Investigation of holocellulose-lignin interactions during pyrolysis of wood meal by TGA-FTIR

Abstract

Pyrolysis of wood meal, a holocellulose-lignin mixture, holocellulose, and lignin was carried out using TGA-FTIR to investigate the effects of holocellulose-lignin interactions on the pyrolysis behavior of wood meal, in this study. The interactions between holocellulose and lignin showed no obvious effects on the pyrolysis behavior of holocellulose in wood meal at temperatures under 325 °C. However, the interactions did inhibit the pyrolysis of both lignin and holocellulose at higher temperatures, probably because of the high energy needed to dissociate the covalent linkages between holocellulose and lignin. Only a portion of covalent linkages were cracked at the temperatures of 215–395 °C, whereas they could be just barely destroyed at 395–565 °C. The char generated from holocellulose that was connected with lignin by unabridged covalent linkages would inhibit the decomposition of lignin at high pyrolysis temperatures by adsorbing on its surface, resulting in a higher char residue yield compared to that of the holocellulose-lignin mixture after pyrolysis.