Study - Multiple Separation Duties

In the following example (taken from Mujtaba, 1997), a continuous column (instead of a CBD) is used for separating three different binary mixtures (different relative volatility) during its available operating period in a year. The column configuration and input data are given in Table 11.7. Each mixture produces a top distillate product with a purity of 90% (0.9 molefraction) in component 1 and a bottom 

Since the top and bottom product compositions are specified, the overall mass balance using Bt = 10.0 kmol and xBI = 0.6, 0.4 will give a total distillate product of 6.25 kmol and a total bottom product of 3.75 kmol. 

Here the feed rate is maximised while the reflux ratio is optimised. The bottom product composition imposes an additional constraint to the problem. The results are summarised in Table 11.8 which gives the maximum feed rate, minimum batch time, optimum reflux ratio, and total number of batches for each mixture and total yearly profit. 

Feed location (from top, condenser counts stage 1), NF= 10 

Total feed, Bj, kmol = 10.0 Vapour rate, V, kmol/hr = 5.0 

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