Question: Profit contours similar to those in Figure have been reported by Gorzinski (1983) for a distillation tower separating normal butane and is obutane in an alkylation process for a petroleum refinery. Based on the shape of the profit contours, discuss the selection of desired values for the distillate and bottoms impurity variables to be used in an automation strategy. (Recall that some variation about the desired values is inevitable.) If only one product purity can be controlled tightly to its desired value, which would be the one you would select to control tightly?
