Catalytic pyrolysis of xylan-based hemicellulose over zeolites

摘要

Xylan was selected as model compound of hemicellulose to investigate its thermal behavior over zeolites by using TG-FTIR. The chemical structure of xylan and characterization of catalysts were first studied. All the three catalysts, HZSM-5, H-P and USY, had obvious influence on deoxygenation and fragmentation reactions during xylan pyrolysis. The dehydration in the initial stage was enhanced and the char formation was suppressed. USY had the best effect on dehydration with the consumption of oxygenated compounds, such as acids and furans. The presence of HZSM-5 and H-P catalyzed the formation of water, CO_2 and alkanes, with the degradation of char residues.