Chemical Reaction Engineering Chapter 3, Part 4: Reaction Stoichiometry Measures Other Than...
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Transcript of Chemical Reaction Engineering Chapter 3, Part 4: Reaction Stoichiometry Measures Other Than...
Chemical Reaction Engineering
Chapter 3, Part 4:
Reaction Stoichiometry
Measures Other Than Conversion
Measures Other Than Conversion
Uses: A. Membrane reactors
B. Multiple reaction
Liquids: Use concentrations, i.e., CA
C A FA
0
Measures Other Than Conversion
Uses: A. Membrane reactors
B. Multiple reaction
Liquids: Use concentrations, i.e., CA
1. For the elementary liquid phase reaction carried out in a CSTR, where V, vo,CAo,k, and Kc are given and the feed is pure A, the combined
mole balance, rate laws, and stoichiometry are:
C A FA
0
A B
rA k C A CB
K C
Measures Other Than Conversion
Uses: A. Membrane reactors
B. Multiple reaction
Liquids: Use concentrations, i.e., CA
1. For the elementary liquid phase reaction carried out in a CSTR, where V, vo,CAo,k, and Kc are given and the feed is pure A, the
combined mole balance, rate laws, and stoichiometry are:
C A FA
0
A B
C A0 CA
rA
VFA0 FA
rA
0 C A 0 C A rA
rA k C A CB
K C
Measures Other Than Conversion
Uses: A. Membrane reactors
B. Multiple reaction
Liquids: Use concentrations, i.e., CA
1. For the elementary liquid phase reaction carried out in a CSTR, where V, vo,CAo,k, and Kc are given and the feed is pure A, the
combined mole balance, rate laws, and stoichiometry are:
C A FA
0
A B
C A0 CA
rA
VFA0 FA
rA
0 C A 0 C A rA
CA 0 C A
k CA CB
K C
rA k C A CB
K C
Measures Other Than Conversion
Uses: A. Membrane reactors
B. Multiple reaction
Liquids: Use concentrations, i.e., CA
1. For the elementary liquid phase reaction carried out in a CSTR, where V, vo,CAo,k, and Kc are given and the feed is pure A, the
combined mole balance, rate laws, and stoichiometry are:
C A FA
0
A B
C A0 CA
rA
VFA0 FA
rA
0 C A 0 C A rA
CA 0 C A
k CA CB
K C
V FB 0 FB
rB
0 C B 0 C B
rB
rA k C A CB
K C
Measures Other Than Conversion
3s, C A 0 2 mol dm3 , K C 10, k 0.1s 1
Measures Other Than Conversion
C B0 CB
rB
0 CB
rB
C B
rA
C B
rA
C B
k CA C B
KC
C B
k CA CB
K C
3s, C A 0 2 mol dm3 , K C 10, k 0.1s 1
Measures Other Than Conversion
C B0 CB
rB
0 CB
rB
C B
rA
C B
rA
C B
k CA C B
KC
2. There are two equations, two unknowns, CA and CB
3s, C A 0 2 mol dm3 , K C 10, k 0.1s 1
C B
k CA CB
K C
Measures Other Than Conversion
• Gases: Use molar flow rates, i.e., FI
C T FT
PRT
, CT 0 FT 0
0
P
RT0
Measures Other Than Conversion
• Gases: Use molar flow rates, i.e., FI
C T FT
PRT
, CT 0 FT 0
0
P
RT0
Measures Other Than Conversion
• Gases: Use molar flow rates, i.e., FI
C T FT
PRT
, CT 0 FT 0
0
P
RT0
Measures Other Than Conversion
• Gases: Use molar flow rates, i.e., FI
C A C T0
FA
FT
PP0
T0
T , CT 0 P0
RT0
C T FT
PRT
, CT 0 FT 0
0
P
RT0
Measures Other Than Conversion
• Gases: Use molar flow rates, i.e., FI
If the above reaction, ,carried out in the gas phase in a PFR, where V, vo,CAo,k, and Kc are given and the feed is pure A, the combined
mole balance, rate laws, and stoichiometry yield, for isothermal operation (T=To) and no pressure drop (P=0) are:
C A C T0
FA
FT
PP0
T0
T , CT 0 P0
RT0
C T FT
PRT
, CT 0 FT 0
0
P
RT0
rA k C A CB
K C
Measures Other Than Conversion
• Gases: Use molar flow rates, i.e., FI
If the above reaction, ,carried out in the gas phase in a PFR, where V, vo,CAo,k, and Kc are given and the feed is pure A, the combined
mole balance, rate laws, and stoichiometry yield, for isothermal operation (T=To) and no pressure drop (P=0) are:
C A C T0
FA
FT
PP0
T0
T , CT 0 P0
RT0
C T FT
PRT
, CT 0 FT 0
0
P
RT0
rA k C A CB
K C
Measures Other Than Conversion
• Gases: Use molar flow rates, i.e., FI
If the above reaction, ,carried out in the gas phase in a PFR, where V, vo,CAo,k, and Kc are given and the feed is pure A, the combined mole
balance, rate laws, and stoichiometry yield, for isothermal operation (T=To) and no pressure drop (P=0) are:
C A C T0
FA
FT
PP0
T0
T , CT 0 P0
RT0
C T FT
PRT
, CT 0 FT 0
0
P
RT0
Use Polymath to plot FA and FB down the length of the reactor.
rA k C A CB
K C
Measures Other Than Conversion
Use Polymath to plot FA and FB down the length of the reactor.
Given:
V0 30 dm 3 , 0 10 dm 3 s, K C 10, k 0.1s 1
Measures Other Than Conversion
Use Polymath to plot FA and FB down the length of the reactor.
Given:
V0 30 dm 3 , 0 10 dm 3 s, K C 10, k 0.1s 1
V
FA
FB
Summary
At the start of the chapter we saw we needed -rA=f(X). This result is achieved in two steps.
Summary
At the start of the chapter we saw we needed -rA=f(X). This result is achieved in two steps.
1. Rate Laws
– -rA=k f(Ci)
– 1st order A--> B or 1st order
-rA=kCA
rA k C A C B
KC
Summary
At the start of the chapter we saw we needed -rA=f(X). This result is achieved in two steps.
1. Rate Laws
– -rA=k f(Ci)
– 1st order A--> B or 1st order
– 2nd order A+B --> C
– Rate laws are found by experiment
-rA=kCA
rA k C A C B
KC
-rA=kACACB
Summary
At the start of the chapter we saw we needed -rA=f(X). This result is achieved in two steps.
1. Rate Laws
– -rA=k f(Ci)
– 1st order A--> B or 1st order
– 2nd order A+B --> C
– Rate laws are found by experiment
2. Stoichiometry
– Liquid:
– Gas:
-rA=kCA
rA k C A C B
KC
-rA=kACACB
C A CA 0 1 X
C A CA 0 1 X
1 X PP0
T0
T
C A CT 0
FA
FT
PP0
T0
T