As cultures become denser, managing dissolved gases becomes increasingly complex. Mitsubishi Chemical—a global leader in materials and bioprocess solutions—is now tackling one of cell manufacturing’s quiet challenges: excess carbon dioxide. When CO₂ accumulates, it lowers pH and forces operators to add alkali, often stressing the cells. A system that removes CO₂ gently and efficiently could make high-density growth more stable and scalable.
What the Patent Reveals
Mitsubishi Chemical’s newly published patent describes an external, closed-loop degassing module that continuously circulates a portion of culture fluid through a housing packed with U-shaped hollow fiber membranes, then returns it to the bioreactor. Inside each membrane, a controlled vacuum draws out dissolved CO₂ through the membrane wall.
By moving the degassing module outside the vessel, the system allows independent control of flow and vacuum, avoids interference with impellers and sensors, and makes the setup easier to scale and maintain. The culture itself remains safely inside the bioreactor, while only the surrounding medium briefly circulates through the external module for CO₂ removal.
Two design choices stand out. First, each hollow fiber is bent into a U-shape, and both open ends are sealed together in a block of resin—a process known as “potting.” The opposite, folded ends remain loose, allowing the fibers to spread naturally inside the housing, which improves liquid contact and prevents clogging. Second, the system calculates the overall mass transfer constant for CO₂ (kLaCO₂) to simulate and optimize parameters such as circulation rate and vacuum level for efficient CO₂ removal without damaging cells. This helps stabilize CO₂ concentration, minimize alkali use, and protect cell integrity. (WO2025205600A1)
The Applicant
Mitsubishi Chemical Corporation is advancing bioprocess engineering through innovations that support controlled, high-density culture systems. This patent aligns with their broader strategy of developing modular tools for efficient, large-scale production of biopharmaceuticals and cultivated foods.
The Inventors
Congratulations to Yoshie Tanizaki for this contribution to improving CO₂ management in cell manufacturing.
Have you modeled or tested membrane-based degassing in your own setup? Share your thoughts below.
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This post is based on publicly available information. Lab Grown Technologies is not affiliated with the inventors or organizations mentioned.