The Hydrochar Activation and Biocrude Upgrading from Hydrothermal Treatment of Lignocellulosic Biomass

The production of hydrochar and biocrude from hydrothermal treatment of lignocellulosic biomass is getting increasing attention, but the quality of hydrochar and biocrude need further improvement before utilization. Many attempts have been carried out on the hydrochar activation and biocrude upgrading. However, different methods play different roles on the property of hydrochar and biocrude, this topic received scant attention in recent review papers. Therefore, the influence of different activation methods on hydrochar property, and the potential application of hydrochar were summarized in this study. Meanwhile, the research progress on biocrude upgrading is reported. Besides, the techno-economic analysis of hydrochar and biocrude from hydrothermal treatment of lignocellulosic biomass are also discussed. Finally, the research needs and future directions on hydrochar activation and biocrude upgrading were proposed. This paper could provide insights for further studies on the utilization of hydrochar and biocrude.