9867

Mixing and Segregation in Chemical Reactors (CSTR versus PFR)

For very fast chemical reactions or viscous liquids, one must take into account the segregation of reactants. The intensity of segregation varies between 0 (perfect mixing) and 1 (no mixing). Mixing intensity can influence reaction rates and selectivities.
This Demonstration displays the segregation intensity versus the mixing time; the blue and red curves correspond to PFR (plug-flow reactor) and CSTR (continuous stirred-tank reactor), respectively. Several conclusions can be drawn from this Demonstration: (1) for fixed values of the mixing time and the reactor residence time, the segregation intensity will be higher for the CSTR, due to the fact that mixing is better in a PFR, where the flow is turbulent; (2) for a fixed residence time, the segregation goes from 0 to unity when the mixing time is varied; indeed, when the mixing time is small or large, the segregation is almost equal to zero or close to unity, respectively; and (3) when the residence time is large, there is a higher chance for mixing to occur in the reactor, since on average reactants are spending more time in the reactor; thus, the segregation takes smaller values corresponding to better mixing.
PFR segregation intensity, , is given by , where is the reactor residence time and is the mixing time.
CSTR segregation intensity, , is given by , where is the reactor residence time and is the mixing time.

SNAPSHOTS

  • [Snapshot]
  • [Snapshot]
  • [Snapshot]

DETAILS

J. Ingham, I. J. Dunn, E. Heinzle, and J. E. Prenosil, Chemical Engineering Dynamics, 2nd ed., Weinheim, Germany: Wiley-VCH, 2000 pp. 444–449.
    • Share:

Embed Interactive Demonstration New!

Just copy and paste this snippet of JavaScript code into your website or blog to put the live Demonstration on your site. More details »

Files require Wolfram CDF Player or Mathematica.









 
RELATED RESOURCES
Mathematica »
The #1 tool for creating Demonstrations
and anything technical.
Wolfram|Alpha »
Explore anything with the first
computational knowledge engine.
MathWorld »
The web's most extensive
mathematics resource.
Course Assistant Apps »
An app for every course—
right in the palm of your hand.
Wolfram Blog »
Read our views on math,
science, and technology.
Computable Document Format »
The format that makes Demonstrations
(and any information) easy to share and
interact with.
STEM Initiative »
Programs & resources for
educators, schools & students.
Computerbasedmath.org »
Join the initiative for modernizing
math education.
Step-by-step Solutions »
Walk through homework problems one step at a time, with hints to help along the way.
Wolfram Problem Generator »
Unlimited random practice problems and answers with built-in Step-by-step solutions. Practice online or make a printable study sheet.
Wolfram Language »
Knowledge-based programming for everyone.
Powered by Wolfram Mathematica © 2014 Wolfram Demonstrations Project & Contributors  |  Terms of Use  |  Privacy Policy  |  RSS Give us your feedback
Note: To run this Demonstration you need Mathematica 7+ or the free Mathematica Player 7EX
Download or upgrade to Mathematica Player 7EX
I already have Mathematica Player or Mathematica 7+