Analytical pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) of sawdust with Al/SBA-15 catalysts

Pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) was employed to achieve fast pyrolysis of sawdust and on-line analysis of the pyrolysis vapors. A mesoporous SBA-15 catalyst and four Al/SBA-15 catalysts with different Si/Al ratios were prepared, and tests were performed to determine their effects on cracking the pyrolysis vapors. After catalysis, levoglucosan was significantly reduced or even completely eliminated. The yields of heavy furans and heavy phenols decreased significantly, while light furans and light phenols increased. Moreover, the catalytic cracking reduced the yields of light aldehydes and ketones, while increased the formation of acetic acid. Catalytic cracking also resulted in the formation of hydrocarbons, but their yields were not high. In regard to the four Al/SBA-15 catalysts, their effects on cracking the pyrolysis vapors were enhanced with the reducing of Si/Al ratios.