Abstract: The invention relates to an integrated device for separating air and heating a gas in the air resulting from said air separation, comprising: an air separation device (9); a heat exchanger (13, 43); a channel for conveying the gas in the air to the heat exchanger; and a channel for conveying water to the heat exchanger, the water-conveying channel being connected to the water inlet or water outlet of a water preheat exchanger (5) or a water deaerator (27). According to the invention, the preheat exchanger and/or the deaerator are connected to an oxy-combustion boiler (19) in order to convey water to and from the boiler, said boiler also being connected to the separation device in order to receive an oxygen-enriched gas (17).