Production and characterisation of fuel pellets from wood residues and selected fractions of sorted household waste

Abstract

This study evaluates the feasibility of producing refuse-derived fuel (RDF) pellets from sawdust, wood residues derived from pruned branches, and sorted household waste fractions (laminated milk cartons and plastic labels/films). Feedstocks were pre-treated and blended at ratios ranging from 7:3 to 10:0, and hot-compressed at temperatures of 110-200°C (with additional trials conducted up to 250°C). The evaluated parameters included higher heating value (HHV), pellet density, moisture content, ash content, and mechanical durability; and the results were compared with Japanese (JP), Korean (KR), European (EU) standards. Process windows that consistently yielded well-formed pellets that met quality requirements were an 8:2 ratio of sawdust to -derived binder at 150-200°C and a 9:1 of wood residues from pruned branches to bottle labels at 120-150°C. Most samples exhibited moisture contents below 10%, mechanical durability of at least 97%, and HHVs ranging from 16.85 to 24.68 MJ/kg. Several blends showed ash contents exceeding the residential-use limits specified by JP and EU standards, but remained suitable for industrial use and co-firing according to KR standards. This approach contributes to energy recovery and value addition for difficult-to-recycle waste streams, offering significant economic and environmental benefits.