The invention relates to a method for separating chlorine from a gaseous anode outlet stream mass flow of an electrochemical cell reactor. In a first aspect, the method makes use of an absorption step, wherein an anode outlet stream mass flow of the electrochemical cell reactor is exposed to an organic solvent being essentially immiscible with water for achieving an exergy-efficient separation of chlorine and hydrogen chloride. In a further aspect, the method makes use of absorption step, wherein the anode outlet stream mass flow is exposed to an ionic liquid, wherein the hydrogen chloride is dissolved in said ionic liquid, thereby forming a gas flow containing essentially chlorine and a solution mass flow comprising the ionic liquid and the hydrogen chloride. The hydrogen chloride is desorbed from the solution mass flow in a desorption step. In another aspect, the method makes use of a distillation step, wherein the anode outlet stream mass flow is separated at a static pressure of at least 2 bar for an exergy-efficient separation.