| 摘要 |
PROBLEM TO BE SOLVED: To provide a plant for purifying acrolein present in the gaseous mixture of acrolein, water, an acid and non-condensing maters. SOLUTION: This plant comprises a cooling column 1 having a means 2 for feeding the flow of a feed gas and a condensing apparatus 3, 3A and 3B having a means for feeding gas to the top of the cooling column 1. In the first stage, the feed gas flow containing acrolein which is generated e.g. by the gas phase oxidation of propylene to acrolein is fractionated into a gaseous distillate and a liquid flow in the cooling column 1. Wherein, the temperature of the liquid flow at the bottom of the column is equal to or lower than the condensation temperature of the flow of a feed gas, and the temperature difference does not exceed 20 deg.C. In the second stage, the gaseous distillate is condensed at a temperature lower than 20 deg.C to give a liquid fraction and a purified gaseous fraction. |
