Unlocking the energy potential of coffee waste: pretreatment effects on anaerobic codigestion efficiency.
REIS, Thiago Medeiros dos; LIRA, Taisa Shimosakai de; CASSINI, Servio Tulio Alves; OLIVEIRA, Jairo Pinto de; PINOTTI, Laura Marina.
REIS, Thiago Medeiros dos; LIRA, Taisa Shimosakai de; CASSINI, Servio Tulio Alves; OLIVEIRA, Jairo Pinto de; PINOTTI, Laura Marina.
Abstract: Coffee, one of the world's most consumed beverages, generates significant amounts of organic waste, which is rich in lipids and biodegradable matter, making it suitable for biogas generation via anaerobic digestion. This study evaluated the biochemical methane potential (BMP) of treated and untreated domestic spent coffee grounds (SCG) and industrial coffee husks (CH) in co-digestion with food waste, using sludge as inoculum. Batch reactors were operated under mesophilic conditions (35 ± 2 °C) for 20 days with varying substrate proportions. The highest methane yields were achieved with 50% treated spent coffee grounds (400 NmL/gVS) and food waste (600 NmL/gVS), while untreated residues exhibited lower performance due to their recalcitrant structure, unfavorable carbon-to-nitrogen (C/N) ratio, and suboptimal pH. Chemical pretreatment reduced lignin content by 38.92% in spent coffee grounds and 44.6% in coffee husks, significantly enhancing biodegradability. The optimal C/N ratio ranged between 20 and 30:1, with pH control being crucial for process efficiency. Treated spent coffee grounds consistently outperformed husks in methane generation. These findings underscore the critical role of pretreatment in enhancing biodegradability and optimizing anaerobic digestion efficiency, reinforcing the viability of coffee residues as a renewable energy source.
@article={003305451,author = {REIS, Thiago Medeiros dos; LIRA, Taisa Shimosakai de; CASSINI, Servio Tulio Alves; OLIVEIRA, Jairo Pinto de; PINOTTI, Laura Marina.},title={Unlocking the energy potential of coffee waste: pretreatment effects on anaerobic codigestion efficiency},journal={Energy Sources Part A: Recovery Utilization and Environmental Effects},note={v. 48, n. 1, p. 2669600 + Supplemental material},year={2026}}