Selective Production of Aromatics by Catalytic Fast Pyrolysis of Furan with In Situ Dehydrogenation of Propane

摘要

Catalytic fast pyrolysis (CFP) of furan was studied with the co-feeding of propane over ZSM-5,CrOx/ Al2O3,and mixed catalysts with both ZSM-5 and CrOx/Al2O3 to combine the dehydrogenation of propane and CFP of furan in the presence of in situ generated propylene.With 15 vol % propane co-feeding,a slight increase in aromatic yield was observed over ZSM-5 catalyst.These enhancement was further improved by using mixed catalysts consisting of CrOx/Al2O3 and ZSM-5 with different weight ratios.Over the best mixed catalyst with CrOx/Al2O3 to ZSM-5 weight ratio of 2,a nearly 2-fold increase in the aromatic yield was obtained.The toluene selectivity was also increased from 37% to 50%.The increase in aromatic yield is directly dependent on the propane to total flow volume ratio.Moreover,the coke formation within ZSM-5 was also reduced,leading to a slower catalyst deactivation.From mechanistic studies,a two-step cascade reaction pathway was observed over the bifunctional mixed catalysts.It was proposed that propane dehydrogenates to propylene over CrOx/Al2O3.The propylene then reacts with furan within ZSM-5 catalyst to selectively form aromatics.This work demonstrates a simple and economical strategy to further improve the CFP technique.