A biomass gasification system with CO2-recycling was developed and examined using the thermal equilibrium model. Performance comparison was conducted against the conventional air gasification system. Sensitivity analyses were performed by varying the gasifier temperature from 750 degrees C to 950 degrees C and testing three kinds of rice husk as feedstock: As harvested, naturally dried, or torrefied. The proposed system produced 7.5 % higher efficiency than the conventional air gasification. Moreover, the system exhausted 302 g-CO2/kWh lower emission and in the form of high purity of CO2 stream that is favorable for sequestration process. The recycled CO2 from the gas turbine acted as an effective heat source for the gasifier as well as gasifying agent. The positive effect of CO2-recycling was more prominent at the lower gasifier temperature. The utilization of high quality feedstock, i.e. low moisture content and low O/C ratio, was favorable for optimizing the effect of CO2-recycling on the system efficiency. Under the examined conditions, the optimum conditions for gaining the highest system efficiency, 39,4%, were a gasifier temperature of 850 degrees C with CO2 recycling ratio of 0.87 and the torrefied feedstock. Application of carbon capture and storage process to the system at the optimum condition resulted in 1.75 kg-CO2/kg-dry-biomass negative carbon intensity with merely 6.5% efficiency penalty. These results show that the CO2-recycling gasification system is promising for effectively applying BECCS concept.