Title:
A PROCESS FOR SEPARATION OF CRUDE NAPHTHALENE DICARBOXYLIC ACID USING REVERSE OSMOSIS
Document Type and Number:
WIPO Patent Application WO2001016067
Kind Code:
A3
Abstract:
Disclosed is a process for purifying 2,6-naphthalene dicarboxylic acid produced by disproportionation and more efficiently recycling byproduct dipotassium salts which includes the steps of: a) Contacting an aqueous solution containing the disalt of 2,6-NDA(2,6-K2NDA) with carbon dioxide to form as a precipitate the monopotassium salt of 2,6-NDA (KHNDA) and an aqueous solution containing 2,3-KHNDA, K2NDA, and potassium bicarbonate; b) Disproportionating said monopotassium salt (KHNDA) to form 2,6-NDA and an aqueous solution containing K2NDA, and potassium bicarbonate; c) Separating said 2,6-NDA and concentrating said aqueous solution containing K2NDA and potassium bicarbonate by reverse osmosis.
Inventors:
DIAZ ZAIDA
RODDEN JOHN B
RODDEN JOHN B
Application Number:
PCT/US2000/021674
Publication Date:
May 10, 2001
Filing Date:
August 08, 2000
Export Citation:
Assignee:
SHELL OIL CO (US)
International Classes:
B01J27/232; C07C51/02; C07C51/15; C07C51/265; C07C51/44; C07C51/41; C07C51/42; C07C51/43; C07C51/47; C07C51/48; C07C51/487; C07C63/38; C08G63/189; (IPC1-7): C07C51/41; C07C51/43; C07C63/38; C07C51/42
Foreign References:
| US3671578A | 1972-06-20 | |||
| US3888921A | 1975-06-10 |
Other References:
DATABASE WPI Derwent World Patents Index; AN 1978-18376A, XP002159814
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