A VERSATILE MODEL FOR SIMULATION OF REACTION AND NONEQUILIBRIUM DYNAMICS IN MULTICOMPONENT FIXED-BED ADSORPTION PROCESSES

Mixtures of large biochemicals can exhibit complex chromatographic behavior. In addition to mass transfer mechanisms, the presence of nonequilibrium adsorption/desorption, aggregation, denaturation and other solution or solid phase reactions can be important. A VErsatile Reaction-SEparation model for Liquid Chromatography applications (VERSE-LC) which considers all these nonequilibrium effects has been developed. The VERSE-LC model equations are spatially discretized by orthogonal collocation on finite elements and the resulting ordinary differential equations are solved in time by a differential/algebraic system solver. Convergence criteria are established for each type of nonequilibrium simulation. A general dimensionless group approach is presented to determine the controlling rate process and thus predict the character of the effluent history. The VERSE-LC model can treat all types of chromatography and simulate frontal, elution and displacement chromatography as well as combinations of these modes; operation may be either isocratic or gradient, VERSE-LC is useful both for gaining a fundamental understanding of complex protein chromatography and for scaling with respect to flowrate, particle size and feed concentration.