Diffusion and damage during delignification of wood biomass (D4mass)

Delignification is a crucial process in the pulp industry that separates lignin and cellulose, the two biobased raw materials with enormous potential.

During this process, the removal of lignin through diffusion is coupled with the accumulation of damage in cell walls, causing cracks and changing the trajectory of diffusion.

In order to correctly predict the delignification process, it is necessary to understand the diffusion and damage phenomena and their coupling.

By using in situ synchrotron X-ray tomography, we were able for the first time to observe microstructural damage in real time during delignification.

But a mechanistic understanding and a quantitative account of the phenomena is still lacking.This project aims to build upon this progress by developing a predictive model that accurately describes the kinetics of delignification at a wood chip level, based on a mechanistic understanding of the coupled diffusion and damage phenomena.

To achieve this, we will carry out a quantitative assessment of the damage occurring within cell walls under delignification, and establish a correlation between the damage factor and the effective diffusivity of lignin through cell walls.Our model will be a powerful tool for simulating and optimising the delignification process, increasing resource efficiency in the pulp industry and new applications based on delignified bulk wood.

Overall, the project contributes to responsible consumption and production with wood biomass.