Alkylene oxide purification systems
AssigneeDow Technology Investments LLC
InventorsJohn F. Szul, James H. McCain, Floyd L. Pfeffer, Harvey E. Andresen, Phillip R. Fairchild, Kent E. Newman
Life of this patent
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Abstract
Embodiments of the present disclosure provide processes, columns, and systems for removing acetaldehyde from alkylene oxide in a feed stream and for providing an alkylene oxide-water stream that can be directly transferred to a glycol reaction process. The alkylene oxide purification column includes a first section to convert a feed stream into a gas phase portion and a liquid phase portion and a second section located in the column above the first section to separate alkylene oxide from the acetaldehyde, water, and other impurities that enter the second section from the first section.
Claims20
A process for separating acetaldehyde from ethylene oxide, comprising:
- introducing a feed stream including, based on its weight, ethylene oxide in a range of about 5 to about 95 percent by weight, to a first section of an ethylene oxide purification column, where the column includes the first section and a second section located above the first section;
- separating the feed stream into a gas phase portion of the feed stream, where the gas phase portion of the feed stream includes ethylene oxide, acetaldehyde, water, and other impurities, and a liquid phase portion of the feed stream including ethylene oxide and water, where the liquid phase portion exits the bottom of the column as an ethylene oxide-water stream that is from 1 to 10 weight percent ethylene oxide based on a total weight of the ethylene oxide-water stream and includes 1 to 65 weight percent of the acetaldehyde of the feed stream;
- and
- separating via a number of separation stages the ethylene oxide from acetaldehyde, water, and other impurities that enter the second section from the first section by heating to produce a purified ethylene oxide exit stream.
A process for separating acetaldehyde from ethylene oxide, comprising:
- introducing a feed stream comprising ethylene oxide in a range of about 5 to about 95 percent by weight to a first section of an ethylene oxide purification column, where the column includes the first section and a second section;
- separating the feed stream into a gas phase portion of the feed stream, where the gas phase portion of the feed stream comprises ethylene oxide, acetaldehyde, water and other impurities, and a liquid phase portion of the feed stream comprising water and up to about 19 weight percent ethylene oxide, based on total weight of the liquid phase portion of the feed stream, where the liquid phase portion exits the bottom of the column as an ethylene oxide-water stream that is from 1 to 10 weight percent ethylene oxide based on a total weight of the ethylene oxide-water stream and includes 1 to 65 weight percent of the acetaldehyde of the feed stream;
- and
- separating via a number of separation stages the ethylene oxide from acetaldehyde, water, and other impurities that enter the second section from the first section by heating to produce a purified ethylene oxide exit stream.
A process for separating acetaldehyde from ethylene oxide, comprising:
- converting, in a first section located in a ethylene oxide purification column, a feed stream including ethylene oxide, water, acetaldehyde, and other impurities into a gas phase portion of the feed stream including ethylene oxide, acetaldehyde, water, and other impurities and a liquid phase portion of the feed stream including ethylene oxide and water, where the liquid phase portion exits the bottom of the column as an ethylene oxide-water stream that is from 1 to 10 weight percent ethylene oxide based on a total weight of the ethylene oxide-water stream and includes 1 to 65 weight percent of the acetaldehyde of the feed stream;
- and
- separating by heating, via a number of separation stages in a second section located in the column above the first section, ethylene oxide from the acetaldehyde, water, and other impurities that enter the second section from the first section;
- collecting, in a tray located at a bottom portion of the second section, ethylene oxide, acetaldehyde, and other impurities in a liquid phase;
- removing, from a first side take-off located at the tray, the collected ethylene oxide, acetaldehyde, and other impurities in the liquid phase;
- and
- removing, from a second side take-off located at a top portion of the second section, a purified ethylene oxide exit stream.
Dependencies are inferred from the claim text.