Narrative: This proposal targets the important problem of converting lignocellulosic substrates to liquid fuel, namely ethanol. In addition, the sugar solution resulting from enzyme hydrolysis can be used as a general fermentation substrate. An attempt will be made to quantify the kinetics of the enzymatic hydrolysis of thermo-chemically pretreated lignocellulosic material. In particular, the work will relate the physical and chemical effects of the "steam-explosion" pretreatment to the kinetics of the subsequent hydrolysis of woody biomass. Area and pore volume available to enzyme action, degree of polymerization, crystallinity index, and lignin content and morphological state will be measured in order to characterize the substrate. These variables, as well as the enzyme concentration and activity and product concentration, are to be followed throughout the hydrolysis reaction. Fundamental studies of this kind will help to lay a basis for the development of new processes for enzymatically converting insoluble lignocellulosic substrates to more valuable products, and to provide a better understanding of heterogeneous enzyme kinetics in general. The resulting mathematical models will be sensitive to process behavior and therefore be valuable in the design and development of efficient, economical production of useful products via enzymatic hydrolysis of insoluble lignocellulosic substrates.
