Aerobic Fermenter Scale-up: Why Equal Mass Transfer Scale-up Doesn't Always Work

North American Mixing Forum
2009 AIChE Annual Meeting
AIChE Annual Meeting
November 9, 2009 - 7:00pm
Transferring oxygen to the liquid is only one of several steps that must occur in an aerobic fermentation. After the oxygen is transferred to the liquid, the liquid must be thoroughly mixed throughout the vessel. Then the oxygen must diffuse through the cell wall before finally being metabolized within the cell.

For some types of biology, conditions for the production of the desired product must be held within close tolerances. These conditions include but are not limited to DO concentration, nutrient concentration, and pH. If not, some cellular organisms will tend to undergo a number of different actions. None, of which is beneficial in producing the desired product. This paper will provide a number of references that provide evidence to this fact.

When a process is scaled-up via equal mass transfer logic, the blend time continues to increase. As the scale becomes larger and larger, the time to blend at some point may become the limiting scale-up criteria, not mass transfer.

From a gassed blend time standpoint, not all mixing systems are created equal. The authors will identify relative blend times for a number of common systems.

The authors will suggest techniques that could be used on smaller scales to determine when scale-up via equal blend time is required.&'
Professional Development Hours
0.4 PDHs
You will be able to download and print a certificate for these PDH credits once the content has been viewed. If you have already viewed this content, please click here to login.
Presenter(s): 

Would you like to access this content?

No problem. You just have to complete the following steps.

You have completed 0 of 2 steps.

  1. Log in

    You must be logged in to view this content. Log in now.

  2. Purchase Technical Presentation

    You must purchase this technical presentation using one of the options below.
    If you already purchased this content recently, please click here to refresh the system's record of ownerships.

Pricing

Credits 0.5 Use credits
List Price $25.00 Buy now
AIChE Members $15.00 Buy now
AIChE Undergraduate Student Members Free Free access
AIChE Graduate Student Members Free Free access
Skill Level: