General Mole Balance Equation Batch Chemical Reaction Engineering (CRE) is the field that studies the rates and mechanisms of chemical reactions and the design of the reactors in which they take place. TODAY’S LECTURE Introduction Definitions General Mole Balance Equation Batch CSTR PFR PBR

Chemical Reaction Engineering Chemical reaction engineering is at the heart of virtually every chemical process. It separates the chemical engineer from other engineers. Industries that Draw Heavily on Chemical Reaction Engineering (CRE) are: CPI (Chemical Process Industries) Dow, DuPont, Amoco, Chevron

Materials on the Web and CDROM http://www.engin.umich.edu/~cre/

Developing Critical Thinking Skills Socratic Questioning is the Heart of Critical Thinking R. W. Paul’s Nine Types of Socratic Questions

Let’s Begin CRE Chemical Reaction Engineering (CRE) is the field that studies the rates and mechanisms of chemical reactions and the design of the reactors in which they take place.

Chemical Identity A chemical species is said to have reacted when it has lost its chemical identity.

Chemical Identity A chemical species is said to have reacted when it has lost its chemical identity. The identity of a chemical species is determined by the kind, number, and configuration of that species’ atoms.

Chemical Identity A chemical species is said to have reacted when it has lost its chemical identity. 1. Decomposition

Chemical Identity A chemical species is said to have reacted when it has lost its chemical identity. 1. Decomposition 2. Combination

Chemical Identity A chemical species is said to have reacted when it has lost its chemical identity. 1. Decomposition 2. Combination 3. Isomerization

Reaction Rate The reaction rate is the rate at which a species looses its chemical identity per unit volume.

Reaction Rate The reaction rate is the rate at which a species looses its chemical identity per unit volume. The rate of a reaction (mol/dm3/s) can be expressed as either the rate of Disappearance: -rA or as the rate of Formation (Generation): rA

Reaction Rate Consider the isomerization AB rA = the rate of formation of species A per unit volume -rA = the rate of a disappearance of species A per unit volume rB = the rate of formation of species B per unit volume

Reaction Rate EXAMPLE: AB If Species B is being formed at a rate of 0.2 moles per decimeter cubed per second, ie, rB = 0.2 mole/dm3/s

Reaction Rate EXAMPLE: AB rB = 0.2 mole/dm3/s Then A is disappearing at the same rate: -rA= 0.2 mole/dm3/s

Reaction Rate EXAMPLE: AB rB = 0.2 mole/dm3/s Then A is disappearing at the same rate: -rA= 0.2 mole/dm3/s The rate of formation (generation of A) is rA= -0.2 mole/dm3/s

NOTE: dCA/dt is not the rate of reaction Reaction Rate For a catalytic reaction, we refer to -rA', which is the rate of disappearance of species A on a per mass of catalyst basis. (mol/gcat/s) NOTE: dCA/dt is not the rate of reaction

Reaction Rate Consider species j: rj is the rate of formation of species j per unit volume [e.g. mol/dm3/s]

Reaction Rate rj is the rate of formation of species j per unit volume [e.g. mol/dm3*s] rj is a function of concentration, temperature, pressure, and the type of catalyst (if any)

Reaction Rate rj is the rate of formation of species j per unit volume [e.g. mol/dm3/s] rj is a function of concentration, temperature, pressure, and the type of catalyst (if any) rj is independent of the type of reaction system (batch reactor, plug flow reactor, etc.)

Reaction Rate rj is the rate of formation of species j per unit volume [e.g. mol/dm3/s] rj is a function of concentration, temperature, pressure, and the type of catalyst (if any) rj is independent of the type of reaction system (batch, plug flow, etc.) rj is an algebraic equation, not a differential equation

General Mole Balance

General Mole Balance

Batch Reactor Mole Balance

CSTR Mole Balance

Plug Flow Reactor

Plug Flow Reactor Mole Balance PFR: The integral form is: This is the volume necessary to reduce the entering molar flow rate (mol/s) from FA0 to the exit molar flow rate of FA.

Packed Bed Reactor Mole Balance PBR The integral form to find the catalyst weight is:

Reactor Mole Balance Summary

Fast Forward to the Future Thursday March 20th, 2008 Reactors with Heat Effects

Production of Propylene Glycol in an Adiabatic CSTR

Solution What are the exit conversion X and exit temperature T? Let the reaction be represented by

KEEPING UP

Separations These topics do not build upon one another Filtration Distillation Adsorption These topics do not build upon one another

These topics build upon one another Reaction Engineering Mole Balance Rate Laws Stoichiometry These topics build upon one another

Heat Effects Isothermal Design Stoichiometry Rate Laws Mole Balance

Rate Laws Mole Balance

Isothermal Design Heat Effects Rate Laws Stoichiometry Mole Balance

Batch Reactor Mole Balance

Batch Reactor Mole Balance

Batch Reactor Mole Balance

Batch Reactor Mole Balance

Batch Reactor Mole Balance

Continuously Stirred Tank Reactor Mole Balance

Continuously Stirred Tank Reactor Mole Balance

Continuously Stirred Tank Reactor Mole Balance

C S T R Mole Balance

CSTR Mole Balance

Plug Flow Reactor

Plug Flow Reactor Mole Balance PFR:

Plug Flow Reactor Mole Balance PFR:

Plug Flow Reactor Mole Balance PFR:

Plug Flow Reactor Mole Balance PFR:

Plug Flow Reactor Mole Balance PFR:

Plug Flow Reactor Mole Balance PFR: The integral form is:

Plug Flow Reactor Mole Balance PFR: The integral form is: This is the volume necessary to reduce the entering molar flow rate (mol/s) from FA0 to the exit molar flow rate of FA.

Packed Bed Reactor Mole Balance PBR

Packed Bed Reactor Mole Balance PBR

Packed Bed Reactor Mole Balance PBR

Packed Bed Reactor Mole Balance PBR

Packed Bed Reactor Mole Balance PBR The integral form to find the catalyst weight is:

Reactor Mole Balance Summary

Reactor Mole Balance Summary

Reactor Mole Balance Summary

Reactor Mole Balance Summary

Chemical Reaction Engineering Asynchronous Video Series Chapter 1: General Mole Balance Equation Applied to Batch Reactors, CSTRs, PFRs, and PBRs H. Scott Fogler, Ph.D.

http://www.engin.umich.edu/~cre

Chemical Reaction Engineering Chemical reaction engineering is at the heart of virtually every chemical process. It separates the chemical engineer from other engineers. Industries that Draw Heavily on Chemical Reaction Engineering (CRE) are: CPI (Chemical Process Industries) Dow, DuPont, Amoco, Chevron Pharmaceutical – Antivenom, Drug Delivery Medicine – Tissue Engineering, Drinking and Driving

Compartments for perfusion Stomach VG = 2.4 l Gastrointestinal tG = 2.67 min Liver Alcohol VL = 2.4 l tL = 2.4 min Central VC = 15.3 l tC = 0.9 min Muscle & Fat VM = 22.0 l tM = 27 min Perfusion interactions between compartments are shown by arrows. VG, VL, VC, and VM are -tissue water volumes for the gastrointestinal, liver, central and muscle compartments, respectively. VS is the stomach contents volume.

Chemical Reaction Engineering Chemical reaction engineering is at the heart of virtually every chemical process. It separates the chemical engineer from other engineers. Industries that Draw Heavily on Chemical Reaction Engineering (CRE) are: CPI (Chemical Process Industries) Dow, DuPont, Amoco, Chevron Pharmaceutical – Antivenom, Drug Delivery Medicine –Pharmacokinetics, Drinking and Driving Microelectronics – CVD

Reaction Rate rA = the rate of formation of species A per unit volume Consider the isomerization AB rA = the rate of formation of species A per unit volume

Reaction Rate Consider the isomerization AB rA = the rate of formation of species A per unit volume -rA = the rate of a disappearance of species A per unit volume

Reactor Mole Balance Summary