Catalytic deoxygenation of model compounds from flash pyrolysis of lignocellulosic biomass over activated charcoal-based catalysts

Abstract

Catalytic deoxygenation of pyrolytic vapors represents a great challenge to produce biofuels by flash pyrolysis of lignocellulosic biomass. A wide variety of catalysts, particularly zeolites, have been investigated for this purpose, however, quick deactivation was often reported. Although they are cheap and can have a hierarchical pore structure, activated charcoal-based catalysts have received only little attention. This paper presents an innovative method to synthesize activated charcoal based catalysts doped with CeO2, Fe2O3 or Mn3O4 nanoparticles. We investigated the performances of those catalysts to deoxygenate two biomass pyrolytic model compounds − acetic acid and guaiacol − on a fixed-bed reactor between 350°C and 450°C. Ceria-based catalyst was highly active and remarkably stable to enhance ketonic decarboxylation of acetic acid, leading to the formation of acetone. Huge amounts of produced phenol attest for the partial deoxygenation of guaiacol, particularly when using iron-based catalyst. This study demonstrates the potential of activated charcoal-based catalysts to produce weak-acidic and partially deoxygenated bio-oils.