Continuous isolation of alpha,beta-unsaturated aldehyde, especially citral, used as fragrance or intermediate by rectifying crude mixture in feed and discharge columns coupled to prevent cross-mixing of vapor and condensate

摘要

In continuous isolation of alpha,beta-unsaturated aldehyde (I) by rectification, crude mixture is fed into feed column above concentration zone (C) and below separation zone (S). Upper combining column (U) and lower combining column (L) with bottom heater communicate with top of C and bottom of S respectively and with discharge column (D). (I) is discharged from side of D and lower and higher boiling compounds respectively from top of U and sump of L.