1. AICHE Contest Week 3 Last Lecture
Terry A Ring
Chemical Engineering
University of Utah

2. Questions for the week
What number density of cells in the production reactor?
Since Mab production is given as 25 pgm/cell/day, what would you recommend?
The cell concentration has a large effect on the size of the production reactor(s).
The cell concentration has a large effect on the throughput and size of the separation system that follow production.
What selling price should I use?
See data in Table on p. 12 of the problem statement
“Demand similar to Avastin”
“produce your product at current titers of 1-2 gm/L as well as 5-10 gm/L”
My CapEx is $X, My OpEx is $Y, are these in the ball park?
I cannot really answer this question.
You might want to look at this in terms of
Drug Price
compare to others in Table on p 12
Profit
Can you have too much profit?
Company Turnover or annual cash flow
“2/3 of biopharmaceuticals come from companies with revenues less than $1 Billion”

3. Questions What do I use to design for Protein A chromatography
Simple equilibrium
Keq=Cmab_Fluid/CMab_Solid
Mass Transfer Limited adsorption
dC/dt = kc(C-C*) = kc(Cmab_Fluid-Keq*CMab_Solid)
kc = Mass Transfer coefficient determined from
NSh NRe correlation for packed bed
Flow rate (or velocity) recommended by resin supplier
Ion exchange equation for breakthrough curve
Cmab_Fluid= f(z,t) in Mass Transfer book
CMab_Solid(t,z)
t=10 s
t=1000 s
z distance in bed
Cmab_Fluid(t,L)
Breakthrough
Curve
10 s
Time
0 s
1000 s

4. Question
Do I need to put into the report the sequential batch Gantt chart?
Yes, put it in section 7 of the report.
Product waste requires “kill tanks.” Do I have to design and cost them?
Yes
Please do not forget the Media Prep and Buffer Prep - tanks mixers and pumps as well as sterile water prep for these.

5. Questions Do I need a mass balance in this report?
Yes, It should appear in Section 6 of the report with the process flow diagram (The text in section 6 should describe both).
It should be based upon the flow diagram – last page of Problem Statement
Please do not forget you losses along the separation train.
What goes into the Energy Balance in Section 8 of the report?
Every unit has an energy demand (and raw material demand) for is part of its operating cycle (reaction, draining, rinsing, steam cleaning, draining, filling).
Table of Utility Requirements

6. Questions
Our report is much less than the max pages. What length of report will meet your expectations?
100 page max. for the body of the report – Note: this is a maximum not a minimum.
Your report must be long enough to explain your design to another engineer without ambiguity. Tell your story well and you are done. Do not worry about the pages it takes to do that.
What information would and would not go on the equipment data sheets?
Sheets for major pieces of equipment only.
Major equipment is elucidated byL
significant cost.
Major is also what is requested by problem statement in the process description.
Something(s) for each of the sections in the process description