(561a) Effects of Microporous Structure on Transient Diffusion and Adsorption of Hydrolytic Enzymes into Biomass

Generation of biofuels from lignocellulosic biomass is an emerging technology which is being investigated all around the world. Enzymatic hydrolysis is a major step in the contemporary process of generation of biofuels. There are many factors which affect the yield of enzymatic hydrolysis such as particle size, porosity, density, maximum adsorption capacity of the biomass about which the data is very limited. Understanding the impact of these parameters on the diffusion and adsorption of enzymes into the biomass is essential for achieving maximum conversion. Guided by pore size distribution measured using NMR cryoporometry, in this study we develop pore-enzyme diffusion models for both adsorbing and non-adsorbing enzymes. By simulating these models in MATLAB software package, we investigate the effects of various biomass particle-related parameters (particle dimensions, porosity) on the characteristic time of enzyme diffusion and adsorption for various biomass types. The model for diffusion of adsorbing and non-adsorbing enzymes is in agreement with the characteristic times from the literature. The model was applied to predict characteristic times for diffusion and adsorption of hydrolytic enzymes into dilute acid-pretreated biomass particles (hybrid poplar).