Method for producing ethylene oxide

Patent metadata

Field	Value
Publication number	US-9518036-B2
Application number	US-201414781245-A
Country	US
Kind code	B2
Filing date	Mar 28, 2014
Priority date	Mar 29, 2013
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

[Problem] To provide a novel technology by which energy efficiency can be further improved in a process for producing ethylene oxide.
[Solution] A method for producing ethylene oxide including: an ethylene oxidation reaction step in which ethylene is subjected to catalytic vapor-phase oxidation using a molecular oxygen-containing gas in the presence of a silver catalyst; supplying an ethylene oxide-containing reaction product gas produced in the ethylene oxidation reaction step to an ethylene oxide absorption column; bringing the reaction product gas into contact with an absorption liquid supplied to the ethylene oxide absorption column; supplying an ethylene oxide-containing column bottom liquid of the ethylene oxide absorption column to an ethylene oxide purification system; purifying ethylene oxide in the ethylene oxide purification system; supplying at least a part of a carbon dioxide gas-containing gas discharged from a column top part of the ethylene oxide absorption column to a carbon dioxide gas absorption column; extracting a carbon dioxide gas-rich absorption liquid obtained by contact of the carbon dioxide gas-containing gas with an absorption liquid as a column bottom liquid of the carbon dioxide gas absorption column; supplying the carbon dioxide gas-rich absorption liquid to an upper part of the carbon dioxide gas stripper column; stripping the carbon dioxide gas from the carbon dioxide gas-rich absorption liquid; and discharging the carbon dioxide gas from a column top part of the carbon dioxide gas stripper column as an exhaust gas, the ethylene oxide purification system including an ethylene oxide purification column provided with a reboiler in a lower part thereof, and a heating medium for heating the reboiler being heated by heat exchange with the exhaust gas.

First claim

The invention claimed is:

1. A method for producing ethylene oxide comprising:
an ethylene oxidation reaction step in which ethylene is subjected to catalytic vapor-phase oxidation using a molecular oxygen-containing gas in the presence of a silver catalyst;
supplying an ethylene oxide-containing reaction product gas produced in the ethylene oxidation reaction step to an ethylene oxide absorption column;
bringing the reaction product gas into contact with an absorption liquid supplied to the ethylene oxide absorption column;
supplying an ethylene oxide-containing column bottom liquid of the ethylene oxide absorption column to an ethylene oxide purification system;
purifying ethylene oxide in the ethylene oxide purification system;
supplying at least a part of a carbon dioxide gas-containing gas discharged from a column top part of the ethylene oxide absorption column to a carbon dioxide gas absorption column;
extracting a carbon dioxide gas-rich absorption liquid obtained by contact of the carbon dioxide gas-containing gas with an absorption liquid as a column bottom liquid of the carbon dioxide gas absorption column;
supplying the carbon dioxide gas-rich absorption liquid to an upper part of the carbon dioxide gas stripper column;
stripping the carbon dioxide gas from the carbon dioxide gas-rich absorption liquid; and
discharging the carbon dioxide gas from a column top part of the carbon dioxide gas stripper column as an exhaust gas, wherein
the ethylene oxide purification system includes an ethylene oxide purification column provided with a reboiler in a lower part thereof, and
a heating medium for heating the reboiler is heated by heat exchange with the exhaust gas.

Assignees

• Nippon Catalytic Chem Ind

Inventors

• Watanabe Akimasa
• Takinami Takahiro
• Morikawa Noriji

Classifications

• B01D2251/304

  of sodium · CPC title

• B01D53/62

  Carbon oxides · CPC title

• B01D53/1487

  Removing organic compounds · CPC title

• B01D53/78

  with gas-liquid contact · CPC title

• Y02C10/04

  Cross-Sectional Technologies · mapped topic