Scale-up Of Simultaneous Saccharification And Ethanol Fermentation Using Lignocellulose Materials As Feedstock

Scale-up is critically important for the commercialization of cellulosic ethanol using lignocellulose material as feedstock due to its high viscosity. A new helical ribbon impeller has been developed for the simultaneous saccharification and ethanol fermentation (SSF) using lignocellulose feedstock in our previous study. In this thesis, a computed fluid dynamics (CFD) model on CFX software was developed on the different scale of bioreactors at the scales of5L,50L,500L. Corn syrup was used as the medium material in the fluid dynamics mock-up experiemnt for testing of calculation accuracy of the CFD model. Then different rheology models were applied to simulate the SSF process. The SSF system showed a clear shear-thining properties of non-Newtonian fluid, and the power consumption result showed that the non-Newtonian model was better fitting the experimental data than that of the Newtonian model. The CFD computation results showed that in the5L,50L,500L SSF fermenter, d/D (d:the diameter of the helical ribbon impeller, D:the diameter of reactor) at0.9was the most efficient value for mixing in the50L biroeactor; when w/D (w:the width of helical impeller) was best at0.05-0.20; the Rushton impeller and the bottom impeller did not give a major effect on the mixing performance.