Chemical Engineering 142
Homework Set #1
100 points total
Due Wednesday, January 27, 2010
Problem 1 (30 points)
A liquid phase reaction, 3A
→
2B + 4C, occurs in an isothermal flow reactor running at
steadystate.
The volumetric flow rate is constant at 4 L h
1
, and the entering molar flow
rate of pure A is 20 mol h
1
.
The reactor is to be designed such that 85% of the A fed is
converted into products.
For each of the assumed forms of the reaction rate,
r
A
, below,
calculate the reactor volume required for a (i) CSTR or (ii) PFR:
(a)
with k = 4 mol h
1
L
1
(b)
with k = 0.3 mol
2
h
1
L
2
(c)
−
r
A
=
k
C
A
with k = 0.1 mol
2
h
1
L
2
(d) If volume is the only parameter in the capital cost of the reactor, what type of reactor
is optimal for the kinetics given in parts (a)(c), and how much money will you save for
each if the cost is $1000/L?
(e) Calculate the residence time,
τ
, for the PFR in part (b). Then, calculate the time
required to obtain the same conversion as the PFR in a batch reactor of the same volume
and same initial concentration.
How do the two times compare?
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '10
 HEY
 Fluid Dynamics, Chemical Engineering, Mole, pH, Reaction, Kinetics, Chemical reaction, CSTR, isothermal flow reactor

Click to edit the document details