Physicochemical properties and combustion kinetics of food waste derived hydrochars

In this work, simulated food waste (15% white bread, 15% palm dates (without seeds), 5% boiled egg (without shells), 20% spent tea leaves, 20% spent coffee ground, and 25% banana peel in parts weight) was subjected to hydrothermal carbonization (HTC) at 180, 200 and 220 degrees C for 120 min. The mass yield and energy yield of the resultant hydrochars viz. HTC180, HTC200, and HTC220 were 69.46, 68.50, 65.35% and 88.91, 87.68, 84.30%, respectively. Among the hydrochars produced, HTC220 had the highest heating value (HHV: 23.61 MJ/kg), while the food waste had a HHV of 18.17 MJ/kg. Activation energy for the combustion of food waste and HTC220 was determined by modelling the thermogravimetric data using the Arrhenius equation and was found to be in the range of 29.98 to 33.51 kJ/mol and 16.52 to 25.47 kJ/mol, respectively. The densification ratio for the three hydrochar samples varied slightly (1.28-1.29). The results indicate that the hydrochar produced from food waste could be a potential to substitute coal combustion.(c) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

In this study, simulated food waste was subjected to hydrothermal carbonization to produce hydrochars. The properties of the hydrochars, including mass yield, energy yield, heating value, and activation energy, were analyzed. The results indicate that the hydrochar produced from food waste has the potential to substitute coal combustion.