Kinetics and thermodynamics of beech wood pyrolysis mechanism

Abstract

ABSTRACT Beech wood pyrolysis is capable of providing fuel as well as invaluable materials of industrial importance besides being CO2-neutral. Mechanistic insights revealed by the kinetics and thermodynamics of beech wood pyrolysis may not only lead to controlling the process but also to optimize its efficiency. However, the literature lacks in some reliable and physically meaningful mechanistic insights into beech wood pyrolysis process. Moreover, beech wood pyrolysis thermodynamics has not yet been reported. Therefore, the present paper puts forward a detailed kinetic and thermodynamic study on the beech wood pyrolysis. The beech wood pyrolysis is firstly deconvoluted into three isolated pseudo-hemicellulose, pseudo-cellulose and pseudo-lignin thermal degradation processes by an effective deconvolution function. Afterwards, generalized integral isoconversional method is applied. It suggests that the three processes follow single-step kinetics. Advanced reaction model determination methodology reveals that the thermal degradation processes of pseudo-hemicellulose, pseudo-cellulose and pseudo-lignin go to completion by respectively following, second order (RO), two-dimensional (2D) nucleation/growth and complicated diffusion mechanisms. The thermodynamics of beech wood pyrolysis puts forth interesting and important information regarding the endothermicity of the processes involved and arrangement/orientation of the activated complexes in transition state. The practical valuation of the present research is also pointed out and discussed.