APPLICATION OF THE CAPACITY-BASED ECONOMIC-APPROACH TO AN INDUSTRIAL-SCALE PROCESS

In a previous paper (Elliott, T. R.; Luyben, W. L. Ind. Eng. Chem. Res . 1995, 34 (11), 39073915) we outlined a generic methodology called th e capacity-based economic approach that can be used to compare or scre en preliminary plant designs by quantifying both steady-state economic s and dynamic controllability. The method provides an analysis tool th at explicitly considers variability in product quality. A simple react or/stripper recycle system was used to demonstrate the method. 4 more complex ternary process with two recycle streams was studied in a subs equent paper (Elliott, T. R.; Luyben, W. L. Ind. Eng. Chem. Res. 1996, 35, 3470-3479). In this paper, we consider an even more complex proce ss consisting of two reaction steps, three distillation columns, two r ecycle streams, and one purge/makeup stream. The essential contributio n of this paper is to demonstrate that the capacity-based economic app roach can be successfully applied to a large industrial-scale process. The system is described by approximately 750 ordinary differential eq uations and has 18 design and control degrees of freedom.