410 likes | 627 Views
Chemical Reaction Engineering Asynchronous Video Series. Chapter 2: Conversion and Reactors in Series H. Scott Fogler, Ph.D. Reactor Mole Balance Summary. Conversion. Conversion. Conversion. Batch Reactor Conversion.
E N D
Chemical Reaction EngineeringAsynchronous Video Series Chapter 2: Conversion and Reactors in Series H. Scott Fogler, Ph.D.
Batch Reactor Conversion • For example, let’s examine a batch reactor with the following design equation:
Batch Reactor Conversion • For example, let’s examine a batch reactor with the following design equation: • Consider the reaction:
Batch Reactor Conversion • For example, let’s examine a batch reactor with the following design equation: • Consider the reaction:
Batch Reactor Conversion • For example, let’s examine a batch reactor with the following design equation: • Consider the reaction: Differential Form: Integral Form:
CSTR Conversion Algebraic Form: There is no differential or integral form for a CSTR.
PFR Conversion PFR
PFR Conversion PFR
PFR Conversion PFR Differential Form: Integral Form:
V Design Equations
V Design Equations
0.01 0 Example
0.01 0 0 Example
0.01 0 0 50 40 30 20 10 0.6 0.8 0.2 0.4 Example X
Reactor Sizing • Given -rA as a function of conversion, -rA=f(X), one can size any type of reactor.
Reactor Sizing • Given -rA as a function of conversion, -rA=f(X), one can size any type of reactor. • We do this by constructing a Levenspiel plot.
50 40 30 20 10 0.6 0.8 0.2 0.4 Reactor Sizing • Given -rA as a function of conversion, -rA=f(X), one can size any type of reactor. • We do this by constructing a Levenspiel plot. • Here we plot either as a function of X.
50 40 30 20 10 0.6 0.8 0.2 0.4 Reactor Sizing • Given -rA as a function of conversion, -rA=f(X), one can size any type of reactor. • We do this by constructing a Levenspiel plot. • Here we plot either as a function of X. • For vs. X, the volume of a CSTR is: XEXIT Equivalent to area of rectangle on a Levenspiel Plot
50 40 30 20 10 0.6 0.8 0.2 0.4 Reactor Sizing • Given -rA as a function of conversion, -rA=f(X), one can size any type of reactor. • We do this by constructing a Levenspiel plot. • Here we plot either as a function of X. • For vs. X, the volume of a CSTR is: • For vs. X, the volume of a PFR is: XEXIT Equivalent to area of rectangle on a Levenspiel Plot =area = area under the curve
Numerical Evaluation of Integrals • The integral to calculate the PFR volume can be evaluated using Simpson’s One-Third Rule:
Numerical Evaluation of Integrals • The integral to calculate the PFR volume can be evaluated using Simpson’s One-Third Rule (see Appendix A.4 on p. 924):
Reactors in Series • Also consider a number of CSTRs in series:
Reactors in Series • Finally consider a number of CSTRs in series: • We see that we approach the PFR reactor volume for a large number of CSTRs in series: X