Pyrolysis and gasification studies of model refuse derived fuel (RDF) using thermogravimetric analysis

Processing Municipal Solid Waste (MSW) into a Refuse Derived Fuel (RDF) reduces experimental variability and improves handling. This study analyzes the pyrolysis of individual components to define the model components that mimic real RDF. Size reduction and effective mixing of nine components of model RDF composition allow for reproducible results in lab scale experiments. Selected individual components as well as the model RDF composite are converted by pyrolysis and gasification at 800 degrees C with a 20 K/min heating rate. The pyrolysis results show that the decomposition profile, product yields, heat of decomposition, and gas composition of the model RDF can be predicted by adding the corresponding values of the individual components in the required proportions. The inorganic content of the individual component chars is found to have a profound effect on the gasification reactivities. Potassium and calcium have the largest catalytic effect during gasification, while silicon and phosphorous inhibit gasification. Potassium mobility and redistribution from orange peels in the model RDF to the other components is determined to be chiefly responsible for the synergistic gasification profile of the char. Furthermore, synergy is observed at different particle size ranges (< 106 mu m and 0.6-0.8 mm) tested. However, the extent of synergy varies in the two cases leading to different reaction times for complete conversion.