Interactive Self-Study Module: Multiple Reactions and Selectivity
Overview:
This module uses screencasts and interactive simulations to explain selectivity when multiple reactions occur and how selectivity depends on reaction conditions and type of reactor. 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:
- Attempt to answer the multiple-choice ConcepTest and solve the example problem before watching the screencasts or working with the simulations.
- Watch the screencasts that explain selectivity and answer the questions within the screencasts.
- Review important equations for multiple reactions and selectivity.
- Use the interactive simulations to further understand selectivity in chemical reactors.
- Try to solve the example problems before watching the solutions in the screencasts.
- Answer the ConcepTests.
- Look at the list of key points, but only after you try to list the key points yourself.
Motivation:
- Multiple reactions occur in most chemical reactors, and selectivity is often more important than reaction rate.
- This module is intended for a reaction engineering/kinetics course.
Before studying this module, you should be able to:
- Formulate elementary rate laws from chemical reactions.
- Distinguish between series and parallel reactions.
- Solve mass balances for Isothermal Batch Reactors (BRs), Isothermal Semibatch Reactors (SBRs), Isothermal Plug Flow Reactors (PFRs), and Isothermal Continuous Stirred Tank Reactors (CSTRs).
After studying this module, you should be able to:
- Determine the instantaneous and/or overall selectivity for a given system.
- Explain how reactant concentrations affect selectivity.
- Determine how to change temperature to increase selectivity.
- Apply the concept of selectivity to solve problems in BRs, SBRs, PFRs, and CSTRs.
- For a given system of reactions, specify what type reactor (or system of reactors) yields the highest selectivity and how the reactor should be operated.