125, the height of the corrugated packing is 14.5m, the number of theoretical plates is 60, the feed is the 30th tower plate, the reflux ratio is 0.5, the top extraction rate is 0.1, the operating pressure is normal pressure, the top temperature is 96.23℃, the bottom temperature is 145.56℃, and 10kg / h of 50% PGMEA and 49.9% H2O azeotrope is extracted from the top of the tower for wastewater treatment. The bottom of the tower is 90kg / h PGMEA above 99.99%, but it contains a certain amount of metal ions. The PGMEA at the bottom of the tower is removed by the metal ion distillation unit.

[0059] The metal removal distillation tower processes 90kg / h of PGMEA at the bottom of the primary distillation tower. The size of the metal removal distillation tower is DN125, the height of the corrugated packing is 14.5m, the number of theoretical plates is 60, the feed is the 30th tower plate, the reflux ratio is 0.8, the top recovery rate is 0.99, the operating pressure is atmospheric pressure, the top temperature is 145.53℃, and the bottom temperature is 145.55℃. 89kg / h of 99.99% PGMEA is produced at the top of the tower, and the rest is intermittently discharged from the bottom of the tower. The overall yield of PGMEA is 93.68%. The amount of wastewater produced accounts for 10% of the raw material processing amount, and the composition is an azeotrope of 50% PGMEA and 49.9% H2O.

[0060] Example 3

[0061] Same as Example 1, but without azeotropic distillation unit, solvent recovery distillation unit and metal ion removal distillation unit. 100kg / h of industrial 95% PGMEA is used as raw material. After pre-removal of particulate matter through a 10-inch 0.5μm perfluorinated filter, it enters a DN200×3000mm 2-stage metal ion adsorption column to remove part of the metal ions, wherein the pore size of the primary chelating agent resin is 0.2μm and the pore size of the secondary chelating agent resin is 0.25μm. Then it enters a 10-inch 0.1μm perfluorinated filter to remove particulate matter precipitated from the filler, and then enters an electrolytically polished primary fractionation distillation tower. The size of the primary distillation tower is DN125, the height of the corrugated packing is 14.5m, the number of theoretical plates is 60, the feed is the 30th tower plate, the reflux ratio is 0.5, the top extraction rate is 0.1, the operating pressure is normal pressure, the top temperature is 96.23℃, the bottom temperature is 145.56℃, and 10kg / h of 50% PGMEA and 49.9% H2O azeotrope is extracted from the top of the tower for wastewater treatment. The bottom of the tower is 90kg / h 99.99% or more PGMEA, but it contains a certain amount of metal ions.

[0062] The yield of PGMEA is 94.73% and the purity is 99.99%, but the metal ions exceed the standard. The wastewater generated accounts for 10% of the raw material treatment amount, and the composition is an azeotrope of 50% PGMEA and 49.9% H2O.

[0063] In summary, the composition of the raw materials and the quality composition of the products of Examples 1 to 3 were tested by high-precision gas chromatography (precision of 0.1 ppb) to analyze the purity of PGMEA, the water content was analyzed by Karl Fischer moisture analyzer, the metal ion weight was analyzed by inductively coupled plasma mass spectrometer, and the particles were tested by laser particle tester. The composition of the raw materials and the quality composition of the products of Examples 1 to 3 are detailed in Table 1 below:

[0064] Table 1 Composition of raw materials and quality composition of products of Example 1 to Example 3

[0065]

[0066] Finally, it should be noted that: the embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above specific implementations, which are merely illustrative and not restrictive. For those of ordinary skill in the art, other different forms of changes or modifications can be made without departing from the scope of protection of the present invention and the claims, all of which are within the protection scope of the present invention.

Claims

1. A semiconductor-grade PGMEA purification system, characterized in that: It includes metal ion adsorption unit, primary fractionation distillation unit, azeotropic distillation unit, phase separation unit, n-butanol raw material unit, solvent recovery distillation unit, and metal ion removal distillation unit; The metal ion adsorption unit is used to receive industrial PGMEA raw materials and remove some metal ions; The primary fractionation and rectification unit is connected to the metal ion adsorption unit, and is used to receive the PGMEA raw material sent by the metal ion adsorption unit, and perform preliminary rectification on the PGMEA raw material; The azeotropic distillation unit is connected to the primary distillation unit, and is used to receive the PGMEA-H2O azeotrope distilled by the primary distillation unit, and perform azeotropic treatment on the PGMEA-H2O azeotrope; The phase separation unit and the n-butanol raw material unit are respectively connected to the azeotropic distillation unit. The phase separation unit is used to receive the top component sent by the azeotropic distillation unit, the light component and the heavy component formed by layering, and the light component is mixed with the n-butanol sent by the n-butanol raw material unit and sent to the azeotropic distillation unit for recycling; The solvent recovery distillation unit is respectively connected to the azeotropic distillation unit, the n-butanol raw material unit, and the metal ion removal distillation tower, and is used to receive the bottom components sent by the azeotropic distillation unit and perform distillation again. The n-butanol distilled from the top of the tower is returned to the n-butanol raw material tank, and the high-purity PGMEA distilled from the bottom of the tower enters the metal ion removal distillation tower; The metal ion removal distillation unit is connected to the primary distillation unit and the solvent recovery distillation unit, and is used to receive the high-purity PGMEA distilled from the primary distillation unit and the solvent recovery distillation unit, and distill the high-purity PGMEA again to form semiconductor-grade PGMEA.

2. The semiconductor-grade PGMEA purification system according to claim 1, characterized in that: The metal ion adsorption unit comprises at least two sets of metal ion adsorbers arranged in series or in parallel, the inlet end of the metal ion adsorption unit is provided with a first precision filter, and the outlet end of the metal ion adsorption unit is provided with a second precision filter; The operating temperature of the metal ion adsorber is 20-50°C, the operating pressure is 1-3 barg, the chelating adsorbent used by the metal ion adsorber is styrene macroporous iminodiacetic acid chelating resin, the pore size of the primary chelating adsorbent resin is 0.1-0.3 μm, the pore size of the secondary chelating adsorbent resin is 0.05-0.5 μm, and the height-to-diameter ratio of the metal ion adsorber is 10-20.

3. The semiconductor-grade PGMEA purification system according to claim 2, characterized in that: The primary fractionation and rectification unit comprises a primary fractionation and rectification tower, a first filter arranged at the top of the primary fractionation and rectification tower, and a second filter arranged at the bottom of the primary fractionation and rectification tower; The number of theoretical plates of the primary fractionation distillation tower is 30-100, the reflux ratio is 0.5-10, the operating pressure is 5-100 kPaG, the tower top operating temperature is 96-116°C, and the tower bottom operating temperature is 146-177°C.

4. The semiconductor-grade PGMEA purification system according to claim 3, characterized in that: The azeotropic distillation unit includes an azeotropic distillation tower, a third filter disposed at the top of the azeotropic distillation tower, and a fourth filter disposed at the bottom of the azeotropic distillation tower; The azeotropic distillation tower uses n-butanol as the azeotropic agent, has a theoretical plate number of 20 to 80, a reflux ratio of 0.1 to 5, an operating pressure of 5 to 100 kPaG, a tower top operating temperature of 92 to 112°C, and a tower bottom operating temperature of 130 to 150°C.

5. The semiconductor-grade PGMEA purification system according to claim 4, characterized in that: The solvent recovery distillation unit comprises a solvent recovery distillation tower, a fifth filter arranged at the top of the solvent recovery distillation tower, and a sixth filter arranged at the bottom of the solvent recovery distillation tower; The number of theoretical plates of the solvent recovery distillation tower is 30-10, the reflux ratio is 4-10, the operating pressure is 5-100 kPaG, the tower top operating temperature is 117-137°C, and the tower bottom operating temperature is 146-166°C.

6. The semiconductor-grade PGMEA purification system according to claim 5, characterized in that: The demetallization ion distillation unit comprises a demetallization ion distillation tower and a third precision filter arranged at the inlet end of the demetallization ion distillation tower, a seventh filter arranged at the top of the demetallization ion distillation tower, an eighth filter arranged at the bottom of the demetallization ion distillation tower, and a fourth precision filter arranged at the outlet end of the seventh filter; The number of theoretical plates of the demetallization distillation tower is 10-40, the reflux ratio is 1-6, the operating pressure is 5-100 kPaG, the tower top operating temperature is 146-150°C, and the tower bottom operating temperature is 146-150°C.

7. The semiconductor-grade PGMEA purification system according to claim 6, characterized in that: The phase separation time of the phase separation unit is 0.5 to 3 hours, and the phase separation temperature is 70 to 92°C.

8. A method for purifying semiconductor-grade PGMEA, using the semiconductor-grade PGMEA purification system according to any one of claims 1 to 7, characterized in that: The steps include: (1) The industrial PGMEA raw materials are filtered and then enter the metal ion adsorption unit to remove some metal ions; (2) The industrial PGMEA raw material after the removal of some metal ions enters the primary fractionation unit for preliminary distillation. After the preliminary distillation, the PGMEA-H2O azeotrope at the top of the tower enters the azeotropic distillation unit, and the high-purity PGMEA at the bottom of the tower enters the metal ion removal distillation unit; (3) The azeotropic distillation unit azeotropes the PGMEA-H2O azeotrope, and the components at the top of the tower enter the phase separation unit after azeotropy, and the components at the bottom of the tower enter the solvent recovery distillation unit; (4) The phase separation unit separates the components at the top of the tower after azeotropy into light components and heavy components, and the light components are mixed with the n-butanol sent from the n-butanol feed unit and sent to the azeotropic distillation unit for recycling; (5) The solvent recovery distillation unit distills the components at the bottom of the tower again after azeotropy, and the n-butanol distilled from the top of the tower is returned to the n-butanol raw material unit, and the high-purity PGMEA distilled from the bottom of the tower enters the metal ion removal distillation unit; (6) The metal ion removal distillation unit further distills the high-purity PGMEA to form semiconductor-grade PGMEA.

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