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KR-20260065926-A - Method for manufacturing ethylmethyl carbonate

KR20260065926AKR 20260065926 AKR20260065926 AKR 20260065926AKR-20260065926-A

Abstract

A method for producing ethyl methyl carbonate, comprising a distillation process A in which a feed containing dimethyl carbonate, ethyl methyl carbonate, and ethanol is fed to a distillation column (A) and a fraction ( AB ) is extracted from the bottom of the distillation column (A), wherein the feed contains dimethyl carbonate at a ratio of 25 mol% or more relative to the total amount of the feed and ethyl methyl carbonate at a ratio of 12 mol% or more relative to the total amount of the feed, wherein the molar ratio of dimethyl carbonate/(ethanol + ethyl methyl carbonate) in the feed is 0.5 to 5.6, the ratio of ethanol to ethyl methyl carbonate in the fraction ( AB ) is 20 mass ppm or less, and furthermore, the ratio of methanol to ethyl methyl carbonate in the fraction ( AB ) is 20 mass ppm or less.

Inventors

  • 에노모토 미야코

Assignees

  • 아사히 가세이 가부시키가이샤

Dates

Publication Date
20260511
Application Date
20241101
Priority Date
20231102

Claims (10)

  1. A distillation process A comprising feeding a feed containing dimethyl carbonate, ethylmethyl carbonate, and ethanol to a distillation column (A) and extracting a fraction ( AB ) from the bottom of the distillation column (A), The above feed contains dimethyl carbonate at a ratio of 25 mol% or more relative to the total amount of the above feed, and ethyl methyl carbonate at a ratio of 12 mol% or more relative to the total amount of the above feed, The molar ratio of dimethyl carbonate/(ethanol + ethylmethyl carbonate) in the above feed is 0.1 to 2.0, and A method for producing ethylmethyl carbonate, wherein the ratio of ethanol to ethylmethyl carbonate in the above fraction (A B ) is 20 mass ppm or less, and furthermore, the ratio of methanol to ethylmethyl carbonate in the above fraction (A B ) is 20 mass ppm or less.
  2. In paragraph 1, (1) A distillation process B for supplying the above fraction (A B ) to a distillation column (B) and extracting the fraction (B B ) from the bottom of the distillation column (B) from which a low-boiling point substance having a boiling point lower than that of ethylmethyl carbonate has been removed, and The distillation process C further comprises supplying the above fraction (B B ) to a distillation column (C) and extracting the fraction (C L ) from the top of the distillation column (C), The purity of ethylmethyl carbonate in the above fraction (C L ) is 99.99 mass% or higher, and or (2) The distillation process D further comprises supplying the above fraction (A B ) to a distillation column (D), extracting the fraction (D B ) from the bottom of the distillation column (D), extracting the fraction (D L ) from the top of the column, and extracting the fraction (D S ) from the middle of the distillation column (D). The ethylmethyl carbonate purity in the above fraction ( D₂S ) is 99.99 mass% or higher, or (3) A distillation process B in which the above fraction (A B ) is supplied to a distillation column (B), and a fraction (B B) from which a low-boiling point substance having a boiling point lower than that of ethylmethyl carbonate has been removed is extracted from the bottom of the distillation column ( B ), and The distillation process D further comprises supplying the above fraction (B B ) to a distillation column (D), extracting the fraction (D B ) from the bottom of the distillation column (D), extracting the fraction (D L ) from the top of the column, and extracting the fraction (D S ) from the middle of the distillation column (D). A method for producing ethyl methyl carbonate in which the purity of the ethyl methyl carbonate in the above fraction ( D₂S ) is 99.99 mass% or higher.
  3. A method for producing ethylmethyl carbonate according to claim 1, wherein the normal pressure of the distillation column (A) is 0 kPaG to 50 kPaG.
  4. A method for producing ethylmethyl carbonate according to claim 1, wherein the method of supplying at least a portion of the dimethyl carbonate among the feeds to the distillation column (A) is to add the liquid alone by a pump.
  5. A method for producing ethylmethyl carbonate according to claim 1, wherein the feed is introduced from the middle section of the distillation column (A).
  6. A method for producing ethylmethyl carbonate according to claim 1, wherein the feed contains ethanol at a ratio of 0.5 mol% or more relative to the total amount of the feed.
  7. A method for producing ethylmethyl carbonate according to claim 1, wherein the distillation column (A) is equipped with trays and/or packing as internals.
  8. In any one of claims 1 to 7, the reaction process further comprises, prior to the distillation process A, an ester exchange reaction between dimethyl carbonate and ethanol in a reaction apparatus to obtain a reaction composition. A method for producing ethylmethyl carbonate, wherein the reaction composition is supplied to the distillation column (A) as at least part of the above feed.
  9. A method for producing ethylmethyl carbonate according to claim 2, further comprising a process of distilling a fraction (C B ) or fraction (D B ) extracted from the bottom of the distillation column (C) or the distillation column (D) to obtain diethyl carbonate having a purity of 99.99 mass% or more.
  10. In any one of paragraphs 1 through 7, A reaction process for obtaining a reaction composition by performing an ester exchange reaction between dimethyl carbonate and ethanol in a reaction apparatus prior to the above distillation process A, A distillation process B for supplying the above fraction (A B ) to a distillation column (B) and extracting a fraction (B B ) from the bottom of the distillation column (B) from which low-boiling point substances having a boiling point lower than that of ethylmethyl carbonate have been removed, and A distillation process C that supplies the above fraction ( B₀B₀ ) to a distillation column (C) and extracts the fraction ( C₀L₀ ) from the top of the distillation column (C). Having more, The reaction composition is supplied to the distillation column (A) as at least a portion of the above feed, and A method for producing ethyl methyl carbonate in which the purity of the ethyl methyl carbonate in the above fraction (C L ) is 99.99 mass% or higher.

Description

Method for manufacturing ethylmethyl carbonate The present invention relates to a method for manufacturing ethylmethyl carbonate. Ethylmethyl carbonate, used as an organic solvent for battery electrolytes, is generally known to be produced through an ester exchange reaction between dimethyl carbonate and ethanol. As a battery electrolyte, ethyl methyl carbonate with a methanol concentration of 20 mass ppm or less and an ethanol concentration of 20 mass ppm or less is generally used, but since the raw material ethanol and the product ethyl methyl carbonate have an azeotropic composition at atmospheric pressure, the rectification to achieve the aforementioned alcohol concentration is inefficient due to low energy efficiency and also inefficient due to large loss of ethyl methyl carbonate. For example, Patent Document 1 proposes a method for separating ethanol from ethylmethyl carbonate using a pressurized tower. Patent Document 2 proposes a means to improve the energy efficiency required for the purification of ethylmethyl carbonate by using a heat pump. FIG. 1 is a schematic diagram of the manufacturing equipment used in the method for manufacturing ethylmethyl carbonate according to the present embodiment. FIG. 2 is a schematic diagram of the manufacturing equipment used in the method for manufacturing ethylmethyl carbonate according to the present embodiment. FIG. 3 is a schematic diagram of the manufacturing equipment used in the method for manufacturing ethylmethyl carbonate according to the present embodiment. FIG. 4 is a schematic diagram of the manufacturing equipment used in the method for manufacturing ethylmethyl carbonate according to the present embodiment. FIG. 5 is a schematic diagram of the manufacturing equipment used in the method for manufacturing ethylmethyl carbonate according to the present embodiment. Hereinafter, embodiments of the present invention (hereinafter referred to as "the present embodiments") will be described in detail with reference to the drawings as necessary, but the present invention is not limited thereto and various modifications are possible within the scope of not departing from the gist thereof. Furthermore, positional relationships such as up, down, left, and right in the drawings shall be based on the positional relationships shown in the drawings unless otherwise specifically stated. In addition, the dimensional ratios in the drawings are not limited to the ratios shown. The meanings of terms and abbreviations used in this specification are explained below. "EMC" means ethylmethyl carbonate. "DMC" stands for dimethyl carbonate. "DEC" stands for diethyl carbonate. "MeOH" means methanol. "EtOH" means ethanol. "A," "B," "C," etc. in distillation column (A), distillation column (B), distillation column (C), and processes A, B, and C are merely symbols for describing the distillation columns and do not limit the composition, order, number, etc. of the distillation columns. A numerical range indicated using "~" represents a range that includes the values listed before and after "~" as minimum and maximum values, respectively. In numerical ranges described stepwise in this specification, the upper or lower limit of a numerical range in any step may be arbitrarily combined with the upper or lower limit of a numerical range in another step. The method for manufacturing ethylmethyl carbonate according to the present embodiment is, A distillation process comprising feeding a feed containing dimethyl carbonate, ethylmethyl carbonate, and ethanol to a distillation column and withdrawing it from the bottom of the distillation column, The above-mentioned feed contains dimethyl carbonate at a ratio of 15 mol% or more relative to the total amount of the above-mentioned feed, and ethylmethyl carbonate at a ratio of 12 mol% or more relative to the total amount of the above-mentioned feed, and The molar ratio of dimethyl carbonate/(ethanol + ethylmethyl carbonate) in the above feed is 0.1 to 2.0, and The ratio of ethanol to ethylmethyl carbonate in the above fraction (A B ) is 20 mass ppm or less, and also the ratio of methanol to ethylmethyl carbonate in the above fraction (A B ) is 20 mass ppm or less. According to the present embodiment, it is possible to produce ethylmethyl carbonate with low ethanol and methanol content with high efficiency. More specifically, in the present embodiment, EMC can be produced with high efficiency in terms of reducing the reflux ratio of the distillation column to reduce the alcohol content ratio, or reducing the loss amount of EMC. In the method for manufacturing EMC according to the present embodiment, it was discovered that, surprisingly, high purity of EMC can be achieved with high efficiency by increasing the concentration of DMC in the feed liquid to the distillation column. It is presumed that the mechanism for producing this effect is that by increasing the concentration of DMC in the feed liquid to a value greater than a predetermined va