This research will focus on the co-combustion of low-quality coal with biomass (rice husk) and Refused Derived Fuels (RDF). Thermogravimetric analysis (TGA) and combustion tests were performed to determine the co-combustion characteristics of various coal-RDF and coal-rice husks blends, at mass ratios of 95:5, 90:10, 85:15, and 80:20, along with the investigation of their physicochemical characteristics. The TGA was carried out from an ambient temperature of 35°C until 900°C in both an inert and oxidative environment. The thermal degradation profile and activation energies (Ea) of the blended samples were obtained from the TGA experiment. The Ea for various coal-rice husk and coal-RDF mixtures were calculated using the Coats-Redfern method. The physicochemical characteristics analysis revealed that the low-rank coal has a gross calorific value (GCV) of 4.813 cal/g. The rice husk and RDF samples were found to have lower (GCV) of 3.358 cal/g and 3.614 cal/g, respectively. The combustion test was carried out using a laboratory-scale fluidized bed furnace. It was found that the kinetics of combustion shows that the more the mixture of biomass, both rice husk and RDF, the lower the activation energy of combustion, this can mean that in a mixture of cofiring coal and biomass, the mixture will burn more easily due to the presence of higher volatile matter than coal. The cofiring stage of each sample shifts to the lower temperature from the coal, this is because rice husk and RDF have more moisture content and have less fixed carbon than coal, moisture content is more easily degraded thermally and burns at low temperatures.