Patent ID: 7169267

Claim:
A process for the separation of C 5 + cuts by distillation into a low-boiler, a medium-boiler and a high-boiler fraction in at least one dividing-wall column, in which a dividing wall is arranged in the longitudinal direction of the column with formation at an upper, common column region, a lower, common column region, a feed part with rectifying section and stripping section, and a withdrawal part with rectifying section and stripping section, with feed of the C 5 + cut into the central region of the feed part, discharge of the high-boiler fraction from the bottom of the column, discharge of the low-boiler fraction via the tap of the column, and discharge of the medium-boiler fraction from the central region of the withdrawal part, wherein the dividing ratio of the liquid reflux at the upper end of the dividing wall is set in such a way that the proportion of high-boiling key components in the liquid reflux over the stripping section of the withdrawal part at the upper end of the dividing wall is from 10 to 80% of a limit value allowed in the medium-boiler fraction, and wherein a heating power in an evaporator at the bottom of the at least one dividing-wall column 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 is from 10 to 80% of the limit value allowed in the medium-boiler fraction.