Title:
Physicochemical Changes of Olive Stone in a Pilot-scale Downdraft Gasifier
Author(s):
Garrido, L., Cuevas, M., Ramírez, E., Sánchez, S.
Document(s):
Paper
Poster
Abstract:
Olive stone is a lignocellulosic by-product widely generated in the European olive oil industry and commonly used as a biofuel. Besides direct combustion, it can also be gasified to produce synthesis gas and biochar with potential applications in energy, agriculture, and wastewater treatment. This study investigated the gasification of fragmented olive stones (endocarps) in a pilot-scale fixed-bed downdraft gasifier, focusing on the physicochemical transformations occurring along the reactor bed. Biomass samples were collected at four reactor heights corresponding to the drying, pyrolysis, oxidation, and reduction zones. Several properties were analysed, including particle size distribution, bulk density, higher heating value (HHV), and moisture adsorption capacity. The results showed that biomass properties strongly depended on reactor position. Biochars obtained from the pyrolysis zone exhibited the highest HHV due to their increased carbon content and lower oxygen and ash contents. In addition, cellulose and hemicellulose contents decreased progressively along the reactor, while lignin concentration increased, promoting carbon enrichment of the solid phase. The pyrolysis zone also showed the lowest moisture adsorption capacity, with a 35% reduction compared to raw olive stone. Overall, the results identify the pyrolysis zone as the most suitable region for producing high-quality biochar for energy applications.
Keywords:
downdraft gasifier, syngas, biochar, olive stone
Topic:
Biomass Conversion for Bioenergy
Subtopic:
Gasification for synthesis gas production
Event:
34th European Biomass Conference and Exhibition
Session:
4BV.5.22
Pages:
601 - 604
ISBN:
978-88-89407-27-1
Paper DOI:
10.5071/34thEUBCE2026-4BV.5.22
Price:
FREE
