Off-line thermochemolysis versus flash pyrolysis for the in situ methylation of lignin: Is pyrolysis necessary?

Abstract

Lignin, a major biopolymer in vascular plants, is shown to undergo thermochemolysis reactions when subjected to flash pyrolysis with in situ methylation using tetramethylammonium hydroxide. The product distribution, composed of methylated lignin monomers, implies that the thermochemolysis involves cleavage of the β-O-4 ether bonds in the lignin. Because thermochemolysis occurs with equal effectiveness at sub-pyrolysis temperatures of 300 °C, we conclude that the analytical method does not require use of specialized pyrolysis equipment, and can be implemented in a batch mode in which internal standards can be added and the products quantified.