Inflatable Bag Bioreactor for Oxygen Mass Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The low solubility of oxygen in water limits the rate of oxygen transfer in biocatalytic reactions, leading to mass-transfer limitations and reduced reaction rates, especially in large-scale syntheses, and existing methods to enhance oxygen transfer often inactivate biological catalysts or are costly and complex.
Innovation Solution
Repurposing inflatable shipping pillows as bioreactors with a resealable valve and using rotary or rocking motion to facilitate high-surface-area mixing between the liquid reaction mixture and oxygen, allowing for continuous exposure and efficient oxygen transfer without mechanical agitation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If aggressive mechanical dispersive methods are used to increase oxygen transfer, then oxygen mass transfer rate is improved, but biological catalysts are inactivated
Solution Approach 1:
The patent uses a flexible bag reactor with a large gas-liquid interfacial area created by the flexible membrane surface. The bag is filled with gas (oxygen or air) and immersed in the liquid reaction mixture, creating numerous contact points between gas and liquid phases without requiring mechanical agitation. This flexible shell structure enables gentle oxygen transfer while maintaining biological catalyst activity.
Solution Approach 2:
The invention employs pneumatic principles by using gas pressure to inflate the flexible bag and create the gas-liquid interface. The gas phase is introduced into the bag at controlled pressure, allowing oxygen to transfer to the liquid phase through the flexible membrane surface without mechanical disruption. This pneumatic approach replaces aggressive mechanical mixing with gentle pressure-driven gas-liquid contact.
2Productivity
If sparged stirred-tank reactors are used for continuous headspace exchange, then oxygen availability is improved, but system complexity and cost increase
Solution Approach 1:
The patent employs a disposable flexible bag reactor that can be easily assembled, used, and discarded. The bag is a simple, inexpensive component that requires no complex infrastructure for gas exchange. After use, the entire system can be disposed of or easily cleaned and reused, eliminating the need for complex continuous exchange systems while maintaining effective oxygen availability during the reaction.
Solution Approach 2:
The invention extracts the essential function of oxygen transfer from complex stirred-tank systems and isolates it in a simple flexible bag. By removing the liquid phase from the headspace and replacing it with a gas-filled flexible bag immersed in the liquid, the system achieves continuous oxygen availability through the flexible membrane interface without requiring complex sparging apparatus or continuous headspace exchange mechanisms.
3Ease of manufacture
If fixed-volume batch reactors with limited headspace are used, then initial oxygen charge is sufficient, but partial pressure of oxygen drops as reaction progresses
Solution Approach 1:
The patent uses a dynamic flexible bag reactor where the gas volume can expand or contract as the reaction progresses. As oxygen is consumed and pressure drops, the flexible bag naturally collapses to maintain optimal gas-liquid contact area. This dynamic adjustment ensures continuous high oxygen partial pressure at the interface without requiring manual intervention or complex pressure control systems, maintaining high reaction rates throughout the process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables low-cost, efficient, and repeatable biocatalytic reactions with high oxygen concentration, maintaining enzyme activity and achieving complete conversion of substrates like glucose to glucosone, even at high concentrations, with minimal equipment and reagents, and scalable to multi-gram scales.
Implementation Method 1
providing high-surface-area mixing between a liquid reaction mixture and a gas for preparative synthesis involving whole cells
Implementation Method 2
Molecular oxygen is considered the 'greenest' oxidant in organic synthesis... Oxygen is abundant, inexpensive, and the product of its reduction ultimately is water
Data Source
AI summary
A method of conducting oxidation in an inflatable bag bioreactor or a batch reactor is provided. The inflatable bag bioreactor or the batch reactor is used as an efficient, economical, and convenient reaction vessel. The inflatable bag bioreactor or batch reactor is rotated or rocked during the reaction to ensure continued exposure of the reaction mixture to the headspace gas in the vessel. The ability of the inflatable bag to expand or contract as the volume of the contents changes helps maintain consistent pressure and avoids the need to replenish the headspace gas.