Method of separating oxygen from an oxygen comprising gas, the method comprising the steps of: performing at least a first and a second period of oxygen separation, the first and the second period of oxygen separation each comprising the steps of guiding an oxygen comprising gas to the primary side of an oxygen separation device (12, 14), the oxygen separation device (12, 14) comprising an oxygen separation sorbent (16, 18), and generating a flow of oxygen enriched gas out of the oxygen separation device (12, 14) by creating a pressure difference between the primary side and the secondary side of the oxygen separation device (12, 14), and performing a cooling period between the first and the second period of oxygen separation, wherein the cooling period comprises the steps of guiding a flushing sorbate through the oxygen separation device (12, 14), the flushing sorbate having an adsorption energy e 1 with respect to the oxygen separation sorbent (16, 18), and guiding a cooling sorbate through the oxygen separation device (12, 14), the cooling sorbate having an adsorption energy e 2 with respect to the oxygen separation sorbent (16, 18), wherein the adsorption energy e 2 is lower with respect to the adsorption energy e 1, and wherein the step of guiding the flushing sorbate through the oxygen separation device (12, 14) and/or the step of guiding the cooling sorbate through the oxygen separation device (12, 14) is performed in dependence of the oxygen separation sorbent temperature such, that the step of guiding the flushing sorbate through the oxygen separation device (12, 14) and/or the step of guiding the cooling sorbate through the oxygen separation device (12, 14) is performed, if the temperature of the oxygen separation sorbent (16, 18) exceeds defined temperature values, whereas in case the temperature is within the limits of the oxygen separation specifications of the respective used oxygen separator, or oxygen separation sorbent, no cooling is performed, wherein the defined temperature values are chosen in dependence of the used oxygen separation sorbent (16, 18) and a substance to be sorbed. performing at least a first and a second period of oxygen separation, the first and the second period of oxygen separation each comprising the steps of guiding an oxygen comprising gas to the primary side of an oxygen separation device (12, 14), the oxygen separation device (12, 14) comprising an oxygen separation sorbent (16, 18), and generating a flow of oxygen enriched gas out of the oxygen separation device (12, 14) by creating a pressure difference between the primary side and the secondary side of the oxygen separation device (12, 14), and performing a cooling period between the first and the second period of oxygen separation, wherein the cooling period comprises the steps of guiding a flushing sorbate through the oxygen separation device (12, 14), the flushing sorbate having an adsorption energy e 1 with respect to the oxygen separation sorbent (16, 18), and guiding a cooling sorbate through the oxygen separation device (12, 14), the cooling sorbate having an adsorption energy e 2 with respect to the oxygen separation sorbent (16, 18), wherein the adsorption energy e 2 is lower with respect to the adsorption energy e 1, and wherein the step of guiding the flushing sorbate through the oxygen separation device (12, 14) and/or the step of guiding the cooling sorbate through the oxygen separation device (12, 14) is performed in dependence of the oxygen separation sorbent temperature such, that the step of guiding the flushing sorbate through the oxygen separation device (12, 14) and/or the step of guiding the cooling sorbate through the oxygen separation device (12, 14) is performed, if the temperature of the oxygen separation sorbent (16, 18) exceeds defined temperature values, whereas in case the temperature is within the limits of the oxygen separation specifications of the respective used oxygen separator, or oxygen separation sorbent, no cooling is performed, wherein the defined temperature values are chosen in dependence of the used oxygen separation sorbent (16, 18) and a substance to be sorbed.