Organic solvents, potentially harmful to the environment, are often used in the pretreatment and processing of cellulosic biomass. A rational selection of solvents and processing conditions would be beneficial to the environment, both from the point of efficient solvent utilization and that of renewable resource valorization, cellulose being an abundant and carbon-neutral feedstock for the production of valuable products such as fuels, chemicals, and polymers. However, fundamental information is lacking on the interplay between nano-scale solvent-cellulose interactions and large-scale biomass solvent processing.
UB CBE's Associate Professor Marina Tsianou and UB Distinguished Professor Paschalis Alexandridis have been addressing this problem with support from the National Science Foundation. In a series of recent publications, the team including students Mohamad Ghasemi and Luz V. Vargas-Aponte have predicted the dissolution kinetics of cellulose for various solvent and particle properties, using a new phenomenological model that captures the relevant molecular and transport phenomena. The relative ability of solvents toward decrystallization and disentanglement has been quantified on the basis of the aforementioned model and experimental data. In ongoing work, the dissolution of polydisperse biomass particles is investigated with a population ensemble model at conditions that emulate large-scale processing. The concerted experimental and modeling efforts by the team improve our understanding of the solvent characteristics affecting cellulose dissolution, and inform the selection of environment-friendly solvents and the design of efficient pretreatment processes for a global optimization of biorefinery operations.