Experimental and theoretical investigations of the pyrolysis of lignin model compounds

There is considerable interest in the utilization of abundant, carbon neutral renewable resources, such as biomass, for the production of transportation fuels and chemicals. Lignin, the second-most abundant naturally occurring biopolymer and a by-product of the pulping process, has received an enormous amount of attention as a consequence of its availability and its potential to produce high value (aromatic) products. However, lignin is underutilized because of the inability to control the thermochemical reactions to produce the desired products and the need upgrade the primary pyrolysis products. Therefore, we are investigating the pyrolysis mechanisms of compounds that model key structural features found in lignin under a variety of pyrolysis conditions to gain mechanistic insight into the reaction pathways and products. In this presentation, we will focus on the impact of methoxy and hydroxy substituents on the rate and product selectivity in the pyrolysis of lignin model compounds containing the β-O-4 linkage. As a consequence of the complexity of the reactions, additional mechanistic insights will be gained by density functional theory calculations on the key reaction steps.