Journal: Bioresource Technology

Authors: Qiaozhi Zhang, Yang Cao, Mingjing He, Hanwu Lei, Hocheol Song, Daniel S. Alessi, Daniel C.W. Tsang

Abstract:

This study investigated the feasibility of a high-loading process with less water consumption for the valorization of wet biomass waste through hydrothermal carbonization (HTC) with and without N₂ pressurization from the views of water saving, carbon utilization, and energy recovery. The results revealed that reducing the liquid-to-solid ratio from 10 to 2.5 significantly improved carbon storage in hydrochar due to preferential carbon sequestration as the solid phase (59.9%) instead of being lost in the liquid phase (∼10%). The pressurized HTC process resulted in a higher stability hydrochar through the devolatilization of secondary char that was less stable, yet resulted in ∼10% 15% more carbon transformation to the gas phase. A cost-benefit analysis further demonstrated the potential of the high-loading HTC process for enhancing energy recovery while minimizing energy consumption during hydrochar production from high-moisture yard waste.

Keywords: Hydrothermal carbonization, Carbon storage, Water saving, Biomass densification, High-loading thermochemical process, Biochar/hydrochar, Waste management/recycling

DOI: https://doi.org/10.1016/j.biortech.2023.130211​