Cellulose-lignin and Xylan-lignin Interactions on the Formation of Lignin-derived Phenols in Pyrolysis Oil

To gain a better understanding of the effect of the interactions between two biomass components (cellulose-lignin and xylan-lignin) on lignin-derived phenolic products, two analysis methods are introduced. With 3:1, 2:1, and 1:1 ratios of cellulose and lignin, and xylan and lignin, the mixtures were subjected to fast pyrolysis, which was carried out in a fixed-bed tubular furnace at 450 to 600 °C. The phenolic content in the bio-oils was analyzed by gas chromatography-mass spectrometry. The product distributions showed that cellulose, xylan, and lignin were the main contributors to the mass of biomass bio-oil, gas, and char, respectively. The char yields decreased and the bio-oil and gas yields increased in the presences of cellulose and xylan. Comparative analyses of both the phenol content and peak area of the two methods suggest that in the case of cellulose and lignin co-pyrolysis, the formation of three kinds of phenolic products is promoted. The strength of this positive effect increased with increasing lignin content. However, the production of hydroxyphenols is promoted, while the productions of guaiacols and syringols are inhibited by the effect of xylan, which creates a different interaction between xylan and lignin.