Control method for a cryogenic rectification

The invention relates to a method for controlling the capacity of a cryogenic rectification plant, in which a fluid in a working at higher pressure column (1) of a cryogenic rectification plant is passed, which the working at higher pressure column (1) and a lower pressure operating the column (2), and wherein the liquid from the sump of the higher pressure column (1) is passed into the lower pressure column operating at (2). The method is characterized in that the amount withdrawn from the sump of the higher pressure column (1) and of working at a low pressure column (2) is supplied to the liquid, via a flow control (4) is controlled, wherein a manipulated variable for the flow control is set to a desired flow rate (4).