Physicochemical characteristics of rubberwood biomass and its thermal decomposition kinetics for thermochemical conversion applications.

Thailand has plentiful rubberwood biomass for biofuel and bioenergy applications, as well as for carbon material production. One of the keys to choosing a biomass conversion process is its effects on the physicochemical properties. In addition, thermochemical conversion of biomass also requires knowledge of its thermal decomposition behavior and kinetics for reactor design; and specification of operating conditions. Thus, the aims of this research were to explore the physicochemical properties of rubberwood biomasses (RWBs) generated alternatively from branches, trunks, and roots. The rubberwood biomass with the best energy properties was then selected to investigate its thermal decomposition behavior and kinetics. The physicochemical properties of RWBs determined were the gross and elemental components, energy properties, lignocellulosic components, and major noncombustible elements. Thermal decomposition observations were carried out by using the thermogravimetric analyzer under a nitrogen atmosphere at heating rates of 5, 10, 20, and 30 °C min−1. The kinetic analysis was conducted by applying the iso-conversional model-free methods of Friedman, Kissinger–Akahira–Sunose (KAS), and Ozawa–Flynn–Wall (OFW). Based on statistical analysis, the results highlighted that the trunks (RTT) possessed the best energy properties. The lignocellulosic and elemental components of RWBs had small differences. The activation energy derived from iso-conversional methods demonstrated consistency with previous studies. The activation energies were in the ranges 159.11–210.61, 168.89–175.06, and 169.96–176.01 kJ mol− 1 according to the Friedman, KAS, and OFW methods, respectively. These explorations are useful for applying the RWB as feedstock in torrefaction and pyrolysis applications. [ABSTRACT FROM AUTHOR]