Pyrolysis kinetics of raw/hydrothermally carbonized lignocellulosic biomass



Pyrolysis of lignocellulosic biomass was performed in a thermogravimetric analyzer at temperature ranging 105 to 800°C at the heating rates of 5, 10, and 20°C min−1. Samples of raw loblolly pine and hydrothermally carbonized loblolly pine were used as feedstocks in pyrolysis study. Thermogravimetric experiments showed that more significant decomposition occurred in the pyrolysis of raw biomass compared with hydrothermally carbonized biomass, so that the raw biomass displayed a much higher volatile content and lower fixed carbon content. Derivative thermogravimetry also showed that one major decomposition reaction took place at a specific heating rate for two biomass feedstocks. Assuming that the decomposition obeys first-order kinetics, kinetic parameters of biomass pyrolysis were determined using two methods proposed by Kissinger and Ozawa, respectively. Both methods gave analogous values of activation energy for raw and hydrothermally carbonized biomass. This study gave further confirmation that the hydrothermal carbonization (HTC) process transforms lignocellulosic biomass into an intermediate feedstock with favorable properties for thermochemical applications. © 2012 American Institute of Chemical Engineers Environ Prog, 2012