Fig. 1.

The schematic illustration of mass transfer for enzyme adsorption on a porous substrate. The adsorption of cellulase onto lignocellulosic biomass includes three consecutive steps: a the external diffusion of cellulase from bulk solution across the liquid film surrounding the solid biomass particles, b internal diffusion of cellulase through the biomass particles by pore volume diffusion and surface diffusion, and c the adsorption of cellulose molecules onto the biomass particles at the active sites