Insights into the Influence of Methanolysis on the Physical-Chemical Structure Variation, Pyrolysis Kinetics and Thermodynamic of Wheat Straw

Alkanolysis had become the promising approach for extracting organic compounds of lignocellulosic biomass, but its effect on the pyrolysis properties of biomass received little attention. In this context, the influence of methanolysis pretreatment on the physical-chemical structure variation, pyrolysis kinetics and thermodynamic of wheat straw (WS) was investigated using four multiple direct tools. C element content of pretreated WS greatly increased and oxygen-containing functional groups was extracted, such as C-O bonds. Scanning electron microscope (SEM) result implied that pretreated WS exhibited the existence of some pore structures. Thermal decomposition behaviors of WS and pretreated WS were conducted by Thermogravimetric analyzer (TGA) at the heating rate of 10, 20, and 30 oC/min, respectively. Three model-free methods such as Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), and Starink were applied to evaluate the pyrolysis kinetics and thermodynamics parameters of three samples. The average Ea values obtained using three model-free methods for R280 oC were higher in comparison to WS and R240 oC. Combined with thermodynamic data analysis of three samples, R280 oC required more external energy for pyrolysis process due to more existence of lignin. This research would provide the new understandings for the pyrolysis process of liquefaction residue of biomass