发明授权
US06444108B1 Process for isolation of dicarboxylic acids and hydroxycarboxlic acids 失效
分离二羧酸和羟基羧酸的方法

Process for isolation of dicarboxylic acids and hydroxycarboxlic acids
摘要:
A first process involves the partial electrodialysis of a dialkali metal salt of an aromatic hydroxycarboxylic acid or a dicarboxylic acid to produce the approximate monoalkali metal salt and the alkali metal hydroxide. The monoalkali metal salt is then treated with an acid such as a bisulfate to recover the aromatic hydroxycarboxylic acid or dicarboxylic acid. The resulting inorganic salt such as sodium sulfate may then be electrolyzed to sodium bisulfate and NaOH. A second process involves the electrodialysis at elevated temperatures of a (di)alkali metal salt of p-hydroxybenzoic acid produce free p-hydroxybenzoic acid and the alkali metal hydroxide. These are efficient and economical methods for recovering the acid and alkali metal hydroxide values, as well as the parent organic compound, from these dialkali metal salts.
信息查询
0/0