Page 178 - Modeling of Chemical Kinetics and Reactor Design
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148    Modeling of Chemical Kinetics and Reactor Design

                                Integrating Equation 3-161 between the boundary conditions  t = 0,
                              C  = C AO  and t = t, C  = C  gives
                               A
                                                         A
                                                   A
                                                  α
                                 −   1    ln [C A − ] C A  = t                          (3-162)
                                  k  + k            C AO
                                   1    2
                              That is:


                                                               α
                                                 α
                                 −   1    ln ( [  C A  − ) − (C AO − )]  = t            (3-163)
                                                      ln
                                  k 1  + k 2
                                Substituting Equation 3-160 into Equation 3-163 gives
                                               (
                                          kC      −C   )
                                  
                                     
                                 −  ln C A  −  2  AO  BO  
                                              k 1  + k 2  
                                  
                                               (
                                            kC     −C   )                            (3-164)
                                                           
                                 − ln C AO −  2  AO    BO    = (k 1  + )t
                                     
                                                                   k
                                                                     2
                                               k 1  + k 2  
                                                           
                                     (  k  + )C  − k C  + k C  
                                  
                                           k
                                 −  ln   1  2  A  2  AO   2  BO 
                                             (k 1 + )                                (3-165)
                                                    k
                                  
                                                      2
                                                                    
                                     k C  + kC     − kC    + kC     
                                                       2
                                 −ln   1  AO  2  AO + )  AO   2  BO   =(k 1  + )t
                                                                            k
                                                                              2
                                                                     
                                               (k 1  k 2           
                                     ( [ {                     )]
                                                  k
                                          k
                                 − ln k 1  + )C A  − (C AO  − C BO
                                            2
                                                   2
                                                                                        (3-166)
                                   ln
                                 − [kC   AO  + k C BO ]} =(k 1  + )t
                                                            k
                                                             2
                                              2
                                      1
                              or
                                       k 1                
                                        +1   C A  −(C AO  −C BO )
                                 −    k 2                    1  + )t               (3-167)
                                                                     k
                                  ln
                                                              =(k
                                                                      2
                                          k 1  C  +C      
                                           k 2  AO  BO    
                                                             
                                    
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