The invention relates to a gas/liquid separation column extending mainly along a vertical axis and comprising an external wall delimiting an internal space in which are arranged at least one first contact member in which the liquid and the gas are brought into contact and at least one dispensing device configured to collect the liquid resulting from the first contact member and to distribute it to a second contact member. At least one box for separating a two-phase fluid is arranged in the internal space of the column between the first contact member and the dispensing device against the wall of the column fed by a duct which passes through a wall of the separation box.