Effect of reducing ends on the pyrolysis characteristics and product distribution of cellulose

• Reduction of cellulose reducing ends makes cellulose more stable during pyrolysis.
• Lower reducing end content leads to lower yields of acids and furans.
• Lower reducing end content leads to higher yield of levoglucosan.
• Acids formed by cellulose reducing ends act as catalysts during pyrolysis.

Reducing ends of original cellulose (Avicel PH101) were converted into glucitol moiety via reduction with NaBH4 (obtaining reduced-cellulose). These two cellulose samples were pyrolyzed by using thermogravimetric analyzer coupled with Fourier transform infrared spectrometry and mass spectrometry (TGA–FTIR–MS) and Pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS) techniques to investigate the effect of reducing ends on pyrolysis characteristics and product distribution of cellulose. TGA–FTIR–MS results showed that more H2O, aldehydes, CO2 were released when original cellulose was pyrolyzed and the temperature at the maximum weight loss rate for original cellulose was 316 °C while it was prolonged to 320 °C for reduced-cellulose with a lower maximum weight loss rate. Py-GC/MS results showed that reduced-cellulose pyrolysis could generate more levoglucosan and less furans, light oxygenates and char, relative to original cellulose. The possible mechanism of the effect of cellulose reducing ends on pyrolysis characteristics and product distribution was proposed. These findings expand the understanding of the detailed molten-phase chemistry of cellulose pyrolysis.