Thermal Deconstruction Opens Biomass for Acid Hydrolysis to Monomeric Sugars

Thermal deconstruction involves rapidly heating then cooling biomass in an inert environment before complete pyrolysis can occur. While some bio-oil and light gases are produced, solid or liquid phase reactions greatly modify the biomass. As shown by microscopy and chemical analysis, thermal deconstruction cracks the biopolymers and loosens their lignocellulosic structure. This change allows molecules to diffuse more readily into and out of the biomass. Furthermore, as the biopolymers fragment into smaller oligomers they become more susceptible to biological decomposition. Three routes for processing both thermally deconstructed cellulose (as a model compound) and biomass were investigated: enzymatic hydrolysis, direct yeast fermentation, and anaerobic digestion.