Method and device for carrying out the distillative separation of C5+ cuts

摘要

A process is proposed for the separation of C₅₊ cuts by distillation into a low-boiler (A), a medium-boiler (B) and a high-boiler fraction (C) in one or more dividing-wall columns (TK), in which a dividing wall (T) is arranged in the longitudinal direction of the column with formation of an upper, common column region ( 1 ), a lower, common column region ( 6 ), a feed part ( 2, 4 ) with rectifying section ( 2 ) and stripping section ( 4 ), and a withdrawal part ( 3, 5 ) with rectifying section ( 5 ) and stripping section ( 3 ), with feed of the C₅₊ cut (A, B, C) into the central region of the feed part ( 2, 4 ), discharge of the high-boiler fraction (C) from the bottom of the column, discharge of the low-boiler fraction (A) via the top of the column, and discharge of the medium-boiler fraction (B) from the central region of the withdrawal part ( 3, 5 ), wherein the dividing ratio of the liquid reflux at the upper end of the dividing wall (T) is set in such a way that the proportion of high-boiling key components in the liquid reflux over the stripping section ( 3 ) of the withdrawal part at the upper end of the dividing wall (T) is from 10 to 80%, preferably from 30 to 50%, of the limit value allowed in the medium-boiler fraction (B), and wherein the heating power in the evaporator at the bottom of the dividing-wall column (TK) is set in such a way that the concentration of the low-boiling key components in the liquid at the lower end of the dividing wall (T) is from 10 to 80%, preferably from 30 to 50%, of the limit value allowed in the medium-boiler fraction (B).