Can coffee grounds be considered as a potential for green energy production?

Coffee is one of the most popular beverages in the world. Over 50% of this mass is discarded after use, becoming a significant waste source known as spent coffee grounds (SCG). SCG usage as a raw material for biogas production emerges with great potential. In this study, we investigated the biochemical composition of SCG and its potential as a green energy source. We demonstrated that SCG can produce 0.1559 Nm
³
CH4/kg COD and that the extraction of polyphenols from the substrates can increase this production by almost 100%. In contrast, acid treatment using HCl showed no effect on gas production from this biomass.