Abstract
The minimum energy or minimum reflux ratio calculation is an important design parameter to distillation separation system. Similarly, determination of minimum number of plates gives a minimum estimate of the capital expenditure required. The rigorous commercial simulator could provide efficient solutions under good estimate for convergence problems. Such estimates may not be readily available for complex columns (multi-feed and multi-draw, azeotropic, reactive, mass-transfer limited distillations). The conventional heuristic shortcut design methods, which had been proposed either have not correct estimate to non-key component distribution caused erroneous results or restrict to specific separation (e.g. direct split, indirect split, sharp split). The objective of this work is to develop a general geometric based shortcut method for estimating the minimum reflux ratio and minimum number of stage that can be used for any columns. It includes the formulation of the problem, finding a suitable numerical algorithm that is efficient and guarantees global convergence. We have proposed the mathematical model to molar un-conservative reactive distillation system are developed a general geometric shortcut design method by formulating the boundary value method into an optimization problem. Furthermore, the influences of mass transfer effects to the design of distillation system are explored based on the Maxwell-Stefan mass transfer approach. Application analysis in various situations such as multi-feed and multi-product, mass transfer limited, and reactive columns will also be carried out. Many examples are implemented to show the ability and capability of the proposed shortcut design methods in conceptual design of distillation separation systems.