Discussion on the calculation of the minimum reflux ratio for multi-stream feed in distillation

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6. Separate the A and B component mixture using a continuous atmospheric distillation column, with a relative volatility of 2.4, and feed it at saturated conditions. The concentration of component A in the feed is 60% (mol); there is also another feed stream with the same component, in which the concentration of A is 22% (mol). The flow rate and condition of these feeds are the same as those of the original mixture, and they are introduced at appropriate tray positions in the column. If the concentration of component A in the overhead distillate is required to be 95% (mol), and the concentration of component A in the bottom stream is required to be 10% (mol), what is the minimum reflux ratio for this column? (A) 2.97 (B) 1.51 (C) 2.0 (D) 0.92 Is there a problem using the average reflux ratio? Saturated liquid feed: q=1, xq=xf, xf=（0.6+0.22）/2=0.41