1. General Mole Balance Equation Batch
Chemical Reaction Engineering (CRE) is the field that studies the rates and mechanisms of chemical reactions and the design of the reactors in which they take place.
TODAY’S LECTURE
Introduction
Definitions
General Mole Balance Equation
Batch
CSTR
PFR
PBR

2. Chemical Reaction Engineering
Chemical reaction engineering is at the heart of virtually every chemical process. It separates the chemical engineer from other engineers.
Industries that Draw Heavily on Chemical Reaction Engineering (CRE) are:
CPI (Chemical Process Industries)
Dow, DuPont, Amoco, Chevron

5. Materials on the Web and CDROM

11. Developing Critical Thinking Skills
Socratic Questioning
is the
Heart of Critical Thinking
R. W. Paul’s Nine Types of Socratic
Questions

12. Let’s Begin CRE
Chemical Reaction Engineering (CRE) is the field that studies the rates and mechanisms of chemical reactions and the design of the reactors in which they take place.

13. Chemical Identity
A chemical species is said to have reacted when it has lost its chemical identity.

14. Chemical Identity
A chemical species is said to have reacted when it has lost its chemical identity.
The identity of a chemical species is determined by the kind, number, and configuration of that species’ atoms.

15. Chemical Identity
A chemical species is said to have reacted when it has lost its chemical identity.
1. Decomposition

16. Chemical Identity
A chemical species is said to have reacted when it has lost its chemical identity.
1. Decomposition
2. Combination

17. Chemical Identity
A chemical species is said to have reacted when it has lost its chemical identity.
1. Decomposition
2. Combination
3. Isomerization

18. Reaction Rate
The reaction rate is the rate at which a species looses its chemical identity per unit volume.

19. Reaction Rate
The reaction rate is the rate at which a species looses its chemical identity per unit volume.
The rate of a reaction (mol/dm3/s) can be expressed as either
the rate of Disappearance: rA
or as
the rate of Formation (Generation): rA

20. Reaction Rate Consider the isomerization AB
rA = the rate of formation of species A per unit volume
-rA = the rate of a disappearance of species A per unit volume
rB = the rate of formation of species B per unit volume

21. Reaction Rate EXAMPLE: AB If Species B is being formed at a rate of
0.2 moles per decimeter cubed per second, ie,
rB = 0.2 mole/dm3/s

22. Reaction Rate EXAMPLE: AB rB = 0.2 mole/dm3/s
Then A is disappearing at the same rate:
-rA= 0.2 mole/dm3/s

23. Reaction Rate EXAMPLE: AB rB = 0.2 mole/dm3/s
Then A is disappearing at the same rate:
-rA= 0.2 mole/dm3/s
The rate of formation (generation of A) is
rA= -0.2 mole/dm3/s

24. NOTE: dCA/dt is not the rate of reaction
Reaction Rate
For a catalytic reaction, we refer to -rA',
which is the rate of disappearance of
species A on a per mass of catalyst basis.
(mol/gcat/s)
NOTE: dCA/dt is not the rate of reaction

25. Reaction Rate Consider species j:
rj is the rate of formation of species j per unit volume [e.g. mol/dm3/s]

26. Reaction Rate
rj is the rate of formation of species j per unit volume [e.g. mol/dm3*s]
rj is a function of concentration, temperature, pressure, and the type of catalyst (if any)

27. Reaction Rate
rj is the rate of formation of species j per unit volume [e.g. mol/dm3/s]
rj is a function of concentration, temperature, pressure, and the type of catalyst (if any)
rj is independent of the type of reaction system (batch reactor, plug flow reactor, etc.)

28. Reaction Rate
rj is the rate of formation of species j per unit volume [e.g. mol/dm3/s]
rj is a function of concentration, temperature, pressure, and the type of catalyst (if any)
rj is independent of the type of reaction system (batch, plug flow, etc.)
rj is an algebraic equation, not a differential equation

29. General Mole Balance

30. General Mole Balance

31. Batch Reactor Mole Balance

32. CSTR Mole Balance

33. Plug Flow Reactor

34. Plug Flow Reactor Mole Balance
PFR:
The integral form is:
This is the volume necessary to reduce the entering molar flow rate (mol/s) from FA0 to the
exit molar flow rate of FA.

35. Packed Bed Reactor Mole Balance
PBR
The integral form to find the catalyst weight is:

36. Reactor Mole Balance Summary

37. Fast Forward to the Future
Thursday March 20th, 2008
Reactors with Heat Effects

38. Production of Propylene Glycol in an Adiabatic CSTR

39. Solution What are the exit conversion X and exit temperature T?
Let the reaction be represented by

48. KEEPING UP

49. Separations These topics do not build upon one another Filtration
Distillation
Adsorption
These topics do not build upon one another

50. These topics build upon one another
Reaction Engineering
Mole Balance
Rate Laws
Stoichiometry
These topics build upon one another

51. Heat Effects
Isothermal Design
Stoichiometry
Rate Laws
Mole Balance

52. Rate Laws
Mole Balance

53. Isothermal Design
Heat Effects
Rate Laws
Stoichiometry
Mole Balance

62. Batch Reactor Mole Balance

63. Batch Reactor Mole Balance

64. Batch Reactor Mole Balance

65. Batch Reactor Mole Balance

66. Batch Reactor Mole Balance

67. Continuously Stirred Tank Reactor Mole Balance

68. Continuously Stirred Tank Reactor Mole Balance

69. Continuously Stirred Tank Reactor Mole Balance

70. C S T R Mole Balance

71. CSTR Mole Balance

72. Plug Flow Reactor

73. Plug Flow Reactor Mole Balance
PFR:

74. Plug Flow Reactor Mole Balance
PFR:

75. Plug Flow Reactor Mole Balance
PFR:

76. Plug Flow Reactor Mole Balance
PFR:

77. Plug Flow Reactor Mole Balance
PFR:

78. Plug Flow Reactor Mole Balance
PFR:
The integral form is:

79. Plug Flow Reactor Mole Balance
PFR:
The integral form is:
This is the volume necessary to reduce the entering molar flow rate (mol/s) from FA0 to the
exit molar flow rate of FA.

80. Packed Bed Reactor Mole Balance
PBR

81. Packed Bed Reactor Mole Balance
PBR

82. Packed Bed Reactor Mole Balance
PBR

83. Packed Bed Reactor Mole Balance
PBR

84. Packed Bed Reactor Mole Balance
PBR
The integral form to find the catalyst weight is:

85. Reactor Mole Balance Summary

86. Reactor Mole Balance Summary

87. Reactor Mole Balance Summary

88. Reactor Mole Balance Summary

98. Chemical Reaction Engineering Asynchronous Video Series
Chapter 1:
General Mole Balance Equation Applied to
Batch Reactors, CSTRs, PFRs, and PBRs
H. Scott Fogler, Ph.D.

106. Chemical Reaction Engineering
Chemical reaction engineering is at the heart of virtually every chemical process. It separates the chemical engineer from other engineers.
Industries that Draw Heavily on Chemical Reaction Engineering (CRE) are:
CPI (Chemical Process Industries)
Dow, DuPont, Amoco, Chevron
Pharmaceutical – Antivenom, Drug Delivery
Medicine – Tissue Engineering, Drinking and Driving

107. Compartments for perfusion
Stomach
VG = 2.4 l
Gastrointestinal
tG = 2.67 min
Liver
Alcohol
VL = 2.4 l
tL = 2.4 min
Central
VC = 15.3 l
tC = 0.9 min
Muscle & Fat
VM = 22.0 l
tM = 27 min
Perfusion interactions between compartments are shown by arrows.
VG, VL, VC, and VM are -tissue water volumes for the gastrointestinal, liver, central and muscle compartments, respectively.
VS is the stomach contents volume.

109. Chemical Reaction Engineering
Chemical reaction engineering is at the heart of virtually every chemical process. It separates the chemical engineer from other engineers.
Industries that Draw Heavily on Chemical Reaction Engineering (CRE) are:
CPI (Chemical Process Industries)
Dow, DuPont, Amoco, Chevron
Pharmaceutical – Antivenom, Drug Delivery
Medicine –Pharmacokinetics, Drinking and Driving
Microelectronics – CVD

110. Reaction Rate rA = the rate of formation of species A per unit volume
Consider the isomerization AB
rA = the rate of formation of species A per unit volume

111. Reaction Rate Consider the isomerization AB
rA = the rate of formation of species A per unit volume
-rA = the rate of a disappearance of species A per unit volume

112. Reactor Mole Balance Summary