Method for purifying n-(alpha-alkoxyethyl)formamide, method for producing high-purity n-(alpha-alkoxyethyl)formamide, and device for purifying n-(alpha-alkoxyethyl)formamide

Patent metadata

Field	Value
Publication number	US-2019241503-A1
Application number	US-201916390132-A
Country	US
Kind code	A1
Filing date	Apr 22, 2019
Priority date	Dec 9, 2016
Publication date	Aug 8, 2019
Grant date	—

Abstract

A method for purifying an N-(α-alkoxyethyl)formamide contained in a mixture thereof with a plurality of distillation columns, the plurality of distillation columns being arranged serially, the method including condensing a distillate from the second or any later-stage distillation column to obtain a condensate and returning at least some of the condensate to the preceding distillation column.

First claim

1 . A method for purifying N-(α-alkoxyethyl)formamide from a mixture containing the N-(α-alkoxyethyl)formamide by using a plurality of distillation columns, wherein
the plurality of distillation columns are disposed in series, and
the method comprises:
condensing an overhead efflux of a distillation column at a subsequent stage to obtain a condensate; and
returning at least a part of the condensate to a distillation column at a preceding stage.

2 . The method for purifying N-(α-alkoxyethyl)formamide according to claim 1 , wherein the condensation is conducted by using a condenser.

3 . The method for purifying N-(α-alkoxyethyl)formamide according to claim 1 , wherein at least one of the plurality of distillation columns is a packed column.

4 . The method for purifying N-(α-alkoxyethyl)formamide according to claim 1 , wherein a temperature of a column bottom liquid in at least one distillation column among the plurality of distillation columns is 100° C. or less.

5 . The method for purifying N-(α-alkoxyethyl)formamide according to claim 1 , wherein the mixture contains water and an alcohol.

6 . The method for purifying N-(α-alkoxyethyl)formamide according to claim 1 , wherein the condensate contains water and N-(α-alkoxyethyl)formamide.

7 . A method for producing high-purity N-(α-alkoxyethyl)formamide from a mixture containing the N-(α-alkoxyethyl)formamide, water, and an alcohol by using a plurality of distillation columns, wherein
the plurality of distillation columns are disposed in series, and
the method comprises:
obtaining an overhead efflux containing an alcohol at a preceding stage and a column bottom liquid at a preceding stage in a distillation column at a preceding stage;
introducing the column bottom liquid at a preceding stage into a distillation column at a subsequent stage;
obtaining an overhead efflux containing water and N-(α-alkoxyethyl)formamide at a subsequent stage and a column bottom liquid containing N-(α-alkoxyethyl)formamide at a subsequent stage in the distillation column at a subsequent stage;
condensing the overhead efflux at a subsequent stage to obtain a condensate; and
returning at least a part of the condensate to the distillation column at a preceding stage.

8 . A device for purifying N-(α-alkoxyethyl)formamide, comprising a plurality of distillation columns for distilling N-(α-alkoxyethyl)formamide-containing liquid, wherein
the plurality of distillation columns are disposed in series, and
the device comprises a return section for returning at least a part of a condensate of an overhead efflux of a distillation column at a subsequent stage to a distillation column at a preceding stage.

9 . The device for purifying N-(α-alkoxyethyl)formamide according to claim 8 , comprising a condenser for condensing the overhead efflux of the distillation column at a subsequent stage.

10 . The device for purifying N-(α-alkoxyethyl)formamide according to claim 9 , wherein the condenser is connected to a column top of the distillation column.

11 . The device for purifying N-(α-alkoxyethyl)formamide according to claim 8 , wherein at least one of the plurality of distillation columns is a packed column.

Assignees

• Mitsubishi Chem Corp

Inventors

• Teramoto Kouji
• Nishimura Hitoshi

Classifications

• B01D3/143

  by two or more of a fractionation, separation or rectification step · CPC title

• C07C231/24 Primary

  Separation; Purification · CPC title

• C07C233/18

  having the carbon atom of the carboxamide group bound to a hydrogen atom or to a carbon atom of an acyclic saturated carbon skeleton · CPC title

• B01D3/26

  Fractionating columns in which vapour and liquid flow past each other, or in which the fluid is sprayed into the vapour, or in which a two-phase mixture is passed in one direction · CPC title

• B01D3/009 Primary

  in combination with chemical reactions · CPC title