Catalytic fast pyrolysis of straw biomass in an internally interconnected fluidized bed to produce aromatics and olefins: effect of different catalysts.

A novel reactor, named internally interconnected fluidized bed (IIFB), was specially designed for catalytic fast pyrolysis (CFP) of straw biomass. Catalytic characteristics of four types of catalysts (ZSM-5, LOSA-1, Gamma-Al2O3 and spent FCC catalysts) for producing aromatics and olefins were investigated in this reactor. The results show that IIFB reactor can realize CFP process. The maximum carbon yields of aromatics (12.8%) and C2-C4 olefins (10.5%) were obtained with ZSM-5. ZSM-5 shows the highest selectivity of naphthalene (12.1%), whereas spent FCC catalyst presents the highest selectivity of benzene (45.5%). The selectivity of ethylene and propylene are equal in the present of ZSM-5 and LOSA-1. Gamma-Al2O3 and spent FCC catalysts show a higher selectivity of ethylene than that of propylene. This paper provides a new reactor for CFP process and some suggestions for choosing catalyst.