Time-Dependent PFR—Complete and Numerical Solutions

The PFR equation that we derived had two parHal derivatives—one in time and one in space. Recall that this is the equation for component A being fed to the PFR  

The time-dependent derivative of concentration is the accumulation term for the differential volume Acr dz. This is essentially the same for all the reactor types we have studied. What makes the PFR different and perhaps more interesting is the spatial derivative. 

Since it was not within our ability to solve the time-dependent equahon, we naturally solved the steady-state problem so that the accumulation term went to zero, which left only the spatial derivative  

This problem is more soluble because it involves only this one derivative. In fact, if we recall that is the velocity in the PFR, then we simplify the equation further  

However, is the ratio of a constant velocity to a differential distance. This has units of reciprocal time. Formally, we can take the constant into the derivative and this gives us gV, 

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