Characteristics and evolution of heavy components in bio-oil from the pyrolysis of cellulose, hemicellulose and lignin

Y Three main components of biomass were pyrolyzed individually in a closed reaction system at 500-700 degrees C for 60s and 90s. Then bio-oil heavy compounds were further analyzed with Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) and Kendrick mass defect (KMD) analysis. The evolution paths of heavy compounds for the different pyrolysis stages were proposed. It was found that the sugars and phenolic-like species in heavy compounds were the most active substances during secondary reactions. Moreover, the rising temperature promoted this secondary reaction of phenolic-like species as the decrease in their abundances growing from 13% to 54%, while contrarily inhibited it for hemicellulose as the decrease in their abundances changing from 44% to similar to 2%. The lignin-derived lipids and unsaturated hydrocarbons that generated in the secondary reactions increased with rising temperature. KMD analysis showed that the heavy compounds of cellulose and hemicellulose prefer homologous evolution during pyrolysis, while those of lignin had more complex evolution paths like cracking and recombination.

Automated summary

The evolution paths of heavy compounds during pyrolysis of biomass components were influenced by temperature, with phenolic-like substances being the most active during secondary reactions. Increasing temperature promoted secondary reactions of phenolic-like species while inhibiting reactions of hemicellulose. Lignin-derived lipids and unsaturated hydrocarbons increased with rising temperature, showing more complex evolution paths compared to cellulose and hemicellulose.