This module uses screencasts and an interactive simulation to explain systems with recycle and purge streams. 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 interactive simulations, 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 screencast that describes systems with recycle and purge and answer the questions within the screencast.
3. Review important equations for purge stream in a system with recycle.
4. Use the interactive simulation and excel spreadsheet to further understand the behavior of a system with recycle and bypass.
5. Try to solve the example problems before watching the solutions in the screencasts.
6. Answer the ConcepTests.
7. Look at the list of key points, but only after you try to list the key points yourself.