Pyrolysis of beech wood (Fagus sylvatica) was investigated based on thermogravimetric analysis coupled with Fourier transform infrared spectrometry analysis at heating rates from 20 Kimin to 60 K/min. The various activation energies were estimated at different conversions by three model-free methods and were in the range of 146.84-174.44 kJ/rnol. The peak locations of three main components (hemicellulose, cellulose and lignin) were predicted more exactly by the K-K method. The absorbance spectra corresponding to the three peak locations were basically the same at different heating rates, indicating that the heating rate had little influence on the produced composition. During the whole pyrolysis process, the evolution of gas components (CO, CO2, methane, methanol and formaldehyde) was consistent with the trend of derivative thermogravimetric curves, and possible formation pathways of main gases were tentatively presented. The amount of these five components produced in the order of most to least produced was formaldehyde > CO2 or methanol > methane > CO. In particular, the amount of formaldehyde was almost triple the amount of methanol and ten times the amount of methane at the maximum peak. (C) 2016 Elsevier Ltd. All rights reserved.