Study on the thermal stability and degradation kinetics of the historical wood: restoration residues collected from Chinese heritage buildings.

Thermal decomposition behavior and kinetics of four kinds of Chinese heritage architectural wood were investigated by thermogravimetric analysis. Experiments were carried out in air atmosphere up to 600°C. The thermal degradation process of historical wood involved a two-step reaction kinetics, consisting of a low-temperature stage (230–370°C) and a high-temperature stage (370–485°C). Distributed activation energies determined using Coats-Redfern method and the first-order model (O₁) have optimum fitness compared with nth-order model functions. The lignocellulosic components of white pine and red pine have similar thermal stability, spruce has the slowest combustion rate or best thermal stability, and the reactivity of charcoal and lignin with oxygen of nanmu was higher than that of other three types of historical wood. The activation energy of four historical wood species is lower than that of most fresh wood and varied from 75.10 to 83.39 kJ/mol in the first stage and 10.75 to 15.97 kJ/mol in the second stage. [ABSTRACT FROM AUTHOR]