Upgrading Refuse-Derived Fuel Properties From Reclaimed Landfill Using Torrefaction

Landfill resource reclamation or landfill mining offers an attractive option to harvest the primary materials remaining behind in landfills or open dump sites. After reclamation, the major fractions left after removing soil-like material are paper and plastic fractions, which can be used transformed to refuse-derived fuel (RDF) as a fuel. However, the variation of constituents in RDF causes to low-quality fuel derived from the reclaimed landfill. The torrefaction process is proposed here to upgrade the fuel properties in terms of heating value, energy density ratio, and hydrophobicity. A torrefaction oven was used to torrefy RDF from reclaimed landfill at a controlled temperature of 250, 300, and 300 degrees C and a residence time of approximately 30 min in an inert environment using Nitrogen gas. The experiment results showed an optimum torrefaction temperature of 250 degrees C, which resulted in the improved heating value of RDF by up to 14.12%, an increased energy yield of 107.78%, and an energy density ratio of 1.14. These results demonstrated greater energy yield from the torrefied RDF compared with raw RDF. The hydrophobic property of torrefied RDF was also improved with the torrefaction process due to low water adsorption capability of torrefied RDF that was evaluated to be only one-half of that of raw RDF. The fuel upgrading of RDF from reclaimed landfill achieved via the torrefaction process improved the fuel properties that offers its direct use or, in conjunction with other coal fuels, for power generation.