In this study, the combustion experiment of coal and torrefied EFB((Empty Fruit Bunch) mixture was conducted to assess the environmental impact of the RPS system. The torrefied EFB was obtained at torrefaction temperature of 300 ℃ and 6.3 min residence time. The proximate analysis of the coal and torrefied EFB was conducted along with the gas analysis of the product gases. The combustion experiment was done in isothermal and non-isothermal conditions in which the temperature was fixed at 900 ℃ and residence time of 20 min for isothermal experiment while the temperature was varied from 120 ℃ to 900 ℃ for non-isothermal experiment. From this study, it was obtained that the concentration of CO2, CO, CH4 and CxHy rapidly increased with the increase in the amount of torrefied EFB in isothermal condition. To its contrast, the concentration of CO2, CO, CH4 and CxHy decreased with increase in the amount of torrefied EFB in non-isothermal experiment.