Homework 1 Problem 5 SuperPro Designer™ Kinetic Fermentation
20 points possible due Friday September 2, 2011 Grader: Alan
Problem Statement:
Understanding cell growth rates and the effects of environmental conditions on
growth is a key aspect of biological engineering. The most common and versatile
method of cell growth analysis used throughout industry is batch fermentation
in a bioreactor.
The fermentation bioreactor enables cell growth to take place under well‐defined
operating conditions. Below is a typical overall fermentation reaction.
100 Media + 70 Oxygen →
28 Biomass + 70 Carbon Dioxide + 10 Impurity + 2 MAB + 60 Water
All of the feed streams enter the reactor at STP. 7,800 kg of water is fed to the
reactor at a flowrate of 100 L/min with a setup time of 5 minutes. 380 kg of media
is also fed to the reactor at a flowrate of 10 kg/min with a setup time of 20
minutes.
This fermentation cycle occurs at a temperature of 37oC with a constant heat rate
of 0.5oC/min. The calculated reaction rate refers to biomass formation (dX/dt)
since biomass was selected as the Rate Reference Component with a max of 0.20
h‐1. Media is the only substrate with a Ks value of 35 mg/L. the reaction is first
order in biomass and has an enthalpy of ‐3,697 kcal/kg at an oxygen reference
temperature of 37oC.
The product will be cooled to 5oC using glycol, which has a cooling rate of
0.5oC/min, and will be transferred out of the fermentor in a process time of 272
minutes.
Determine the amount of time required to completely consume the reaction
components and what is the rate limiting reactant for this system.
Method of Solution:
Use the SuperPro DesignerTM to simulate the batch process.
Solution:
1) Open the SuperPro DesignerTM program and start a new process file.
2) Select “Batch Mode” and click OK.
3) To register the process components select Tasks → Pure Components 
Register, Edit/View Properties… from the toolbar.
4) Type biomass in the source box, highlight the appropriate component, and
click the Register button in the center of the edit window.
5) Add carbon dioxide and sodium chloride to the selected component list.
When adding these components a warning message will appear, click OK
to ignore.
Note: If you add a component by mistake, click on the component
number and delete the selection by clicking the delete button in the
upper right hand corner of the Registered Pure Components box.
6) Components that are not found in the SuperPro Designer databank must
be added into the simulation by the user and are therefore considered user
define components. To enter a user defined component, click the Add a
New Component button , which is in the upper right hand corner of the
Registered Pure Components box. Do so now to add the component
impurity.
7) The New Component Definition window will appear. Type in the
component name Impurity, which will automatically fill in the subsequent
naming regions of this window, click OK to close.