A system of recycle oxy-fuel combustion comprising: an oxidant heater for recycling waste heat from a boiler and cooling flue gas from said boiler having an internal sector arrangement comprising: a flue gas side consisting of a sector, through which a flue gas stream having a gas pressure, flows away from a boiler having a gas exit as said flue gas stream leaves said gas exit; and a counterflowing combustion oxidant side, said combustion oxidant side being comprised of: at least one secondary combustion oxidant sector through which an oxygenated secondary combustion oxidant stream flows toward the boiler, said secondary combustion oxidant stream having a gas pressure; and at least two primary combustion oxidant sectors through which a pressurized cold primary combustion oxidant stream flows toward the boiler; said primary combustion oxidant stream having a gas pressure greater than that of said secondary combustion oxidant stream and said flue gas stream; wherein two of said at least two primary combustion oxidant sectors are positioned adjacent to both the flue gas side and to said at least one secondary combustion oxidant sector; and wherein said at least one secondary combustion oxidant sector is located between said at least two primary combustion oxidant sectors; characterized by a primary oxidant fan for feeding primary oxidant flow to said oxidant heater positioned upstream from said oxidant heater; and a primary oxidant mixer for introducing oxygen into said primary combustion oxidant stream positioned downstream from said oxidant heater. an oxidant heater for recycling waste heat from a boiler and cooling flue gas from said boiler having an internal sector arrangement comprising: a flue gas side consisting of a sector, through which a flue gas stream having a gas pressure, flows away from a boiler having a gas exit as said flue gas stream leaves said gas exit; and a counterflowing combustion oxidant side, said combustion oxidant side being comprised of: at least one secondary combustion oxidant sector through which an oxygenated secondary combustion oxidant stream flows toward the boiler, said secondary combustion oxidant stream having a gas pressure; and at least two primary combustion oxidant sectors through which a pressurized cold primary combustion oxidant stream flows toward the boiler; said primary combustion oxidant stream having a gas pressure greater than that of said secondary combustion oxidant stream and said flue gas stream; wherein two of said at least two primary combustion oxidant sectors are positioned adjacent to both the flue gas side and to said at least one secondary combustion oxidant sector; and wherein said at least one secondary combustion oxidant sector is located between said at least two primary combustion oxidant sectors; characterized by a primary oxidant fan for feeding primary oxidant flow to said oxidant heater positioned upstream from said oxidant heater; and a primary oxidant mixer for introducing oxygen into said primary combustion oxidant stream positioned downstream from said oxidant heater. a flue gas side consisting of a sector, through which a flue gas stream having a gas pressure, flows away from a boiler having a gas exit as said flue gas stream leaves said gas exit; and a counterflowing combustion oxidant side, said combustion oxidant side being comprised of: at least one secondary combustion oxidant sector through which an oxygenated secondary combustion oxidant stream flows toward the boiler, said secondary combustion oxidant stream having a gas pressure; and at least two primary combustion oxidant sectors through which a pressurized cold primary combustion oxidant stream flows toward the boiler; said primary combustion oxidant stream having a gas pressure greater than that of said secondary combustion oxidant stream and said flue gas stream; at least one secondary combustion oxidant sector through which an oxygenated secondary combustion oxidant stream flows toward the boiler, said secondary combustion oxidant stream having a gas pressure; and at least two primary combustion oxidant sectors through which a pressurized cold primary combustion oxidant stream flows toward the boiler; said primary combustion oxidant stream having a gas pressure greater than that of said secondary combustion oxidant stream and said flue gas stream; wherein two of said at least two primary combustion oxidant sectors are positioned adjacent to both the flue gas side and to said at least one secondary combustion oxidant sector; and wherein said at least one secondary combustion oxidant sector is located between said at least two primary combustion oxidant sectors; a primary oxidant fan for feeding primary oxidant flow to said oxidant heater positioned upstream from said oxidant heater; and a primary oxidant mixer for introducing oxygen into said primary combustion oxidant stream positioned downstream from said oxidant heater.