Solution Found!
Suppose that the distillation column shown in Fig. 13.2
Chapter 13, Problem 13.3(choose chapter or problem)
Suppose that the distillation column shown in Fig. 13.2 has been designed to separate a methanol-water mixture that is 50% methanol (MeOH). This high-purity column has a large number of trays and a nominal distillate composition of xn = 5 ppm of MeOH. Because a composition analyzer is not available, it is proposed to control xn indirectly, by measuring and controlling the liquid temperature at one of the following locations: (a) The reflux stream (b) The top tray in the rectifying section (c) An intermediate tray in the rectifying section, midway between the feed tray and the top tray Discuss the relative advantages and disadvantages of each choice, based on both steady-state and dynamic considerations.
Questions & Answers
QUESTION:
Suppose that the distillation column shown in Fig. 13.2 has been designed to separate a methanol-water mixture that is 50% methanol (MeOH). This high-purity column has a large number of trays and a nominal distillate composition of xn = 5 ppm of MeOH. Because a composition analyzer is not available, it is proposed to control xn indirectly, by measuring and controlling the liquid temperature at one of the following locations: (a) The reflux stream (b) The top tray in the rectifying section (c) An intermediate tray in the rectifying section, midway between the feed tray and the top tray Discuss the relative advantages and disadvantages of each choice, based on both steady-state and dynamic considerations.
ANSWER:Problem 13.3
Suppose that the distillation column shown in Fig. 13.2 has been designed to separate a methanol-water mixture that is 50% methanol (MeOH). This high-purity column has a large number of trays and a nominal distillate composition of 
(a) The reflux streams
(b) The top tray in the rectifying section
(c) An intermediate tray in the rectifying section, midway between the feed tray and the top tray
Discuss the relative advantages and disadvantages of each choice, based on both steady-state and dynamic considerations.
Step by Step Solution
Step 1 of 5
The figure 13.2 from the textbook. Is shown below.
Figure 1