Langmuir-Hinshelwood Reaction in a Plug Flow Reactor
Oxygen oxidizes to on a supported metal catalyst in an isothermal plug flow reactor. Use buttons to select plots of partial pressures, catalyst coverage or reaction rate as a function of distance down the reactor. Use sliders to vary the temperature and the ratio of the feed partial pressure to the feed partial pressure. Because the rate-determining step is the reaction of adsorbed and adsorbed , and because adsorbs more strongly than , increasing the feed partial pressure can decrease the rate of formation. This happens when the surface coverage becomes much higher than the surface coverage.
Contributed by: Garrison J. Vigil (December 2015)
Additional contributions by: Rachael L. Baumann, John L. Falconer, J. Will Medlin, and Nick Bongiardina
(University of Colorado Boulder, Department of Chemical and Biological Engineering)
Open content licensed under CC BY-NC-SA
1. the rate-determining step is the surface reaction between carbon monoxide and atomic oxygen
2. carbon dioxide rapidly desorbs from catalyst surface
3. ideal plug flow reactor.
The fractional coverages for the reaction are determined from Langmuir isotherms:
for simplicity, ,
where is the adsorption equilibrium constant of species and is the partial pressure.
The rate of reaction is:
where is the rate constant.
The partial pressures of , and are calculated from material balances:
where is distance down the reactor.
 Langmuir Isotherms for a Binary Mixture [Video]. (Sep 1, 2016) www.colorado.edu/learncheme/kinetics/LanmuirIsothermsBinaryMixture.html.