ChE
ChE 400  Reactive Process Engineering
Complete Reactor Balance Equations
1
PFR/BR balance equations (steady state):
PFR/BR balance equations (steady state):
dT
=
dV
HRij = heat of reaction i
S
pe
ChE
ChE 400  Reactive Process Engineering
Reactions and Reactors
L11
L1
If we want to run a chemical process in order to convert some reactants
(the reactor feed) to some product (the reactor efflu
ChE
ChE 400  Reactive Process Engineering
Comparing Reactors
One of the most basic criteria of reactor selection is the reactor size
necessary to achieve a desired conversion in a reaction. We saw ab
ChE
ChE 400  Reactive Process Engineering
Reaction rate
L31
L3
reaction rate describes change in concentration of reactants and
products with time
>
r = dCj/dt
r is proportional to the reactant co
ChE
ChE 400  Reactive Process Engineering
Multiple Reactions
L111
L11
We have largely considered single reactions
so far in this class
How many industrially important processes
involve a single r
ChE
ChE 400  Reactive Process Engineering
The Morse Potential
L71
L7
Lets have a look at a very simple model reaction:
F + HH <=>
<=>
We can describe the
energy of this system
based on the relativ
ChE
ChE 400  Reactive Process Engineering
Review of Fitting Kinetic Data
L61
L6
True or false: The goal of fitting kinetic
data is to find the true rate expression.
What are the two general metho
ChE
ChE 400  Reactive Process Engineering
Heterogeneous Catalysis
L211
L21
The principle:
Example: ethylene hydrogenation to ethane on Ni catalyst
C2 H 4 + H 2
Ni
C2 H 6
Heterogeneous Catalysis = a
ChE
ChE 400  Reactive Process Engineering
Thermodynamics revisited
L131
L13
How can I do an energy balance for a reactor system?
1st law of thermodynamics (differential form):
dE =dq dw
dE dq dw
E
ChE 400  Reactive Process Engineering
Another look at equilibrium limitations
L16L161
We have previously looked into optimizing S and X, but what about r?
Optimization with respect to Cj obvious (d
ChE
ChE 400  Reactive Process Engineering
Multiple Reactions Complex Kinetics
L121
L12
With an increasing number of reaction steps in a reaction network, the overall
observed reaction kinetics beco
ChE
ChE 400  Reactive Process Engineering
Scale, Scope & Impact of Catalysis
L201
L20
What do they do for the chemical industry?
Catalysts have an enormous impact on the chemical industry because t
ChE
ChE 400  Reactive Process Engineering
1/r plots: a brief reminder
L101
L10
1/r
Xtarget X
ChE
ChE 400  Reactive Process Engineering
1/r plots: a brief reminder
L102
L10
1/r
Xtarget X
ChE
ChE
ChE 400  Reactive Process Engineering
The Adiabatic CSTR
L15L151
Accumulation = Input  Output + Production

Q
Steady state, Ws = 0:
Stead
Need to replace r = f(cA,T) !
Combine with mass balance:
V