From waste to renewable energy: Exploring the co-gasification of cashew nutshells and plastic waste

Abstract

The urgent need for decarbonization drives the search for renewable energy alternatives. This experimental study investigates the feasibility of co-gasifying polymeric waste and cashew nutshells (CNS) in a bubbling fluidized bed reactor. FTIR reveals that plastic mixture primarily comprises polystyrene, polycarbonate, polyethylene terephthalate, and polyamide; XRF indicates that CNS is predominantly composed of potassium (60.98 %), while plastic waste contains high chlorine (42.1 %). Elemental analysis shows CNS is rich in carbon (51.6 %) and oxygen (39.8 %). Co-gasification produces syngas with a mean lower heating value of 10.8 MJ/Nm3, mainly composed of nitrogen (60.7 %). The high nitrogen content dilutes the syngas energy, suggesting that optimizing reactor conditions and feedstock blending, such as chlorine reduction via pretreatment, may enhance high-energy gases like hydrogen and carbon monoxide. The findings highlight the potential of co-gasifying CNS and plastic waste for renewable energy production and provide a basis for future studies to improve process efficiency and scalability.