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CSTR or Mixed flow reactor

Space time generally:

T = 1/S = (CAO)(V)/(FAo) = V/Vo

Where ,

T= space time

S = space velocity

CAo= initial concentration of A = moles of A

entering/volume of feed

V= reactor volume

FAo= moles of A entering / time

When conversion of A at inlet is zero, XA0= 0

T = (CAo) ( XA) / ( - rA)

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When conversion of A at inlet is not zero :

T = CAo ( XAf - XAo ) / (- rA)

In terms of concentration for constant density system (for liquid

phase reactions):

T = (CAoCA) / ( - rA)

-rA= k ( CA)n

CA= CAo( 1- XA)

For 1st

order reaction :

i ) K T = XA/ (1-XA)

ii) K T = (CAOCA ) / CA

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For variable density system (for gaseous phase reactions):

T = CAoXA / ( -r A)

-r A= k ( CA)n

CA= CAo( 1- XA) / ( 1+ EAXA)

For 1st

order reaction :

K T = XA( 1+ EAXA) /(1-XA)

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Plug flow reactor

When conversion of A at inlet is zero :

T = CAo xAf

rAdXA0

)/(

When conversion of A at inlet is not Zero :

T = CAo XAf

XAorAdXA )/(

For constant density system (for liquid phase reaction) in terms of

concentration:

T = - CAf

CAorAdCA )/(

-rA= k ( CA)n

CA= CAo( 1- XA)

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For variable density system:

T = CAo xAf

rAdXA0

)/(

-rA= k (CA)n

CA = CAo( 1- XA) / ( 1+ EAXA)

For 1st order reaction variable density:

K T = - ( 1+ EA) ln ( 1- XA) - EAXA

For second order reaction variable density :

CAoK T = 2 EA( 1+ EA) Ln (1-XA) + (E)2 XA+ (EA+1 ) XA/(1-XA)

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Note: Vf = Vo ( 1 + EAXA)