(458h) Modeling of Multicomponent Sorption of Fermentation Products on Resin Sorbents

Industrial-scale production of fuels and chemicals from renewable feedstocks via fermentation technologies has rapidly developed in recent years. Ethanol is one such biofuel that is being produced on a large scale using yeast fermentation. The broth from fermentation contains about 15% ethanol along with a variety of compounds such as carboxylic acids, glycerol, and sugars which are generated as byproducts during fermentation. Separation of ethanol from such complex broths using conventional distillation and sorbent drying, as currently practiced, is highly energy intensive. Packed bed adsorbers using various resins have been studied as more efficient alternatives, due to their selectivity and ability to operate in a continuous mode. Using mathematical models for the analyses of these systems offers the flexibility to study and understand the effect of different operational parameters on the separation process. The aim of this research is to develop a model of the sorption process for the separation of ethanol from fermentation broth using COMSOL Multiphysics® software. The PDEs representing multicomponent diffusion and equilibrium sorption of organic acids and ethanol were developed and solved in the Coefficient form PDE interface available in COMSOL. The effects of initial concentration, resin affinity, and other parameters on fixed-bed breakthrough curves including roll-over effects will be presented.