RT Journal Article
T1 Sequential cascade biorefinery for the valorization of spent coffee grounds: Energy, biodiesel, furfural, and biochar production
A1 Loaiza Rodríguez, Javier Mauricio
A1 Palma López, Alberto
A1 García Domínguez, Juan Carlos
A1 Díaz Blanco, Manuel Jesús
A1 Alfaro Martínez, Ascensión
AB This study presents a sequential biorefinery approach for the integrated valorization of spent coffee grounds (SCG) within a circular economy framework. The process comprises multiple operational units. Initially, SCG are pelletized for direct combustion, demonstrating promising energy potential. In the second unit, coffee oil is extracted via Soxhlet using hexane, isopropanol, and ethanol, and subsequently converted into biodiesel through transesterification, yielding a biofuel with a favorable fatty acid profile. The third unit involves ultrasound-assisted cold alkaline extraction (CAE) of the residual solid to selectively recover hemicelluloses with minimal degradation. Optimal CAE conditions (40 °C, 90 min, 100 g L−1 NaOH) enhanced hemicellulose yield while maintaining high calorific value (21.529 kJ kg−1), comparable to the raw material (21.560 kJ kg−1). The hemicellulose-rich liquor was subjected to acid hydrolysis for furfural production, with maximum yield (590.3 mg L−1) achieved under central experimental conditions (2% acid, 160 °C). The solid residue from hydrolysis underwent pyrolysis to produce biochar. Kinetic analysis of the pyrolysis process using the Flynn–Wall–Ozawa method on TGA data enabled determination of activation energy without assuming a specific reaction model. The results confirm the feasibility of integrating thermochemical and biochemical pathways for SCG valorization, supporting the development of sustainable biorefineries and contributing to renewable energy and chemical production within circular economy strategies.
PB Elsevier
SN 2589-014X (electrónico)
YR 2026
FD 2026
LK https://hdl.handle.net/10272/28280
UL https://hdl.handle.net/10272/28280
LA eng
NO Loaiza, J. M., Palma, A., García, J. C., Díaz, M. J., & Alfaro, A. (2026). Sequential cascade biorefinery for the valorization of spent coffee grounds: Energy, biodiesel, furfural, and biochar production. Bioresource Technology Reports, 34, 102754. https://doi.org/10.1016/j.biteb.2026.102754
NO The authors want to acknowledge the financial support from EPIT- Feder 2021–2027, University of Huelva, “Cascade biorefinery from agroforestry waste and energy crops within the framework of the cir cular economy” (EPIT1382023). And Spanish Ministry of Science, Innovation and Universities, Grant proyect: “Forest waste and high productivity hardwoods species hydrolytic and thermochemical refinery for obtaining value-added chemicals”, (REF: MICIIN PID2020- 112875RB-C21), and Dr. Javier Mauricio Loaiza thanks a the co-funded by Junta of Andalusia (Spain) through post-doctoral Grant No. DC 21_00664.
DS Repositorio Institucional de la Universidad de Huelva
RD 14 jul 2026