Pyrolysis characteristics, kinetics and thermodynamics of the plywood material in high-speed trains

Abstract

The pyrolysis characteristics, kinetics and thermodynamics of a typical plywood material, namely the Huangjinguomu plywood in high-speed trains in nitrogen were studied in the present study. It was indicated that three peaks occurred in the reaction rate curves. The pyrolysis process can be divided into three stages, namely stage 1: 0<a<0.1, stage 2: 0.1<a<0.7 and stage 3: 0.7<a<1. With the increase in the heating rate, the first and third peak reaction rate decreased, while the second peak reaction rate increased. The average reaction rate in stage 1 and throughout the entire pyrolysis process decreased. The average reaction rate in stage 2 increased. The average reaction rate in stage 3 remained almost constant. The second stage may be nominally considered to be a one-step reaction. The pyrolysis of the Huangjinguomu plywood was a non-spontaneous and endothermic process. The AG value maintained almost constant with the progressing of the thermal decomposition. The average values of AH, AG and AS were 191.55 kJ/mol, 139.29 kJ/mol and 92.93 J/(molK), respectively.