Lecture 13 Tuesday 2/19/08Complex Reactions

A +2B --> C2A + 3C --> D

• Liquid Phase PFR• Liquid Phase CSTR• Gas Phase PFR• Gas Phase Membrane Reactor Sweep Gas Concentration Essentially Zero Sweep Gas Concentration Increases with Distance

• Semibatch Reactor

More Multiple Reactions

CSTR (1) A + 2B →C (2) 2A + 3C → D

Mole balance:

Rates:

Parameters:

3222

211 CACCBAAA CCkrCCkr

00

00

0

0

0

0

000

000

VrCVD

VrCVC

VrCVCVB

VrCVCVA

DD

CC

BBB

AAA

00021 , , , , , VVCCkk BACA

0001.00001.0

3

1

3

2 2

132

121

0

0/

22221111

222111

221221

3222

211

D

C

D

CDC

CDCAACAB

DCACBA

DDCCCBBAAA

CACC

BAAA

CV

CV

F

FS

rrrrrrrr

rrrrrr

rrrrrrrrrr

CCkr

CCkr

PFR gas phase (no pressure drop)

(1) A + 2B →C (2) 2A + 3C → D

Mole balance:

Rates: Same

Stoich:

DD

BB

CC

AA

rdV

dFDr

dV

dFB

rdV

dFCr

dV

dFA

FFFFF

DCBAT

0000

yF

FCCy

F

FCCy

F

FCCy

F

FCC

T

DTD

T

CTC

T

BTB

T

ATA

1

0 else then 00001.0 if

y

F

FV

F

FS

D

C

D

C

Membrane Reactor (no pressure drop)

(1) A + 2B →C (2) 2A + 3C → D

Mole balance:

Rates: Same

Stoich: Same

Sweep gas balance:

DD

BB

CCC

AA

rdV

dFDr

dV

dFB

RrdV

dFCr

dV

dFA

CsweepCCC

T

T

T

T

CCkR

F

F

ydV

dy

F

F

ydW

dy

00 2

2

CCSW

CVCSWVCSW

RdV

dF

VRFF

0

SWT

SWTCSWSWSW

SW

CSWCSWCSW

F

FFVV

V

FCC

0

00

:2 Case 0:1 Case

Semibatch

(1) A + 2B →C (2) 2A + 3C → D

Mole balance:

Rates: Same

B

FA0

Vrdt

dN

Vrdt

dN

Vrdt

dN

VrFdt

dN

DD

CC

BB

AAA

0

)0( else then )0001.0( if

/

00

D

CDC

DD

CC

BB

AA

N

NtS

V

NC

V

NC

V

NC

V

NC

tvVV