Cellulose Engineering for Increased Hydrolysis

Gilad Alfassi, Chemical Engineering, Technion, Haifa, Israel
Dmitry Rein, Chemical Engineering, Technion, Haifa, Israel
Sofia Napso, Chemical Engineering, Technion, Haifa, Israel
Yachin Cohen, Chemical Engineering, Technion, Haifa, Israel

Biofuels produced from renewable resources may help minimizing fossil fuel burning and CO2 production. Cellulose is considered as one of the most bio renewable abundant materials on earth, yet the production of cellulosic bio-fuels is not fully utilized mainly due to costs of conversion.

Enzymatic hydrolysis enhancement results by interrupting the crystalline structure using different solvents, where the most favorable structure is the amorphous hydrogel. Cellulose hydrogels fabricated directly from native cellulose via cellulose dissolution and subsequent regeneration with water. The hydrogel macromolecules possess the same degree of polymerization as the initial one, indicating no degradation.

Using HR-SEM we showed that cellulose hydrogel in aqueous suspension exhibit two types of structures – a dense exterior surface region and a more porous interior network. Furthermore the exterior surfaces of different hydrogels indicate that their porosity is concentration related, higher concentration had smaller pores and vice versa. We found that the main differences in hydrogel structure, both the surface and internal porosity, are manifest in the process of enzymatic hydrolysis. These differences disappear due to particle size reduction by high shear forces, and hydrolysis rate increases by 2-7 times. These findings have important implications in bio-fuel production by reducing enzymes and solvents usage.