A method and apparatus for distillative separation of a mixture comprising three or more components including at least one low boiler, at least one medium boiler, and at least one high boiler, the method comprising feeding the mixture of three or more components to a first distillation column, removing the at least one high boiler as a bottom fraction from the first distillation column, feeding a top fraction of the first distillation column to a second distillation column, removing the at least one medium boiler via a sidestream takeoff from the second distillation column, removing the at least one low boiler as a top fraction from the second distillation column, and feeding a bottom takeoff stream from the second distillation column to the first distillation column as a reflux, wherein the first and the second distillation columns have vertical dividing walls.