We previously simulated the fuel reactor behavior of a chemical looping combustion process. Here, we report on the effects of temperature on the fuel reactor behavior. We found that unburned fuel weight fraction was reduced by nearly half when the temperature increased from 690 0C to 950 0C indicating a substantial increase in the fuel conversion rate. The simulations also showed that the bubble size in the fuel reactor increases with temperature. This study clearly indicates the need to optimize the temperature in the fuel reactor with respect to the fuel conversion rate.