CONSTRUCTIVE TARGETING APPROACHES FOR THE SYNTHESIS OF CHEMICAL REACTOR NETWORKS

The impact of the reaction system and reactor design on the character of the flowsheet has been appreciated by many researchers in process synthesis. In this paper, we develop bounds, or targets, on a given performance index of an isothermal reacting system. A targeting model based on optimizing flows between different reacting environments is described, which provides a sufficiently rich representation of the reactor network. The model is formulated as a dynamic optimization problem, and solution strategies are presented. A linear programming simplification, which corresponds to the segregated flow limit, is derived for the targeting model. Sufficient conditions for global optimality of this simplification are described. Moreover, even when these conditions do not apply, tests formulated as nonlinear programs can be applied to evaluate the suitability and enhancement of the target obtained by the segregated flow model. This approach leads to an iterative process for the targeting problem, based on two alternative methods. Also, the reactor network is straightforward to realize from the targeting solution. The approach is demonstrated on numerous isothermal reaction mechanisms and is compared to literature results. The extension of this approach to embedding the reactor target within a process flowsheet is also presented.