A novel immobilized bioreactor based on CFD simulation for fuel ethanol production from corn

Area of Science:

• Biotechnology
• Chemical Engineering
• Renewable Energy

Background:

• Traditional ethanol production methods face challenges with mass transfer and efficiency.
• Immobilized-cell fermentation (ICF) offers potential but is hindered by issues like embedding and chemical crosslinking.

Purpose of the Study:

• To evaluate the feasibility of ethanol production using a surface-immobilized bioreactor.
• To analyze mass transfer characteristics using computational fluid dynamics (CFD).
• To compare the performance of surface-immobilized fermentation with traditional stirred fermenters.

Main Methods:

• Computational fluid dynamics (CFD) simulation to analyze mass transfer in a 50 L surface-immobilized bioreactor.
• Ethanol fermentation experiments using corn hydrolysate with both immobilized and free cells.
• Semi-continuous fermentation process optimization.

Main Results:

• The surface-immobilized bioreactor demonstrated a uniform flow field, enhancing cell-substrate interaction.
• Ethanol productivity increased by 20.59% compared to traditional methods.
• Corn consumption per ton of ethanol decreased by 5.90%.
• Semi-continuous fermentation further improved productivity by 30.88% and yield by 3.06 percentage points.

Conclusions:

• Surface immobilization technology overcomes mass transfer limitations of traditional ICF.
• The developed bioreactor design and process optimization show significant industrial application potential for efficient ethanol production.
• This method offers advantages such as a broad raw material spectrum and process stability.