PURPOSE: To remove the metallic corrosion products from the reaction liquid by an ion-exchange process, at the time of producing acetic acid and acetic anhydride by carbonylation under anhydrous condition, and to recycle the noble metal and organic phosphonium or organic ammonium compound without post-treatment.
CONSTITUTION: Acetic acid and acetic anhydride are obtained by carbonylating at least one compound among methyl acetate, methanol, or dimethyl ether under anhydrous condition in the presence of a catalytic system incorporating a group VIII noble metal, co-catlayst such as methyl iodide, organic phosphonium or organic ammonium salt, and in some cases an accelerator of lithium salt. In this process, the reaction liquid containing metallic corrosion products and the catalytic system is brought into contact with an ion exchanger, and the reaction solution is separated from the ion-exchanger while the accelerator is desorbed from the ion exchanger at first and is recycled into the carbonylation reaction together with the reaction liquid separated from the ion exchanger. Subsequently the ion exchanger is regenerated by a strong mineral acid and used again in the carbonylation reaction after being cleaned with acetic acid and acetic anhydride.
RAINHARUTO GURADORU
ERUHARUTO IEEGERUSU
ANDOREASU ZAIDERU
PEETERU PURINTSU
