A novel approach to inulin depolymerization: A Monte Carlo based model

Abstract

• Monte Carlo model for inulin depolymerization. • End-biting/internal random cleavage mechanism was adopted. • The detailed molecular weight distribution can be simulated. • The model can distinguish between two scission mechanisms. • The obtained kinetic parameters are in line with literature. Modelling the depolymerization of natural and synthetic polymers is still a challenge in the field of chemical reaction engineering, as the classical approaches based on complex consecutive/parallel reaction mechanisms show limited capabilities in predicting phenomena that nature would do statistically. A Kinetic Monte Carlo model is proposed, which assumes that polymers can be cleaved following two parallel reaction mechanisms: (i) end-biting (i.e., unzipping), (ii) internal random cleavage. The model was studied via a systematic parametric investigation, and it showed high flexibility in predicting detailed product distribution and concentration profiles of monomers as a function of reaction time. The model was applied to a industrially interesting case: inulin hydrolysis, giving mostly fructose as reaction product. A very good fit was obtained and the model was capable to explain the often-overlooked details observed in the experimental results, e.g., the sigmoidal kinetics in the early stages of the hydrolysis and its dependence on experimental conditions.