The chemical compositions of two kinds of secondary biomass,auricularia residue and pleurotus ostreatus residue,were analyzed in comparison with their raw material.The pyrolysis of the three kinds of material was also performed.Compared with the raw material,the cellulose,hemicellulose,lignin contents of both the mushroom residues decrease significantly,and the content of ash increases.The change of chemical components not only lessens the yield of bio-oil,but also alters the component of bio-oil.The uppermost composition in the bio-oil from the raw material is cyclobutanol,whereas acetic acid or 2,2,6,6-tetramethyl-4-piperdone is dominant in the bio-oil from Auricularia residue and pleurotus ostreatus residue respectively.The selectivity of 2,2,6,6-tetramethyl-4-piperdone and 4-methyl-3-penten-2-one in the bio-oil from pleurotus ostreatus residue reached 35.3 % and 33.1 %.
Fe/Al2O3,Co/Al2O3 and Ni/Al2O3 catalysts were prepared by impregnation method.The catalytic pyrolysis catalyzed by Al2O3 and the above mentioned catalysts as well as the direct pyrolysis of polystyrene(PS)were investigated comparably.Comparing with direct pyrolysis of PS,a high conversion of PS and a high selectivity of styrene monomer(61.5%)could be obtained over Co/Al2O3,furthermore reduced carbon deposition was observed.The selectivity of monomer increased over Fe/Al2O3 and Ni/Al2O3 while the oil yield decreased.The loading of transition metal enhanced the basicity of Al2O3 support,which led to increase of β-chain-breaking and resulted in higher selectivity of styrene monomer(about 60 %)over Fe/Al2O3,Co/Al2O3 and Ni/Al2O3 than that over Al2O3.The three catalysts prevented effectively the cross-linking reaction of the newly formed monomers in PS pyrolysis.
