Interactive Self-Study Module: Absorption Columns

Overview:

An absorption column is a steady-state flow system in which an impurity (solute) in a gas phase is absorbed into a liquid phase. The column is often a packed tower in which gas flows up and liquid flows down. This module uses screencasts and an interactive simulation to explain absorption columns. It then provides a step-by-step quiz simulation and example problems to allow the user to test themselves. Your retention of material in this module will increase if you write down reasons for your answers to ConcepTests, questions in screencasts, and questions to answer before using the interactive simulation, and you try to solve the example problems before watching the screencast solutions. We suggest using the learning resources in the following order:

  1. Attempt to answer the multiple choice ConcepTest and solve the example problem before watching the screencasts or working with the simulations.
  2. Watch the screencasts that describe absorption columns and answer the questions within the screencasts.
  3. Review important equations for absorption columns.
  4. Use the interactive simulation to further understand how absorption columns change when parameters are varied.
  5. Use the quiz interactive simulation to test your understanding by carrying out step-by-step preparation of the diagram to determine the number of equilibrium stages.
  6. Try to solve the example problems before watching the solutions in the screencasts.
  7. Answer the ConcepTests.
  8. Look at the list of key points, but only after you try to list the key points yourself.
Motivation:
  • This module is intended for a separations course.
Before studying this module, you need to be able to:
After studying this module, you should be able to:
  • Carry out mass balances on an absorption column.
  • Determine the number of stages needed to carry out a process to remove an impurity (solute) from a gas stream using absorption into a liquid stream.
  • Explain how changing pressure and temperature affect absorption and the number of stages needed for separations.
  • Explain where the solute concentrations are high and where they are low in an absorption column.