Page 484 - Elements of Chemical Reaction Engineering Ebook
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Sec. 8.3   Nonisotherrnal Continuous-Flow Reactors             455

                                      Energy balance. Recalling Equation (8-30), we have
                                  Q - Ws - FAO ,x(@, ep,(T - To)) - FAoXIAHi, (TR) + A?,,(T  - TR)] = 0   (8-30)

                                  From the problem statement
                                                    Adiabatic:   Q = 0
                                                    No work:   W = 0
                                                    Atp = ?p,  - Cp, = 141 - 141 = 0
                                  Applying the conditions above to Equation (8-30) and rearranging gives


                                                                                           (E8-6.9)

                                              c@,C,,, = cpA+@l?pI
                                                                =

                                                    = 159.5 J/mol.K

                                                                 - - 6900)x
                                                                  (
                                                        T  = 330+
                                                                   159.5
                                                          I  T  = 330 + 43.3X 1           (E8-61.10)
                                  Substituting for the activation energy, T, , and k, in Equation (E8-6.3), we obtain
                                                                     [& - $11

                                                     k  = 31.1 exp[-
                                                                               1
                                                    1  k  = 31.1 erp[7906 (-]I   I
                                                    I
                                                                                          (E8-6.11)


                                  Substituting  for AH,,  , T2, and K,(T,)  In Equation (E8-6.4) yields







                                                                                          (E8-6.12)


                                  Recalling the rate law gives us
                                                               [  (  41
                                                      -r,  =kC,,  I  - 1 + - x             (E8-6.7)


                                  At equilibrium
                                                              -rA = 0
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