Comparison of Fast Pyrolysis Behavior of Cornstover Lignins Isolated by Different Methods

The effect of lignin isolation methods on lignin fast pyrolysis was investigated utilizing an online product analysis methodology to give high mass balance closure for the products. Lignin samples with high purity were isolated from cornstover using three methods: Björkman milling, organosolv extraction, and gamma-valerolactone (GVL) extraction. Although milled wood lignin has been extensively studied, characterization and the fast pyrolysis of milled cornstover lignin has not been previously reported. The current study shows that the milled cornstover lignin contains a higher molecular weight and more aryl ether linkages relative to organosolv and GVL extracted cornstover lignin. During fast pyrolysis, considerably more phenolics, especially those with side chain double bonds derived from aryl ether cleavage, were formed from the milled cornstover lignin concomitant with less char formation.