Investigation on catalytic pyrolysis of pine sawdust: Catalyst screening by Py-GC-MIP-AED

On line Py-GC coupled to microwave induced plasma and atomic emission detector (Py-GC-MIP-AED) was used for screening the effect of various catalysts on the carbon yield of solid residue, gas and bio-oil from the pyrolysis at 500 °C of pine sawdust. Bio-oil was further divided into volatile, semi-volatile and non-volatile (i.e. heavy matter HM) fractions. The ability of Py-GC-MIP-AED for screening purposes was investigated by comparing the results with those obtained from preparative pyrolysis with a bench scale reactor. Catalyst screening was performed on 31 catalysts directly admixed with pine sawdust at 1/1 (w/w) ratio. Tested catalysts included mesoporous silica supported metal oxides, bulk metal oxides, clays, zeolites and catalysts for methanol synthesis from syngas (MS). A significant decrease in non-volatile fraction and slight decrease in bio-oil yield were obtained with ZnO, CuO, Fe₂O₃ and mixed oxide catalysts usually used for methanol synthesis from syngas. These materials actively transformed non-volatile fraction into GC detectable products with a net increase of gas, volatile or semi-volatile products.