Evolutions towards a circular economy, including the replacement of fossil resources by renewable ones, have become increasingly important in the abatement of climate change. Lignin from lignocellulose constitutes an interesting resource for materials applications or for the production of renewable aromatics. However, due to its complexity and chemical heterogeneity, the reaction mechanisms governing lignin valorizations are not well understood, yet. Moreover, the vast amount of elementary steps involved poses a significant challenge for traditional ‘molecular’ microkinetic models. Capturing the chemistry within a limited number of reaction families and component types, as done in Single-Event MicroKinetics (SEMK), is a first prerequisite to solve this issue. Yet, rather than its ‘molecular’ version, an innovative ‘stochastic’ variant will be developed, specifically designed to cope with this complex biopolymer. First, a lignin representation in terms of reactive moieties instead of individual molecules will be developed. Subsequently, the reaction mechanism of the reductive depolymerization will be elucidated and a SEMK model will be constructed. During the model development, special attention will be paid to the thermodynamic non-ideality of the reaction mixture. Finally, the potential of the model to steer the lignin feedstock selection as well as fine-tune the reaction conditions in order to meet a priori imposed selectivity specifications, will be demonstrated.