Isothermal Plug Flow Reactor with Recycle
A first-order reaction is carried out in an isothermal plug flow reactor (PFR) with recycle. The fresh feed concentration () and volumetric flow rate  are known. Use sliders to change the recycle ratio and the PFR volume. The correct reactant exit concentration  is obtained iteratively: the reactor feed concentration  is guessed with the slider, the PFR mass balance is then solved to determine , and a mass balance around the mixing point before the PFR yields the calculated  value. Next, change the " guess" using the slider until the calculated  (the black arrow on the left) equals 0.2 mol/L (the center of the green circle). The graph on the right plots the reactant concentration down the PFR using the guessed  value. For larger values of the recycle ratio, the PFR with recycle behaves like a continuous stirred-tank reactor (CSTR).

Download the CDF file to view the simulation using the free