+
P2 workshop
Problem objective
Process costs
Product costs
+
Class questions
Fundamental Girls of CME

1 - Which column are we modeling in Chemcad? The large,
industrial one, or the lab one?

2 - Our final objective is to propose an experiment modeling
this large industrial column, right?

3 - Which column are we doing the cost analysis for?

4 - Which column are we doing the innovation analysis for?
+ Which column are we modeling in Chemcad? The
large, industrial one, or the lab one?

Q. Our understanding is that we are designing a large,
industrial scale column.

A.You are primarily modeling the big one, which has flows that
should be within the typical range of the correlations for
flooding, tray pressure drop, efficiencies, etc. When you have a
solution that you like and think would be ‘stable’ in the lab, then
transfer the conditions you have selected to a 30 ml/min flow, 8
tray column with a 5 cm diameter, sieve trays,..
+ Our final objective is to propose an experiment
modeling this large industrial column, right?

A.You have stated the primary objective well.We want to
predict conditions for the lab experiment that the next student
groups can check.
+ Which column are we doing the cost analysis for?

Q. We will do the cost analysis on the large column to make
sure it is a realistic and profitable column in real life.

A. Cost analysis on the large column. This will inform the team
with respect to what a commercial separation of the feed would
cost. When you have a crude optimization of the large column
case, you will understand better what some of the cost and
operating constraints. This should help provide a more realistic
scenario for students to replicate in lab.
+ Which column are we doing the innovation analysis
for?

Q. From this column we are designing a small scale experiment that
students would do (for example, telling them what they are given, what
their desired product is, details of the physical column, and suggestions
on reflux ratios. From that point, they would determine the most efficient
reflux ratios and costs of running their column as part of their
experiment). We would then apply the innovation analysis to our
experiment design?

A. The objective of designing the experiment before running it is to help
students run the actual equipment. For example, with specified column
operating conditions – feed condition, flows in and out, expected stage
efficiencies – you will know the complete temperature profile at steadystate and how sensitive this might be to operating conditions changes (I.e.,
via a sensitivity analysis).Without a simulation, operators would have no
idea what temperatures or flows to ‘hit’. If you were going to operate a
piece of industrial equipment in a plant setting, the process
engineer/plant manager should not let you touch a button until you can
demonstrate that you know what will happen. Usually, this would extend to
what to do in case of column flooding, a bad control valve, etc.
+
Process costs
Stripping column to generate a
relatively pure 2PrOH bottoms stream

Approach

Establish example material balances
for the stripping column, setting 4 of
6 variables

Run 3 to 4 trials changing one
variable

Or

Sensitivity analysis for the same
+
Example trial:
F = 100; xF = 0.5; xD = 0.95, 80% < %2-PrOH recovery < 90%
case study
F
Xf
Xd
% PrOH recovery
100
0.5
0.95
variable
kJ/kg-K
kJ/kg
4.187
2270
latent heat
Cp, water of steam
% PrOH
condenser reboiler
CW, kg/h
CW cost,
steam, kg/h steam, lb/h utilities,
Cw, m3 /h
XB
recovery
duty,, kJ/h duty, kJ/h
$/h
$/yr
0.8 -7.22E+06
7.94E+06
86171
86
$1.72
3.50E+03
$50.70
$419,379
0.85 -1.22E+07
1.32E+07
145259
145
$2.91
5.81E+03
$84.26
$697,319
0.9 -2.64E+07
2.71E+07
315262
315
$6.31
1.19E+04
$173.11 $1,435,339
0.088
0.068
0.056
+
Product costs
Libguides.uky.edu/CME

http://libguides.uky.edu/CME

Chemical pricing =
http://libguides.uky.edu/c.php?g=2229
48&p=1476423

http://www.sigmaaldrich.com/unitedstates.html
+
http://libguides.uky.edu/CME
+
+ Click 1 = Select a year
Click 2 = search within this pub
+
+
What is the product cost for a year
of operation?
cost
feed
MeOH
2PrOH
total
800
1.14
$912
$0.91
euro per metric ton
dollars/euro
$/1000 kg 2PrOH
$ per kg 2PrOH
$1.11
3.89
$0.29
0.792
$0.36
$/gallon MeOH
liters/ gallon
$/liter
g/cm3
$/kg MeOH
kmol/h
kg/h
50
50
100
$/h
1602
3005
4607
$/yr
$577.18
$4,617,434
$2,740.56 $21,924,480
$3,317.74 $26,541,914