#### Residence Time Distribution: Example Problems

Try to solve these problems before watching the solutions in the screencasts.

##### Example Problem 1

A slug of tracer was added to the feed stream for a stirred tank reactor, which was running at steady state. The tracer concentration was measured as a function of time at the reactor exit.

From these data, determine the average residence time for the reactor and the standard deviation of the residence time distribution.

##### Example Problem 2

A non-ideal, continuous stirred tank reactor (CSTR) has the normalized response to a step function input of a tracer show in the figure. The step input starts at t=0.

a) Develop a 3-parameter model of this non-ideal reactor. The model can consist of ideal reactors, recycle, bypass, and hold-up.

b) Determine the values of the parameters for the model. The total reactor volume is 1.5 L and the inlet volumetric feedrate is 0.10 L/min.

c) Sketch the exit age distribution for the non-ideal reactor.