Page 152 - Modeling of Chemical Kinetics and Reactor Design
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122    Modeling of Chemical Kinetics and Reactor Design

                                Equation 3-42 is resolved into partial fractions as

                                           1           ≡  p  +          q
                                  A[
                                 C ( C BO − C ) +  C A]  C A    C ( [  BO − C ) +  C A]  (3-43)
                                            AO
                                                                        AO
                                1 ≡ ( [  BO  − C AO ) + C A ]  + qC A                    (3-44)
                                    pC


                                Equating the coefficients of C  and the constant on both the right
                                                             A
                              and left side of Equation 3-44 gives
                                “Const”    1 = p(C BO  –C AO )

                                “C ”       0 = p + q
                                   A
                              where

                                p = 1/(C BO  – C AO )                                    (3-45)

                              and

                                q = –1/(C    –C  )                                       (3-46)
                                          BO   AO
                                Substituting p and q into Equation 3-43 and integrating between the
                              limits gives

                                    C A                C A                             
                                                                                        
                                  
                                 −   ∫     dC A      −  ∫            ) ( [  dC A       
                                                                                        
                                  C   (C BO  −C AO )C A    (C BO  −C AO  C BO  −C AO )+C A ]
                                   AO                  C AO
                                    t
                                   ∫
                                 = kdt                                                   (3-47)
                                    0


                                                            C (            
                                      1        C AO          BO − C )+  C A  
                                                                     AO
                                                                               =
                                             ln
                                 C (  BO −  C )   C A  + ln       C (    BO  −  C AO  +  C )   kt  (3-48)
                                                                          AO 
                                            
                                         AO
                                       C    C (   − C ) +  C 
                                                           A 
                                 ln    AO    BO  AO       =  kC (  BO  − C )  t    (3-49)
                                                                          AO
                                         
                                                              
                                       C BO   C A        
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