Structural features of chars from the pyrolysis of cane trash in a fluidized-bed/fixed-bed reactor under both slow and fast heating rate conditions were investigated using Raman spectroscopy. Chars from the pyrolysis of coals were also investigated for comparison. Spectra were curve-fitted using 10 Gaussian bands representing different structural features of the chars. Differences in the total Raman intensity between cane trash chars and the chars of 3 coals of varying rank were great at low pyrolysis temperature (600 degrees C) but decreased as the pyrolysis temperature was increased to 900 degrees C. Both low (10 K min(-1)) and high (> 10(3)-10(4) K s(-1)) particle heating rates resulted in increased aromatization and relative aromatic ring size with increasing pyrolysis temperature from 600 to 900 degrees C. However, pyrolysis at slow and fast heating rates gave chars of very different structural features as revealed by Raman spectroscopy.