Interactions among the components of lignocellulosic biomass in catalytic fast pyrolysis

Thermogravimetric(TG) and pyrolysis-gas chromatograph-mass spectrometer(Py-GC-MS) tests were used to measure cellulose,hemicellulose,and lignin concentrations and their mixtures for various mass ratios.The interactions among the three components of lignocellulosic biomass were then evaluated after they were catalytically fast pyrolyzed with a ZSM-5zeolite catalyst.The results show that although cellulose,hemicellulose,and lignin produced quite different primary pyrolysis products,they were converted to similar final products that were predominantly aromatic hydrocarbons in the catalytic fast pyrolysis process(CFP).the lignin component produced considerable amounts of coke deposits on the zeolite,which resulted in catalyst deactivation.Thus,the presence of lignin interfered with the conversion of the cellulose and hemicellulose components in CFP,resulting in a decrease in the overall aromatic biomass yield containing the three components.Further,the inhibition effects increased with increasing lignin content in the biomass and increased CFP pyrolysis time.The results of this study suggest that for lignocellulose containing high contents of lignin,biomass pretreatment may be needed to selectively remove the lignin component to improve the overall conversion of biomass and decrease the catalyst deactivation.