A survey of catalysts for aromatics from fast pyrolysis of biomass

[Display omitted] •Aromatics from renewable feedstock using pyrolysis and catalysis.•Synthesis of mesoporous form of sulfated zirconia.•Comparison of sulfated zirconia, red mud, Al–MSU–S and HZSM-5.•Catalyst acidity and porosity affects yield and aromatic selectivity.•Mesoporous catalysts deoxygenate producing gas and coke, HZSM-5 maximizes aromatics. A comparative evaluation of ten catalysts for biomass pyrolysis was performed using poplar (DN-34) as the feedstock. Five of the catalysts consisted of HZSM-5 with different silica:alumina ratios (SAR, 23, 30, 55, 80 and 280). The other five catalysts were sulfated zirconia (SO42− ZrO2), 20% SO42− ZrO2 dispersed on a mesoporous MCM-41 silica support, Al–MSU–S alumnosilicate exhibiting a foam-like mesopore structure, Al–MSU–S aluminosilicate exhibiting wormhole mesopores, and a bauxite waste product known as red mud. Analytical pyrolysis in tandem with GC/MS showed that all of the catalysts except for HZSM-5 resulted in low aromatic chemical production. Highly acidic sulfated zirconia catalysts were not selective to aromatics and produced significant coke and non-condensable gases. Mesoporous MSU–S catalysts exhibiting high pore volume and acidity also gave high gas and coke yields. Among the HZSM-5 catalysts evaluated, those with the lowest SAR provided the highest yields of total aromatics and the lowest levels of undesired coke.