Analysis of the Design and Optimization of Preparative Chromatography on the Basis of the Separation of a Real Post-reaction Mixture

The operating conditions for preparative chromatography, as for any industrial process, must be optimized. Such optimization is based on thorough understanding of process variables and economics. Optimization of the operating conditions is the best justification for detailed study of the fundamentals of nonlinear chromatography. It is difficult to optimize a separation without a clear understanding of how the thermodynamics of competitive phase equilibria, the finite rate of mass transfer, and dispersion phenomena combine to affect the individual band profiles of the components to be separated. The operating conditions determine the objectives of the process – yield, productivity, and, ultimately, the cost of the separation. Because of the severe nonlinearity of the chromatography model, the problem of optimization is difficult to solve, and because of the large number of operating variables and the complexity of the objective functions, the solution found can easily be the result of trapping in a local optimum. It is, therefore, necessary to use an effective mathematical tool for global optimization of nonlinear problems. In this work a chromatographic process for separation of the cis and trans isomers of furyl analogues of natural plant terpenes from a real post-synthesis mixture has been optimized. Typical problems during the optimization, which are discussed below, were: (a) formulation of a model of the process dynamics; (b) specification of model variables such as isotherm data, system efficiency, and physicochemical properties of the system; (c) specification of the objectives of the separation process and the process operating variables; and (d) selection of the optimization procedure.