Page 240 - Modeling of Chemical Kinetics and Reactor Design
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210    Modeling of Chemical Kinetics and Reactor Design


                                 t  =    1
                                 12
                                     kp AO  RT
                                    =  RT                                               (3-325)
                                      kp
                                        AO
                                (3)  The decomposition of nitrous oxide (N O) to nitrogen and
                                                                           2
                              oxygen is represented by

                                 2NO →   2N +  O                                        (3-326)
                                   2        2    2
                                The half-life t  of the general nth order reaction is
                                             1/2
                                       2 (  n 1  − 1)  C 1− n
                                         −
                                 t  =             AO
                                           (
                                              −
                                 12       kn 1)
                              Therefore, using Equation 3-324 gives

                                        −
                                          −
                                           1 
                                               AO 
                                       n 1
                                      2
                                 t 12 =  kn 1− )   p RT  1− n                         (3-327)
                                       (
                                Taking the natural logarithm of Equation 3-327 gives
                                              −
                                 ln t (  12) =  ln  2 n 1 − − 1  + ( 1− n)  ln     p RT   (3-328)
                                                                AO 
                                            kn 1)
                                             (
                                Equation 3-328 can be expressed in the form

                                Y = AX  B                                               (3-329)

                                Linearizing Equation 3-329 gives

                                ln Y = ln A + B ln X                                    (3-330)

                              where the slope B = 1 – n.
                                From Table 3-19, we can construct the independent variable p /RT
                                                                                          O
                              at the constant temperature of 1,015 K and the gas constant R =
                              0.08206 (l • atm/mol • k) (Table 3-21). The dependent variable is t .
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