Effect of molasses binder on the pelletization of food waste hydrochar for enhanced biofuel pellets production

In this study, molasses was used as binder for the pelletization of hydrochar to enhance the fuel and storage properties. The basic fuel properties of the pellets including the proximate analysis and the higher heating value (HHV) were evaluated. The compressive strength was assessed and binding surface of the pellets was analyzed by SEM and ZIESS microscope, and the moisture uptake and combustion properties were analyzed by TG. The results suggested that, with molasses addition from 10% to 20%, the HHV of pellets was decreased while the mass density and energy density of the pellets significantly increased to a range of 947.1-1301.9 kg/m(3) and 23.55-33.40 GJ/m(3), respectively. The sold bridge formation from molasses by recrystallization of sugar enhanced the tensile strength of the pellets, with 260-20% exhibiting the highest value (6.44 MPa), while the maximum load distance of the molasses pellets decreased. In addition, the molasses binder also delayed the moisture uptake rate and slightly increased the EMC content which depended more on the HTC temperature. The combustion analysis showed that the molasses binder decreased the ignition temperature (17-42 degrees C), and the maximum mass lose rate decreased about 0.6-0.8%degrees C, indicating that molasses pellets was combusted in a moderate process. The results suggested that molasses binder assisted pelletization of hydrochar from food waste had potentials for the preparation as solid biofuel.