Patent ID: 6232491
Filing Date: 2001-05-15
Classification: C07C

Abstract:
A process for the purification of the reaction products of a direct addition reaction comprising reacting ethylene with acetic acid in the presence of a catalyst to form ethyl acetate and purifying the recycle streams, the purification process comprising the steps of(i) feeding the reaction products to an acid removal column (A) where acetic acid is removed from the base of the column, at least a fraction comprising light ends comprising hydrocarbons, ethyl acetate, ethanol, diethyl ether and water are withdrawn overhead and fed into a decanter (A1) for separation of said overheads into an ethyl acetate-rich phase and an aqueous phase,(ii) recycling at least a portion of the ethyl acetate-rich phase and substantially all of the aqueous phase from decanter (A1) as reflux separately back to column (A) at or near the top thereof,(iii) feeding the remainder of the ethyl acetate-rich phase from decanter (A1) to a refining column (C) at or near the top thereof,(iv) removing from column (C):(a) a base product comprising substantially refined ethyl acetate which is fed to a purification column (E);(b) an overhead product comprising light ends including acetaldehyde and diethyl ether which is fed to an aldehyde removal column; and(c) a side-draw comprising primarily ethyl acetate, ethanol and some water which is removed at a point below the feed point of the ethyl acetate-rich phase from column (A),(v) removing a purge comprising acetaldehyde at or near the top of the aldehyde removal column and recycling the diethyl ether recovered from the base of the aldehyde removal column to the esterification reactor, and(vi) purifying the refined ethyl acetate in column (E).