Abstract This work presents first-of-a-kind results on the enhanced oil recovery (EOR) by CO 2 stream of oxy-fuel-fired circulating fluidized bed (CFB) boilers for Constant Furnace Size Scenario and Constant Thermal Power Scenario. The CO 2 flow rate, the associated impurities and the furnace thermal properties are investigated. The total mass flow rate of the EOR gas in Constant Furnace Size Scenario for the oxy-fuel case of 70% O 2 concentration becomes more than 2.6 times of the one with 29% O 2 concentration. The oxy-fuel CFB usage for EOR offers the opportunity of reconfigurable manufacturing system (RMS) where the CO 2 production capacity is flexible to market demand. While the increased CO 2 mass flow rates at elevated O 2 concentrations is in favor of Constant Furnace Size Scenario, the mass flow rates of the impurities of O 2 , CO and H 2 O also increase leading to higher costs for gas cleaning before sending the CO 2 stream for EOR injection. The relatively low outgoing CO level in addition to considerably lower furnace CO maxima compared to the other scenario are merits of Constant Thermal Power Scenario.