Analysis of the flexibility of Distillation Columns Under Feed Perturbations

HOCH, PATRICIA M.; ELICECHE, ANA M.

Energy and the Environment - AIChE Pub. No 137

AIChE

Año: 2000; p. 42 - 46

In this paper, we analyze the changes on the flexibility of a distillation column, considering that the composition of the feed is uncertain within a certain known range. The capacity of the column to accommodate such changes will be explored posing an optimization problem to maximize the flexibility. The optimization variables used are the reflux ratio, the product flow rates, and the number of stages and feed location. The constraints of this optimization problem can be divided into two groups: Constraints related to the column capacities, and operating constraints.The number of stages of the column is considered as a capacity for the optimization procedure, as well as the diameter of the plates and the heat exchanger areas. The operating constraints are the desired separation objectives like composition and recovery in the top and bottom products. The objective function to be maximized is the maximum displacement from the nominal point in different directions of the uncertain space, as shown in Hoch et al. (1995).