Thermochemical properties and life cycle assessment of waste spent coffee grounds

Abstract

Abstract Spent coffee grounds (SCGs) represent a widely available organic residue with significant potential for energy valorization. This study evaluates the feasibility of converting SCGs into fuel pellets. Thermochemical characterization indicated promising properties for energy recovery and informed the development of a subsequent life cycle assessment (LCA). A cradle-to-gate LCA, performed using the ILCD methodology, assesses four pelletization scenarios: a baseline grid-powered process, sun drying, photovoltaic electricity supply, and their combination.The results identify drying and transportation as the dominant contributors to environmental impacts. The combined sun drying and photovoltaic scenario achieves the lowest impacts across all assessed categories, reducing greenhouse gas emissions and fossil resource depletion by more than 50% compared to the baseline.A sensitivity analysis was conducted on key parameters, including moisture content (25%, 50%—baseline scenario, and 75%), electricity supply based on alternative European grid mixes, and transportation distance for both the collection of SCGs and the distribution of pellets. The analysis highlights the importance of balanced moisture content, the influence of electricity generation profiles, and the benefits of reduced transportation distances on overall environmental performance.A preliminary cost–benefit perspective is also presented to outline key economic considerations, forming the basis for a more detailed techno-economic assessment in future work.