Pyrolysis behaviors of wood and its constituent polymers at gasification temperature

Pyrolysis behavior of wood at gasification temperature (800 °C) was investigated focusing on the behaviors of the wood constituent polymers [cellulose, hemicellulose (glucomannan and xylan) and lignin (milled wood lignin)]. Tar compositions (iso-propanol-soluble and water-soluble tar fractions), which were characterized with GPC, GC–MS, GC-FID (oxime-TMS analysis), capillary electrophoresis and 1H NMR analysis, were quite different between wood polysaccharides and lignin. Furthermore, comparison of the tar- and secondary char-forming behaviors indicated that comparatively stable primary tar from wood polysaccharides undergo secondary reactions including carbonization after condensation at the reactor wall with lower temperature than their boiling points, while that primary tar from lignin is more reactive to give the vapor phase carbonization products during volatilization.