Reactivity and reaction pathways in thermochemical treatment of selected lignin-like model compounds under hydrogen rich conditions

Representative lignin-like model compounds have been used to study the depolymerisation mechanisms for lignin hydrodeoxygenation during thermochemical conversion by solvolysis. Oligomeric lignin model compounds have been synthesised and fully characterised, and the degradation products that were formed after pyrolysis were successfully isolated and identified, thereby providing new insights into the fragmentation pathways and mechanisms. This facilitates the more target-oriented approach of the utilisation of world's second largest biomass resource, lignin, to produce e.g. fuel compounds and valuable fine chemicals.

► Lignin-like model compounds have been synthesised and reacted under formic acid assisted thermochemical conversion (LtL conditions).
► A large number of pyrolysis degradation products were successfully isolated and structurally identified.
► Knowledge about fragmentation pathways and mechanisms are accomplished.
► Radical initiated homolytic cleavages, demethoxylation and hydrodeoxygenation are important processes.
► A deeper understanding of the fundamental reactions and reaction mechanisms of the one-step depolymerisation of lignin-like structures are provided.