Qualitative assessment of beach wrack and the influence of pretreatment methods on fuel characterization for energy production

The accumulation of beach wracks poses significant challenges to coastal management, particularly in tourist areas, affecting environmental quality and aesthetics. This study explores the qualitative characteristics of beach wrack as a biofuel source for combustion appliances. Samples collected from beaches in Veneto, Italy, were analyzed according to EN ISO standards for solid biofuels. Proximate and ultimate analysis, heating value, and ash melting behaviour were determined. Raw samples (BW-R) exhibited high moisture content (77%), a substantial ash content (44%), and low heating value (10.7 MJ kg-1), making them unsuitable for direct energy applications. Pretreatments were performed to enhance the properties of the material. One portion was mechanically sieved (BW-S) to remove sand, while another was sieved and washed (BW-SW) to remove the remaining salt and sand. Sieving reduced the ash content to 24% and increased the heating value to 15.3 MJ kg-1. The key improvements came from washing and sieving, which lowered ash content to 13% and increased heating value to 18.1 MJ kg-1. Washing also raised the ash deformation temperature to 1,290 °C, enhancing thermal stability. Pretreatments increased C and H content while reducing S and O, with no significant change in N. Due to high ash content, mixing with sawdust was necessary, resulting in mixtures showing better properties: 4.0% ash for Mix30 (30% beach wrack, 70% sawdust) and 6.9% for Mix50 (50% each) and increased heating values. However, challenges remain in converting beach wrack into viable fuel due to material losses during pretreatment, high costs, and environmental concerns from plastics.