In-situ catalytic upgrading of bio-oil from rapid pyrolysis of biomass over hollow HZSM-5 with mesoporous shell

To solve the issue of narrow micropores in traditional protonic type Zeolite Socony Mobil-5 (HZSM-5) catalysts in the restricting of large-molecular reactants/products diffusion, hollow HZSM-5 with a mesoporous shell was prepared using a hydrothermal method combined with a tetrapropylammonium hydroxide (TPAOH) treatment process. Applying for in-situ catalyst upgrading of bio-oil from rapid pyrolysis of biomass, the obtained most efficient catalyst of Hollow(30)-TP resulted in aromatic hydrocarbon yields in the range of 78.49-78.67% for cellulose and hemicellulose, which is much greater than those using the traditional HZSM-5 (61.06-68.26%). Furthermore, in the case using real biomass (cedar) with an optimal biomass/catalyst weight ratio of 1:2, the aromatic hydrocarbon yield reached up to 80.16%. In addition, this catalyst exhibited excellent reusability and regeneration property due to the increased accessibility to the acid sites in the hollow HZSM-5 for the improving of the reaction rate as well as the reducing of coking.

Automated summary

The issue of narrow micropores in traditional protonic type Zeolite Socony Mobil-5 (HZSM-5) catalysts, which restrict the diffusion of large-molecular reactants/products, was tackled by preparing hollow HZSM-5 with a mesoporous shell. The efficient catalyst of Hollow(30)-TP showed significantly higher aromatic hydrocarbon yields for cellulose and hemicellulose compared to traditional HZSM-5, and exhibited excellent reusability and regeneration due to increased accessibility to acid sites.