Theoretical exploration of char formation during lignin pyrolysis

Conversely, unsaturated functionalities exhibit high resistance to homolytic cleavage and are more thermally stable.<br><br>In Chapter 3, we propose a reaction mechanism for the formation of aromatic char clusters from the products of lignin decomposition. Here, through investigation of sixteen parallel pathways, we show clearly how unsaturated lignin derived monomers may concatenate through cycloaddition reactions and subsequently aromatise through elimination reactions to yield polycyclic char clusters.<br><br>Chapter 4 is concerned with the aggregation of these char clusters through a continuation of the reactions reported in the previous chapter.

By employing the Same Level Different Basis approach, the growth of condensed char clusters up to eleven rings is modelled and the impact of cluster size on reaction barriers is assessed.<br><br>Chapter 5 contains concluding remarks that draw upon the results reported in Chapters 2-4. This chapter also proposes new avenues for the investigation of lignin char formation and the potential impact of the work contained herein to other closely related fields.