| 摘要 |
FIELD: industrial organic synthesis. ^ SUBSTANCE: invention relates to improved process of purifying reaction products formed in a direct addition process comprising reaction of ethylene with acetic acid in presence of acid catalyst to yield ethyl acetate and purification of recycle products. Process consists of two stages: (i) feeding reaction products into column A to remove acid, discharging acetic acid from the bottom of column and, from the top of column, at least one fraction including low-boiling components containing, among others, hydrocarbons, ethyl acetate, ethanol, diethyl ether, and water, which fraction(s) is passed to decantation apparatus A1 to separate the fraction(s) into ethyl acetate-rich phase and water phase; (ii) separately returning at least a part of ethyl acetate-rich phase and essentially all water phase from decantation apparatus A1 into the top or near the top section of column A to act as phlegm; (ii) feeding the rest of ethyl acetate-rich phase from decantation apparatus A1 into the top or near the top section of refining column C; (iv) discharging from column A: bottom product comprising essentially refined ethyl acetate, which is sent to purification column E; and top product including low-boiling components containing, among others, acetaldehyde and diethyl ether, which is sent to aldehyde-removal column; and side-cut fraction mainly comprising ethyl acetate, ethanol, and some amount of water, which fraction is run off un the point below the point where ethyl acetate-rich phase from column A is introduced; withdrawing acetaldehyde-containing waste from the top or near the top of column to discard aldehyde and to return diethyl ether (taken from the bottom of column to scavenge aldehyde) into etherification reactor; (vi) purifying refined ethyl acetate in column E. ^ EFFECT: enabled removal acetaldehyde impurities to eliminate its negative effect on etherification catalyst. ^ 28 cl, 1 dwg, 13 tbl |
