Integrated gasification fuel cells (IGFCs) integrating high-temperature solid oxide fuel cell technology with CO₂ capture processes represents highly-efficient power systems with negligible CO₂ emissions. Flame burning with pure oxygen is an ideal method for fuel cell exhaust gas treatment, and this report describes experimental and numerical studies regarding an oxy-combustor for treating the exhaust gas of a 10 kW IGFC system anode. The applied simulation method was verified based on experiments, and the key performance indices of the combustor were studied under various conditions. It was determined that 315 K was the ideal condensation temperature to obtain flame stability. Under these pure oxygen flame burning conditions, CO was almost completely converted, and the dry mole fraction of CO₂ after burning was ≥ 0.958 when there was up to 5% excess O₂. Overall, 5% excess O₂ was recommended to maximize CO₂ capture and promote other environmental considerations. Additionally, the optimal tangential fuel jet angle to control the liner temperature was approximately 25°. The total fuel utilization had to be high enough to maintain the oxygen flame temperature of the anode exhaust gas below 1800 K to ensure that the system was environmentally friendly. The results presented herein have great value for designing IGFCs coupled with CO₂ capture systems.