Oxytree Pruned Biomass Torrefaction: Process Kinetics

Abstract

Oxytree is a fast-growing energy crop with C4 photosynthesis. In this research, for the first time, the torrefaction kinetic parameters of pruned Oxytree biomass (<i>Paulownia</i> <i>clon</i> in Vitro 112) were determined. The influence of the Oxytree cultivation method and soil class on the kinetic parameters of the torrefaction was also investigated. Oxytree pruned biomass from a first-year plantation was subjected to torrefaction within temperature range from 200 to 300 °C and under anaerobic conditions in the laboratory-scale batch reactor. The mass loss was measured continuously during the process. The relative mass loss increased from 1.22% to 19.56% with the increase of the process temperature. The first-order constant rate reaction (<i>k</i>) values increased from 1.26 × 10^-5 s^-1 to 7.69 × 10^-5 s^-1 with the increase in temperature. The average activation energy for the pruned biomass of Oxytree torrefaction was 36.5 kJ∙mol^-1. Statistical analysis showed no significant (<i>p</i> < 0.05) effect of the Oxytree cultivation method and soil class on the <i>k</i> value. The results of this research could be useful for the valorization of energy crops such as Oxytree and optimization of waste-to-carbon and waste-to-energy processes.