| 摘要 |
PROBLEM TO BE SOLVED: To post-treat liquid crude vinyl acetate extremely reducing a lost amount of vinyl acetate by introducing a specific amount of water and acetic acid to the liquid crude vinyl acetate to be used from above the adding position to liquid crude vinyl acetate in a distillation column. SOLUTION: This method for post-treating of liquid vinyl acetate is composed of subjecting liquid crude vinyl acetate containing acetic acid, water, ethyl acetate, and occasionally a small amount of the other impurities to a post treating by distillation and obtaining a mixture containing mainly vinyl acetate and water as a top product and mainly acetic acid as a distilled solution product, then pulling out a side flow having high concentration of ethyl acetate, thus condensing its top product, phase separating and returning a part of the vinyl acetate phase into the distilling column as a refluxing flow. In the post- treating method, 0.1-5 wt.% of water based on a liquid crude vinyl acetate and 0.1-60 wt.% of acetic acid based on the liquid crude vinyl acetate are introduced into the distillation column from above the adding position of the liquid crude vinyl acetate. This method is suitable, for instance, for liquid crude vinyl acetate containing 12-30 wt.% of vinyl acetate, 3-10 wt.% of water, 0.01-0.2 wt.% of ethyl acetate and balance of acetic acid.
|
