Method for producing nitrous acid ester, and method for producing dialkyl oxalate and dialkyl carbonate

摘要

A method for producing nitrous acid ester in which nitric oxide, oxygen, and an alcohol are reacted, thereby generating nitrous acid ester includes a step of generating nitrous acid ester by supplying a bottom liquid from a bottom part of the reaction column, and nitric oxide and/or carbon monoxide, a step of supplying nitrous acid ester to the reaction column; a step of supplying a reaction liquid containing water, nitric acid, and the alcohol to a nitric acid condensing column from the reactor; and a step of separating a low-boiling point component by distillation from the reaction liquid under control of a concentration of the alcohol in a condensed liquid being generated at a bottom part of the nitric acid condensing column to be less than 4.0% by weight so as to introduce the condensed liquid into the reactor from the nitric acid condensing column.

主权项

1. A method for producing nitrous acid ester in which an alcohol is supplied to an upper part of a reaction column for producing nitrous acid ester, is made to flow downward from the upper part to a lower part of the reaction column, nitric oxide and oxygen, or a gas mixture thereof is supplied to the lower part of the reaction column, and nitric oxide, oxygen, and the alcohol are reacted, thereby generating nitrous acid ester, the method comprising:
a step of extracting a bottom liquid containing water, nitric acid, and an alcohol from the bottom part of the reaction column so as to supply the bottom liquid to a reactor, and supplying nitric oxide and/or carbon monoxide to the reactor; a step of generating nitrous acid ester by brining nitric oxide and/or carbon monoxide into contact with the bottom liquid in the reactor; a step of supplying nitrous acid ester obtained in the reactor to the reaction column; a step of supplying a reaction liquid containing water, nitric acid, and the alcohol to a nitric acid condensing column from a lower part of the reactor; and a step of separating a low-boiling point component by distillation from the reaction liquid in the nitric acid condensing column under control of a concentration of an alcohol in a condensed liquid being generated at a bottom part of the nitric acid condensing column to be less than 4.0% by weight, and extracting the condensed liquid from the lower part of the nitric acid condensing column so as to introduce the condensed liquid into the reactor.