Chapter 18: Models for Nonideal Reactors

Self Test 14.1: Sketch of F curves

The F curves for two different tubular reactors is shown below, for a closed–closed system

(a)  Which curve has the higher Peclet number?  Explain.

(a) Curve 1

(b) Curve 2

(c) Curve 3

(b)  Which curve has the higher dispersion coefficient?  Explain.

(a) Curve 1

(b) Curve 2

(c) Curve 3

(c)  If this F-curve is for the tanks-in-series model applied to two different reactors which curve uses the largest number of tanks to model the real reactor, (1) or (2)?

(a) Curve 1

(b) Curve 2

(c) Curve 3


Go to the Solution

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Solution

For plug flow (Da = 0 and Pe = ¥) we have

For small deviation from plug flow

For a CSTR Da = ¥ ‚

(a)  For small Da large Pe.

(b)  For large Da small Pe

(c)  For Plug flow represented by tanks-in-series n ® ¥. Therefore curve (1) is close to plug flow, therefore n is greater for modeling curve than for curve ‚.

 


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