Device for preparing electronic-grade ethyl lactate and method for preparing electronic-grade ethyl lactate by using device

Abstract

The invention relates to a device for preparing electronic-grade ethyl lactate and a method for preparing electronic-grade ethyl lactate by using the device. In one embodiment, a method is disclosed. The apparatus for preparing electronic grade ethyl lactate comprises a reactor for preparing crude ethyl lactate by reacting ethanol input through an ethanol delivery line and lactic acid input through a lactic acid delivery line in the presence of an acid catalyst, a lactic acid recovery column for preparing a first mixture by distilling an input crude ethyl lactate and separating lactic acid from the crude ethyl lactate, an initial fluid purification column for preparing a second mixture by distilling the input first mixture and separating ethanol from the first mixture, a product column for preparing a purified product by distilling the input second mixture and removing impurities from the second mixture, and a storage unit for storing the purified product delivered into the storage unit.

Description

Technical Field

[0001] The invention relates to a device for preparing electronic-grade ethyl lactate and a method for preparing electronic-grade ethyl lactate by using the device. Background Art

[0002] Ethyl lactate is used as a solvent for paints and coatings, a solvent for electronic photoresists, and a thinner for cleaning in the manufacture of electronic components such as displays and semiconductors. Ethyl lactate is used particularly in semiconductor manufacturing processes by mixing with thinner compositions for photoresists. The physical properties of ethyl lactate include a density of 0.97 g / cm 3 , boiling point is 156℃, flash point is 52℃, viscosity is 2.38cps (25℃).

[0003] In order to use ethyl lactate in the semiconductor manufacturing process, organic impurities, various types of metal ion impurities (such as sodium ions (Na + ) and iron ions (Fe 2+ )), and other fine particles.

[0004] Therefore, ethyl lactate used for photoresist in semiconductor technology needs to be composed of high-purity compounds. Ethyl lactate can be processed into various quality types according to its use, such as the purity of ethyl lactate, the content of water, the content of metal ions, and the acidity.

[0005] Background technology related to the present invention is disclosed in Korean Patent Publication No. 10-1515981, published on April 30, 2015, and entitled “Method for recovering high-purity organic acid and organic acid alkyl ester from organic acid fermentation solution”. Summary of the invention

[0006] The present invention aims to provide a device for preparing electronic grade ethyl lactate, which has an excellent effect of removing impurities such as organic compounds and metal ions in the preparation of ethyl lactate and can prepare ultra-high purity ethyl lactate.

[0007] The invention also relates to a device for preparing electronic-grade ethyl lactate, which has excellent effects of preventing decomposition and oxidation of ethyl lactate and elution of metal ions during the preparation and storage of ethyl lactate.

[0008] The present invention also relates to an apparatus for preparing electronic grade ethyl lactate with excellent productivity and economic feasibility.

[0009] The present invention also relates to a method for preparing electronic-grade ethyl lactate by using the device for preparing electronic-grade ethyl lactate.

[0010] One aspect of the present invention provides an apparatus for preparing electronic grade ethyl lactate. In one embodiment, the apparatus for preparing electronic grade ethyl lactate includes: a reactor for preparing crude ethyl lactate by reacting ethanol input through an ethanol delivery pipeline and lactic acid input through a lactic acid delivery pipeline in the presence of an acid catalyst; a lactic acid recovery tower for preparing a first mixture by distilling the input crude ethyl lactate and separating lactic acid from the crude ethyl lactate; an initial fluid purification tower for preparing a second mixture by distilling the input first mixture and separating ethanol from the first mixture; a product tower for preparing a purified product by distilling the input second mixture and removing impurities from the second mixture; and a storage unit for storing the purified product after being transported to the storage unit, wherein the lactic acid separated in the lactic acid recovery tower and the ethanol separated in the initial fluid purification tower are input into the reactor, and the product tower and the storage unit have inner walls, and the material of the inner wall includes one or more of fluorine-based resins and surface-polished metals.

[0011] In one embodiment, the reactor may include one or more of a batch reactor and a continuous reactor.

[0012] In one embodiment, the acid catalyst may include one or more of a solid acid catalyst and a liquid acid catalyst, wherein the solid acid catalyst may include a strongly acidic ion exchange resin, and the liquid acid catalyst may include one or more of p-toluenesulfonic acid, methanesulfonic acid, sulfuric acid, phosphoric acid, nitric acid, and hydrochloric acid.

[0013] In one embodiment, the apparatus for preparing electronic grade ethyl lactate may further include a dehydration device, the ethanol separated in the initial fluid purification tower is transported to the dehydration device to remove water from the ethanol, and the ethanol from which water is removed may be input into the reactor.

[0014] In one embodiment, the apparatus for preparing electronic grade ethyl lactate may further include a purified product discharge pipeline connected to the storage unit to discharge the purified product to the outside, wherein the purified product discharge pipeline may include a filtering device for removing fine particles in the purified product.

[0015] In one embodiment, the product column may include a first product column for preparing a first purified product by performing vacuum distillation on the input second mixture to preliminarily remove impurities from the second mixture; and a second product column for preparing a second purified product by performing vacuum distillation on the input first purified product to secondarily remove impurities from the first purified product.

[0016] In one embodiment, the interior of one or more of the reactor, the lactic acid recovery column, the initial fluid purification column, the product column, and the storage unit may have an inert gas environment.

[0017] Another aspect of the present invention provides a method for preparing electronic grade ethyl lactate using an apparatus for preparing electronic grade ethyl lactate. In one embodiment, the method for preparing electronic grade ethyl lactate includes: in the presence of an acid catalyst, ethanol input into a reactor through an ethanol delivery pipeline and lactic acid input into a reactor through a lactic acid delivery pipeline are reacted to prepare crude ethyl lactate; a first mixture is prepared by distilling the crude ethyl lactate input into a lactic acid recovery tower to separate lactic acid from the crude ethyl lactate; a second mixture is prepared by distilling the first mixture input into an initial fluid purification tower to separate ethanol from the first mixture; a purified product is prepared by vacuum distilling the second mixture input into a product tower to remove impurities from the second mixture; and the purified product is transported to a storage unit and stored, wherein the lactic acid separated in the lactic acid recovery tower and the ethanol separated in the initial fluid purification tower are input into the reactor, and the product tower and the storage unit have inner walls, and the material of the inner wall includes one or more of a fluorine-based resin and a surface-polished metal.

[0018] In one embodiment, the acid catalyst may include one or more of a solid acid catalyst and a liquid acid catalyst, wherein the solid acid catalyst may include a strongly acidic ion exchange resin, and the liquid acid catalyst may include one or more of p-toluenesulfonic acid, methanesulfonic acid, sulfuric acid, phosphoric acid, nitric acid, and hydrochloric acid.

[0019] In one embodiment, the reactor may include one or more of a batch reactor and a continuous reactor.

[0020] In one embodiment, crude ethyl lactate can be prepared by inputting a liquid acid catalyst, ethanol, and lactic acid into a batch reactor and reacting them at a temperature of 50° C. to 100° C. according to the conditions of the following formula 1:

[0021]

[0022] In Formula 1, E1 represents the number of moles of ethanol input through the ethanol delivery pipeline, E2 represents the number of moles of ethanol input from the initial fluid purification tower, C1 represents the content (wt%) of the liquid acid catalyst, L1 represents the number of moles of lactic acid input through the lactic acid delivery pipeline, and L2 represents the number of moles of lactic acid input from the lactic acid recovery tower.

[0023] In one embodiment, crude ethyl lactate can be prepared by inputting a solid acid catalyst, ethanol and lactic acid into a batch reactor and reacting them at a temperature of 50° C. to 100° C. according to the conditions of the following formula 1-1:

[0024]

[0025] In Formula 1-1, E1 represents the number of moles of ethanol input through the ethanol delivery pipeline, E2 represents the number of moles of ethanol input from the initial fluid purification tower, C2 represents the content (wt%) of the solid acid catalyst, L1 represents the number of moles of lactic acid input through the lactic acid delivery pipeline, and L2 represents the number of moles of lactic acid input from the lactic acid recovery tower.

[0026] In one embodiment, crude ethyl lactate can be prepared by inputting ethanol and lactic acid into a packed bed continuous reactor filled with a solid acid catalyst and reacting them at a temperature of 50° C. to 100° C. according to the conditions of the following formula 2:

[0027]

[0028] In Formula 2, E1 represents the number of moles of ethanol input through the ethanol delivery pipeline, E2 represents the number of moles of ethanol input from the initial fluid purification tower, L1 represents the number of moles of lactic acid input through the lactic acid delivery pipeline, and L2 represents the number of moles of lactic acid input from the lactic acid recovery tower.

[0029] In one embodiment, the preparation of the purified product may include preparing a first purified product by performing vacuum distillation on the second mixture input to the first product column to remove impurities from the second mixture for the first time; and preparing a second purified product by performing vacuum distillation on the first purified product input to the second product column to remove impurities from the first purified product for the second time.

[0030] In one embodiment, the first purified product and the second purified product may be prepared by vacuum distillation at pressures of 0.3 bar and 0.01 bar, respectively.

[0031] The device for preparing electronic-grade ethyl lactate and the method for preparing electronic-grade ethyl lactate using the device according to the present invention can show excellent effects of removing impurities such as organic compounds and metal ions, and excellent effects of preventing decomposition, oxidation and elution of metal ions of ethyl lactate during the preparation and storage of ethyl lactate, and can prepare ultra-high-purity ethyl lactate, so that during the preparation and storage of ethyl lactate, it has excellent effects of preventing decomposition and oxidation of ethyl lactate and has excellent productivity and economic feasibility, and is suitable for application in the process of manufacturing electronic components such as displays or semiconductors. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A device for preparing electronic grade ethyl lactate according to one embodiment of the present invention is shown.

[0033] Figure 2 A method for preparing electronic grade ethyl lactate according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0034] In describing the present invention, detailed descriptions of related known technologies or configurations are omitted to avoid unnecessarily obscuring the subject matter of the present invention.

[0035] In addition, the terms to be described below are defined in consideration of the functions in the embodiments of the present invention and may vary according to the intention or habits of the user or operator. Therefore, the definition of the terms should be based on the contents of the entire specification.

[0036] The main organic impurities generated in the synthesis and purification of ethyl lactate according to the present invention include lactic acid oligomers, ethyl pyruvate, methyl lactate, ethyl 2-hydro butanoate, 2-(1-ethoxyethoxy)propanoic acid, and 2-hydroxy-3-methylbutyric acid. These impurities are generated due to the combination of ethanol and lactic acid in the preparation of ethyl lactate and the side reaction with organic acids not including lactic acid contained in the lactic acid raw material or other alcohol impurities in the ethanol raw material. In addition to this, impurities may also be generated in other ways, such as decomposition products obtained by decomposition of ethyl lactate and ethyl lactate oxidation products generated by contact of ethyl lactate with air during purification.

[0037] In addition, the lactic acid raw material used in the present invention may be lactic acid produced (synthesized) by microbial fermentation, and the nutrients (K + 、Zn 2+ Metal ion impurities may be generated by the presence of salt and dust in the air. In addition, since ethyl lactate has the property of dissociating metal ions, the metal materials in the preparation and storage facilities may dissolve metal ions.

[0038] Therefore, the present invention provides an apparatus for preparing ultra-high purity ethyl lactate by effectively removing the above impurities and a method for preparing ethyl lactate using the apparatus.

[0039] Device for preparing electronic grade ethyl lactate

[0040] One aspect of the present invention relates to an apparatus for preparing electronic grade ethyl lactate.

[0041] Figure 1The device for preparing electronic grade ethyl lactate according to one embodiment of the present invention is shown. Figure 1 , an apparatus 1000 for preparing electronic grade ethyl lactate includes a reactor 100 for preparing crude ethyl lactate by reacting ethanol input through an ethanol delivery pipeline 10 and lactic acid input through a lactic acid delivery pipeline 12 in the presence of an acid catalyst; a lactic acid recovery tower 110 for preparing a first mixture by distilling the input crude ethyl lactate and separating lactic acid from the crude ethyl lactate; an initial fluid purification tower 120 for preparing a second mixture by distilling the input first mixture and separating ethanol from the first mixture; product towers 130 and 132 for preparing a purified product by distilling the input second mixture and removing impurities from the second mixture; and a storage unit 140 for storing the purified product transported to the storage unit, wherein the lactic acid separated in the lactic acid recovery tower 110 and the ethanol separated in the initial fluid purification tower 120 are both input to the reactor 100.

[0042] In one embodiment, the acid catalyst may include one or more of a solid acid catalyst and a liquid acid catalyst.

[0043] The solid acid catalyst may include a strongly acidic ion exchange resin. For example, the strongly acidic ion exchange resin may include a styrene-divinyl benzene copolymer having a sulfonic acid group (-SO3H) as an exchange group. When the solid acid catalyst is included, crude ethyl lactate can be easily prepared due to the excellent reactivity between ethanol and lactic acid.

[0044] For example, as the solid acid catalyst, one or more of Amberlyst-15, 35 and 46 may be used.

[0045] In one embodiment, the liquid acid catalyst may include one or more of p-toluenesulfonic acid (PTSA), methanesulfonic acid (MSA), sulfuric acid, phosphoric acid, nitric acid, and hydrochloric acid. When the liquid acid catalyst is included, crude ethyl lactate can be easily prepared due to the excellent reactivity between ethanol and lactic acid.

[0046] In one embodiment, the reactor 100 may include one or more of a batch type reactor and a continuous type reactor. The batch type reactor may use one or more of a solid acid catalyst and a liquid acid catalyst.

[0047] In one embodiment, the continuous reactor may use a packed bed continuous reactor filled with a solid acid catalyst, but the present invention is not limited thereto.

[0048] Reference Figure 1 The crude ethyl lactate can be transported from the reactor 100 to the lactic acid recovery tower 110 through the crude ethyl lactate transport line 14. The lactic acid recovery tower 110 prepares a first mixture by distilling the crude ethyl lactate to separate lactic acid. Figure 1 The separated lactic acid can be input into the reactor 100 through the lactic acid recovery line 16 provided at the lower part of the lactic acid recovery tower 110, and thus can be used to prepare crude ethyl lactate. When the lactic acid separated as described above is input into the reactor and used, excellent productivity and economic feasibility can be exhibited.

[0049] Reference Figure 1 The first mixture may be transferred to the initial fluid purification tower 120 through the first transfer line 20 disposed at the upper portion of the lactic acid recovery tower 110. The initial fluid purification tower 120 separates ethanol by distilling the first mixture, thereby generating a second mixture.

[0050] The ethanol separated in the initial fluid purification column 120 may be input to the reactor 100 for preparing crude ethyl lactate. When the ethanol separated as described above is input to the reactor and used, excellent productivity and economic feasibility may be exhibited.

[0051] In one embodiment, the apparatus 1000 for preparing electronic grade ethyl lactate may further include a dehydration device 150, and the ethanol separated in the initial fluid purification tower 120 is transported to the dehydration device 150 to remove water from the ethanol.

[0052] In one embodiment, the separated ethanol can be input to the dehydration device 150 through the ethanol discharge pipeline 24 provided at the upper portion of the initial fluid purification tower 120 to remove water. The ethanol from which water is removed can be input to the reactor 100 through the ethanol recovery pipeline 26 provided at the dehydration device 150, and used to prepare crude ethyl lactate. In the process of removing water from ethanol, the purity of ethanol can be improved, and thus excellent esterification efficiency can be exhibited.

[0053] In one embodiment, the water generated in the dehydration device 150 may be discharged to the outside through the third discharge line 44 .

[0054] In one embodiment, for the product tower, an internal structure capable of minimizing the pressure difference, such as a packing-type structure, can be applied to prevent the decomposition of ethyl lactate due to the temperature increase in the vacuum distillation for removing organic impurities and metal ions. In the vacuum distillation process under the above conditions, the decomposition of ethyl lactate can be easily prevented.

[0055] In one embodiment, the product tower and the storage unit have inner walls, and the material of the inner wall includes one or more of a fluorine-based resin and a surface-polished metal. When the fluorine-based resin or the surface-polished metal is not used as the material of the inner wall of the product tower, dissociation of metal ions occurs during the preparation of the purified product, resulting in an increase in the impurity content.

[0056] For example, the product tower and the storage unit may have an inner wall whose material includes one or more of polytetrafluoroethylene and a surface-polished metal. As another example, the product tower and the storage unit may use a material in which one surface of the metal is coated with polytetrafluoroethylene.

[0057] In one embodiment, the surface finishing metal may be polished by one or more of mechanical polishing and electropolishing.

[0058] refer to Figure 1 The product tower may include a first product tower 130 for preparing a first purified product by distilling a second mixture input from the initial fluid purification tower 120 through the second transfer line 22 and preliminarily removing impurities of the second mixture; and a second product tower 132 for preparing a second purified product by distilling a first purified product input from the first product tower 130 through the third transfer line 30 and secondarily removing impurities from the first purified product. The first product tower 130 and the second product tower 132 both have inner walls, and the material of the inner walls includes one or more of a fluorine-based resin and a surface-finished metal.

[0059] In one embodiment, in the first product tower 130, impurities generated when preparing the first purified product may be discharged to the outside through the first discharge line 34; and in the second product tower 132, impurities generated when preparing the second purified product may be discharged to the outside through the second discharge line 36.

[0060] refer to Figure 1 The second purified product prepared in the second product column 132 can be transferred to the storage unit 140 for storage through the fourth transfer line 32. The storage unit 140 has an inner wall, and the material of the inner wall of the storage unit 140 includes one or more of a fluorine-based resin and a surface-finished metal.

[0061] In one embodiment, the device for preparing electronic grade ethyl lactate may further include a purified product discharge pipeline 40, which is connected to the storage unit 140 and discharges the purified product to the outside. In the purified product discharge pipeline 40, a filtering device 160 for removing fine particles from the purified product may be included. In one embodiment, the filtering device may include a multi-stage fine filter. When the filtering device is further included, the purity of the purified product can be further improved.

[0062] In one embodiment, at the rear end of the filtering device 160 of the purified product discharge line 40 , a circulation line 42 may be further included for inputting the purified product from which fine particles have been removed into the storage unit 140 .

[0063] In one embodiment, the inside of one or more of the reactor, lactic acid recovery tower, initial fluid purification tower, product tower, and storage unit can have an inert gas environment. Under the above conditions, the oxidation of ethyl lactate can be easily prevented. Inert gas, for example, can include one or more of nitrogen (N2) and argon (Ar). For example, the inside of the reactor, lactic acid recovery tower, initial fluid purification tower, product tower, and storage unit can use an inert gas blanketing device (not shown) to provide an inert gas environment.

[0064] Method for preparing electronic grade ethyl lactate using an apparatus for preparing electronic grade ethyl lactate

[0065] Another aspect of the present invention relates to a method for preparing electronic grade ethyl lactate using the apparatus for preparing electronic grade ethyl lactate.

[0066] In one embodiment, a method for preparing electronic grade ethyl lactate comprises: (S10) preparing crude ethyl lactate; (S20) preparing a first mixture; (S30) preparing a second mixture; (S40) preparing a purified product; and (S50) storing the purified product.

[0067] More specifically, the method for preparing electronic grade ethyl lactate includes: preparing crude ethyl lactate by reacting ethanol input into a reactor through an ethanol delivery pipeline and lactic acid input into a reactor through a lactic acid delivery pipeline in the presence of an acid catalyst (S10); preparing a first mixture by distilling the crude ethyl lactate input into a lactic acid recovery tower to separate lactic acid from the crude ethyl lactate (S20); preparing a second mixture by distilling the first mixture input into an initial fluid purification tower to separate ethanol from the first mixture (S30); preparing a purified product by vacuum distilling the second mixture input into a product tower to remove impurities from the second mixture (S40); and transporting the purified product to a storage unit and storing it (S50).

[0068] Hereinafter, a method for preparing electronic grade ethyl lactate using an apparatus for preparing electronic grade ethyl lactate will be described step by step in detail.

[0069] (S10) Step of preparing crude ethyl lactate

[0070] This is a step of preparing crude ethyl lactate by reaction (esterification) of ethanol and lactic acid input into the reactor through an ethanol transfer line and a lactic acid transfer line in the presence of an acid catalyst.

[0071] In one embodiment, the crude ethyl lactate may include ethyl lactate, water, unreacted lactic acid, unreacted ethanol, a catalyst, metal ions, and organic impurities (lactic acid oligomers, etc.).

[0072] In one embodiment, the purity of the ethanol imported by the ethanol delivery line can be 90% to 99%. For example, the purity of the ethanol imported by the ethanol delivery line can be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%.

[0073] In one embodiment, the purity of the lactic acid input through the lactic acid delivery line can be 85% to 95%. For example, the purity of the lactic acid input through the lactic acid delivery line can be 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, or 95%.

[0074] The solid acid catalyst may include a strongly acidic ion exchange resin. The strongly acidic ion exchange resin may include, for example, a styrene-divinylbenzene copolymer having a sulfonic acid group (-SO3H) as an exchange group.

[0075] In one embodiment, the liquid acid catalyst may include one or more of p-toluenesulfonic acid (PTSA), methanesulfonic acid (MSA), sulfuric acid, phosphoric acid, nitric acid, and hydrochloric acid.

[0076] In one embodiment, the reactor may include one or more of a batch reactor and a continuous reactor.

[0077] In one embodiment, the reaction temperature of the reactor may be 50° C. to 100° C. Under the above reaction temperature conditions, esterification can be easily performed and crude ethyl lactate can be easily prepared. For example, the reaction temperature of the reactor can be 50°C, 51°C, 52°C, 53°C, 54°C, 55°C, 56°C, 57°C, 58°C, 59°C, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, 76°C, 77°C, 78°C, 79°C, 80°C, 81°C, 82°C, 83°C, 84°C, 85°C, 86°C, 87°C, 88°C, 89°C, 90°C, 91°C, 92°C, 93°C, 94°C, 95°C, 96°C, 97°C, 98°C, 99°C or 100°C.

[0078] In one embodiment, crude ethyl lactate may be prepared by inputting a liquid acid catalyst, ethanol, and lactic acid into a batch reactor and reacting them at a temperature of 50° C. to 100° C. under the conditions according to the following Formula 1:

[0079]

[0080] In Formula 1, E1 represents the number of moles of ethanol input through the ethanol delivery pipeline, E2 represents the number of moles of ethanol input from the initial fluid purification tower, C1 represents the content (wt%) of the liquid acid catalyst, L1 represents the number of moles of lactic acid input through the lactic acid delivery pipeline, and L2 represents the number of moles of lactic acid input from the lactic acid recovery tower.

[0081] E1, E2, C1, L1, and L2 in Formula 1 are defined based on a reaction mixture including ethanol, lactic acid, and a liquid acid catalyst input to a batch reactor.

[0082] When the input amount conditions of Formula 1 are satisfied, esterification can be easily performed, thereby easily preparing crude ethyl lactate.

[0083] In one embodiment, crude ethyl lactate may be prepared by inputting a solid acid catalyst, ethanol, and lactic acid into a batch reactor and reacting them at a temperature of 50° C. to 100° C. under the conditions according to the following formula 1-1:

[0084]

[0085] In Formula 1-1, E1 represents the number of moles of ethanol input through the ethanol delivery pipeline, E2 represents the number of moles of ethanol input from the initial fluid purification tower, C2 represents the content (wt%) of the solid acid catalyst, L1 represents the number of moles of lactic acid input through the lactic acid delivery pipeline, and L2 represents the number of moles of lactic acid input from the lactic acid recovery tower.

[0086] E1, E2, C2, L1 and L2 in Formula 1-1 are defined based on a reaction mixture including ethanol, lactic acid and a solid acid catalyst input into a batch reactor.

[0087] When the input amount conditions of Formula 1-1 are satisfied, esterification can be easily performed, thereby easily preparing crude ethyl lactate.

[0088] In one embodiment, crude ethyl lactate may be prepared by inputting ethanol and lactic acid into a packed bed continuous reactor filled with a solid acid catalyst and reacting them at a temperature of 50° C. to 100° C. under the conditions according to the following Formula 2:

[0089]

[0090] In Formula 2, E1 represents the number of moles of ethanol input through the ethanol delivery pipeline, E2 represents the number of moles of ethanol input from the initial fluid purification tower, L1 represents the number of moles of lactic acid input through the lactic acid delivery pipeline, and L2 represents the number of moles of lactic acid input from the lactic acid recovery tower.

[0091] E1, E2, L1 and L2 in Formula 2 are defined based on a reaction mixture including ethanol, lactic acid and a solid acid catalyst input to a packed bed continuous reactor.

[0092] When the input amount conditions of Formula 2 are satisfied, esterification can be easily performed, thereby easily preparing crude ethyl lactate.

[0093] In one embodiment, when a packed bed continuous reactor is used, the residence time of ethanol and lactic acid can be 1 to 6 hours. Under the above residence time conditions, esterification occurs easily, thereby easily preparing crude ethyl lactate.

[0094] (S20) Step of preparing a first mixture

[0095] This is a step of preparing a first mixture by distilling crude ethyl lactate input to a lactic acid recovery column to separate lactic acid from the crude ethyl lactate.

[0096] In one embodiment, the first mixture may include water, a liquid acid catalyst, unreacted ethanol, ethyl lactate, metal ions, and organic impurities.

[0097] In one embodiment, the distillation can be carried out at a temperature of 60° C. to 120° C. Under the above conditions, lactic acid can be easily separated from crude ethyl lactate. For example, the distillation can be carried out at a temperature of 60° C., 65° C., 70° C., 75° C., 80° C., 85° C., 90° C., 95° C., 100° C., 105° C., 110° C., 115° C., or 120° C.

[0098] In one embodiment, when the acid catalyst is liquid, it can be separated together with the lactic acid.The liquid acid catalyst can be input to the reactor and can be used to prepare crude ethyl lactate.

[0099] The lactic acid separated from the lactic acid recovery tower can be input to the reactor and used to prepare crude ethyl lactate. The lactic acid separated as described above can be input to the reactor, thereby showing excellent productivity and economic feasibility.

[0100] (S30) Step of preparing a second mixture

[0101] This is a step of preparing a second mixture by distilling the first mixture input to the initial fluid purification column to separate ethanol from the first mixture.

[0102] In one embodiment, the second mixture may include ethyl lactate, metal ions, organic impurities, and the like.

[0103] In one embodiment, the distillation can be carried out at a temperature of 60° C. to 120° C. Under the above conditions, ethanol can be easily separated from the first mixture. For example, the distillation can be carried out at a temperature of 60° C., 65° C., 70° C., 75° C., 80° C., 85° C., 90° C., 95° C., 100° C., 105° C., 110° C., 115° C., or 120° C.

[0104] The ethanol separated from the initial fluid purification column can be input into the reactor and used to prepare crude ethyl lactate. The ethanol separated as described above can be input into the reactor, thereby showing excellent productivity and economic feasibility.

[0105] (S40) Step of preparing a purified product

[0106] This is a step of preparing a purified product by subjecting the second mixture input to the product column to vacuum distillation to remove impurities from the second mixture.

[0107] In one embodiment, for the product tower, an internal structure capable of minimizing the pressure difference, such as a packed structure, can be applied to prevent ethyl lactate from decomposing due to the temperature increase in the vacuum distillation for removing organic impurities and metal ions. In the vacuum distillation process under the above conditions, the decomposition of ethyl lactate can be easily prevented.

[0108] In one embodiment, the product tower and the storage unit have inner walls, and the material of the inner wall includes one or more of a fluorine-based resin and a surface-polished metal. When the fluorine-based resin or the surface-polished metal is not used as the material of the inner wall of the product tower, the dissociation of metal ions is likely to occur during the preparation of the purified product, resulting in an increase in the impurity content.

[0109] In one embodiment, the surface finishing metal may be polished by one or more of mechanical polishing and electropolishing.

[0110] For example, the product tower and the storage unit may have inner walls whose material includes one or more of polytetrafluoroethylene and surface-polished metal. As another example, the product tower may use a material in which one surface of the metal is coated with polytetrafluoroethylene.

[0111] In one embodiment, the step of preparing the purified product may include preliminarily removing impurities in the second mixture by vacuum distilling the second mixture input to the first product tower, thereby preparing a first purified product; and secondarily removing impurities from the first purified product by vacuum distilling the first purified product input to the second product tower, thereby preparing a second purified product. Under the above conditions, high-purity ethyl lactate can be prepared by easily removing impurities such as organic compounds and metal ions contained in the second mixture.

[0112] In one embodiment, the first purified product and the second purified product can be prepared by vacuum distillation at 0.3 bar and 0.01 bar, respectively. Through the vacuum distillation carried out under the above conditions, high-purity ethyl lactate can be prepared by easily removing impurities such as metal ions included in the second mixture. For example, the first purified product and the second purified product can be prepared by vacuum distillation at 0.3 bar, 0.25 bar, 0.2 bar, 0.15 bar, 0.1 bar, 0.09 bar, 0.08 bar, 0.07 bar, 0.06 bar, 0.05 bar, 0.04 bar, 0.03 bar, 0.02 bar or 0.01 bar.

[0113] For example, each of the first purified product and the second purified product can be prepared by vacuum distillation performed at a temperature of 80° C. to 120° C. and at 0.3 bar and 0.01 bar, respectively. By vacuum distillation performed under the above conditions, high-purity ethyl lactate can be prepared by easily removing impurities such as metal ions included in the second mixture.

[0114] The first purified product and the second purified product can be prepared by vacuum distillation, for example, by vacuum distillation carried out at 80°C, 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 11°C5 or 120°C at 0.3 bar and 0.01 bar, respectively.

[0115] (S50) Step of storing the purified product

[0116] This is a step of storing the purified product (or the second purified product) after it is transferred to the storage unit.

[0117] In one embodiment, the purified product delivered to the storage unit can be discharged to the outside through a purified product discharge pipeline, and a filtering device can be included in the purified product discharge pipeline to remove fine particles in the purified product. In one embodiment, the filtering device can include a multi-stage fine filter. When a filtering device is further included, the purity of the purified product can be further improved.

[0118] In one embodiment, the inside of one or more of the reactor, lactic acid recovery tower, initial fluid purification tower, product tower, and storage unit may have an inert gas environment. Under the above conditions, ethyl lactate can be prevented from being easily oxidized. Inert gas, for example, may include one or more of nitrogen (N2) and argon (Ar).

[0119] Hereinafter, the configuration and function of the present invention will be described in more detail in conjunction with the preferred embodiments of the present invention. However, these embodiments may be presented as preferred embodiments of the present invention, and these embodiments may not be interpreted as limiting the present invention in any sense. For the contents not described in detail herein, those of ordinary skill in the art can technically infer according to the embodiments of the present invention, and will not be repeated here.

[0120] Embodiments and comparative examples

[0121] Example 1

[0122] like Figure 1 The device 1000 for preparing electronic grade ethyl lactate is shown. Subsequently, after ethanol and lactic acid are respectively input into the batch reactor 100 of the device 1000 for preparing electronic grade ethyl lactate through the ethanol transfer line 10 and the lactic acid transfer line 12, crude ethyl lactate is prepared by inputting a liquid acid catalyst (p-toluenesulfonic acid) and performing esterification at a temperature of 80°C.

[0123] Then, a first mixture is prepared by transferring the crude ethyl lactate in the reactor 100 to the lactic acid recovery tower 110 through the crude ethyl lactate transfer line 14 and removing the lactic acid and the liquid acid catalyst by distillation at a temperature of 60° C. to 120° C. The separated lactic acid is input to the reactor 100 through the lactic acid recovery line 16 provided at the lower part of the lactic acid recovery tower 110, and is used to prepare crude ethyl lactate.

[0124] The first mixture is input to the initial fluid purification tower 120 through the first transfer line 20 disposed at the upper portion of the lactic acid recovery tower 110, and is distilled at a temperature of 60°C to 120°C to separate ethanol from the first mixture, thereby preparing a second mixture.

[0125] The separated ethanol is input to the dehydration device 150 through the ethanol discharge pipeline 24 provided at the initial fluid purification tower 120 to remove water, and the ethanol from which water is removed in the dehydration device 150 is input to the reactor 100 through the ethanol recovery pipeline 26 provided at the dehydration device 150, and is thus used for the preparation of crude ethyl lactate.

[0126] The second mixture prepared in the initial fluid purification tower 120 is input into the first product tower 130 through the second transfer line 22, and is subjected to vacuum distillation at a temperature of 80° C. to 120° C. at 0.3 bar or 0.01 bar to remove organic impurities and metal ion impurities, thereby preparing a first purified product. The first purified product is input into the second product tower 132 through the third transfer line 30, and is subjected to vacuum distillation at a temperature of 80° C. to 120° C. at 0.3 bar or 0.01 bar to remove organic impurities and metal ion impurities, thereby preparing a second purified product. The second purified product is transferred to the storage unit 140 through the fourth transfer line 32 and stored. The second purified product in the storage unit 140 is discharged to the outside through the purified product discharge line 40, and the purified product discharge line 40 is equipped with a filtering device (multi-stage fine filter 160) for removing fine particles from the purified product.

[0127] The first product tower 130 and the second product tower 132 adopt a packed internal structure, and the first product tower 130, the second product tower 132 and the storage unit 140 use electropolished metal (stainless steel SUS304) as the inner wall material, and ethyl lactate is prepared in a nitrogen environment in the reactor, the lactic acid recovery tower, the initial fluid purification tower, the first product tower, the second product tower, and the storage unit.

[0128] Meanwhile, crude ethyl lactate was prepared by inputting a liquid acid catalyst, ethanol and lactic acid into a batch reactor under the conditions of the following formula 1:

[0129]

[0130] In Formula 1, E1 represents the number of moles of ethanol input through the ethanol delivery pipeline, E2 represents the number of moles of ethanol input from the initial fluid purification tower, C1 represents the content (wt%) of the liquid acid catalyst, L1 represents the number of moles of lactic acid input through the lactic acid delivery pipeline, and L2 represents the number of moles of lactic acid input from the lactic acid recovery tower.

[0131] E1, E2, C1, L1 and L2 of Formula 1 are obtained by calculating the input amounts of ethanol and lactic acid input into the batch reactor, and C1 is obtained based on the entire reaction mixture including ethanol, lactic acid and a catalyst, wherein the input catalyst is a liquid acid catalyst.

[0132] Example 2

[0133] Ethyl lactate was prepared in the same manner as in Example 1, except that crude ethyl lactate was prepared according to the conditions shown in Table 1 below.

[0134] Example 3

[0135] Ethyl lactate was prepared in the same manner as in Example 1, except that ethanol and lactic acid were respectively introduced into a batch reactor 100 of an apparatus 1000 for preparing electronic grade ethyl lactate through an ethanol delivery line 10 and a lactic acid delivery line 12, and a solid acid catalyst (strongly acidic ion exchange resin, Amberlyst 15) was introduced, and esterification was carried out at a temperature of 70° C. to prepare crude ethyl lactate.

[0136] Here, crude ethyl lactate is prepared by inputting a solid acid catalyst, ethanol, and lactic acid into a batch reactor under the conditions of the following formula 1-1:

[0137]

[0138] In Formula 1-1, E1 represents the number of moles of ethanol input through the ethanol delivery pipeline, E2 represents the number of moles of ethanol input from the initial fluid purification tower, C2 represents the content (wt%) of the solid acid catalyst, L1 represents the number of moles of lactic acid input through the lactic acid delivery pipeline, and L2 represents the number of moles of lactic acid input from the lactic acid recovery tower.

[0139] E1, E2, L1 and L2 in Formula 1-1 are obtained by calculating the input amounts of ethanol and lactic acid input into the batch reactor, and C2 is obtained based on the entire reaction mixture including ethanol, lactic acid and a catalyst, wherein the input catalyst is a solid acid catalyst.

[0140] Examples 4 and 5

[0141] Ethyl lactate was prepared in the same manner as in Example 3, except that crude ethyl lactate was prepared according to the conditions shown in Table 1 below.

[0142] Example 6

[0143] Ethyl lactate was prepared in the same manner as in Example 1, except that ethanol and lactic acid were respectively introduced into a packed bed continuous reactor 100 filled with a solid acid catalyst (strong acid ion exchange resin, Amberlyst 15) of an electronic grade ethyl lactate production apparatus 1000 through an ethanol delivery pipeline 10 and a lactic acid delivery pipeline 12, and esterification was performed at a temperature of 60° C. to prepare crude ethyl lactate.

[0144] Here, crude ethyl lactate is prepared by inputting ethanol and lactic acid into a packed bed continuous reactor filled with a solid acid catalyst under the conditions of the following formula 2:

[0145]

[0146] In Formula 2, E1 represents the number of moles of ethanol input through the ethanol delivery pipeline, E2 represents the number of moles of ethanol input from the initial fluid purification tower, L1 represents the number of moles of lactic acid input through the lactic acid delivery pipeline, and L2 represents the number of moles of lactic acid input from the lactic acid recovery tower.

[0147] E1, E2, L1 and L2 in Formula 2 are obtained based on the total moles of ethanol and lactic acid input into the packed bed continuous reactor.

[0148] Example 7

[0149] Ethyl lactate was prepared in the same manner as in Example 6, except that crude ethyl lactate was prepared under the conditions shown in Table 1 below.

[0150] In the preparation of electronic grade ethyl lactate according to Examples 1 to 7, the weight ratio of the yield of the product to its theoretical yield was calculated as the yield according to the input of the raw materials, and the results are shown in Table 1 below.

[0151] Table 1

[0152]

[0153] Referring to the results in Table 1, it can be found that in Examples 1 to 7 of the present invention, the yield of the preparation of electronic grade ethyl lactate is 95% or more, showing excellent production efficiency.

[0154] Comparative Example 1

[0155] Ethyl lactate was prepared in the same manner as in Example 1, except that stainless steel (SUS304) was used as the material of the inner walls of the first product column, the second product column, and the storage unit.

[0156] Comparative Example 2

[0157] Ethyl lactate was prepared in the same manner as in Example 1, except that stainless steel (SUS316) was used as the material of the inner walls of the first product column, the second product column, and the storage unit.

[0158] Comparison Example 3

[0159] Ethyl lactate was prepared in the same manner as in Example 1, except that duplex stainless steel was used as the material of the inner walls of the first product column, the second product column, and the storage unit.

[0160] Experimental Example

[0161] For the ethyl lactate (second purified product) prepared in Example 1 and Comparative Examples 1 to 3, the contents of iron (Fe), nickel (Ni) and chromium (Cr) ions were measured using a measuring device (NexION 2000 series ICP-MS / PerkinElmer), and the results are shown in Table 2 below.

[0162] Table 2

[0163]

[0164] Referring to the results in Table 2, it can be found that compared with Comparative Examples 1 to 3, Example 1, in which electropolished metal is used as the material of the inner wall of each of the first product tower, the second product tower and the storage unit, has higher efficiency in removing metal ion impurities and higher effect in preventing metal ions from dissociating from the inner wall during storage of ethyl lactate in the preparation of ethyl lactate.

[0165] Examples 8 and 9 and Comparative Examples 4 to 6

[0166] In order to confirm the effects of UV blocking and nitrogen blanketing on the purity of ethyl lactate, the ethyl lactate sample prepared in Example 1 was prepared, and each of the ethyl lactate samples in Examples 8 and 9 and Comparative Examples 4 to 6 was prepared by charging and storing in a storage container under the conditions shown in Table 3 below. In Comparative Examples 5 and 8, the storage container was wrapped with black vinyl to block UV.

[0167] For the ethyl lactate samples in Examples 8 and 9 and Comparative Examples 4 to 6, the purity of ethyl lactate immediately after storage and the purity of ethyl lactate after 30 days in the open air (normal temperature) were compared, and the results are shown in Table 3 below.

[0168] Table 3

[0169]

[0170] Referring to the results in Table 3, it can be found that according to the present invention, when UV and oxygen are blocked in the preparation of ethyl lactate, high-purity ethyl lactate can be prepared by suppressing the decomposition of ethyl lactate.

[0171] As described above, the present invention has been described with reference to the embodiments. It should be understood by those skilled in the art that the present invention can be implemented in a modified form without departing from the basic features of the present invention. Therefore, the disclosed embodiments should be considered to be illustrative rather than restrictive. The scope of the present invention is shown in the claims rather than in the above description, and all differences within their equivalent ranges should be interpreted as being included in the present invention.

[0172] Description of Reference Numerals

[0173] 10: Ethanol delivery pipeline 12: Lactic acid delivery pipeline

[0174] 14: Crude ethyl lactate delivery pipeline 16: Lactic acid recovery pipeline

[0175] 20: First delivery pipeline 22: Second delivery pipeline

[0176] 24: Ethanol discharge pipeline 26: Ethanol recovery pipeline

[0177] 30: The third delivery pipeline 32: The fourth delivery pipeline

[0178] 34: First discharge pipeline 36: Second discharge pipeline

[0179] 40: Purified product discharge pipeline 42: Circulation pipeline

[0180] 44: Third discharge line 100: Reactor

[0181] 110: Lactic acid recovery tower 120: Initial fluid purification tower

[0182] 130: First product tower 132: Second product tower

[0183] 140: Storage unit 150: Dehydration equipment

[0184] 160: Filter device

[0185] 1000: Apparatus for preparing electronic grade ethyl lactate

Claims

1. A device for preparing electronic grade ethyl lactate, characterized in that: include: A reactor for preparing crude ethyl lactate by reacting ethanol input through an ethanol delivery pipeline and lactic acid input through a lactic acid delivery pipeline in the presence of an acid catalyst; a lactic acid recovery tower for preparing a first mixture by distilling the input crude ethyl lactate to separate lactic acid from the crude ethyl lactate; an initial fluid purification column for preparing a second mixture by distilling the input first mixture to separate ethanol from the first mixture; a product column for preparing a purified product by distilling the input second mixture to remove impurities from the second mixture; as well as a storage unit for storing the purified product delivered to the storage unit, wherein the lactic acid separated in the lactic acid recovery tower and the ethanol separated in the initial fluid purification tower are input into the reactor; and The product tower and the storage unit have inner walls, and a material of the inner wall includes one or more of a fluorine-based resin and a surface-finished metal.

2. The device according to claim 1, characterized in that The reactor includes one or more of a batch reactor and a continuous reactor.

3. The device according to claim 1, characterized in that The acid catalyst includes one or more of a solid acid catalyst and a liquid acid catalyst. The solid acid catalyst comprises a strongly acidic ion exchange resin; and The liquid acid catalyst includes one or more of p-toluenesulfonic acid, methanesulfonic acid, sulfuric acid, phosphoric acid, nitric acid and hydrochloric acid.

4. The device according to claim 1, characterized in that Also includes: a dehydration device for removing water from the ethanol separated in the initial fluid purification tower and conveyed to the dehydration device; The ethanol from which water has been removed is input into the reactor.

5. The device according to claim 1, characterized in that Also includes: a purified product discharge pipeline connected to the storage unit to discharge the purified product to the outside; Wherein, a filtering device is arranged in the purified product discharge pipeline to remove fine particles in the purified product.

6. The device according to claim 1, characterized in that The product column comprises: a first product column for preparing a first purified product by performing vacuum distillation on the input second mixture to preliminarily remove impurities from the second mixture; and A second product column is used for preparing a second purified product by performing vacuum distillation on the input first purified product to secondarily remove impurities from the first purified product.

7. The device according to claim 1, characterized in that The interior of one or more of the reactor, the lactic acid recovery column, the initial fluid purification column, the product column, and the storage unit has an inert gas environment.

8. A method for preparing electronic grade ethyl lactate using the device for preparing electronic grade ethyl lactate according to any one of claims 1 to 7, characterized in that: include: In the presence of an acid catalyst, reacting ethanol fed into a reactor through an ethanol feed line and lactic acid fed into the reactor through a lactic acid feed line to produce crude ethyl lactate; preparing a first mixture by distilling the crude ethyl lactate input to a lactic acid recovery tower to separate lactic acid from the crude ethyl lactate; preparing a second mixture by distilling the first mixture input to an initial fluid purification column to separate ethanol from the first mixture; preparing a purified product by subjecting the second mixture fed to a product column to vacuum distillation to remove impurities from the second mixture; as well as transporting the purified product to a storage unit and storing the purified product, wherein the lactic acid separated in the lactic acid recovery tower and the ethanol separated in the initial fluid purification tower are input into the reactor; and The product tower and the storage unit have inner walls, and a material of the inner wall includes one or more of a fluorine-based resin and a surface-finished metal.

9. The method according to claim 8, characterized in that The acid catalyst includes one or more of a solid acid catalyst and a liquid acid catalyst. The solid acid catalyst comprises a strongly acidic ion exchange resin; and The liquid acid catalyst includes one or more of p-toluenesulfonic acid, methanesulfonic acid, sulfuric acid, phosphoric acid, nitric acid and hydrochloric acid.

10. The method according to claim 8, characterized in that The reactor includes one or more of a batch reactor and a continuous reactor.

11. The method according to claim 9, characterized in that The crude ethyl lactate is prepared by inputting a liquid acid catalyst, ethanol, and lactic acid into a batch reactor according to the conditions of Formula 1, and reacting the ethanol and the lactic acid at a temperature of 50° C. to 100° C., wherein Formula 1 is: In Formula 1, E1 represents the mole number of the ethanol input through the ethanol delivery pipeline, E2 represents the mole number of the ethanol input from the initial fluid purification tower, C1 represents the content of the liquid acid catalyst in wt%, L1 represents the mole number of the lactic acid input through the lactic acid delivery pipeline, and L2 represents the mole number of the lactic acid input from the lactic acid recovery tower.

12. The method according to claim 9, characterized in that The crude ethyl lactate is prepared by inputting a solid acid catalyst, ethanol, and lactic acid into a batch reactor and reacting the ethanol and the lactic acid at a temperature of 50° C. to 100° C. according to the conditions of Formula 1-1: In the formula 1-1, E1 represents the mole number of the ethanol input through the ethanol delivery pipeline, E2 represents the mole number of the ethanol input from the initial fluid purification tower, C2 represents the content of the solid acid catalyst in wt%, L1 represents the mole number of the lactic acid input through the lactic acid delivery pipeline, and L2 represents the mole number of the lactic acid input from the lactic acid recovery tower.

13. The method according to claim 9, characterized in that The crude ethyl lactate is prepared by inputting ethanol and lactic acid into a packed bed continuous reactor filled with a solid acid catalyst according to the conditions of Formula 2, and reacting the ethanol and the lactic acid at a temperature of 50° C. to 100° C., wherein Formula 2 is: In Formula 2, E1 represents the number of moles of the ethanol input through the ethanol delivery pipeline, E2 represents the number of moles of the ethanol input from the initial fluid purification tower, L1 represents the number of moles of lactic acid input through the lactic acid delivery pipeline, and L2 represents the number of moles of lactic acid input from the lactic acid recovery tower.

14. The method according to claim 8, characterized in that The preparation of the purified product comprises: preparing a first purified product by subjecting the second mixture input to a first product column to vacuum distillation to preliminarily remove impurities from the second mixture; and The second purified product is prepared by subjecting the first purified product input to a second product column to vacuum distillation to secondarily remove impurities from the first purified product.

15. The method according to claim 14, characterized in that The first purified product and the second purified product were prepared by vacuum distillation at 0.3 bar and 0.01 bar, respectively.

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