“…Besides assessing their availability, it is also equally important to understand the chemical characteristics of these SCG wastes in order to ensure their renewability. To begin with, Spent coffee grounds (SCG) wastes are primarily made up of cellulose and hemicellulose compounds (Wei et al, 2019;Ballesteros et al, 2014;Vardon et al, 2013), followed by significant amount of lignin, caffeine, fatty and amino acids, polysaccharides and polyphenols, flavonoids and Millard products, and tannins (Pujol et al, 2013;Campos-Vega et al, 2015;Atabani et al, 2019;Rivera et al, 2020;Espuelas et al, 2020;Zabaniotou & Kamaterou, 2019;Limousy et al, 2013;Mata et al, 2018;Cruz et al, 2012;Murthy & Naidu, 2012). Especially, these wastes contain 11.6%-13.2% of cellulose, 37.2%-41.0% of hemicellulose, and 22.2-34.94% of lignin (Potip & Wongwuttanasatian, 2018;Lee et al, 2017;Brunerová et al, 2019); and which varies along with coffee species and coffee preparation technique (Blinová & Sirotiak, 2019).…”