The present invention relates to a method for continuously operating a distillation column, which is designed to separate a mixture S, which contains essentially a substance A and a substance B, which boils significantly higher than substance A. In the method according to the invention, the reflux ratio is changed according to the feed flow and, at the same time, the energy input by means of the heat-transfer medium is changed proactively (so-called feed-forward control) by accounting for the feed flow by means of feed-forward control. At the same time, the bottom temperature is observed and the control structure is changed if the bottom temperature falls too far when the heat-transfer medium is reduced by means of the feed flow.