Effect of Crystallinity and Degree of Polymerization On the Fast Pyrolysis Decomposition Products of Cellulose

Fast pyrolysis has received significant attention as a possible pathway for converting biomass to transportation fuels and chemicals.  Cellulose is the most prominent component in biomass; however, its degradation pathway is not fully understood. More so, the effects of the fundamental structure of cellulose in fast pyrolysis have not been extensively investigated.  This study aims to determine the effect of the crystallinity and degree of polymerization on the primary degradation products of cellulose.  Pyroprobe-GC-MS was used to examine the volatile fraction, while a secondary GC measured CO and CO₂, and residual char amount was also recorded.  This experimental configuration allowed for a full carbon mass balance.  The pyrolysis was performed on a CDS pyroprobe with set-point temperature of 600°C to imitate pilot scale pyrolysis temperatures.  The preliminary results showed that levoglucosan and glycolaldehyde are key primary degradation products, and their amounts were quantified on the GC-MS via standard calibrations.  The results from these experiments are shedding light on the competing mechanisms of cellulose thermal degradation, as well as offering insights on the optimal biomass that will produce more desirable products.