Reactor Design

At the end of this learning unit, the student is able to :

• Axe 1: 1.1, 1.2, 1.3;
• Axe 2: 2.2, 2.4, 2.5;
• Axe 3: 3.2;
• Axe 4: 4.1, 4.4;
• Axe 5: 5.3, 5.5, 5.6;
• Axe 6: 6.1, 6.3.

• Describe the different aspects of mass, heat and momentum balances.
• Derive the fundamental continuity equations for species and energy, both in the general form and in specific simplified forms.

• Derive the continuity equations for isothermal and nonisothermal batch reactors.
• Use the continuity equations for isothermal and nonisothermal batch reactors for reactor simulation and design.
• Explain different optimal operation policies and control strategies.

• Derive the continuity equations for adiabatic and nonadiabatic, isothermal and nonisothermal plug flow reactors.
• Use the continuity equations for plug flow reactors for reactor simulation and design.

• Derive the mass and energy balances of a perfectly mixed flow reactor.
• Use the mass and energy balances for reactor simulation and design.
• Make a choice between a plug flow reactor and a completely mixed flow reactor for a given application based on different criteria (conversion, selectivity, heat of reaction, etc..).
• Analyze the stability of a perfectly mixed flow reactor and study the eventual transient behavior.

• Describe the different types of fixed bed reactors.
• Describe some of the important applications of fixed bed reactors.
• Describe and apply the different factors involved in the preliminary design of fixed bed reactors.
• Describe the different types of models that are used for the simulation and design of fixed bed reactors and their assumptions.

• Derive the basic one-dimensional model for fixed bed reactors.
• Apply the basic one-dimensional model for the simulation and design of fixed bed reactors.
• Describe runaway in a fixed bed reactor.
• Explain the use of a multibed adiabatic reactor and the way to calculate the number of beds required (including the graphical method) and their size.
• Explain the use of a multitubular reactor and the way to calculate its size, the number of tubes, and the temperature of the heat exchanging medium.
• Derive the model equations for the case of a fixed bed reactor with heat exchange between the feed and effluent or between the feed and reacting gas.
• Describe autothermal operation.
• Describe the phenomenon of catalyst deactivation and the related nonsteady-state behavior of fixed bed reactors.
• Explain the use of a one-dimensional model with axial mixing and derive the model equations.
• Explain the use of two-dimensional pseudohomogeneous models for fixed bed reactors.

• Derive the one-dimensional model for fixed bed reactors that allows accounting for interfacial gradients and to apply this model for reactor simulation and design.
• Derive the one-dimensional model for fixed bed reactors that allows accounting for interfacial and intraparticle gradients and to apply this model for reactor simulation and design.

• Explain macro- and micro-mixing in reactors.
• Qualitatively explain the different types of models explicitly accounting for mixing.
• Explain the concept, potential and limitations of residence time distribution (RTD) methods.
• Calculate the RTD of a perfectly mixed vessel.
• Experimentally determine the RTD of a reactor.
• Derive information on the flow pattern from the RTD.
• Derive the RTD for series of n completely stirred tanks.
• Apply the RTD to the simulation and design of reactors, with direct application to

• Describe the concept of multi-zone models.
• Describe the concept of axial dispersion and tanks-in-series models and to derive and apply the continuity equations.

• Describe the technological aspects of fluidized bed and riser reactors.
• Describe the most important applications of fluidized bed reactors.
• Describe the most important features of the fluidization and transport of solids.
• Define and model heat transfer in fluidized beds.
• Derive the two-phase model for fluidized bed reactors.
• Derive the basic model for a transport or riser reactor.
• Apply the fluidized bed and riser reactor models for reactor simulation and design.

• Describe the different types of multiphase flow reactors:

• Describe (including their assumptions), derive and apply the most frequently used design models for multiphase flow reactors:

• Look up scientific and technical information in a text book.
• Report a technical study in a scientific and concise way (mini-project "Methane steam reforming: reactor simulation and sensitivity study").
• Work in small groups.
• Be critical and ask questions.
• Verify the units of the different variables and terms appearing in mathematical equations.
• To use a corpus of scientific and technical knowledge, allowing to solve given problems in the discipline studied.
• To analyze, organize and develop an engineering approach for process development responding to specific needs or a given problem, the analysis of a given physical phenomenon or a system.
• To contribute, as a team member, to the realization of a project with a given discipline or multiple disciplines according to a well described approach.
• To efficiently communicate by writing and presentation, in English or French, the results of a well-defined project.
• To show a rigorous behavior and critical thinking in carrying out scientific or technical tasks with respect for ethical issues.