Converting coffee silverskin to value-added products by a slow pyrolysis-based biorefinery process

This work aims to transform coffee silverskin (CSS), the only waste from roasting process, that worldwide amounts about 76 million kg/year, into value-added products within an integrated slow pyrolysis process. The study, performed at 280 °C, 400 °C and 500 determined potential applications of resulting fractions. Biochar has been studied as adsorbent organic pollutants in water, using methylene blue (MB) methyl orange (MO), which are respectively cationic anionic aromatic dyes, model compounds, with biochar giving highest removal values, 98% MB 40% MO. Moreover, CSS could be used obtain renewable energy its combustion, 22.6–24.2 MJ/kg calorific values. liquid fraction a source caffeine, among phenolics, aqueous phase presenting concentration caffeine (14.3 g/L). Concerning gas fraction, it heat for biomass drying before pyrolysis. Hence, use described would allow zero-waste achieved industry, thus promoting green circular economy production chemicals materials biorefinery context.