99B-24 |
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L. WANG and C. L. Weller. Dept. of Biological Systems Engineering, Univ. of Nebraska, Lincoln, 207 L.W. Chase Hall, Lincoln, NE 68583 Grain sorghum wax is composed of large amounts of fatty aldehydes, fatty alcohols, and fatty acids with minor components including hydrocarbons, wax esters (WE), steryl esters (SE) and triacylglycerols (TG). Adsorption phenomenon has played a key role in bioseparation. Silica column chromatography has been a promising method for fractioning the sorghum lipid (wax) but has not yet gained wide – spread use. The chromatography column is a packed bed of small nano- or micro- structured porous particles. The porous adsorbent is a core element in an adsorption process. Selective surfaces of the adsorbent are important for separating or purifying a mixture of biomolecules. Quantitative description of microscopic and macroscopic transport phenomena in an adsorbent column is a key issue for analyzing and designing an adsorption process. The objective of this research was to develop a mathematical model for analyzing the adsorption-based separation process of sorghum lipid. Molecular modeling of thermodynamics based on geometric and energetic information of adsorbent - adsorbates was used to unravel the complex factors that determined the adsorption mechanisms, selectivity and diffusion properties of adsorbents. Meanwhile, the multiscale transport phenomena in the nano- or micro- pores within the particles and in the macropores formed by the space between the particles were modeled, respectively. The model was verified by experiments on separation of sorghum lipid using a silica column (15 cm length, 4.5 cm diameter). The model was further used to analyze the adsorption kinetics, multi-component adsorption isotherms and transport characteristics of the process. Simulations based on the model enable us to gain a much better physical insight into how molecules move within porous materials and to design cost-effective large-scale adsorption-based processes and equipment for sorghum lipid separation.
Session 99B, Food Engineering: Process analysis, control and modeling
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