PROCESS FOR FLASHING REACTION MEDIUM COMPRISING LITHIUM ACETATE

摘要

PROBLEM TO BE SOLVED: To provide an improved acetic acid production process having an improved separation step, increased production capacity and a lower operating cost.SOLUTION: There is provided the acetic acid production process in which methyl iodide concentration is maintained in a vapor product stream formed in a flashing step. The process includes introducing a lithium compound into a reactor and maintaining lithium acetate in a reaction medium at 0.3 to 0.7 wt.%. The reaction medium is supplied to the flashing step. The methyl iodide concentration in the vapor product stream ranges from 24 wt.% to less than 36 wt.% based on weight of the vapor product stream. An acetaldehyde concentration in the vapor product stream is maintained in the range of 0.005 to 1 wt.%. The vapor product stream is distillated in a first column to obtain an acetic acid product stream comprising acetic acid, hydrogen iodide in an amount of 300 wppm or less and/or methyl iodide in an amount of 0.1 to 6 wt.% and also to obtain an overhead stream comprising methyl iodide, water and methyl acetate.SELECTED DRAWING: Figure 1