Carbon catalyzed hydrolysis of cellulose to produce glucose and bio-active cello-oligosaccharides
Cellulose is an abundant polymer available in a large amount as waste and energy crop. It is considered as one of the most important sources of renewable chemicals and fuels. In this talk, I will present our findings on carbon catalyzed total hydrolysis of cellulose to glucose, and partial hydrolysis to water soluble cello-oligosaccharides.
Glucose is the precursor for synthesis of renewable plastics, biofuels and industrial chemicals. Its synthesis from cellulose is the first step in the biorefinery scheme. However, insolubility and recalcitrance of cellulose prevents development of a cost-effective process. Using a combination of carbon catalyst and slurry reactor, we demonstrated the first contineous process for hydrolysis of cellulose to glucose.
Cello-oligosaccharides are bioactive molecules that elicit an immune response in plants and prevents diseases in animals. Soluble acids or enzymes are detrimental to plants and animals and they should be avoided during cellulose hydrolysis. Carbon catalysts show higher reactivity towards cellulose due to strong adsorption of large cellulose molecules on the hydrophobic surface of carbon. Presence of weakly acidic functional groups on carbon surface hydrolyzes the adsorbed cellulose yielding shorter molecules. Once formed, soluble cello-oligosaccharides are desorbed from the catalyst surface and are removed from the reactor by a semi-flow process. The collected cello-oligosaccharides are contaminant free and can be directly used in agriculture industry. This solution when applie d to plants shows activation of genes responsible to detect and evade fungal attack.
With an focus on industrial application, we aim to commercialize the cellulose hydrolysis process for synthesis of renewable chemicals and bioactive molecules.
Institute for Catalysis, Hokkaido University, Japan