A distillation column is a process unit in which a feed mixture is separated by multiple partial vapor izations and condensations to form two or more product streams. The overhead product stream is rich in the most volatile components of the feed mixture (the ours that vagunizes readily), and the bottom product stream is rich in the least volatile components. The following flowchart shows a distillation column with two feed streams and three product streams: gh 0.0 0.97 C 5300 kati kg Ng F ike Ahl 1200 0.70 kg kg Falk zalke Che migh) Ang Ng 0.40 kg C 2 (a) How many independent material balances may be written for this system? (b) How many of the unknown flow rates and/or mole fractions must be specified before the others may he calculated? (See Example 4.3-4. Also, remember what you know about the component mole fractions of a mixture-for example, the relationship between xy and y.) Brietly explain your answer. (c) Suppose values are given for , and sy. Give a series of equations, each involving only a single unknown, for the remaining variables. Circle the variable for which you would solve. (Once a variable has been calculated in one of these equations, it may appear in subsequent cquations without being counted as an unknown.)
