1. Optimal Reactor Configuration for Lactic Acid Production
Libby Bol

2. Introduction Commercially produced as a commodity chemical
Fermentation limitations
Product inhibition
Substrate inhibition
pH control

3. Reactor Options
Two-Stage cell recycle reactor with membrane separation
High cell concentration
High productivity
Electrokinetic bioreactor
Removes product as it is formed
Does not rely on chemical pH control

4. Assumptions
Normalized reactor conditions are representative of actual conditions
Cell growth approximately follows Monod Kinetics

5. Calculations
Reactor volume required to form 100g/h

6. Calculations
Lactic Acid Balance

7. Comparison 1.8 0.021 204 24.8 92 18 Two-stage Cell Recycle
Electrokinetic Bioreactor
Volume
1.8
0.021
Expected Concentration
204
24.8
Actual Concentration 92 18

8. Complications Electrokinetic reactor Cell Recycle Mixing problems
If voltage increase is required for larger reactor, could damage cells
Cell Recycle
High cell conc. could foul membrane

9. Conclusions
Cell Recycle reactor is safest alternative for industrial use
Additional testing on pilot scale equipment of electrokinetic bioreactor should be done

10. Questions