Mass balances are demonstrated for a reactor system. Pure \(A\) is fed to the system and two parallel reactions take place in the reactor:
\(A \rightarrow B\) (desired)
\(A \rightarrow C\) (undesired)
A separation unit after the reactor removes some of the unreacted \(A\) and recycles it back to the feed stream. Use a slider to set the recycle ratio, which is the ratio of the recycle flow rate to the fresh feed flow rate. Set the reactor selectivity, which is the (flow rate of \(B\)) / (flow rate of \(C\)) leaving the reactor, with a slider. Set the reactor conversion, which is the percent of \(A\) entering the reactor that is consumed, with a slider. The overall conversion of \(A\) is the percent of the feed (100 mol A/hr) that is consumed. The yield is the percentage of the feed that is converted to the desired product \(B\). A negative flow rate of \(A\) exiting the system indicates an impossible combination of reaction selectivity and reactor conversion.
Pure \(A\) is fed to the reactor where two parallel reactions occur:
\(A \rightarrow B\) (desired),
\(A \rightarrow C\) (undesired).
A separation unit splits the reactant \(A\) from products \(B\) and \(C\), and some \(A\) is recycled back to the reactor. The recycle ratio \(R\) is the ratio of the recycle flow rate to the fresh feed flow rate:
The yield \(Y_D\) is the fraction of the feed that is converted to the desired product \(B\):
The reactor selectivity \(S_{D/U}\) is the ratio of the desired product \(B\) to the undesired product \(C\):
The reactor conversion is the fraction of \(A\) entering the reactor that is consumed:
The overall conversion is the fraction of the feed that is consumed:
| \(R\) | recycle ratio |
| \(\dot{n}_{A,\text{in}}\) | fresh feed flow rate of \(A\) (100 mol/hr) |
| \(\dot{n}_{A,R}\) | recycle flow rate of \(A\) (mol/hr) |
| \(\dot{n}_{A,\text{out}}\) | flow rate of \(A\) exiting the system (mol/hr) |
| \(\dot{n}_{r,\text{in}}\) | flow rate of \(A\) entering the reactor (mol/hr) |
| \(\dot{n}_{r,\text{out}}\) | flow rate of \(A\) exiting the reactor (mol/hr) |
| \(\dot{n}_B\) | flow rate of desired product \(B\) (mol/hr) |
| \(\dot{n}_C\) | flow rate of undesired product \(C\) (mol/hr) |
| \(Y_D\) | yield of desired product \(B\) |
| \(S_{D/U}\) | reactor selectivity |
| \(x_S\) | reactor (single-pass) conversion of \(A\) |
| \(x_O\) | overall conversion of \(A\) |
This simulation was created in the Department of Chemical and Biological Engineering at University of Colorado Boulder for LearnChemE.com by John L. Falconer using Claude AI. It is a JavaScript/HTML5 implementation of a Mathematica simulation by Michael Wrobel. It was prepared with financial support from the National Science Foundation (DUE 2336987 and 2336988). Address any questions or comments to LearnChemE@gmail.com.