BATCH DISTILLATION METHOD AND BATCH DISTILLATION COLUMN WITH SIDE DISCHARGE POINT

The invention provides a method for recovering a thermally unstable compound as main fraction from pharmaceutical waste or synthesis streams, comprising - providing a batch distillation column comprising a bottom discharge point (15), a top discharge point (8) and at least one side discharge point (16, 18) that is positioned between the bottom discharge point (15) and the top discharge point (8), - heating the pharmaceutical waste or synthesis stream at a pressure of less than 50 mbar in the batch distillation column (2), the pharmaceutical waste or synthesis stream comprising the thermally unstable compound, a low-boiling fraction with at least one component that has a boiling point that is lower than the boiling point of the thermally unstable compound, and a high-boiling fraction with at least one component that has a boiling point that is higher than the boiling point of the thermally unstable compound, - discharging a first running comprising at least a portion of the low-boiling fraction via the top discharge point (8) in the batch distillation column (2), - after discharge of the first running, simultaneous discharge of a main fraction comprising the thermally unstable compound via the side discharge point (8) and of a top fraction comprising at least a portion of the low-boiling fraction via the top discharge point (8).