4. TUBULAR REACTORS WITH LAMINAR FLOW
Tubular reactors in which homogeneous reactions are conducted can be empty or packed conduits
of various cross-sectional shape. Pipes, i.e tubular vessels of cylindrical shape, dominate. The
flow can be turbulent or l
ChE 505 Chapter 7N: Appendix
Updated 02-08/05
Chapter 7: Appendix
Diffusion: A General Treatment of Molecules and Ions
We have seen that diffusion may be regarded as the net movement of solutes in solution (or in gas phase)
due to a concentration gradient
CHE 471
LECTURE 5B
PRECISION OF KINETIC MEASUREMENTS:
Random errors can never be completely avoided in kinetic measurements but we can
often estimate the maximum possible error in our measurements of concentrations,
temperature fluctuations, etc.
In gener
UPDATED 02/10/03 - AW
7A. A BRIEF SUMMARY OF ELEMENTARY GAS-PHASE REACTIONS
We will classify these as:
- bimolecular
- trimolecular
- unimolecular
7A-1. Bimolecular Reactions
Bimolecular gas phase reactions can occur:
between two molecules
between a free
CHE 471
LECTURE 5A
EXAMPLES OF EVALUATION OF RATE FORMS FROM KINETIC
DATA IN BATCH SYSTEMS
EXAMPLE 1: Determine the reaction order and the rate constant for a single reaction of
the type A products based on the following experimental information obtained
ChE 512 Course Notes
Chapter 2
2.
CHARACTERIZATION OF MACROMIXING
2.1
Residence Time Distributions, What are they?
In describing a
flow pattern in any flow system, reactors in particular, since the hydrodynamic
equations of flow are too complex to solve,
5.4 Application of Perturbation Methods to the Dispersion Model for Tubular Reactors
The axial dispersion model for tubular reactors at steady state can be described by the following
equations:
1 d 2 c dc
Rn c n = 0
2
Pe dz
dz
1 dc
z= 0
1=c
Pe dz
dc
z=
5. THE AXIAL DISPERSION MODEL
The axial dispersion model can readily be extended to apply to turbulent flow conditions. Under
such conditions the velocity profile is almost flat and averaging with respect to radial position is
possible. The axial dispersi
ChE 512
Spring 2004
Updated 01/05
Chemical Reaction Engineering Notes
M. P. Dudukovic
1.
EFFECT OF MIXING ON REACTOR PERFORMANCE FOR
HOMOGENEOUS SYSTEMS - INTRODUCTION
In dealing with homogeneous reaction systems we have seen that basically all problems e
5.2 Mixing in a Pipeline
When instead of a reactor problem we deal with problems of mixing of one material that flows
after another as both are being pumped through the same pipe line, we use the dispersion or
Taylor diffusion model (depending whether the
5.1 Addenda: (Inversion of the Transfer Function for the Dispersion Model)
It might be instructive to show how to obtain the solution to eq (109) and the effect of B.C. on
that solution.
By taking the Laplace transform of eq (109) we get
1 d 2 c dc
sc =
ChE 471
Fall 2005
LECTURE 7
NONISOTHERMAL OPERATION OF IDEAL REACTORS
Continuous Flow Stirred Tank Reactor (CSTR)
To
T
Fjo, Qo
Fj
V
Tmo
V
To
or
T
Fj
Fjo, Qo
Tm
Tmo
Tm
Figure 1:
Schematic of CSTR with jacket and coil
Assumptions:
Homogeneous system
s
a) Si
ChE 471
Fall 2008
LECTURE 7a
Nonisothermal Chemical Reactors
So far we have dealt with isothermal chemical reactors and were able, by using only as many
species mass balances as there are independent reactions to relate reactor size, inlet and outlet
comp
ChE 471
Fall 2005
LECTURE 8
NONISOTHERMAL OPERATION OF IDEAL REACTORS
Plug Flow Reactor
To
T
Fjo, Qo
Fj
Tm,Qm
T
To
Tm
Tmo
Tm
Assumptions:
1.
2.
3.
Homogeneous System
Single Reaction
Steady State
Two types of problems:
1.
2.
Given desired production rate,
ChE 471
Lecture 9
Fall 2005
WALL COOLED TUBULAR REACTORS: AVOIDANCE OF HOT SPOTS
The pioneering work of Bilous and Amundsen (AIChE J. 2, 117, 1956) showed that a plug flow
reactor (PFR) cooled from the wall can exhibit extreme parametric sensitivity to sm
ChE 471
Lecture 10
Fall 2005
SAFE OPERATION OF TUBULAR (PFR) ADIABATIC REACTORS
In an exothermic reaction the temperature will continue to rise as one moves along a plug flow
reactor until all of the limiting reactant is exhausted. Schematically the adiab
Lecture 7
Fall 2012
EXTENSION OF IDEAL MIXED REACTOR (CSTR) CONCEPTS :
SIMULTANEOUS REACTION AND SEPARATION
Multifunctional reactors perform more than one function (e.g. reaction and separation) and are a
good example of process intensification (e.g. achi
CHE 471
LECTURE 5
EVALUATION OF RATE EXPRESSIONS FROM EXPERIMENTAL
DATA
In spite of the advances made by absolute kinetic rate theories, the ultimate determination
of the kinetic rate form and the evaluation of the appropriate kinetic parameters has to be
ChE 471: LECTURE 4
Fall 2003
IDEAL REACTORS
One of the key goals of chemical reaction engineering is to quantify the relationship between
production rate, reactor size, reaction kinetics and selected operating conditions. This requires a
mathematical mode
ChE 471
Lecture 6
October 2005
Ideal Reactors and Multiple Reactions
Isothermal Operation
Selection of a proper flow pattern is the key factor in achieving desired selectivities and yields in
multiple reactions. For every multiple reaction system of known
B. Joseph Required Reading :
ChE 477
PS # ENERGY
Energy Integration
Handout. Heat Exchanger Networks . Excerpted from Douglas' book. Chapter 19, Section 3.5. Improvements in Heat Integration. This chapter discusses the concept of minimum utility calculati