Wet torrefaction of biomass waste into value-added liquid product (5-HMF) and high quality solid fuel (hydrochar) in a nitrogen atmosphere

In this research, we conducted a comprehensive investigation into the influence of reaction conditions on the WT process, evaluating its effects on the surface morphology and elemental composition of the resulting hydrochar, as well as on the formation of value-added liquid products, such as 5-hydroxymethylfurfural (5-HMF). During the course of our study, we utilized wood cellulose pulp residue (WCPR) as the feedstock and subjected it to WT in a nitrogen atmosphere. This process encompassed a temperature range of 180–260 °C, H2O/WCPR ratios ranging from 10 to 25, and reaction durations spanning from 15 to 60 min. Our findings unequivocally revealed that the reaction conditions during the WT of WCPR significantly influence the properties of the resulting hydrochar and the distribution of liquid products. Elemental and proximate analyses showed that as the reaction temperature and time increased during the WT of WCPR, the hydrochar composition experienced significant changes, including an increase in carbon content and a reduction in oxygen content.