The performance of an integrated gasification combined cycle based power plant using a mixture of municipal solid waste (MSW) and coal was evaluated. The parametric sensitivities of avoidance in CO2 emission (ACE) and the energy return on energy investment (EROEI) were analyzed by MSW-coal ratio, gasifier temperature, and the air supplied for gasification as the independent variables. The data on ACE and EROEI simulated by Aspen Plus at different combinations of input parameters, pre-set using the Box-Behnken type design of experiments, were employed. Through response surface methodology, a valid model demonstrating the strong influence of MSW-coal ratio and gasifier temperature on both the ACE and EROEI was developed.