To provide a cost effective system and method which allows a regenerative oxidant heater design which minimizes the loss of costly oxygen typically caused by internal leakage between the air and gas sides of a regenerative oxidant heater, and which simultaneously aids in achieving a balance between acceptable heat exchange within the oxidant heater and reasonable oxidant heater exit gas temperatures.

A primary oxidant fan 31, for feeding primary oxidant flow to a regenerative oxidant heater 10, is located before (or upstream from) the regenerative oxidant heater 10. A primary oxidant mixer 32 for injecting oxidant into the primary oxidant stream 25, is located after (or downstream from) the regenerative oxidant heater 10.