Related Experiment Video
Updated: Apr 6, 2026
14:33
Optimize Flue Gas Settings to Promote Microalgae Growth in Photobioreactors via Computer Simulations
Published on: October 1, 2013
15.0K
Global performance parameters for different pneumatic bioreactors operating with water and glycerol solution:
G Y Rodriguez1, M Valverde-Ramírez1, C E Mendes1
1Graduate Program of Chemical Engineering, Federal University of São Carlos, C.P. 676, São Carlos, SP, 13565-905, Brazil.
Bioprocess and Biosystems Engineering
|August 1, 2015
Summary
The concentric-tube airlift bioreactor demonstrated superior performance in gas holdup and oxygen transfer compared to bubble column and split-tube airlift designs. This study provides key data for selecting and designing efficient pneumatic bioreactors.
Area of Science:
- Biochemical Engineering
- Fluid Dynamics
- Process Optimization
Background:
- Pneumatic bioreactors are crucial for aerobic fermentations, requiring efficient gas-liquid mass transfer.
- Global performance parameters like gas holdup and volumetric oxygen transfer coefficient guide bioreactor selection and design.
- Understanding fluid dynamics and mass transfer in different bioreactor geometries is essential for optimizing bioprocesses.
Purpose of the Study:
- To compare the performance of three pneumatic bioreactor geometries: bubble column, concentric-tube airlift, and split-tube airlift.
- To determine global performance parameters, including gas holdup and volumetric oxygen transfer coefficient (k L a), using experimental data and CFD simulations.
- To analyze liquid circulation velocity in relation to bioreactor geometry and fluid properties.
Main Methods:
- Experimental evaluation of gas holdup and volumetric oxygen transfer coefficient (k L a) in three bioreactor types (5 L working volume).
- Utilization of two Newtonian fluids (distilled water and 10 cP glycerol solution) at high flow rates.
- Implementation of a novel Computational Fluid Dynamics (CFD) modeling procedure for simulation and comparison with experimental results.
Main Results:
- The concentric-tube airlift bioreactor exhibited the highest gas holdup and volumetric oxygen transfer coefficient (k L a).
- CFD simulations for gas holdup showed good agreement with experimental data.
- Bubble diameter and shape were identified as significant factors influencing k L a.
Conclusions:
- The concentric-tube airlift design is the optimal choice for pneumatic bioreactors demanding high gas holdup and volumetric oxygen transfer.
- CFD modeling provides a reliable method for predicting bioreactor performance.
- Bioreactor geometry significantly impacts gas-liquid mass transfer efficiency, influencing process outcomes.
Related Concept Videos
01:18Bioreactor Controls-II
56
In aerobic fermentations, oxygen is vital for microbial growth and metabolite production. Since air comprises only about 20% oxygen and the gas is poorly soluble in water—just 9 ppm at 20°C—supplying sufficient oxygen becomes a critical challenge, especially in high-demand processes like yeast growth or citric acid production. Even a fully saturated broth may offer only a few seconds of oxygen availability.To address this, sterile or scrubbed air is introduced into the...
56
01:29Bioreactor Design and Operational System
90
Bioreactors are engineered vessels designed to cultivate microorganisms under controlled conditions for industrial bioprocessing. They maintain sterility and allow precise regulation of pH, temperature, oxygen, and nutrient levels to optimize microbial growth and metabolite production. Bioreactors range from small laboratory units of 1 liter to industrial systems holding up to 500,000 liters, though only about 75% of their volume is actively used for fermentation. The remaining headspace...
90
01:30Designing Growth Media for Bioreactors
60
Growth media provide essential nutrients that support cell growth and metabolism, thereby enhancing the yield of valuable products such as enzymes, antibiotics, and biomass. Designing an effective growth medium involves balancing all components to prevent nutrient limitations or toxic excesses, both of which can impair growth and reduce product yields.Composition of a Typical Growth MediumA typical growth medium contains carbon and nitrogen sources, salts, vitamins, trace elements, and...
60
01:28Bioreactor Controls-I
66
Maintaining optimal conditions within fermenters is essential for maximizing microbial productivity and ensuring process efficiency. This lesson focuses on key parameters—temperature, foam, pH, carbon dioxide, oxygen, and pressure—and their precise measurement and control strategies in fermentation systems.Temperature ControlTemperature regulation is critical due to the exothermic nature of many fermentation processes. In small laboratory fermenters, temperature is commonly...
66
01:14Scale-Up Processes
74
The scale-up of microbial fermentation processes is essential in industrial biotechnology, allowing the transition from laboratory-scale experiments to commercial-scale production while aiming to maintain product yield and quality. This process requires meticulous adjustment of equipment design, process parameters, and contamination control strategies to accommodate increasing culture volumes.At the laboratory scale, cultures are typically maintained in 1 to 10-liter glass or autoclavable...
74