Abstract: An improved method of producing acetic acid includes condensing overhead vapor from a light ends column and decanting the condensed vapor to a light phase and a heavy phase. The heavy phase consists predominantly of methyl iodide and at least a portion of the decanted heavy phase is refluxed to the light ends column. Acetic acid content of the light ends column overhead stream and water content of the light ends column product (sidedraw) stream are both decreased, improving purification efficiency.

Abstract: An improved apparatus and method of producing acetic acid includes condensing overhead vapor to provide reflux to the light ends column as well as condensing vapor from a central portion of the light ends column to increase capacity. Throughput or load on the light ends column is substantially reduced without compromising product quality.