#### Pressure Drop in Packed Bed Reactors: Interactive Simulation

This simulation was prepared using Mathematica. Download the free Wolfram player, and then download the simulation CDF file (link given below or click on figure to download). A screencast below shows how to use the simulation.

##### Simulation: Pressure Drop in a PBR using Ergun Equation

A first-order, irreversible, gas-phase reaction A → B takes place in two isothermal, packed-bed catalytic reactors; they have the same diameter but different lengths (14 m and 21 m). Only A is fed to the reactors. The inlet pressure is the same for each reactor; the outlet pressure changes when particle diameter is changed with the slider, but each reactor has the same outlet pressure. As a result, the inlet molar flow rate of A is lower for the longer reactor. Show plots of conversion, pressure, reactant molar flow rate, and volumetric flow rate as a function of distance down the reactor for both reactors with buttons. The Ergun equation is used to model the pressure drop.

**Try to answer these questions before determining the answers with the simulation**. We suggest that you write down the reasons for your answers.

- As the size of particles in a packed bed increases, does the pressure drop increase, decrease, or essentially not change?
- For two reactors of the same length but different pressure drops, will conversion be higher or lower in the reactor with the larger pressure drop? Why?