Monday, November 8, 2010: 2:35 PM
253 A Room (Salt Palace Convention Center)
Amino acids produced by fermentation are purified on a very large scale by ion exchange. The performance of these operations is often limited by diffusion in the resin beads. Thus, multicolumn systems are often used to maximize productivity. However, designing and optimizing such systems is not straightforward and requires a through understanding of the complex interactions of ion exchange and solution equilibrium and diffusional transport. This paper provides an overview of the results of a collaborative effort aimed at developing fundamentally based models. In particular, we focus on (a) the description of equilibrium binding and diffusional transport of amino acids in cation exchange resins; (b) the benefits of using higher temperature to enhance process performance by increasing mass transfer kinetics, while leaving the capacity unchanged; and (c) the modeling and optimization of multicolumn systems incorporating in-process recycling of wash and desorbent streams and pH changes to maximize capture efficiency.