FLEXIBILITY ANALYSIS OF AN ETHYLENE PLANT

It is desirable to know the variations around the normal feed conditio ns that a real plant can handle ensuring feasible operation and to det ect the plant bottlenecks for these perturbations. This information is provided by a flexibility analysis of the real plant. Perturbations o n total flow rate and ethane composition are expected in the feed of a n ethylene plant. Due to the fact that only two uncertain parameters a re contemplated, the maximum feasible displacement from the nominal po int in different directions of the uncertain space can be evaluated. T he maximum displacement is determined solving a nonlinear programming problem where the main operating conditions of the plant are the optim ization variables. An active capacity constraint indicates a plant bot tleneck. Therefore the flexibility analysis of a real plant allows the quantification of the perturbations that the plant can accommodate fo r different directions of interest, associating bottlenecks with scena rios in which they will take place.