Potential Conversion of Plastic Waste in Old Landfill to Fuel

Abstract

This work aimed to investigate the potential of plastic waste in old landfill as a resource to produce pelletized RDF. Old landfill contents at different ages of 4-5, 5-10 and over 10 years old were excavated and sorted. The combustible part consisted mostly of plastics at 34.0, 21.9 and 22.1% at younger to the older age in order. The non-combustible part composted of soil-like material from 63.8 to 76.3% which made up of daily cover soil and organic debris. High calorific value of the plastic waste of 33.11-43.41 MJ/kg was not diluted by the mixing of binder. Heated compaction method was used in the formation of RDF pellets in this study. Bulk density was linearly increased with higher compaction pressure (R2 = 0.9655). Besides, the vertical compressive strength of the formed pellets increased by 82 kg/cm2 when the compaction pressure changed from 7 to 21 kg/cm2 and started to decrease when it was above 21 kg/cm2. Meanwhile the horizontal compressive strength was rather stable and appeared independent of the compaction pressure. Calorific value of the RDF produced was high because no binder of lower calorific value was used, enabling it to meet the specified European standard for its calorific value.