Application of an Fourier Transform-Infrared Imaging Tool for Measuring Temperature or Reaction Profiles in Pyrolyzed Wood

FT-IR imaging was used to monitor the structural and chemical changes of wood particles under various pyrolysis conditions. The temperature or reaction profile inside pyrolyzed wood was obtained from a novel approach using chemical images coupled with multivariate analysis. Poplar sections 100 mu m thick were pyrolyzed at 250-500 degrees C and the resulting FT-IR images were used as standards to determine the temperature in a poplar wood block (5 mm x 5 mm x 20 mm). Principal component analysis (PCA) and partial least-squares (PLS) regression were used to develop predictive models to map the temperature profile in the pyrolyzed wood. The results indicate that FT-IR imaging coupled with multivariate analysis is a powerful tool to study the heat transfer effects in the pyrolysis of thick wood particles. We believe that this is a unique and novel approach to visualize the chemical changes in heated biomass and thermal effects in other materials.