10182

# Breakthrough Curves for Adsorption with Longitudinal Diffusion Assuming Linear Equilibrium

An important unit operation in biotechnology and chemical engineering is fixed-bed adsorption.
Species to be separated, called separands, are either in the mobile phase or adsorbed by the stationary phase. The separands are subject to convection, mechanical dispersion, and molecular diffusion.
A mass balance, obtained by considering a disk of cross-sectional area equal to that of the column, gives:
,
where and are the concentrations of the separand in the mobile and stationary phases, respectively, is the void fraction of the column, is the mobile phase superficial velocity, is the effective dispersivity of the separand in the column, is the longitudinal position in the column, and finally is time.
Since linear equilibrium is assumed: . Also consider that mass transfer resistances are negligible (i.e.,
The breakthrough curve, the separand concentration versus time at the exit of the column, can be determined experimentally or computed numerically. In the present Demonstration, breakthrough curves are computed for a variety of values of the relevant parameters.

### PERMANENT CITATION

 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 » Download Demonstration as CDF » Download Author Code »(preview ») Files require Wolfram CDF Player or Mathematica.

#### Related Topics

 RELATED RESOURCES
 The #1 tool for creating Demonstrations and anything technical. Explore anything with the first computational knowledge engine. The web's most extensive mathematics resource. An app for every course—right in the palm of your hand. Read our views on math,science, and technology. The format that makes Demonstrations (and any information) easy to share and interact with. Programs & resources for educators, schools & students. Join the initiative for modernizing math education. Walk through homework problems one step at a time, with hints to help along the way. Unlimited random practice problems and answers with built-in Step-by-step solutions. Practice online or make a printable study sheet. Knowledge-based programming for everyone.