(349e) Recovery of Large Amount of Levoglucosan Produced by the Fast Pyrolysis of Acid Infused Biomass From the Reactor

Authors: 
Kuzhiyil, N., Iowa State University
Brown, R. C., Iowa State University


We have previously shown that infusion of mineral acids converts alkali and alkaline earth metals in biomass into thermally-stable salts, reducing their catalytic activity during fast pyrolysis.  The suppression of metal-catalyzed ring breaking reactions allows depolymerization to dominate pyrolysis reactions, resulting in enhanced yields of levoglucosan (LG). In a bench scale fluid bed pyrolyzer, however, the large amount of LG formed by the fast pyrolysis of acid infused switchgrass at 500°C led to bed agglomeration. It was inferred that the agglomeration was caused by LG polymerization and charring taking place at about 270°C and 280°C respectively. Analytical pyrolysis studies using micropyrolyzer/GC/FID showed that temperatures between 350 and 400°C are more suitable for collecting LG from acid-infused biomass. The present work explored various techniques such as low temperature pyrolysis and higher sweep gas flow rates to improve the recovery of LG using a bench scale fluid bed and auger reactors.