Assume the individual film coefficients change according to the relationship

\[
h_{i} \alpha \text { velocity }{ }^{0.8}
\]

a. Estimate the effect of process flow changes on the overall heat transfer coefficient.

b. Determine the process flowrate that provides an IPA conversion of 0. 9 resulting from an increase in utility temperature of \(50^{\circ} \mathrm{C}\).

c. Does the assumption of constant overall heat transfer coefficient result in a higher or lower estimate of the process feed rate? If you worked Problem 23. 25, you have this value for comparison.

Problems 23. 21-23.26 investigate the performance of the acetone reactor system. The reaction kinetics are presented in Section 23. 5.3. The reactor and internal heat exchanger are fixed. For the base case, the active volume of the reactor is \(5.1 \mathrm{~m}^{3}\) at the operating conditions given in Figure 23. 10. Unless otherwise stated, the heat transfer coefficient and reactor pressure drop are to be assumed constant. The feed temperature, pressure, and component concentrations remain constant. For these calculations, assume the utility fluid to be n-heptadecane (at pressures more than \(30 \mathrm{bar}\) ). At the base case, the utility flow is \(58 \mathrm{kmol} / \mathrm{h}\).

Figure 23.10

Data from section 23.5.3

Transcribed Image Text:

Reactor Feed 234 2.16 Equipment Specifications 407 HTM in R-401 R-401 HTM out MOC - carbon steel 357 Vessel Size: Diameter - 1.85 m Length - 8 m Reactor Effluent Tubes: 350 Number - 448 1.91 Diameter - 2 in (5.1 cm) Flowrates (kmol/h) Length - 20 ft (6.1 m) Stream 2a 3 Heat Transfer Coefficient: Hydrogen 34.78 60 W/mC Acetone 0.16 34.94 IPA 38.64 3.86 Temperature (C) Water 19.04 19.04 Pressure (bar)