Hydrothermal co-carbonization of hazelnut and pistachio shells to hydrochar as potential energy source: Synergistic effects of process parameters on hydrochar characteristics

The synergistic effects of co-hydrothermal carbonization (co-HTC) of hazelnut and pistachio shells (HS and PS) were aimed to explore and the impacts of blending ratio of feedstocks and retention time on hydrochar characteristics were studied in detail. A remarkable synergistic increment revealed in terms of the mass yield, energy content, and carbon and nitrogen retentions. The higher energy parameters of co-hydrochars showed that coHTC application upgraded the fuel quality of the product. The support of co-HTC process for development of aromaticity and surface enriched with oxygenated functional groups was verified with FTIR spectrum. Anionic and cationic dye adsorptions were conducted to test the removal ability of both single and co-hydrochars. The possible adsorption mechanisms of the dyes were elucidated. This comprehensive research demonstrated that coHTC of HS and PS could be a promising pathway for designing high-performance products for energy and environmental fields.