reactor design for multiple rxns

7/24/2019 Reactor Design for Multiple Rxns

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Slides courtesy of Prof M L Kraft, Chemical & Biomolecular Engr e!t, "ni#ersity of $llinois, "r%ana-Cham!aign

L9-1

'e#ie() $sothermal 'eactor esign$n *ut- +eneration .ccumulation1 Set u! mole %alance for

s!ecific reactor

/ eri#e design e0 in

terms of .for each

reactor

Batch CS2' P3'

4 Put C5is in terms of

.and !lug into r.

6 Plug r.into design e0 & sol#e for the time

7%atch8 or 7flo(8 re0uired for a s!ecific .

or the .o%tained for gi#en , :, time, etc

7;e (ill al(ays loo/

Reaction order

needs to bedetermined.

XAA

A0A0

dXt =N

-r V

XA dX

AV =FA0 -rA0

955: 5 5 d?3 3 r d9

dt + =

A0 A

A

F XV=

-r

5: 5 .: . : :5

. :

C C 2 =PC

1 P 2 =

+ = + n

. 5r


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L9-/

'e#ie() .nalysis of 'ate ata

@ Constant-#olume %atch reactor for homogeneous reactions) ma


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L9-4

'e#ie() Method of Ecess. + B A !roducts Sus!ect rate e0 -r.


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L9-6

'e#ie() ifferential Method

1 Plot C.Ht #s t

/ etermine dC.Hdt from !lot %y

gra!hical or numerical methods

a8 ra( rectangles on the gra!h2hen dra( a cur#ed line so that

the area a%o#e the cur#e that is

cut off of each rectangle

a!!roimately fills the unfilled

area under the cur#e%8 -dC.Hdt is read using the #alue

(here the cur#e crosses a

s!ecified time

4 Plot ln7-dC.Hdt8#s ln C.

: :

;here r.


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'e#ie() $ntegral Method

@ . trial-and-error!rocedure to find reaction order

@ uess the reaction order integrate the differential

e0uation

@ Method is used most often (hen reaction order is


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3or the reaction . !roducts

3or a first-order reaction - r. < C.ln 7C.:HC.8

t

3or a second-order reaction - r. < C.2

1HC.

t

3or a ero-order reaction -r.

reactor design for multiple rxns

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