Example - Single Separation Duty

Al-Tuwaim and Luyben (1991) considered the following optimisation problem. 

See the original reference for more examples with binary and ternary mixtures. Also the sensitivities of the steam cost, materials of constructions and pay back period on the design and operation are presented in detail in Al-Tuwaim and Luyben (1991). 

Design and Operation Optimisation for Single and Multiple Separation Duties Problem Formulation and Solution 

Mujtaba and Macchietto (1996) presented a general design and operation optimisation problem formulation and solution for single and multiple separation duties. 

RR CAP DIA AR, AC Capital Cost Steam Cost Total Cost 

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When both streams are fed to the same column, the above considerations still apply, but their relative importance may vary. If one of the streams is predicted to have a higher optimum feed tray than the other on account of both its composition and thermal conditions, then the optimum feed trays in the two-feed column would correspond to the same relative locations as with the streams fed separately. However, if the two factors are contradictory, as in this example, the optimum feed locations in the two-feed column may or may not correspond to the relative single-feed optimum locations. In the two-feed toluene-xylene column, the reboiler duty is minimized when feed 1 is higher than feed 2, which is contrary to the single-feed optimum feed trays. With the two-feed column, the... 

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