Chemical Reactor Design_P. Harriott

8/18/2019 Chemical Reactor Design_P. Harriott

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Scilab Textbook Companion for

Chemical Reactor Design

by P. Harriott1

Created bySneha R Iyer

B-Tech Chemical EngineeringChemical Engineering

SASTRA University ,ThanjavurCollege Teacher

NACross-Checked by

Spandana

July 14, 2015

1Funded by a grant from the National Mission on Education through ICT,http://spoken-tutorial.org/NMEICT-Intro. This Textbook Companion and Scilabcodes written in it can be downloaded from the ”Textbook Companion Project”section at the website http://scilab.in


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Book Description

Title: Chemical Reactor Design

Author: P. Harriott

Publisher: CRC Press

Edition: 1

Year: 2002

ISBN: 978-0824708818

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Scilab numbering policy used in this document and the relation to theabove book.

Exa Example (Solved example)

Eqn Equation (Particular equation of the above book)

AP Appendix to Example(Scilab Code that is an Appednix to a particularExample of the above book)

For example, Exa 3.51 means solved example 3.51 of this book. Sec 2.3 meansa scilab code whose theory is explained in Section 2.3 of the book.

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Contents

List of Scilab Codes 4

1 Homogeneous Kinetics 6

2 Kinetic Models for Heterogeneous Reactions 15

3 Ideal Reactors 19

4 Diffusion and Reaction in Porous Catalysts 39

5 Heat and Mass Transfer in Reactors 52

6 Nonideal Flow 61

7 Gas Liquid Reactions 72

8 Multiphase Reactors 96

9 Fluidized Bed Reactors 104

10 Novel Reactors 108

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List of Scilab Codes

Exa 1.4 Activation energy from packed bed data . . . . . . . . 6Exa 1.5 Methods to determine km and vm . . . . . . . . . . . 11Exa 2.1 Effectiveness factor for solid catalyzed reaction . . . . 15Exa 3.1 Time to reach desired conversion for bimolecular batch

reaction . . . . . . . . . . . . . . . . . . . . . . . . . . 19Exa 3.2 Residence time and heat generation for four STR s in

series . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Exa 3.3 Effect of temperature on yield . . . . . . . . . . . . . . 23Exa 3.4 Volume of reactor for Gas Phase isothermal reaction . 26Exa 3.5 Rate Equation to fit Initial Rate data . . . . . . . . . 27Exa 3.6 Optimum reaction temperature . . . . . . . . . . . . . 31Exa 3.7 Equilibrium temperature as a function of conversion and

optimum feed temperature . . . . . . . . . . . . . . . 33

Exa 4.1 Diffusivity of Chlorine and tortuosity in catalyst pellet 39Exa 4.2 Effective diffusivity of O2 in air . . . . . . . . . . . . . 42Exa 4.3 Influence of Pore diffusion over rate . . . . . . . . . . 44Exa 4.4 Effectiveness factor for solid catalyzed reaction . . . . 46Exa 4.5 The optimum pore size distribution for a spherical pellet 48Exa 5.1 Temperature Profiles for tubular reactor . . . . . . . . 52Exa 5.2 Maximum internal temperature difference . . . . . . . 55Exa 5.3 Overall heat transfer coefficients and radial average bed

temperature for packed bed reactor . . . . . . . . . . . 56Exa 6.1 Power Consumption at 300 rpm speed of stirrer and

blending time . . . . . . . . . . . . . . . . . . . . . . . 61

Exa 6.2 Effect of diffusion on conversion for laminar flow . . . 64Exa 6.3 Effect of Axial dispersion and length on conversion . . 66Exa 6.4 Conversion in packed bed for same superficial velocity 68

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Exa 7.1 Overall Reaction Rate Coefficient Percent Resistance

Reaction Volume and Reactor Size . . . . . . . . . . . 72Exa 7.2 The gradient for B in the liquid film . . . . . . . . . . 75Exa 7.3 Overall mass transfer coefficient and percent resistance 76Exa 7.4 Local selectivity due to mass transfer limitations . . . 78Exa 7.5 Maximum rate of CO absorption and Dimensions of

Bubble Column Reactor . . . . . . . . . . . . . . . . . 80Exa 7.6 Fraction of O2 Power of agitator kLa and average dis-

solved oxygen concentration . . . . . . . . . . . . . . . 85Exa 7.7 Apparent value of kLa regime of operation and selectiv-

ity dependency on gas mixing . . . . . . . . . . . . . . 91Exa 8.1 Gas absorption coefficient and fraction of overall resis-

tance . . . . . . . . . . . . . . . . . . . . . . . . . . . 96Exa 8.2 External Mass Transfer resistance . . . . . . . . . . . 98Exa 8.3 Apparent rate constant and consistency . . . . . . . . 100Exa 9.1 Model II Volumetric Mass Transfer Coefficient K . . . 104Exa 9.2 Model II Fraction unconverted naphthalene . . . . . . 106Exa 10.1 Fraction unconverted naphthalene based on model II . 108Exa 10.2 Conversion as a function of No of Gauzes . . . . . . . 110

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Chapter 1

Homogeneous Kinetics

Scilab code Exa 1.4 Activation energy from packed bed data

1 / / H a r r i o t P . , 2 0 0 3 , C he m ic al R e a ct o r D e s ig n ( I−E d i t i o n) M a r c e l D ek ke r , I n c . , USA , pp 4 3 6 .

2 //C hapt e r−1 Ex1 . 4 Pg No . 233 / / T i t l e : A c t i v a t i o n e n er g y f ro m p ac ke d b ed d at a4 //

============================================================

5 clear

6 clc

7 clf

8 // COMMON INPUT9 L = [0 1 2 3 4 5 6 9]; / /Bed l e n g t h i n f e e t ( f t )

10 T = [3 30 338 348 361 380 4 15 447 458 ] //T e mpe r at ur eC or re sp on di ng t he bed l e ng t h g i ve n ( C )11 R = 1 . 9 8 5 8 7 E - 3 ; / / Gas c o n s t a n t ( k c a l / m ol K)12

13 //CALCLATION ( Ex1 . 4 . a )

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14 // B a s i s i s 1 mol o f f e e d A( F u r f u r a l ) X m ol es r e a c t ed

t o f or m F u r fu r a n and CO15 x = ( T - 3 3 0 ) . / 1 3 0 ; // C on ve rs i on b as ed on f r a c t i o n a lt em p er a tu r e r i s e

16 n = length ( T ) ; // 6 m ol es o f steam p er mole o f F u r f u r ali s u se d t o d e c r ea s e t em pe ra tu re r i s e i n t h e b ed

17 P _ m o l = x + 7 ; // T ot al No . o f m ol es i n p ro du ct s tr ea m18 for i = 1 : ( n - 1 )

19 T _ av g ( i ) = ( T ( i ) + T ( i +1 ) ) / 2

20 P _ m ol a v g ( i ) = ( P _ m ol ( i ) + P _ m ol ( i + 1 ) ) / 2

21 d e l t a _ L ( i ) = L ( i + 1 ) - L ( i )

22 k _ 1 ( i ) = ( ( P _ m o l a v g ( i ) ) / d e l t a _ L ( i ) ) * log ( ( 1 - x ( i ) )

/ ( 1 - x ( i + 1 ) ) )23 u 1 ( i ) = ( 1 / ( T _ a v g ( i ) + 2 7 3 . 1 5 ) ) ;

24 end

25 v 1 = ( log ( k _ 1 ) ) ;

26 i = length ( u 1 ) ;

27 X 1 = [ u 1 ones ( i ,1 ) ] ;

28 r e s u l t1 = X 1 \ v 1 ;

29 k _ 1 _ d a s h = exp ( r e s u l t 1 ( 2 , 1 ) ) ;

30 E 1 = ( - R ) * ( r e s u l t 1 ( 1 , 1 ) ) ;

31

32 //OUTPUT ( Ex1 . 4 . a )33 / / C o n s o l e O ut pu t

34 mprintf ( ’ \n OUTPUT Ex1 . 4 . a ’ ) ;35 mprintf ( ’ \n

============================================================n ’ )

36 mprintf ( ’ L \ t \ t T \ t \ t x \ t \ t T a ve ra ge \ t (7+x ) ave\ t k 1 ’ )

37 mprintf ( ’ \n( f t ) \ t \ t ( C ) \ t \ t \ t \ t ( C ) \ t ’ )38 mprintf ( ’ \n

============================================================

’ )39 for i = 1 : n - 1

40 mprintf ( ’ \n%f \ t %f \ t %f ’ , L ( i + 1 ) , T ( i + 1 ) , x ( i + 1 ) )41 mprintf ( ’ \ t %f \ t %f \ t %f ’ , T _ a v g ( i ) , P _ m o l a v g ( i ) , k _ 1

( i ) )

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42 end

43 mprintf ( ’ \n\nThe a c t i v a t i o n e ne rg y from t he s l o p e =%f k c a l / m ol ’ , E1 ) ;44 //

============================================================

45

46

47 / / T i t l e : I I O rd er R e a ct i o n48 //

============================================================

49 //CALCULATION ( Ex 1 . 4 . b )50 for i = 1 : ( n - 1 )

51 T _ av g ( i ) = ( T ( i ) + T ( i +1 ) ) / 2

52 P _ m ol a v g ( i ) = ( P _ m ol ( i ) + P _ m ol ( i + 1 ) ) / 2

53 d e l t a _ L ( i ) = L ( i + 1 ) - L ( i )

54 k _ 2 ( i ) = ( ( P _ m o l a v g ( i ) ) / d e l t a _ L ( i ) ) * ( ( x ( i + 1 ) - x ( i ) )

/ ( ( 1 - x ( i + 1 ) ) * ( 1 - x ( i ) ) ) )

55 u 2 ( i ) = ( 1 / ( T _ a v g ( i ) + 2 7 3 . 1 5 ) ) ;

56 end

57 v 2 = ( log ( k _ 2 ) ) ;

58 plot ( u 1 . * 1 0 0 0 , v 1 , ’ o ’

, u 2 . * 1 0 0 0 , v 2 , ’ ∗ ’

) ;

59 x l a b e l ( ” 1000/T ( Kˆ−1) ” ) ;60 y l a b e l ( ” l n k 1 o r l n k 2 ”) ;61 xtitle ( ” l n k v s 1 00 0/T ” ) ;62 l e g e n d ( ’ l n k 1 ’ , ’ l n k 2 ’ ) ;63 j = length ( u 2 ) ;

64 X 2 = [ u 2 ones ( j ,1 ) ] ;

65 r e s u l t2 = X 2 \ v 2 ;

66 k _ 2 _ d a s h = exp ( r e s u l t 2 ( 2 , 1 ) ) ;

67 E 2 = ( - R ) * ( r e s u l t 2 ( 1 , 1 ) ) ;

68

69 //OUTPUT ( Ex 1 . 4 . b )70 mprintf ( ’ \n OUTPUT Ex1 . 4 . b ’ ) ;71 mprintf ( ’ \n

============================================================n ’ )

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72 mprintf ( ’ L \ t \ t T \ t \ t x \ t \ t T a ve ra ge \ t (7+x ) ave

\ t k 2 ’ )73 mprintf ( ’ \n( f t ) \ t \ t ( C ) \ t \ t \ t \ t ( C ) \ t ’ )74 mprintf ( ’ \n

============================================================’ )

75 for i = 1 : n - 1

76 mprintf ( ’ \n%f \ t %f \ t %f ’ , L ( i + 1 ) , T ( i + 1 ) , x ( i + 1 ) )77 mprintf ( ’ \ t %f \ t %f \ t %f ’ , T _ a v g ( i ) , P _ m o l a v g ( i ) , k _ 2

( i ) )

78 end

79 mprintf ( ’ \n\nThe a c t i v a t i o n e ne rg y from t he s l o p e =

%f k c a l / m ol ’ , E2 ) ;80

81 // FILE OUTPUT82 f i d = mopen ( ’ .\ Chapter1−Ex4−Output . tx t ’ , ’ w ’ ) ;83 mfprintf ( f i d , ’ \n OUTPUT Ex1 . 4 . a ’ ) ;84 mfprintf ( f i d , ’ \n

============================================================n ’ )

85 mfprintf ( f i d , ’ L \ t \ t T \ t \ t x \ t \ t T a ve ra ge \ t(7+x) ave \ t k 1 ’ )

86 mfprintf ( f i d , ’ \n( f t ) \ t \ t ( C ) \ t \ t \ t \ t ( C ) \t ’ )

87 mfprintf ( f i d , ’ \n============================================================’ )

88 for i = 1 : n - 1

89 mfprintf ( f i d , ’ \n%f \ t %f \ t %f ’ , L ( i + 1 ) , T ( i + 1 ) , x ( i+ 1 ) )

90 mfprintf ( f i d , ’ \ t %f \ t %f \ t %f ’ , T _ a v g ( i ) , P _ m o l a v g ( i) , k _ 1 ( i ) )

91 end

92 mfprintf ( f i d , ’ \n\nThe a c t i v a t i o n e ne rg y fro m t hes l o p e =%f k c a l / m ol ’ , E1 ) ;

93 mfprintf ( f i d , ’ \n\n============================================================n ’ )

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94 mfprintf ( f i d , ’ \n OUTPUT Ex1 . 4 . b ’ ) ;

95 mfprintf ( f i d , ’ \n============================================================n ’ )

96 mfprintf ( f i d , ’ L \ t \ t T \ t \ t x \ t \ t T a ve ra ge \ t(7+x) ave \ t k 2 ’ )

97 mfprintf ( f i d , ’ \n( f t ) \ t \ t ( C ) \ t \ t \ t \ t ( C ) \t ’ )

98 mfprintf ( f i d , ’ \n============================================================’ )

99 for i = 1 : n - 1

100 mfprintf ( f i d , ’ \n%f \ t %f \ t %f ’ , L ( i + 1 ) , T ( i + 1 ) , x ( i+ 1 ) )

101 mfprintf ( f i d , ’ \ t %f \ t %f \ t %f ’ , T _ a v g ( i ) , P _ m o l a v g ( i) , k _ 2 ( i ) )

102 end

103 mfprintf ( f i d , ’ \n\nThe a c t i v a t i o n e ne rg y fro m t hes l o p e =%f k c a l / m ol ’ , E2 ) ;

104 mclose ( all ) ;

105

106 //

============================================================END OF PROGRAM===========================================

107 / / D i s c l a i m e r ( Ex1 . 4 . a ) : The l a s t v a l u e o f t a vg andk 1 c o r r e sp o n di n g t o L=9 i n T a bl e 1 . 6 ( Pg No .2 5) o f t he t ex tb oo k i s a m i sp r i n t .

108 / / The v a l ue s h ou l d be 4 5 2 . 5 and 4 . 9 55 4 7 6r e s p e c t i v e l y i n st e ad o f 455 a nd 1 8 . 2 a s p r i n te di n t h e t e xt b o ok .

109 // Hence t h e r e i s a c ha nge i n t he a c t i v a t i o n e ne rg yo b ta i n ed fro m t he c od e

110 // The a ns we r o b ta i n ed i s 2 1 . 39 3 5 k c a l / mol i n s t e a do f 27 k c al / mol a s r e po r t e d i n t he t ex tb oo k .

111 / / F ig ur e 1 . 8 i s a p l o t be t we en l n k 1 v s 1 00 0/Ti n s t e ad o f k 1 v s 10 00 /T as s t at e d i n t hes o l u t i o n o f Ex1 . 4 . a

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112 //

============================================================

113 / / D i s c l a i m e r ( Ex1 . 4 . b ) : T he re i s a d i s c r e p a n c yb et wee n t he computed v a lu e o f a c t i v a t i o n e ne rg yand v a lu e r e p o r te d i n t ex tb o ok

114 / / E rr or c ou ld have be en on s i m i l a r l i n e s a sr e p o r t e d f o r e x am p le Ex . 1 . 4 . a

115 / / F ur th er , i n t e r m e i d a t e v a l u e s f o r Ex . 1 . 4 . b i s n ota v a i l a b l e / r e p o rt e d i n t ex t bo o k and h en ce c o ul dn o t b e c o mp a re d .

116 / / F ig ur e 1 . 8 i s a p l o t be t we en l n k 2 v s 1 00 0/T

i n s t e ad o f k 2 v s 10 00 /T as s t at e d i n t hes o l u t i o n o f Ex1 . 4 . b

Scilab code Exa 1.5 Methods to determine km and vm


2 //C hapt e r−1 Ex1 . 5 Pg No . 293 / / T i t l e : Me th od s t o d e t e r m i ne km and vm4 //

============================================================

5 clear

6 clc

7 clf

8 //INPUT9 S = [ 2 ; 5 ; 1 0 ; 1 5 ] * 1 0 ^ ( - 3 ) ; // C o nc e nt r at i on o f s u b s t r a t e [

HCO3]10 r _ r e c i p r o c a l = [ 9 5 ; 4 5 ; 2 9 ; 2 5 ] * 1 0 ^ ( 3 ) ; // R e c i p r o ca l r a t e s

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( L−se c /mol )

1112 //CALCULATION13 // P lo t 1 r e f e r e q u at i on 1 . 24 Pg No . 2 914 x 1 = ( S ) . ^ ( - 1 ) ;

15 y 1 = r _ r e c i p r o c a l ;

16 s c f ( 0 )

17 plot ( x 1 , y 1 * 1 0 ^ ( - 3 ) , ’RED ’ ) ;18 x l a b e l ( ” 1/ [ S ] ”) ;19 y l a b e l ( ” (1 / r ) ∗10 ˆ−3 ” ) ;20 xtitle ( ” 1/ r v e rs u s 1/ S” ) ;21 p = length ( x 1 ) ;

22 X _ 1 = [ x 1 ones ( p , 1 ) ] ;23 R 1 = X _ 1 \ y 1 ;

24 s l o p e ( 1 ) = R 1 ( 1 , 1 ) ;

25 i n t e r c e p t ( 1 ) = R 1 ( 2 , 1 ) ;

26 v _ m ( 1 ) = ( 1 / ( i n t e r c e p t ( 1 ) ) ) ; //Maximum Re ac ti on Rate (mol/L−se c )

27 k _ m ( 1 ) = s l o p e ( 1 ) * v _ m ( 1 ) ; / / M i c h a e l i s −Mento n c o n s t a n t28

29 // P lo t 2 r e f e r e q u at i on 1 . 25 Pg No . 2 930 x 2 = S ;

31 y 2 = S . * r _ r e c i p r o c a l ;

32 s c f ( 1 )

33 plot ( x 2 * 1 0 ^ ( 3 ) , y 2 ) ;

34 x l a b e l ( ” ( S ) ∗1 0 ˆ 3 ” ) ;35 y l a b e l ( ” ( S ) / r ” ) ;36 xtitle ( ” ( S ) / r v e r s u s ( S ) ”) ;37 q = length ( x 2 ) ;

38 X _ 2 = [ x 2 ones ( q , 1 ) ] ;

39 R 2 = X _ 2 \ y 2 ;

40 s l o p e ( 2 ) = R 2 ( 1 , 1 ) ;

41 i n t e r c e p t ( 2 ) = R 2 ( 2 , 1 ) ;

42 v _ m ( 2 ) = 1 / ( s l o p e ( 2 ) ) ; //Maximum R e a c t i on R at e ( mol /L−se c )

43 k _ m ( 2 ) = i n t e r c e p t ( 2 ) / ( s l o p e ( 2 ) ) ; / / M i c h a e l i s −Mentonc o n s t a n t

44

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45

46 //OUTPUT47 mprintf ( ’ \n============================================================’ ) ;

48 mprintf ( ’ \n \ t \ t M e t h o d 1 \ t M e t hod 2 ’ ) ;49 mprintf ( ’ \n

============================================================’ ) ;

50 i =1

51 mprintf ( ’ \n S l o p e \ t%f \ t%f ’ , s l o p e ( i ) , s l o p e ( i+ 1 ) ) ;

52 mprintf ( ’ \n I n t e r c e p t \ t%f \ t%f ’ , i n t e r c e p t ( i ) ,i n t e r c e p t ( i + 1 ) ) ;

53 mprintf ( ’ \n Km (M) \ t%f \ t%f ’ , k _ m ( i ) , k _ m ( i+ 1 ) ) ;

54 mprintf ( ’ \n Vm( m ol / L−s e c ) %f \ t%f ’ , v _ m ( i ) , v _ m ( i+ 1 ) ) ;

55

56 // FILE OUTPUT57 f i d = mopen ( ’ .\ Chapter1−Ex5−Output . tx t ’ , ’ w ’ ) ;58 mfprintf ( f i d , ’ \n

============================================================’ ) ;59 mfprintf ( f i d , ’ \n \ t \ t M e t h o d 1 \ t M e t hod 2 ’ ) ;60 mfprintf ( f i d , ’ \n

============================================================’ ) ;

61 i =1

62 mfprintf ( f i d , ’ \n S l o p e \ t%f \ t%f ’ , s l o p e ( i ) ,s l o p e ( i + 1 ) ) ;

63 mfprintf ( f i d , ’ \n I n t e r c e p t \ t%f \ t%f ’ , i n t e r c e p t( i ) , i n t e r c e p t ( i + 1 ) ) ;

64 mfprintf ( f i d , ’ \n Km (M) \ t%f \ t%f ’ , k _ m ( i ) ,k _ m ( i + 1 ) ) ;

65 mfprintf ( f i d , ’ \n Vm( m ol / L−s e c ) %f \ t%f ’ , v _ m ( i ) ,v _ m ( i + 1 ) ) ;

66 mclose ( f i d ) ;

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67

68 // ============================================================END OF PROGRAM=================================

69 // D i s c l a im e r : L ea s t S qu ar e method i s u se d t o f i n dt he s l o p e and i n t e r c e p t i n t h i s ex ampl e .

70 // Hence t he v a l u e s d i f f e r from t he g r a p h i c a l l yo bt ai ne d v a lu e s o f s l o p e and i n t e r c e p t i n t h et e x t b o o k .

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Chapter 2

Kinetic Models for

Heterogeneous Reactions

Scilab code Exa 2.1 Effectiveness factor for solid catalyzed reaction

1 / / H a r r i o t P . , 2 0 0 3 , C he m ic al R e a ct o r D e s ig n ( I−E d i t i o n) M a r c e l D ek ke r , I n c . USA , pp 4 3 6 .

2 //C hapt e r−2 E x2 . 1 Pg No . 5 23 / / T i t l e : E f f e c t i v e n e s s f a c t o r f o r s o l i d c a ta l y z e d

r e a c t i o n4 //

============================================================

5 clear

6 clc

7 clf8 //INPUT9 // Case : I c o n st a n t h yd ro ge n p r e s s u r e : P H2= 2 11 0

t o r r10 P _ B = [7 0 1 85 2 86 ]; // B en ze ne P r e s s u r e ( t o r r )

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11 r _1 = 1 E -3 * [4 .2 7 5 .4 6 .1 2 ]; / / ( m ol / h r g ) o b s e rv e d

r a t e s12 P _ H 2 _ c o n s t = 2 1 1 0 ; / / C o n st a nt H yd ro ge n P r e s s u r e ( t o r r )13

14

15 / / Case : I I C on st an t b en ze ne p r e s s u r e P B c on st =70t o r r

16 P _ H 2 = [ 1 05 0 2 1 05 2 9 88 ] ; / / H yd ro ge n P r e s s u r e ( t o r r )17 r _ 2 =1 E - 3 * [ 3. 81 4 .2 7 4 .5 ]; // ( m ol / h r g ) o b s e rv e d

r a t e s18 P _ B _ c o n s t = 7 0 ; / / C o n st a nt B en ze ne P r e s s u r e ( t o r r )19

20 //CALCULATION21 // Case : I c o n st a n t h yd ro ge n p r e s s u r e : P H2= 2 11 0

t o r r22

23 n = length ( P _ B )

24 for i = 1 : n

25 Y _ 1 ( i ) = ( P _ B ( i ) * P _ H 2 _ c o n s t / r _ 1 ( i ) ) ^ ( 1 / 3 ) ;

26 X _ 1 ( i ) = P _ B ( i ) ;

27 end

28 c o e f s _ I = regress ( X _ 1 ’ , Y _ 1 ’ ) ;

29 i n t e r c e p t _ 1 = c o e f s _ I ( 1 )

30 s l o p e _ 1 = c o e f s _ I ( 2 )

31

32 / / Case : I I C on st an t b en ze ne p r e s s u r e P B c on st =70t o r r

33 m = length ( P _ H 2 )

34 for i = 1 : n

35 Y _ 2 ( i ) = ( P _ B _ c o n s t * P _ H 2 ( i ) / r _ 2 ( i ) ) ^ ( 1 / 3 ) ;

36 X _ 2 ( i ) = ( P _ H 2 ( i ) ) ^ 0 . 5 ;

37 end

38 c o e f s _ I I = regress ( X _ 2 ’ , Y _ 2 ’ ) ;

39 i n t e r c e p t _ 2 = c o e f s _ I I ( 1 ) ;40 s l o p e _ 2 = c o e f s _ I I ( 2 ) ;

41 c o e f _ 1 = ( i n t e r c e p t _ 1 ) ^ 0 . 5 ;

42 c o e f _ 2 = ( s l o p e _ 1 * s l o p e _ 2 ) ^ ( 1 / 2 ) * ( s l o p e _ 1 / s l o p e _ 2 ) *

i n t e r c e p t _ 1 ;

16


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43

44 function y = f u n c t 1 ( K _ H 2 )45 y = c o e f _ 2 * K _ H 2 ^ 0 . 5 - c o e f _ 1 * K _ H 2 ^ ( 4 / 3 ) - 1

46 e n d f u n c t i o n

47

48 [ K _ H 2 _ r e s ] = fsolve ( 0 , f u n c t 1 ) ;

49

50 K _ B = K _ H 2 _ r e s ^ ( 4 / 3 ) * ( s l o p e _ 1 / s l o p e _ 2 ) ;

51

52 k = ( 0 . 6 3 5 ) ^ ( - 1 / 3 ) * K _ B ^ 2 / K _ H 2 _ r e s ;

53 s c f ( 0 )

54 plot ( X _ 1 , Y _ 1 , ’−∗− ’ )

55 xtitle ( ’ B e nz e ne H y d r o g e n a t i o n ( a ) V a r i a b l e b e n z e n ep r e s s u r e ’ )

56 x l a b e l ( ” P B ( t o r r ) ” ) ;57 y l a b e l ( ” ( P H2 P B /1 0 ˆ3 r ) ̂ ( 1 / 3 ) ” ) ;58 l e g e n d ( ’T=67.6 C ’ ) ;59

60 s c f ( 1 )

61 plot ( X _ 2 , Y _ 2 , ’−∗− ’ )62 xtitle ( ’ B e nz e ne H y d r o g e n a t i o n ( b ) V a r i a b l e h y d ro g e n

p r e s s u r e ’ )63 x l a b e l (

” P H2 ( t o r r ) ”) ;

64 y l a b e l ( ” ( P H2 P B /1 0 ˆ3 r ) ̂ ( 1 / 3 ) ” ) ;65 l e g e n d ( ’T=67.6 C ’ ) ;66

67 //OUTPUT68 mprintf ( ’ \n S o lv i n g f o r t h e t h r e e p ar am et er s g i v e s ’ )

;

69 mprintf ( ’ \n K H2 = %f t o r r ˆ−1 ’ , K _ H 2 _ r e s ) ;70 mprintf ( ’ \n K B = %f t o r r ˆ−1 ’ , K _ B ) ;71 mprintf ( ’ \n k = %E ’ , k ) ;72

73 // FILE OUTPUT74 f i d = mopen ( ’ .\ Chapter2−Ex1−Output . tx t ’ , ’ w ’ ) ;75 mfprintf ( f i d , ’ \n S o l v i ng f o r t he t h r e e p ar am et er s

g i v e s ’ ) ;76 mfprintf ( f i d , ’ \n K H2 = %f t o r r ˆ−1 ’ , K _ H 2 _ r e s ) ;

17


19/115

77 mfprintf ( f i d , ’ \n K B = %f t o r r ˆ−1 ’ , K _ B ) ;

78 mfprintf ( f i d , ’ \n k = %E ’ , k ) ;79 mclose ( f i d ) ;80

81 //=============================================================

82 // D i s c l a im e r : Page 53 There i s a t yp o i n t hee qu a ti o n f o r Y o b t ai ne d f o r Model c a se I :C on st an t h yd ro ge n p r e s s u r e and v a r i a b l e b en ze nep r e s s ur e f o r m u l at i o n

83 // From F i g 2 . 7 ( a ) , I t i s e v id e nt t ha t f o r P H2 =

21 10 t or r , t h r e e e x p e ri m en t al p o i n ts a r ec o n si d e r e d f o r l i n e a r r e g r e s s i o n . However , fromt a b l e 2 . 1 , o nl y two p o i n ts c o rr e sp o n ds t o P H2 =2 11 0 t o r r . I n c om pa ri so n w it h F ig . 2 . 7 ( a ) , t het a b l e v al ue c o r r e s p o nd i n g t o P H2 = 2105 i s a l s or ea d a s P H2 = 2 1 1 0 .

84 / / T h er e f o re t he v a l ue s o f t he c o ns t a nt s a red i f f e r e n t from t ha t o b ta i n ed i n t he t ex tb oo k .A l s o r e g r e s s i o n i s u s e d t o o bt ai n t h e v al u e s o f s l o p e s and i n t e r c e p t w he re as t he t ex tb oo k

c o n s i d e r s g r a p h i c a l method f o r t he c om pu ta ti on o f t he c o de s

18


20/115

Chapter 3

Ideal Reactors

Scilab code Exa 3.1 Time to reach desired conversion for bimolecular batchreaction


2 //C hapt e r−1 E x3 . 1 Pg No . 8 4

3 // T i t l e : Time t o r ea c h d e s i r e d c o n v e r si o n f o rb i m ol e c u l a r b at c h r e a c t i o n

4 //============================================================

5 clear

6 clc

7 //INPUT8 C _ A 0 = 1 ; // Assuming 1 mol b a s i s f o r t he l i m i t i n g

r e a c t a n t

9 C _ B 0 _ o l d = 1 . 0 2 ; // 2% Ex ce ss o f r e a ct a n t B i s s u p p l i e d10 R _ o l d = C _ B 0 _ o l d / C _ A 0 ; / / R e f er e q u a t i o n 3 . 7 Pg No .11 X _ A = 0 . 9 9 5 ; // C on ve rs io n i n te r m s o f l i m i t i n g r e a ct a n t12 t _ o l d = 6 . 5 ; // Time r e q u i r e d f o r t he g i ve n c o n ve r si o n (

hr )

19


21/115

13 C _ B 0 _ n e w = 1 . 0 5 ; // 5% E xc es s o f r e a c t a n t B

14 R _ n e w = C _ B 0 _ n e w / C _ A 0 ; / / R e f er e q u a t i o n 3 . 7 Pg No . 8 31516 //CALCULATION17 k =( log ( ( R _ o ld - X _ A ) / ( R _ o l d * ( 1 - X _ A ) ) ) / ( ( R _ ol d -1 ) * t _ o l d

* C _ A 0 ) ) ;

18 t _ n e w = log ( ( R _ n ew - X _ A ) / ( R _ n e w * ( 1 - X _ A ) ) ) / ( ( R _ ne w - 1 ) * k *

C _ A 0 ) ;

19

20 //OUTPUT21 mprintf ( ’ \nTime r e q u i r e d t o a c h i ev e r e q u i r e d

c o n v e r s i o n f o r 5%% e x c e s s o f B= %f h r ’ , t _ n e w ) ;

2223 // FILE OUTPUT24 f i d = mopen ( ’ . \ Chapter3−Ex1−Output . tx t ’ , ’w ’ ) ;25 mfprintf ( f i d , ’ \nTime r e q u i r e d t o a c h i ev e r e q u i r e d

c o n v e r s i o n f o r 5%% e x c e s s o f B= %f h r ’ , t _ n e w ) ;26 mclose ( f i d ) ;

27 //=================================================END OF PROGRAM==================================

Scilab code Exa 3.2 Residence time and heat generation for four STR sin series


2 //C hapt e r−3 Ex3 . 2 Pg No . 963 // T i t l e : R es i de n ce t im e and h ea t g e n e r a t i o n f o r f o u r

STR ’ s i n s e r i e s4 //============================================================

5 clear

20


22/115

6 clc

7 // COMMON INPUT8 X _ A = 0 . 9 5 ; // G ive n c o n v e r s i o n9 t _ b a t c h = 6 ; // B atch t im e t o r ea c h t he d e s i r e d

c o n v e r s i o n10 N =4 //No . o f r e a c t o r s i n s e r i e s11 X _ f i n a l = X _ A ;

12

13 //CALCULATION ( Ex3 . 2 . a )14 k = log ( ( 1 / ( 1 - X _ A ) ) ) / t _ b a t c h ; // R e f er e q u a t i on 3 . 2 9 Pg

No . 9 015 t _ 1 = ( ( 1 / ( 1 - X _ A ) ) ^ ( 1 / N ) - 1 ) / k ; / / R e f er e q u a t i o n 3 . 4 0 Pg

No . 9416 t _ T o t = N * t _ 1 ;

17

18 //OUTPUT ( Ex3 . 2 . a )19 mprintf ( ’ \n OUTPUT Ex3 . 2 . a ’ ) ;20 mprintf ( ’ \n

============================================================’ ) ;

21 mprintf ( ’ \nThe t o t a l r e s i d e n c e t i m e o f t h e f o u rr e a c t o r s i n s e r i e s = %f hr ’ , t _ T o t ) ;

22

23 //============================================================

24

25 / / T i t l e : H ea t g e n e r a t i o n i n CSTR i n S e r i e s26 //

============================================================

27 //CALCULATION ( Ex3 . 2 . b )28 t _ 1 = ( ( 1 / ( 1 - X _ f i n a l ) ) ^ ( 1 / N ) - 1 ) / k ; / / R e f e r e q u a t i o n

3 . 4 0 Pg No . 9429 for i = 1 : N

30 X ( i ) = 1 - ( 1 / ( 1 + k * t _ 1 ) ^ ( i ) ) ;

31 end

32

21


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33 d e l Q _ b y _ Q ( 1 ) = ( X ( 1 ) ) / X _ f i n a l ; // R a t i o o f h ea t

g e n e ra t ed i n 1 s t r e a c t o r34 for i = 1 : N - 135 d e l Q _ b y _ Q ( i + 1 ) = ( X ( i + 1 ) - X ( i ) ) / X _ f i n a l ; / / R at i o

o f h ea t g e n e r a te d i n 2nd , 3 r d and 4 t hr e a c t o r s

36 end

37

38 //OUTPUT ( Ex3 . 2 . b )39 mprintf ( ’ \n

============================================================n ’ )

40 mprintf ( ’ \n OUTPUT Ex3 . 2 . b ’ ) ;41 mprintf ( ’ \n

============================================================’ ) ;

42 mprintf ( ’ \ n Re ac to r v e s s e l \ t C o n ve r si o n \ t F r a c ti o no f t o t a l h e a t r e l e a s e d \n ’ )

43 mprintf ( ’ \n============================================================’ )

44 for i = 1 : N

45 mprintf ( ’ \n %d \ t \ t %0 . 3 f \ t \ t \ t %0 . 3 f \n ’

,i ,

X ( i ) , d e l Q _ b y _ Q ( i ) )

46 end

47

48 // FILE OUTPUT49 f i d = mopen ( ’ . \ Chapter3−Ex2−Output . tx t ’ , ’w ’ ) ;50 mfprintf ( f i d , ’ \n OUTPUT Ex3 . 2 . a ’ ) ;51 mfprintf ( f i d , ’ \n

============================================================’ ) ;

52 mfprintf ( f i d , ’ \nThe t o t a l r e s i d e n c e t i m e o f t h e f o u r

r e a c t o r s i n s e r i e s = %f hr ’ , t _ T o t ) ;53 mfprintf ( f i d , ’ \n

========================================================’ )

54 mfprintf ( f i d , ’ \ n Re ac to r v e s s e l \ t C o nv e rs i o n \ t

22


24/115

F ra c t i o n o f t o t a l h ea t r e l e a s e d \n ’ )

55 mfprintf ( f i d , ’ \n========================================================’ )

56 for i = 1 : N

57 mfprintf ( f i d , ’ \n %d \ t \ t %0 . 3 f \ t \ t \ t %0 . 3 f \n ’ , i , X ( i ) , d e l Q _ b y _ Q ( i ) )

58 end


60

61

62 //

============================================================END OF PROGRAM================================

Scilab code Exa 3.3 Effect of temperature on yield

1 / / H a r r i o t P . , 2 0 0 3 , C he m ic al R e a ct o r D e s ig n ( I−E d i t i o n

) M a r c e l D ek ke r , I n c . , USA , pp 4 3 6 .2 //C hapt e r−3 Ex3 . 3 Pg No . 973 // T i t l e : E f f e c t o f t em p er a tu re on y i e l d4 //

============================================================

5 clear

6 clc

7 //INPUT8 C _ A 0 = 1 ; / / I n i t i a l c o n c e n t r a t i o n o f A

9 C _ B 0 = 5 ; / / I n i t i a l c o n c e n t r a t i o n o f B10 E 1 = 1 5 ; / / A c t i v a t i o n e n er g y f o r f i r s t r e a c t i o n ( k c a l )11 E 2 = 2 0 ; // A c t i va t i o n e ne rg y f o r s ec on d r e a c t i o n ( k c a l )12 X _ A = 0 . 8 8 ; // T ot a l c o nv e r s i o n o f r e a c t a n t A13 Y = 0 . 8 1 ; // Y i e l d f o r t he r e a c t i o n t o p ro du ce C

23


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14 R = 1 . 9 8 7 ; //Gas Cons tan t ( c a l /Kˆ−1 m o l ˆ−1)

15 T _ 0 = 3 5 0 ; / / T e m p e r a t ur e (K )1617 //CALCULATION18 / / As sum in g f i r s t o r d e r by t a k i n g c o n c e n t r a t i o n o f B

c on st an t s i n c e B i s i n E x ce ss19 C _ A = C _ A0 * ( 1 - X _ A ) ; / / U n r ea c te d amount o f A20 C _ B = C _ B 0 - Y ; / / U n r ea c te d amount o f B21 k 1 _ p l u s _ k 2 _ t = ( X _ A / ( 1 - X _ A ) ) ;

22 S = Y / X _ A ; //A t 350K23 k 1 _ b y _ k 2 = 1 1 . 5 7 ;

24 k 1 _ p l u s _ k 2 _ b y _ k 2 = k 1 _ b y _ k 2 + 1 ; // R ef e r Ex3 . 3 f o r t he

c od ed e q u a t i o n s25 k 2 _ t = k 1 _ p l u s _ k 2 _ t / k 1 _ p l u s _ k 2 _ b y _ k 2 ;

26 k1_t= k1_plus_k2_t -k2_t ;

27 T = 3 4 5 ;

28 for i = 1 : 7

29 T = T + 5 ;

30 T e m p ( i ) = T ;

31 k 1 _ d a s h _ t ( i ) = k 1 _ t * exp ( ( ( E 1 * 1 0 0 0 / R ) * ( ( 1 / T _ 0 ) - ( 1 / T ) ) ) )

; / / A r r h e n i u s l a w32 k 2 _ d a s h _ t ( i ) = k 2 _ t * exp ( ( ( E 2 * 1 0 0 0 / R ) * ( ( 1 / T _ 0 ) - ( 1 / T ) ) ) )

;/ / A r r h e n i u s l a w33 k 1 _ p l u s _ k 2 _ t _ n e w ( i ) = k 1 _ d a s h _ t ( i ) + k 2 _ d a s h _ t ( i ) ;

34 X _ A _ n e w ( i ) = k 1 _ p l u s _ k 2 _ t _ n e w ( i ) / ( 1 + k 1 _ p l u s _ k 2 _ t _ n e w ( i

) ) ;

35 S _ n e w ( i ) = ( ( k 1 _ d a s h _ t ( i ) / k 2 _ d a s h _ t ( i ) ) / ( 1 + ( k 1 _ d a s h _ t (

i ) / k 2 _ d a s h _ t ( i ) ) ) ) ;

36 Y _ n e w ( i ) = S _ n e w ( i ) * X _ A _ n e w ( i ) ;

37 end

38

39 //OUTPUT40 mprintf ( ’=======================================’ ) ;

41 mprintf ( ’ \n\ t T \ t X A \ t S \ t Y ’ ) ;42 mprintf ( ’ \n\ t K \ t (−) \ t (−) \ t (−) ’ ) ;43 mprintf ( ’ \n======================================’ ) ;44 for i = 1 : 7

45 mprintf ( ’ \n\ t %d \ t %0 . 3 f \ t %0 . 3 f \ t %0 . 3 f ’ ,

24


26/115

T e m p ( i ) , X _ A _ n e w ( i ) , S _ n e w ( i ) , Y _ n e w ( i ) ) ;

46 end47 m a x i m u m = max ( Y _ n e w ) ;

48 mprintf ( ’ \n\ t \nThe maximum v a l u e o f y i e l d i s %f ’ , ma ximu m ) ;

49 mprintf ( ’ \n\ t \nHigh y i e l d i s o b ta i n ed b etw een 3 65Kt o 3 75K ’ ) ;

50

51 // FILE OUTPUT52 f i d = mopen ( ’ . \ Chapter3−Ex3−Output . tx t ’ , ’w ’ ) ;53 mfprintf ( f i d , ’

=======================================’ ) ;

54 mfprintf ( f i d , ’ \n\ t T \ t X A \ t S \ t Y ’ ) ;55 mfprintf ( f i d , ’ \n\ t K \ t (−) \ t (−) \ t (−) ’ ) ;56 mfprintf ( f i d , ’ \n

======================================’ ) ;57 for i = 1 : 7

58 mfprintf ( f i d , ’ \n\ t %d \ t %0 . 3 f \ t %0 . 3 f \ t %0 . 3 f ’ , T e m p ( i ) , X _ A _ n e w ( i ) , S _ n e w ( i ) , Y _ n e w ( i ) ) ;

59 end

60 m a x i m u m = max ( Y _ n e w ) ;

61 mfprintf ( f i d , ’ \n\ t \nThe maximum v a l u e o f y i e l d i s

%f ’, m a x i m u m ) ;

62 mfprintf ( f i d , ’ \n\ t \nHigh y i e l d i s o b ta i n ed b etw een3 6 5K t o 3 7 5K ’ ) ;


64 //======================================================END OF PROGRAM===================================================

65 / / D i s c l a i m e r : R e f er Ex3 . 3 i n t h e t e xt b o ok TheA r rh e ni u s la w e q ua t i on h as a t yp o e r r o r .

E x po n en t ia l term m i s s in g i n t he t ex tb o ok

25


27/115

Scilab code Exa 3.4 Volume of reactor for Gas Phase isothermal reaction


2 //C hapt e r−3 Ex3 . 4 Pg No . 1 013 / / T i t l e : Volume o f r e a c t o r f o r Gas P ha se i s o t h e r m a l

r e a c t i o n4 //

============================================================

5 clear

6 clc

7 //INPUT8 / / F i r s t O rd er R e a c t io n9 / / B a s i s : 1 mol o f f e e d

10 k = 0 . 4 5 ; // R ate c o n st a n t o f f i r s t o r d er r e a c t i o n ( s −1)11 v 0 = 1 2 0 ; / / V o l u m e t r i c f l o w r a t e ( cm3 / s )

12 C _ A 0 = 0 . 8 ; / / I n i t i a l am ou nt o f r e a c t a n t A ( m o l )13 X _ A = 0 . 9 5 ; // C on ve rs io n i n t er ms o f r e a c t a n t A14 C _ i n e r t = 0 . 2 ; // C o n c en t r a t io n o f i n e r t ( N i t ro g e n ) i n

f e e d15

16 //CALCULATION17 E _ A = ( ( 2 * C _ A 0 + C _ i n e r t ) - ( C _ A 0 + C _ i n e r t ) ) / ( C _ A 0 + C _ i n e r t )

; / / Volume f r a c t i o n18 T o t _ m o l = ( C _ A 0 + C _ i n e r t ) + ( E _ A ) ; // T o ta l No . o f m o le s19 V = v 0 * ( ( - ( E _ A ) * X _ A ) + T o t _ m o l * ( log ( 1 / ( 1 - X _ A ) ) ) ) / ( k ) ; //

R e f er P er fo rm a nc e E qu a ti o n e q u a t io n 3 . 4 4 and 3 . 4 2

i n Pg No . 1 0020 V _ l = V * 1 0 ^ - 3 ; / / Volume o f r e a c t o r i n l i t e r s21

22 //OUTPUT

26


28/115

23 mprintf ( ’ \n\ tThe Volume o f t he r e a c t o r r e q ui r e d f o r

t h e g i v e n c o n v e r s i o n i s %. 0 f cm3 o r %0 . 2 f l i t e r s ’, V , V _ l ) ;24

25 // FILE OUTPUT26 f i d = mopen ( ’ .\ Chapter3−Ex4−Output . tx t ’ , ’ w ’ ) ;27 mfprintf ( f i d , ’ \n\ tThe Volume o f t he r e a c t o r r e q u i r e d

f o r t he g i ve n c o n ve r si o n i s %. 0 f cm3 o r %0 . 2 f l i t e r s ’ , V , V _ l ) ;


29 //============================================================

END OF PROGRAM==========================================

Scilab code Exa 3.5 Rate Equation to fit Initial Rate data


2 //C hapt e r−3 Ex3 . 5 Pg No . 1 043 / / T i t l e : R at e E q ua t io n t o f i t I n i t i a l R at e d a ta4 //

============================================================

5 clear

6 clc

7 c l f ( )

8 //INPUT ( Ex3 . 5 . 1 )9 // I n i t i a l Rate Data

10 B _b y_ A= [5 7 10 20 3 7]; //B/A M ol R at i o11 r _ 0 =[ 75 65 50 3 3 1 8] ; / / Ra te ( m ol / h r g )

27


29/115

12

13 //CALCULATION ( Ex3 . 5 . 1 )14 / / A ss um in g E l ey R i d e a l Mech an is m f o r t h e b e n ze n ea l k y l a t i o n w i th p r o p yl en e

15 for i = 1 : 5

16 C _B ( i ) = ( B _ b y _A ( i ) / ( 1 + B _ b y_ A ( i ) ) ) ; // I n t e rm s o f Mol F r a a c t i o n

17 C _A ( i ) = ( 1 /( 1 + B _ b y _A ( i ) ) ) ;

18 C A _ C B ( i ) = C _ B ( i ) * C _ A ( i ) ;

19 C _ b y _ r ( i ) = C A _ C B ( i ) / r _ 0 ( i ) ;

20 end

21 c o e f s = regress ( C _ A , C _ b y _ r ) ; / /The e q u a t i on ( ( C B∗C A ) /

r 0 )= 1 / ( k∗K A ) + ( C A /k )22 s c f ( 0 )

23 plot ( C _ A , C _ b y _ r , ’ ∗ ’ ) ;24 xtitle ( ’ T es t o f E le y−R i d e a l mo del f o r b en z en e

a l k y l a t i o n ’ ) ;25 x l a b e l ( ’ CA , Mol F r a c t i o n ’ ) ;26 y l a b e l ( ’CA CB/ r 0 ’ ) ;27 i n t e r c e p t = c o e f s ( 1 ) ;

28 s l o p e = c o e f s ( 2 ) ;

29 K _ A = s l o p e / i n t e r c e p t ;

30 k = 1 / ( s l o p e ) ;

31 K _ A _ k = k * K _ A ;

32

33 //OUTPUT ( Ex3 . 5 . 1 )34 mprintf ( ’ \n OUTPUT Ex3 . 5 . 1 ’ ) ;35 mprintf ( ’ \n

=================================================’ )

36 mprintf ( ’ \nThe r a t e e q ua t i on f o r El ey−R i d e l yM ec hanism i s :\ n r= %0 . 0 fC A C B /(1+%0 . 2 fC A ) ’ ,K _ A _ k , K _ A ) ;

37 //============================================================

38

39 // T i t l e : C on ve rs i on a s a f u n c t i o n o f S pa ce v e l o c i t y

28


30/115

40 //

============================================================

41 //INPUT ( Ex3 . 5 . 2 )42 x = [ 0. 16 0 .3 1 0 .4 0 0 .7 5] ;

43 E x p _ I n v er s e _ WH S V = ( 1 0^ - 3 ) * [ 4 8 . 2 1 7 3 9 ]; //WeightH ou rl y S pa ce V e l o c i t y

44 F e e d _ r a t i o = 1 0 ;

45

46 //CALCULATION ( Ex3 . 5 . 2 )47 // The i n t e g r a t e d r a t e e qu a ti o n i n t er ms o f

c o n v e r s i o n l n ( 1/ (1 −X) ) +0.2 36X= 6 0 .4 /WHSV ( Page no

. 1 06 )48 function [ y ] = i n t e g r a t e d _ r a t e _ e q n ( x 0 )

49 y = log ( 1 . /( 1 - x 0 )) + 0 .2 3 6. * x 0 - 6 0 .4 .*

E x p _ I n v e r s e _ W H S V


51

52 n = length ( x )

53 x 0 = 0 . 9 * ones ( 1 , n ) ; // P r ov id e g u es s v al ue f o rc o n v e r s i o n

54 [ x _ p r e d i c t e d ] = fsolve ( x 0 , i n t e g r a t e d _ r a t e _ e q n , 1 d - 1 5 ) ;

// U si ng f s o l v e t o d et er mi ne c o n ve r s io n fromi n t e g r a t e d r a te e x p r e s s i o n f o r e a c h o p er a ti n gWHSV

55

56 s c f ( 1 )

57 plot (Exp_Inverse_WHSV ,x, ’ ∗ ’ ,Exp_I nverse_WHSV ,x_predicted , ’−− ’ )

58 xtitle ( ’ I n t e g r a l a n a l y s i s ’ , ’ In v e r s e of WHSV ’ , ’C o n v e r s i o n ’ )

59 l e g e n d ( ’ E x p e r i m e n t a l ’ , ’ P r e d i c t e d ’ )60

61 //OUTPUT ( Ex3 . 5 . 2 )62 / / C o n s o l e O ut pu t63 mprintf ( ’ \n

=================================================\n ’ ) ;

29


31/115

64 mprintf ( ’ \n OUTPUT Ex3 . 5 . 2 ’ ) ;

65 mprintf ( ’ \n P r e d i c t e d and E x pe r im e nt a l C o n ve r si o nV a l u e s ’ )66 mprintf ( ’ \n

=================================================’ )

67 mprintf ( ’ \n1 0 ˆ3/WHSV\ t X e x p e r i me n t a l \ t X p r e d i c t e d ’ )68 mprintf ( ’ \n

=================================================’ )

69 for i = 1 : n

70 mprintf ( ’ \n %0 . 2 f \ t \t%0 . 2 f \ t \t%0 . 2 f ’ ,

E x p _ I n v e r s e _ W H S V ( i ) * 1 0 ^ 3 , x ( i ) , x _ p r e d i c t e d ( i ) )71 end

72

73 // FILE OUTPUT74 f i d = mopen ( ’ .\ Chapter3−Ex5−Output . tx t ’ , ’ w ’ ) ;75 mfprintf ( f i d , ’ \n OUTPUT Ex3 . 5 . 1 ’ ) ;76 mprintf ( ’ \n

=================================================’ )

77 mfprintf ( f i d , ’ \nThe r a t e e q ua t i on f o r El ey−R i d e l y

M ec hanism i s :\ n r= %0 . 0 fC A C B /(1+%0 . 2 fC A ) ’,

K _ A _ k , K _ A ) ;

78 mfprintf ( f i d , ’ \n=================================================\n ’ )

79 mfprintf ( f i d , ’ \n OUTPUT Ex3 . 5 . 2 ’ ) ;80 mfprintf ( f i d , ’ \n P r e d i c t e d and E x pe r im e nt a l

C o n v er s i o n V a l u es ’ )81 mfprintf ( f i d , ’ \n

=================================================’ )

82 mfprintf ( f i d , ’ \n1 0 ˆ3/WHSV\ t X e x p e r i me n t a l \t X p r e d i c t e d ’ )

83 mfprintf ( f i d , ’ \n=================================================’ )

30


32/115

84 for i = 1 : n

85 mfprintf ( f i d , ’ \n %0. 2 f \ t \t%0. 2 f \ t \t%0 . 2 f ’ ,E x p _ I n v e r s e _ W H S V ( i ) * 1 0 ^ 3 , x ( i ) , x _ p r e d i c t e d ( i ) )86 end

87 mclose ( f i d )

88

89 //===========================================END OFPROGRAM=================================

90 // D i s c l a im e r : R e g r es s i o n method i s u se d t o f i n d t hes l o pe and i n t e r c e p t i n Ex3 . 5 . 2 .

91 / / Hence t h e r a t e e q u a t i o n d i f f e r f ro m t h eg r a p h i c a l l y o bt ai ne d v a l u es o f s l o p e and

i n t e r c e p t i n t he t ex tb oo k .

Scilab code Exa 3.6 Optimum reaction temperature


2 //C hapt e r−3 Ex3 . 6 Pg No . 1 143 / / T i t l e : Optimum r e a c t i o n t e m p e r a tu r e4 //

============================================================

5 clear

6 clc

7 //INPUT8 d e l _ H = - 2 0 * 1 0 ^ 3 ; / / Hea t o f r e a c t i o n ( c a l )9 T _ e q = [ 5 00 7 0 0] ; / / E q u i v a l e n t t e m p e r a t u r e s (K)

10 R = 1 . 9 8 7 ; / / Gas C o n s ta n t ( c a l / m ol K)11 E 2 _ b y _ E 1 = 2 ; // R at io o f a c t i v a t i o n e ne rg y12

13 //CALCULATION14 T _ o p t ( 1 ) = T _ e q ( 1 ) / ( 1 + ( log ( E 2 _ b y _ E 1 ) * ( R / ( - d e l _ H ) ) ) *

31


33/115

T _ e q ( 1 ) ) ; / / R e f er e q u a t i o n 3 . 6 3 Pg No . 1 13

15 T _ o p t ( 2 ) = T _ e q ( 2 ) / ( 1 + ( log ( E 2 _ b y _ E 1 ) * ( R / ( - d e l _ H ) ) ) *T _ e q ( 2 ) ) ;

16 d e l t a _ T ( 1 ) = T _ e q ( 1 ) - T _ o p t ( 1 ) ;

17 d e l t a _ T ( 2 ) = T _ e q ( 2 ) - T _ o p t ( 2 ) ;

18

19

20 //OUTPUT21 mprintf ( ’ \n \ t \ t T e mp e ra t u re 1 \ t T e mp e ra t ur e 2

’ ) ;22 mprintf ( ’ \n \ t \ t

==================================’ ) ;

23 mprintf ( ’ \n( T e q − T op t ) (K) : \t%0. 0 f \ t \t%0 . 0 f ’ , d e l t a _ T ( 1 ) , d e l t a _ T ( 2 ) ) ;

24 mprintf ( ’ \n T o pt (K) :\ t \t%0. 0 f \ t \t%0 . 0 f ’ , T _o pt( 1 ) , T _ o p t ( 2 ) ) ;

25

26 f i d = mopen ( ’ .\ Chapter3−Ex6−Output . tx t ’ , ’ w ’ ) ;27 mfprintf ( f i d , ’ \n \ t \ t T e mp e ra t u re 1 \ t

T e mp er at ur e 2 ’ ) ;28 mfprintf ( f i d , ’ \n \ t \ t

==================================’ ) ;29 mfprintf ( f i d ,

’ \n( T e q − T op t ) (K) : \t%0. 0 f \ t \t%0. 0 f ’ , d e l t a _ T ( 1 ) , d e l t a _ T ( 2 ) ) ;30 mfprintf ( f i d , ’ \n T o pt (K) :\ t \t%0. 0 f \ t \t%0 . 0 f ’ ,

T _ o p t ( 1 ) , T _ o p t ( 2 ) ) ;


32

33 //=========================================================END OF PROGRAM=====================================

34 // D i s cl a i me r : There i s an a r i t h me t i c e r r o r i n t he

optimum t e m p er a t u re s o b t a i ne d i n t h e t e xt b o ok .35 // Based on t he v a l u e s ( T eq − T o p t ) 1 =17 a nd ( T e q

− T o p t ) 2 =32 t h e optimum t e m p e r a t u r e s o b t a i n e da r e

36 / / T o pt 1 =483 K and T o pt 2 =668 K r e s p e c t i v e l y .

32


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Scilab code Exa 3.7 Equilibrium temperature as a function of conversionand optimum feed temperature

1 / / H a r r i o t P , 2 0 0 3 , C he mi ca l R e a ct o r D e si g n ( I−E d i t i o n )

M ar c e l De kk e r , Inc . USA , pp 4362 //C hapt e r−3 Ex3 . 7 Pg No . 1 153 // T i t l e : E q u il i b ri u m t em p er at u re a s a f u n c t i o n o f

c o n v e r s i o n a nd Optimum F ee d T e m p er a t u r e4 //

============================================================

5 clear

6 clc

7 // COMMON INPUT8 P _ o p t = 1 . 5 ; / / ( atm ) O p er a ti n g p r e s s u r e o f f i r s t

c o n v e r t e r9 x = [ 0. 5 0 .6 0 .7 0 .8 0 .9 0 .9 5] ; // C o nv e rs i o n o f SO2

10 k = [2 E - 06 5 .1 E - 06 1 0. 3 E -0 6 1 8E - 06 2 7E - 06 3 7. 5 E - 06 4 8E

- 06 59 E -0 6 69 E -0 6 77 E - 06 ] ; / / R at e C o ns t an t ( g m ol/ g c at s e c atm )

11 T = 4 2 0 : 2 0 : 6 0 0 ; / / T em pe ra tu re ( C )12 X = 0 . 6 8 ;

13 T _ F = 7 0 0 ; //F e e d T e mpe r at ur e ( K)14 C _ p i _8 0 0 = [ 1 2 . 53 1 8 .6 1 8 . 06 7 . 51 ] ;

15 F = 1 0 0 ; // ( mol ) amount o f f e e d

16 d e l t a _ H _ 7 0 0 = - 2 3 2 7 0 ; / / ( c a l / m ol )17 p e r c e n t _ S O 2 _ f = 1 1 ; / / (%) P e r c e n t a g e o f SO2 i n f e e d18

19

20 //CALCULATION ( Ex3 . 7 . a )

33


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21 n = length ( x ) ;

22 m = length ( k ) ;23 for i = 1 : n

24 K _ e q ( i ) = ( ( x ( i ) / ( 1 - x ( i ) ) ) ) * ( ( 1 0 0 - 5 . 5 * x ( i ) )

/ ( 1 0 - 5 . 5 * x ( i ) ) ) ^ 0 . 5 * ( 1 / P _ o p t ) ^ 0 . 5 ;

25 T _ e q ( i ) = ( 1 1 4 1 2 / ( log ( K _ e q ( i ) ) + 1 0 . 7 7 1 ) ) ;

26 P _ O 2 ( i ) = ( 1 0 * ( 1 0 - 5 . 5 * x ( i ) ) * P _ o p t ) / ( 1 0 0 - 5 . 5 * x ( i ) ) ;

27 P _ S O 3 ( i ) = ( 1 1 * x ( i ) * P _ o p t ) / ( 1 0 0 - 5 . 5 * x ( i ) ) ;

28 P _ S O 2 ( i ) = ( 1 1 * ( 1 - x ( i ) ) * P _ o p t ) / ( 1 0 0 - 5 . 5 * x ( i ) ) ;

29 end

30

31 for i = 1 : n

32 for j = 1 : m33 r ( j , i ) = k ( j ) * ( P _ S O 2 ( i ) / P _ S O 3 ( i ) ) ^ 0 . 5 * ( P _ O 2 ( i )

- ( P _ S O 3 ( i ) / ( P _ S O 2 ( i ) * K _ e q ( i ) ) ) ^ 2 )

34 end

35 r _ m a x ( i ) = max ( r ( j , i ) ) ;

36 end

37 c l f ( )

38 s c f ( 0 )

39 plot (x,T_eq -273, ’ ∗ ’ ) ;40 xtitle ( ’ T em pe ra tu re i n S t ag e 1 o f an SO2 c o n v e r t e r ’ )

;

41 x l a b e l ( ’ x , SO2 C o n v e r s i o n ’ ) ;42 y l a b e l ( ’ T e mp e ra t u re , C ’ ) ;43

44 //CALCULATION ( Ex3 . 7 . b )45 n _ S O 2 = F * p e r c e n t _ S O 2 _ f * 1 0 ^ - 2 * ( 1 - X ) ;

46 n _ S O 3 = F * p e r c e n t _ S O 2 _ f * 1 0 ^ - 2 * X ;

47 n _ O 2 = ( 1 0 - 5 . 5 * X ) ;

48 n _ N 2 = 7 9 ;

49 s i g m a _ n _ C _ p i = n _ S O 2 * C _ p i _ 8 0 0 ( 1 ) + n _ S O 3 * C _ p i _ 8 0 0 ( 2 ) +

n _ O 2 * C _ p i _ 8 0 0 ( 3 ) + n _ N 2 * C _ p i _ 8 0 0 ( 4 ) ;

50 T e m p _ c h a n g e = ( F * p e r c e n t _ S O 2 _ f * 1 0 ^ ( - 2 ) * X * ( - 1 ) *d e l t a _ H _ 7 0 0 ) / s i g m a _ n _ C _ p i ; / / R e f er e q u a t i o n 3 . 6 0P g N o . 1 1 0

51 mprintf ( ’ \nHeat C ap ac it y e v a lu a t ed a t 8 00 K : %0 . 0 f (c a l / C ) ’ , s i g m a _ n _ C _ p i ) ;

34


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52 mprintf ( ’ \n Te mp er at ur e Ch ang e t o c a r r y o u t t h e

r e a c t i o n a t T F ,\ n us in g t he e ne rg y t o h ea t t hep r o d u ct g a s : %0 . 0 f C ” , T e mp ch an ge ) ;53 / / From g r a p h i c a l p r o c ed u r e ( F i g ur e 3 . 1 9 , Pg No . 1 1 8 )

t h e f i n a l t e m p er at u re i s o bt ai ne d a s 4 10 C54 T F = 4 10 ; // ( C ) F i n a l t e mp e r at u r e55 / /From F i g u re 3 . 1 9 , Pg No . 1 1 8 t e mp e r at u r e f o r

c o r r e sp o n di n g c o n ve r s io n i s o bt ai ne d56 X s t a g e = [ 0 . 1 ; 0 . 2 ; 0 . 3 ; 0 . 4 ; 0 . 5 ; 0 . 6 ]57 T s t ag e = [ 4 4 1 ; 4 7 0 ; 5 0 0 ; 5 4 0 ; 5 6 5 ; 5 8 0 ]58 m=le ng th ( X st ag e ) ;59 f o r i = 1:m

60 K eq ( i )=exp (( 11 41 2/ T st ag e ( i ) ) −10.7 71) ;61 end62 k = 1 0 ˆ −6∗ [ 5. 25 1 4 . 15 27 48 6 1 . 5 6 9 ] ; / / From T a bl e 3 . 5

C or re sp o nd in g t o t he s t a g e t em pe ra t ur e d at ao b ta i n ed fo rm F i gu r e 3 . 1 9

63 f o r i = 1:m64 P SO2 ( i ) =11∗(1− X st ag e ( i ) ) ∗P opt /( 100 −5 . 5∗

X st ag e ( i ) )65 P SO3 ( i ) =11∗X st a ge ( i ) ∗P opt /( 100 −5. 5∗ X st a ge ( i )

)66

P O2( i ) =10∗(10 −5.5∗ X st ag e ( i ) ) ∗P opt /( 100 −5 . 5∗X st ag e ( i ) )67 r ( i )=k ( i ) ∗ ( P SO2 ( i )/P SO3 ( i ) ) ̂ 0 .5 ∗ ( P O2( i )−(

P SO3 ( i ) /( P SO2 ( i ) ∗K eq ( i ) ) ) ̂ 2 ) ∗ 1 0 ˆ 6 ;68 i n v e r s e r ( i ) = (1 / r ( i ) ) ;69 end70 s c f ( 1 )71 p l o t ( X s t ag e , i n v e r s e r , ’ * ’ ) ;72 x t i t l e ( ’ 1/ r vs x ’, ’X ( c o n v e r s i o n ) ’ , ’ 10ˆ−6/r ’ ) ;73

74

75 //OUTPUT ( Ex3 . 7 . a )76 mprintf ( ’ \n\n OUTPUT Ex3 . 7 . a ’ ) ;77 mprintf ( ’ \n

============================================================’ ) ;

35


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78 mprintf ( ’ \n X\ t P h i \ t \ t T e q \ t T e q \ t \ t r m a x ’ ) ;

79 mprintf ( ’ \n −\t (atmˆ −0. 5) \ t (K) \ t ( C ) \ t \ t ( g m ol / g c a tse c ) ’ ) ;80 mprintf ( ’ \n

============================================================’ ) ;

81 for i = 1 : n - 1

82 mprintf ( ’ \n %0 . 2 f \t%0. 2 f \ t %0 . 0 f \t%0. 0 f \ t \t % 0 . 6 E’ , x ( i ) , K _ e q ( i ) , T _ e q ( i ) , T _ e q ( i ) - 2 7 3 , r _ m a x ( i ) ) ;

83 end

84 mprintf ( ’ \n %0 . 2 f \t %0 . 2 f \ t \t%0. 0 f \t%0. 0 f \ t \t % 0 . 6 E ’ ,x( n ) , K _ e q ( n ) , T _ e q ( n ) , T _ e q ( n ) - 2 7 3 , r _ m a x ( n ) ) ;

8586 //OUTPUT ( Ex3 . 7 . b )87 mprintf ( ’ \n\n\n OUTPUT Ex3 . 7 . b ’ ) ;88 mprintf ( ’ \n

============================================================’ ) ;

89 mprintf ( ’ \n===========================================’ ) ;

90 mprintf ( ’ \n 10 ˆ−6/ r \tX ( c o n v e r s i o n ) ’ ) ;91 mprintf ( ’ \n ( g mo l / g c a t , s ) \ t (−) ’ ) ;92 mprintf (

’ \n===========================================’ ) ;93 for i = 1 : m

94 mprintf ( ’ \n %0 . 2 f \ t \ t \t%0. 2 f ’ , i n v e r s e _ r ( i ) ,X _ s t a g e ( i ) ) ;

95 end

96 mprintf ( ’ \nFrom g r a p h i c a l p r oc e du r e ( 1/ r v s x ) t heoptimum t e m pe r a tu r e o b t a i ne d i s T o pt : 4 12 C ’ ) ;

97

98 // FILE OUTPUT99 f i d = mopen ( ’ .\ Chapter3−Ex7−Output . tx t ’ , ’ w ’ ) ;

100 mfprintf ( f i d , ’ \nHea t C a pa c it y e v a l u a t e d a t 8 00 K : %0. 0 f ( c a l / C ) ’ , s i g m a _ n _ C _ p i ) ;

101 mfprintf ( f i d , ’ \n Te mp er at ur e Ch ang e t o c a r r y o u t t h er e a c t i o n a t T F ,\ n us in g t he e ne rg y t o h ea t t hep r o d u ct g a s : %0 . 0 f C ” , T e mp ch an ge ) ;

36


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102 m f p r i n t f ( f i d , ’ \ n O UT PU T E x3 . 7 . a ’) ;

103 mfprintf ( f i d , ’ \n============================================================’ ) ;

104 mfprintf ( f i d , ’ \n X\ t P h i \ t \ t T e q \ t T e q \ t \ t r m a x ’ ) ;105 mfprintf ( f i d , ’ \n −\t (atmˆ −0. 5) \ t (K) \ t ( C ) \ t \ t ( gmol /

g c a t s e c ) ’ ) ;106 mfprintf ( f i d , ’ \n

============================================================’ ) ;

107 for i = 1 : n - 1

108 mfprintf ( f i d , ’ \n %0 . 2 f \t%0. 2 f \ t %0 . 0 f \t%0. 0 f \ t \

t % 0 . 6 E ’ , x ( i ) , K _ e q ( i ) , T _ e q ( i ) , T _ e q ( i ) - 2 7 3 ,r _ m a x ( i ) ) ;

109 end

110 mfprintf ( f i d , ’ \n %0 . 2 f \t %0 . 2 f \ t \t%0. 0 f \t%0. 0 f \ t \t%0. 6 E ’ , x ( n ) , K _ e q ( n ) , T _ e q ( n ) , T _ e q ( n ) - 2 7 3 , r _ m a x ( n ) ) ;

111 mfprintf ( f i d , ’ \n\n\n OUTPUT Ex3 . 7 . b ’ ) ;112 mfprintf ( f i d , ’ \n

============================================================’ ) ;

113 mfprintf ( f i d , ’ \n

===========================================’) ;

114 mfprintf ( f i d , ’ \n 10 ˆ−6/ r \tX ( c o n v e r s i o n ) ’ ) ;115 mfprintf ( f i d , ’ \n ( g mo l / g c a t , s ) \ t (−) ’ ) ;116 mfprintf ( f i d , ’ \n

===========================================’ ) ;117 for i = 1 : m

118 mfprintf ( f i d , ’ \n %0 . 2 f \ t \ t \t%0. 2 f ’ , i n v e r s e _ r ( i ), X _ s t a g e ( i ) ) ;

119 end

120 mfprintf ( f i d , ’ \nFrom g r a p h i c a l p r oc e du r e ( 1/ r v s x )t h e optimum t e m pe r a tu r e o b t a i ne d i s T o pt : 4 12

C ’ ) ;121 mclose ( f i d ) ;

122

123 //==========================================================

37


39/115

END OF PROGRAM

======================================124 / / D i s c l a i m e r : The optimum t e m p e r a tu r e f o r e a chc o n v e r s i o n i s f o un d by t r i a l a t maximum r a t e a ndt h e k i n e t i c d a t a i n t he t ex tb oo k i s n o ts u f f i c i e n t t o c a l c u l a t e t h e optimum t e m p e r a t u r ei n t he c od e .

38


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Chapter 4

Diffusion and Reaction in

Porous Catalysts

Scilab code Exa 4.1 Diffusivity of Chlorine and tortuosity in catalyst pel-let


) M a r c e l D ek ke r , I n c . , USA , pp 4 3 6 .2 //C hapt e r−4 Ex4 . 1 Pg No . 1 353 // T i t l e : D i f f u s i v i t y o f C h lo r in e and t o r t u o s i t y i n

c a t a l y s t p e l l e t4 //

============================================================

5 clear

6 clc

7

8 // COMMON INPUT9 S _ g = 2 3 5 ; / / T o ta l s u r f a c e p e r gram ( m2/ g )10 V _ g = 0 . 2 9 E - 6 ; / / P o r e v ol um e p e r gram ( cm3 / g )11 r h o _ p = 1 . 4 1 ; // D en s it y o f p a r t i c l e ( g /cm3 )12 D _ H e = 0 . 0 0 6 5 ; // E f f e c t i v e d i f f u s i v i t y of He ( c m2/ se c )

39


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13 D _ A B = 0 . 7 3 ; / / a t 1 atm and 2 98K

14 M _ H e = 4 ; // M o l ec u l ar w e ig h t o f He15 M _ C l 2 = 7 0 . 0 9 ; // M o l ec u l ar w e ig h t o f Cl 216 T _ r e f = 2 9 3 ; / / R e f e r e n c e t e m p e r at u r e17 T _ d e g C = 3 0 0 ;

18 T _ 0 1 = T _ d e g C + 2 7 3 ; / / R e a c t i o n t e m p e r a t u r e (K) ( E x4 . 1 . a )19 T _ 0 2 = 2 9 8 ; / / O p e ra t i n g t e m p e r a tu r e ( Ex4 . 1 . b )20 T _ 0 3 = 5 7 3 ; / / o p e r a t i n g t e m p e r a tu r e ( Ex4 . 1 . c )21 P _ r e f = 1 ; / / R e f e r en c e p r e s s u r e22 D _ C l 2 _ C H 4 = 0 . 1 5 ; / / a t 1 atm 2 7 3K23 P = 1 5 ; // o p e r a t i ng p r e s s u r e24 / / t au = 1 . 25 ; / / From v a l u e c a l c u l a t e d i n Ex4 . 1 . b Pg . No

. 13625

26

27 //CALCULATION ( Ex4 . 1 . a )28 r _ b a r = 2 * V _ g / S _ g ; / / Mean P o re r a d i u s29 D _ C l 2 _ E x _ a = D _ H e * ( ( M _ H e / M _ C l 2 ) * ( T _ 0 1 / T _ r e f ) ) ^ ( 0 . 5 ) ; //

A ss um in g K nu ds en f l o w a t 5 7 3K30

31 //CALCULATION ( Ex4 . 1 . b )32 r _ ba r = 2 * V _ g * ( 1 0^ 6 ) / ( S _ g * ( 1 0^ 4 ) ) ;

33 D _ K = 9 7 0 0 * ( r _ b a r ) * ( T _ r e f / M _ H e ) ^ ( 0 . 5 ) ;/ / K nu ds en f l o w34 D _ A B 1 = D _ A B * ( 2 9 3 / 2 9 8 ) ^ ( 1 . 7 ) // a t 1 . 5 atm and 29 3K

35 D _ p o r e = 1 / ( ( 1 / D _ K ) + ( 1 / D _ A B 1 ) ) ; // p or e d i f f u s i o n36 E p s i l o n = V _ g * r h o _ p * ( 1 0 ^ 6 ) ;

37 t a u = ( D _ p o r e * E p s i l o n ) / D _ H e ; / / T o r t u s i t y38

39 //CALCULATION ( Ex4 . 1 . c )40 D _ C l 2 _ C H 4 _ n e w = D _ C l 2 _ C H 4 * ( P _ r e f / P ) * ( T _ 0 3 / T _ r e f ) ^ ( 1 . 7 )

;

41 D _ K _ C l 2 = 9 7 0 0 * r _ b a r * sqrt ( T _ 0 3 / M _ C l 2 ) ;

42 D _ p o r e = 1 / ( ( 1 / D _ C l 2 _ C H 4 _ n e w ) + ( 1 / D _ K _ C l 2 ) ) ;

43 E p s i l o n = V _ g * r h o _ p ;44 D _ C l 2 _ E x _ c = D _ p o r e * E p s i l o n / t a u ;

45

46

47 //OUTPUT

40


42/115


43/115

T _0 3 , P , D _ Cl 2 _E x _c ) ;

69 mclose ( f i d )70 //============================================END OFPROGRAM

=================================================

Scilab code Exa 4.2 Effective diffusivity of O2 in air


2 //C hapt e r−4 Ex4 . 2 Pg No . 1 403 / / T i t l e : E f f e c t i v e d i f f u s i v i t y o f O2 i n a i r4 //

============================================================

5 clear

6 clc

7 // COMMON INPUT

8 S _ g = 1 5 0 ; / / T o ta l s u r f a c e p e r gram ( m2/ g )9 V _ g = 0 . 4 5 ; / / P o re v ol um e p e r g ram ( cm3 / g )

10 V _ i = 0 . 3 0 ; / / M i c r o p o r e v ol um e p e r g ram ( cm3 / g )11 V _ a = 0 . 1 5 ; / / M a cr o po r e v ol um e p e r gram ( cm3 / g )12 r h o _ P = 1 . 2 ; // D en s it y o f p a r t i c l e ( g /cm3 )13 t a u = 2 . 5 ; // T o r t u si t y14 r _ b a r _ i = 4 0 * ( 1 0 ^ ( - 8 ) ) ; / / M i c ro p o r e r a d i u s15 r _ b a r _ a = 2 0 0 0 * ( 1 0 ^ ( - 8 ) ) ; / / M ac ro po re r a d i u s16 D _ A B = 0 . 4 9 ; / / For N 2 O 2 a t 1 atm ( cm2 / s )17 M _ O 2 = 3 2 ; / / M o l ec u l a r w e ig h t o f O2

18 T = 4 9 3 ; / / O p e r e a t i n g T e m p er a t u re (K)1920

21

22 //CALCULATION ( Ex4 . 2 . a )

42


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23 E p s i l o n = V _ g * r h o _ P ;

24 D _ K _ i = 9 7 0 0 * ( r _ b a r _ i ) * sqrt ( T / M _ O 2 ) ; / / Kn udsen f l o w f o rm i c r o p o r e25 D _ P o r e _ i = 1 / ( ( 1 / D _ K _ i ) + ( 1 / D _ A B ) )

26 D _ K _ a = 9 7 0 0 * ( r _ b a r _ a ) * sqrt ( T / M _ O 2 ) ;

27 D _ P o r e _ a = 1 / ( ( 1 / D _ K _ a ) + ( 1 / D _ A B ) ) ; / / // K nudsen f l o w f o rm a c r o p o r e

28 D _ P o r e _ A v g = ( V _ i * D _ P o r e _ i + V _ a * D _ P o r e _ a ) / ( V _ i + V _ a ) ;

29 D _ e = E p s i l o n * D _ P o r e _ A v g / t a u ;

30

31 //CALCULATION ( Ex4 . 2 . b )32 E p s i l o n = V _ g * r h o _ P ;

33 r _ b a r = 2 * V _ g / ( S _ g * 1 0 ^ 4 ) ;34 D _ K = 9 7 0 0 * ( r _ b a r ) * sqrt ( T / M _ O 2 ) ;// Knudsen Flow35 D _ P o r e = 1 / ( ( 1 / D _ K ) + ( 1 / D _ A B ) ) ;

36 t a u = D _ P o r e * E p s i l o n / D _ e ;

37

38 //OUTPUT39 mprintf ( ’ \n OUTPUT Ex4 . 2 . a ’ ) ;40 mprintf ( ’ \n

=================================================’ ) ;

41 mprintf ( ’ \n The e f f e c t i v e d i f f u s i v i t y o f O2 i n a i r =%0. 2 e cm2/s ’ , D _ e ) ;

42 mprintf ( ’ \n\n OUTPUT Ex4 . 2 . b ’ ) ;43 mprintf ( ’ \n

=================================================’ ) ;

44 mprintf ( ’ \n The c a l c u l a t e d s u r f a c e mean p or e r a d i us= %. 0 e cm ’ , r _ b a r ) ;

45 mprintf ( ’ \n The p r e d i c t e d p o r e d i f f u s i v i t y = %0 . 2 ecm2/ s e c ’ , D _ P o r e ) ;

46 mprintf ( ’ \n The c o r r es p o n d i ng t o r t u s i t y = %0 . 2 f ’ ,tau

) ;47

48 // FILE OUTPUT49 f i d = mopen ( ’ .\ Chapter4−Ex2−Output . tx t ’ , ’ w ’ ) ;50 mfprintf ( f i d , ’ \n OUTPUT Ex4 . 2 . a ’ ) ;

43


45/115

51 mfprintf ( f i d , ’ \n

=================================================’ ) ;52 mfprintf ( f i d , ’ \n The e f f e c t i v e d i f f u s i v i t y o f O2 i n

a i r = %0 . 2 e cm2 / s ’ , D _ e ) ;53 mfprintf ( f i d , ’ \n\n OUTPUT Ex4 . 2 . b ’ ) ;54 mfprintf ( f i d , ’ \n

=================================================’ ) ;

55 mfprintf ( f i d , ’ \n The c a l c u l a t e d s u r f a c e mean p or er a d i u s = %. 0 e cm ’ , r _ b a r ) ;

56 mfprintf ( f i d , ’ \n The p r e d i c t e d p o r e d i f f u s i v i t y = %0

. 2 e cm2/ se c ’ , D _ P o r e ) ;57 mfprintf ( f i d , ’ \n The c o r r es p o n d i ng t o r t u s i t y = %0 . 2 f

’ , t a u ) ;58 mclose ( f i d ) ;

59

60

61 //======================================================END OF PROGRAM========================================

Scilab code Exa 4.3 Influence of Pore diffusion over rate


2 //C hapt e r−4 Ex4 . 3 Pg No . 1 54

3 // T i t l e : I n f l u e n c e o f Pore d i f f u s i o n o ve r r a t e4 //============================================================

5 clear

44


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6 clc

7 //INPUT8 d _ p = 1 / 4 ; // S p h e r i c a l C a t a ly s t p e l l e t s i z e ( i n ch )9 k = [ 7. 6 *1 0 ^ - 3 1 4 *1 0 ^ - 3 ] ; / / R e a c t i on r a t e s ( m ol / h r )

10 f _ A = [ 0 .1 0 . 2] ; // Feed f r a c t i o n o f r e ac t a n t A11 D _ e = 0 . 0 0 8 5 ; // D i f f u s i v i t y o f A ( cm2/ s )12 r ho _p = 1 .4 ; // D en si ty o f c a t a l y s t p a r t i c l e ( g /cm3 )13 V _ r e f = 2 2 4 0 0 ; / / r e f e r e n c e v ol um e ( cm3 )14 T _ r e f = 2 7 3 ; / / R e f e r e n c e T e mp e ra t ur e (K)15 P _ r e f = 1 ; / / R e f e r en c e P r e s s u r e ( atm )16 P = 1 . 2 ; / / O p e ra t i n g P r e s s u r e ( atm )17 T _ C = 1 5 0 ;

18 T = T _ C + 2 7 3 ; / / O p e r a t i n g T e m p er a t u re (K)19

20 //CALCULATION21 / / Fo r 1 0% o f A22 C _ A ( 1 ) = f _ A ( 1 ) * T _ r e f * P _ r e f / ( V _ r e f * T * P ) ;

23 R = d _ p * 2 . 5 4 / 2 ;

24 k _ a p p ( 1 ) = k ( 1 ) * r h o _ p / ( 3 6 0 0 * C _ A ( 1 ) ) ; / / R e f e r e q u a t i o n4 . 5 3 Pg . No . 15 3

25 p h i _ a p p ( 1 ) = R * sqrt ( k _ a p p ( 1 ) / D _ e ) ; / / R e f e r e q u a t i o n4 . 5 5 Pg . No . 15 5

26 C _ A ( 2 ) = f _ A ( 2 ) * T _ r e f * P _ r e f / ( V _ r e f * T * P ) ;

27 // I f C A i s d o u b l e d t h e o rd er i s q u i t e c l o s e t o 1 ,from t h e F ig ur e 4 . 8 Pg . No . 1 48 , r e f e r v al ue o f e f f e c t i v e n e s s

28 e t a _ g r a p h = 0 . 4 2 ;

29 k _ a p p ( 2 ) = k _ a p p ( 1 ) / e t a _ g r a p h ;

30 p h i _ a p p ( 2 ) = R * sqrt ( k _ a p p ( 2 ) / D _ e ) ;

31 e t a _ c a l c = ( 3 / p h i _ a p p ( 2 ) ) * ( ( 1 / tanh ( p h i _ a p p ( 2 ) ) ) - ( 1 /

p h i _ a p p ( 2 ) ) ) ;

32 e f f _ r a t e = ( 1 - e t a _ g r a p h ) * 1 0 0 ;

33

34 //OUTPUT35 mprintf ( ’ \n The e f f e c t i v e n e s s fro m g ra ph = %0 . 2 f \n

The c a l c u l a t e d e f f e c t i v e n e s s = %0 . 2 f ’ ,eta_graph ,e t a _ c a l c ) ;

36 mprintf ( ’ \n The p or e d i f f u s i o n d e c r e as e d t h e r a t e by

45


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%. 0 f%% ’ , e f f _ r a t e ) ;

3738 // FILE OUTPUT39 f i d = mopen ( ’ .\ Chapter4−Ex3−Output . tx t ’ , ’ w ’ ) ;40 mfprintf ( f i d , ’ \n The e f f e c t i v e n e s s from gr a ph = %0 . 2

f \n The c a l c u l a t e d e f f e c t i v e n e s s = %0 . 2 f ’ ,eta_graph ,e ta_calc );

41 mfprintf ( f i d , ’ \n The p or e d i f f u s i o n d e c r e as e d t h er a t e b y % . 0 f%% ’ , e f f _ r a t e ) ;


43 //============================================================

END OF PROGRAM===============================

Scilab code Exa 4.4 Effectiveness factor for solid catalyzed reaction

1 / / H a r r i o t P . , 2 0 0 3 , C he m ic al R e a ct o r D e s ig n ( I−E d i t i o n) M a r c e l D ek ke r , I n c . USA , pp 4 3 6 .

2 //C hapt e r−4 E x4 . 4 Pg No . 1 5 73 / / T i t l e : E f f e c t i v e n e s s f a c t o r f o r s o l i d c a ta l y z e d

r e a c t i o n4 //

============================================================

5 clear

6 clc

7 //INPUT8 D _ e _ A = 0 . 0 2 ; // ( c m2/ s )

9 D _ e _ B = 0 . 0 3 ; // ( c m2/ s )10 D _ e _ C = 0 . 0 1 5 ; // ( c m2/ s )11 X _ f _ A = 0 . 3 ;

12 X _ f _ B = ( 1 - X _ f _ A ) ;

13 e t a _ a s s u m e d = 0 . 6 8 ; // E f f e c t i v e n e s s f a c t o r from F ig . 4 . 8

46


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f o r f i r s t o r d er r e a c t i o n

14 T = 1 5 0 ; / / ( d e g C )15 T _ K = T + 2 7 3 ; //(K)16 r = 0 . 3 ; // ( cm ) R ad iu s o f c a t a l y s t s p h er e17 P _ o p t = 4 ; / / ( a tm ) O p e ra t i n g P r e s s u r e18 R = 8 2 . 0 5 6 ; / / ( c m3 atm /K m ol ) G as c o n s t a n t19

20

21 //CALCULATION22 / / K i n e t i c e q u a t i on r= ( 2 .5∗1 0 ˆ −5∗P A∗P B ) / ( 1 + 0 . 1∗P A

+2∗P C ) ˆ 223 P _ A = X _ f _ A * P _ o p t ;

24 P _ B = X _ f _ B * P _ o p t ;25 r _ s t a r = ( 2 . 5 * 1 0 ^ - 5 * P _ A * P _ B ) / ( 1 + 0 . 1 * P _ A ) ^ 2 ;

26 C _ A = P _ A / ( R * T _ K ) ;

27 k = r _ s t a r / C _ A ;

28 P h i = r * ( k / D _ e_ A ) ^ ( 0 . 5) ;

29 P _ A _ b a r = e t a _ a s s u m e d * P _ A ;

30 d e l t a _ P _ A = P _ A * ( 1 - e t a _ a s s u m e d ) ;

31 d e l t a _ P _ B = d e l t a _ P _ A * ( D _ e _ A / D _ e _ B ) ;

32 P _ B _ b a r = P _ B - d e l t a _ P _ B ;

33 d e l t a _ P _ C = d e l t a _ P _ A * ( D _ e _ A / D _ e _ C ) ;

34 P _ C _ b a r = d e l t a _ P _ C ;

35 r _ c a l c = ( 2 . 5 * 1 0 ^ - 5 * P _ A _ b a r * P _ B _ b a r ) / ( 1 + 0 . 1 * P _ A _ b a r + 2 *

P _ C _ b a r ) ^ 2

36 e t a _ c a l c = r _ c a l c / r _ s t a r ;

37 e t a _ a p p r o x = ( e t a _ c a l c + e t a _ a s s u m e d ) / 2 ;

38

39 //OUTPUT40 / / C o n s o l e O ut pu t41 mprintf ( ’ \ t Ba se d on a v e ra ge p r e s s u r e s c a l c u l a t e d

Rate and E f f e c t i v e n e s s f a c t o r ’ ) ;42 mprintf ( ’ \n\ t r : %0 . 2 E ( mol / s cm3 ) ’ , r _ c a l c ) ;

43 mprintf ( ’ \n\ t e t a c a l c : %0 . 3 f ’ , e t a _ c a l c ) ;44 mprintf ( ’ \n The a c tu a l v al ue o f E f f e c t i v e n e s s f a c t o r

e t a a c t u a l : %0 . 1 f ’ , e t a _ a p p r o x ) ;45

46 / / F i l e O ut pu t

47


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47 f i d = mopen ( ’ .\ Chapter4−Ex4−Output . tx t ’ , ’ w ’ ) ;

48 mfprintf ( f i d , ’ \ t Ba se d o n a v er a ge p r e s s u r e sc a l c u l a t e d Rate and E f f e c t i v e n e s s f a c t o r ’ ) ;49 mfprintf ( f i d , ’ \n\ t r : %0 . 2 E ( mol / s cm3 ) ’ , r _ c a l c ) ;50 mfprintf ( f i d , ’ \n\ t e t a c a l c : %0 . 3 f ’ , e t a _ c a l c ) ;51 mfprintf ( f i d , ’ \n The a c tu a l v al ue o f E f f e c t i v e n e s s

f a c t o r e t a a c t u a l : %0 . 1 f ’ , e t a _ a p p r o x ) ;52 mclose ( f i d ) ;

53 //================================================END OF PROGRAM============================================================

Scilab code Exa 4.5 The optimum pore size distribution for a sphericalpellet


2 //C hapt e r−4 Ex4 . 5 Pg No . 1 643 // T i t l e : The optimum p or e s i z e d i s t r i b u t i o n f o r a

s p h e r i c a l p e l l e t4 //

============================================================

5 clear

6 clc

7 //INPUT8 d _ p e l l e t = 5 * 1 0 ^ - 1 ; // C a ta l ys t p e l l e t s i z e ( cm )

9 k _ c a t = 3 .6 ; / / T ru e R at e C o ns t an t ( s e c −1)10 V _ g _ c at = 0 .6 0 ; // P or e Volume o f t h e c a t a l y s t ( cm3 /g )11 S _ g _ c a t = 3 0 0 * 1 0 ^ 4 ; // S u r f a ce a r ea o f c a t a l y s t ( cm2/ g )12 d p = 0 . 0 2 ; // S i z e o f p owdered c a t a l y s t ( cm )13 r ho _p = 0 .8 ; // D en si ty o f c a t a l y s t p a r t i c l e ( g /cm3 )

48


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14 r _ b a r_ n a r ro w = 4 0 *1 0 ^( - 1 0 ) // n ar row d i s t r i b u t i o n

15 D _ KA = 0 .0 1 2 ; // (cm2/ se c )16 D _A B = 0 .4 0 ; // (cm2/ se c )17 r _ m a c r o = 2 0 0 0 * 1 0 ^ ( - 1 0 ) ; / / F or M a c ro p o r es18 V _ c a t = 1 / r h o _ p ; // T o ta l c a t a l y s t vo lu me ( cm3 /g )19 e t a = 1 ; / / Fo r p owd er ed c a t a l y s t20

21 //CALCULATION22 e p s i l o n = V _ g _ c a t / V _ c a t ;

23 r _ b a r = 2 * V _ g _ c a t / S _ g _ c a t ;

24 R = d p / 2 ;

25 R _ p e l l e t = d _ p e l l e t / 2 ;

26 D _ p o r e _ a = 1 / ( ( 1 / D _ K A ) + ( 1 / D _ A B ) ) ;27 t a u = 3 ; / / A ss um ed v a l u e28 D _ e _ c a t = D _ p o r e _ a * e p s i l o n / t a u ;

29 P h i _ a p p = R * sqrt ( k _ c a t / D _ e _ c a t ) ; / / R e f er e q u a t i o n 4 . 5 5Pg . No . 1 53

30 D _ K B = D _ K A * ( r _ m a c r o / r _ b a r _ n a r r o w ) ;

31 D _ p o r e _ b = 1 / ( ( 1 / D _ K B ) + ( 1 / D _ A B ) ) ;

32 V _ a _ e n d = 0 . 3 5 ;

33 d e l _ V _ a = - 0 . 0 5 ;

34 V _ a = V _ g _ c a t : d e l _ V _ a : V _ a _ e n d ;

35 for i = 1 : 6

36 V_b(i) =V_g_cat -V_a( i); // R e f er E qu a ti o n 4 . 8 1 Pg .No . 1 64

37 S _ a ( i ) = 2 * ( V _ a ( i ) / r _ b a r _ n a r r o w ) * ( 1 0 ^ - 6 ) ;

38 S _ b ( i ) = 2 * ( V _ b ( i ) / r _ m a c r o ) * ( 1 0 ^ - 6 ) ;

39 S _ g ( i ) = S _ a ( i ) + S _ b ( i ) ;

40 k ( i ) = k _ c a t * S _ g ( i ) / ( S _ g _ c a t * 1 0 ^ - 4 ) ;

41 D _ e ( i ) = ( ( D _ p o r e _ a * V _ a ( i ) + D _ p o r e _ b * V _ b ( i ) ) /

V _ g _ c a t ) * ( e p s i l o n / t a u ) ;

42 p h i ( i ) = R _ p e l l e t * sqrt ( k ( i ) / D _ e ( i ) ) ;

43 e t a ( i ) = ( 3 / p h i ( i ) ) * ( ( 1 / tanh ( p h i ( i ) ) ) - ( 1 / p h i ( i ) ) )

;44 e t a _ k ( i ) = e t a ( i ) * k ( i )

45 end

46 //OUTPUT47 mprintf ( ’ \n

49


51/115

===========================================================

’ )48 mprintf ( ’ \nV a \ t V b \ t \ t S a \ t S b \ t S g \t k \ t D e \ t p h i \ t e t a \ t e t a k ’ ) ;

49 mprintf ( ’ \nVolume \ t cm3/g \ t \ t S u r f a ce Area \ t m2/g \ t \ t s−1 \ t cm2 / s \ t (−)\ t (−) \ t (−) ’ ) ;

50 mprintf ( ’ \n==========================================================’ )

51 for i = 1 : 6

52 mprintf ( ’ \n % . 2 f \ t %0 . 2 f \ t \ t %. 0 f \ t %. 1 f \ t %0 . 1 f \ t \ t %0 . 2 f \t%0 . 2 e\t%0. 2 f \ t

%0. 2 f \ t %0 . 2 f ’ , V _ a ( i ) , V _ b ( i ) , S _ a ( i ) , S _ b( i ) , S _ g ( i ) , k ( i ) , D _ e ( i ) , p h i ( i ) , e t a ( i ) ,

e t a _ k ( i ) ) ;

53 end

54

55 // FILE OUTPUT56 f i d = mopen ( ’ .\ Chapter4−Ex5−Output . tx t ’ , ’ w ’ ) ;57 mfprintf ( f i d , ’ \n

===========================================================’ )

58 mfprintf ( f i d , ’ \nV a \ t V b \ t \ t S a \ t S b \ tS g \ t k \ t D e \ t p h i \ t e t a \ t e t a k ’ ) ;

59 mfprintf ( f i d , ’ \nVolume \ t cm3 / g \ t \ t S u r f a ce Area \t m2/g \ t \ t s−1 \ t cm2 / s \ t (−)\ t (−) \ t(−) ’ ) ;

60 mfprintf ( f i d , ’ \n==========================================================’ )

61 for i = 1 : 6

62 mfprintf ( f i d , ’ \n % . 2 f \ t %0 . 2 f \ t \ t %. 0 f \ t%.1 f \ t %0 . 1 f \ t \ t %0 . 2 f \t%0 . 2 e\t%0. 2 f

\ t %0 . 2 f \ t %0 . 2 f ’ , V _ a ( i ) , V _ b ( i ) , S _ a ( i ), S _ b ( i ) , S _ g ( i ) , k ( i ) , D _ e ( i ) , p h i ( i ) , e t a ( i )

, e t a _ k ( i ) ) ;

63 end

64 //

50


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============================================================

END OF PROGRAM===================================================

51


53/115

Chapter 5

Heat and Mass Transfer in

Reactors

Scilab code Exa 5.1 Temperature Profiles for tubular reactor

1 / / H a r r i o t P . , 2 0 0 3 , C he m ic al R e a ct o r D e s ig n ( I−E d i t i o n) M a r c e l D ek ke r , I n c . USA , pp 4 3 6

2 //C hapt e r−5 Ex5 . 1 Pg No . 1 853 // T i t l e : T empe ra tur e P r o f i l e s f o r t u bu l ar r e a c t o r4 //

============================================================

5 clear

6 clc

7 clf

8 //INPUT9 d e l t a _ H = - 2 5 0 0 0 ; / / ( k c a l / m ol ) E n t ha l p y10 D = 2 ; / / ( cm ) D i a me t er o f T u bu l a r R e a c t o r11 C _ A 0 = 0 . 0 0 2 ; / / ( mol / cm3 ) I n i t i a l c o n c e n t r a t i o n o f f e e d12 k = 0 . 0 0 1 4 2 ; / / ( s −1) R at e C o n s ta n t

52


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13 E _ b y _ R = 1 5 0 0 0 ; / / ( K−1)

14 r h o = 0 . 8 ; / / ( g / c m 3 )15 c _ p = 0 . 5; / / ( c a l / g C )16 U = 0 . 0 2 5 ; // ( c a l / s e c c m 2 C )17 u = 6 0 ; // (cm/s )18

19

20 //CALCULATION21 function d i f fe q n = S i m u l_ d i f f_ e q n ( l , y , T _j )

22 d i f fe q n ( 1 ) = ( k * exp ( E _ b y _ R * ( ( 1 / T _ i n i t i a l ) - ( 1 / y ( 2 )

) ) ) ) * ( 1 - y ( 1 ) ) / u ; // D e r i v a t i v e f o r t he f i r s tv a r i a b l e

23 d i f fe q n ( 2 ) = ( C _ A0 * ( k * exp ( E _ b y _ R * ( ( 1 / T _ i n i t i a l )- ( 1 / y ( 2 ) ) ) ) ) * ( 1 - y ( 1 ) ) * ( - 1 * d e l t a _ H ) - U * ( 4 / D ) * ( y

( 2) - T _ j ) ) / ( u * r ho * c _ p ) ; // D e r i v a t i v e f o r t h es ec on d v a r i a b l e


25

26 // =======================================27

28 T _j _d at a = [ 3 48 349 350 3 51 ];

29 m = length ( T _ j _ d a t a ) ;

30 n = 1 ;

31 while n


55/115

( 3 , : ) , ’ k− ’ , l , T _ d a t a ( 4 , : ) , ’ g− ’ )

46 xtitle ( ’ Te mper at ur e P r o f i l e s f o r a j a c k e t e d t u bu l arr e a c t o r ’ )47 x l a b e l ( ” L e n gt h ( cm ) ” )48 y l a b e l ( ” T e m p e r a t ur e (K) ” )49 l e g e n d ( [ ’ 34 8 ’ ; ’ 349 ’ ; ’ 35 0 ’ ; ’ 351 ’ ]) ;50

51 s c f ( 1 )

52 plot ( l , x _ d a t a ( 1 , : ) , ’ r− ’ , l , x _ d a t a ( 2 , : ) , ’ b− ’ , l , x _ d a t a( 3 , : ) , ’ k− ’ , l , x _ d a t a ( 4 , : ) , ’ g− ’ )

53 xtitle ( ’ C o nv er s io n f o r a j a ck e te d t u b ul a r r e a c t o r ’) ;

54 x l a b e l ( ” L e n gt h ( cm ) ” )55 y l a b e l ( ” C o n v e r s i o n ” )56 l e g e n d ( [ ’ 34 8 ’ ; ’ 349 ’ ; ’ 35 0 ’ ; ’ 351 ’ ]) ;57

58 //OUTPUT59 mprintf ( ’ \n The T em pe ra tu re p r o f i l e s f o r f o u r f e e d

t e mp e ra t u re s a r e p l o t t e d ’ ) ;60 mprintf ( ’ \n F or T0 : 3 4 8 K a t t a i n s i t s maximum

t e mp e r at u r e a t c o n v e r s i o n o f a bo ut 25%%−30%%’ ) ;61 mprintf ( ’ \n At T0 : 3 5 1 K t he t em p er a tu re i n c r e a s e s by

6 . 5 C h i g h s e n s t i v i t y t h a t t h e r e a c t o r i sn e a r in g u n s t a bl e ’ ) ;62

63 // FILE OUTPUT64 f i d = mopen ( ’ .\ Chapter5−Ex1−Output . tx t ’ , ’ w ’ ) ;65 mfprintf ( f i d , ’ \n The T em pe ra tu re p r o f i l e s f o r f o u r

f e e d t e mp e ra t u re s a r e p l o t t e d . ’ ) ;66 mfprintf ( f i d , ’ \n F or T0 : 3 4 8 K a t t a i n s i t s maximum

t e mp e r at u r e a t c o n v e r s i o n o f a bo ut 25%%−30%%’ ) ;67 mfprintf ( f i d , ’ \n At T0 : 3 5 1 K t h e t e m pe r a tu r e

i n c r e a s e s by 6 .5 C h i g h s e n s t i v i t y t h a t t h e

r e a c t o r i s n e a r i ng u n s t a b l e ’ ) ;68 mclose ( f i d ) ;

69

70 //===================================================

54


56/115

END OF PROGRAM

======================================================

Scilab code Exa 5.2 Maximum internal temperature difference


) M a r c e l D ek ke r , I n c . , USA , pp 4 3 6 .2 //C hapt e r−5 Ex5 . 2 Pg No . 1 943 / / T i t l e : Maximum i n t e r n a l t e m pe r a tu r e d i f f e r e n c e4 //

============================================================

5 clear

6 format (16)

7 clc

8 //INPUT9 T _ C = 2 0 0 ; / / T e m p e r a t ur e ( C )

10 P = 1 . 2 ; / / P r e s s u r e ( atm )11 f _ e t h y l e n e = 0 . 0 5 ; // f r a c t i o n o f e t hy l e n e12 k _ s = 8 * 1 0 ^ ( - 4 ) ; // S o l i d c o n d u c t i v i t y ( c a l / s e c c m C )13 D _ e = 0 . 0 2 ; // D i f f u s i v i t y f o r e t hy l e n e ( cm2/ s )14 d e l _ H = - 3 2. 7 *1 0 ^ (3 ) ; // Heat o f r e a c t i o n ( c a l )15 V _ r e f = 2 2 4 0 0 ; / / r e f e r e n c e v ol um e ( cm3 )16 T _ r e f = 2 7 3 ; / / R e f e r e n c e T e mp e ra t ur e (K)17 P _ r e f = 1 ; / / R e f e r en c e P r e s s u r e ( atm )18 T _ K = T _ C + 2 7 3 ; / / R e a c t i o n T e m p er a t u r e (K)19

20 //CALCULATION21 C _ s = f _ e t h y l e n e * P * T _ r e f / ( V _ r e f * T _ K * P _ r e f ) ;22 T c _ m i n u s _ T s = D _ e * C _ s * ( - d e l _ H ) / k _ s ; / / R e f e r e q u a t i o n

5 . 5 1 Pg No . 19 423

55


57/115

24 //OUTPUT

25 mprintf ( ’ \n\ t Th e maximum i n t e r n a l t e m p e r a t u r ed i f f e r e n c e %0 . 3 f C ’ , T c _ m i n u s _ T s ) ;26

27 // FILE OUTPUT28 f i d = mopen ( ’ .\ Chapter5−Ex2−Output . tx t ’

Documents

Chemical Reactor Design_P. Harriott