Living Example 16-3 Wolfram and Python
1. Vary and find the combination of parameters for which the exit conversion is virtually the same for both early mixing and late mixing.
2. Find the combination of parameters for which there is a maximum difference between early mixing and late mixing.
3. Explain your findings for (i) and (ii) and then write a set of conclusions.

Example 16-3

Examples of early and late mixing for a given RTD Consider a second-order reaction being carried out in a real CSTR that can be modeled as two different reactor systems: In the first system an ideal CSTR is followed by an ideal PFR; in the second system the PFR precedes the CSTR. To simplify the calculations, let τs and τp each equal 1 minute, let the reaction-rate constant equal 1.0 m³/kmol·min, and let the initial concentration of liquid reactant, C_A0, equal 1.0 kmol/m³. Find the conversion in each system. For the parameters given, we note that in these two arrangements the RTD function, E(t), is the same

Two graphs are shown. In the first graph, the vertical axis represents E of t and the horizontal axis represents time. The graph plotted is concave upward decreasing curve. The curve starts at (tau subscript PFR, 1 over tau subscript CSTR) and decreases gradually. In the second graph, the vertical axis represents F of t and the horizontal axis represents time. The curve plotted starts at (tau subscript PFR, 0) and increases gradually to a maximum value of F(t) equals 1. Here, T subscript p equals T subscript s equals 1 minute, tau K equals 1 meter cubed over kilo mole, and C subscript A0 equals 1 kilo mole per meter cubed. Also, r subscript equals negative k times (C subscript A) squared.

Transcribed Image Text:

1 TCSTR E(t) N TPFR 1.0 TPFR T T = 1 min tk = 1 m/kmol and CAO = 1 kmol/m3 TA=-KC