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US 4,400,559 AGranted
Process for preparing ethylene glycol
AssigneeThe Halcon SD Group, Inc.
InventorVijay S. Bhise
Life of this patent
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Abstract
Ethylene glycol is prepared by a process in which ethylene oxide is extracted from an aqueous solution with near-critical or super-critical carbon dioxide. Thereafter an ethylene oxide--carbon dioxide--water mixture is contacted with a catalyst to form ethylene carbonate, which is then hydrolyzed to ethylene glycol in the presence of the same catalyst. The ethylene glycol is separated as product and the carbon dioxide and the catalyst are recycled.
Claims9
A process for the preparation of ethylene glycol from an aqueous solution of ethylene oxide comprising the steps of:
- (a) contacting said aqueous solution of ethylene oxide with sufficient carbon dioxide at near-critical or super-critical conditions to extract substantially all of the ethylene oxide into the carbon dioxide and forming an ethylene oxide-rich carbon dioxide phase containing a minor amount of water and an ethylene oxide-lean aqueous phase;
- (b) contacting said ethylene oxide-rich carbon dioxide phase of (a) with a carbonation catalyst under carbonation conditions to form an ethylene carbonate-rich carbon dioxide stream;
- (c) adding water to the catalyst-containing ethylene carbonate-rich stream of (b) and hydrolyzing said ethylene carbonate to ethylene glycol and carbon dioxide;
- (d) flashing off from the ethylene glycol-containing stream of (c) the carbon dioxide formed in the hydrolysis and returning said carbon dioxide to the (near) super-critical extraction of (a);
- (e) separating the ethylene glycol from the flashed stream of (d);
- and
- (f) recovering and recycling to the carbonation reaction the catalyst added in (b).
4 more elements
Dependencies are inferred from the claim text.