METHOD OF RECOVERING ACETIC ACID FROM DILUTE AQUEOUS FLOWS RESULTING DURING CARBONYLATION PROCESS Russian patent published in 2000 - IPC

FIELD: chemical industry. SUBSTANCE: described are processes for preparing acetic acid by carbonylation of methanol, dimethyl ether or methyl acetate. Carbonylation reaction produces reaction mixture containing acetic acid, water and impurities. Alkane and alkane-like compounds and catalytic admixtures of metal carbonyls are isolated by rectification, and flows are recycled into carbonylation reactor to produce flow of concentrated dehydrated acetic acid and one or more aqueous flows containing from 5 to 30 wt.% of acid. Said aqueous flows containing acetic acid are treated with methanol in catalytic distillation plant containing cation-exchange resin in acid form. Acetic acid is made to react with methanol to form methyl acetate. Water is separated by distillation from organic compounds. The resulting additional amount of methyl acetate is combined with recirculating flows admitted into carbonylation reactor. EFFECT: increased yield of acetic acid due to lower losses thereof at rectification stages. 2 dwg, 5 tbl