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Vacuum-Assisted Gas Stripping Extractive Fermentation for Process Intensification of Sorghum-Based Bioethanol
Letícia P Almeida1, Mateus N Esperança2, Antonio J G Cruz1
1Graduate Program of Chemical Engineering, Federal University of São Carlos, São Carlos, SP 13565-905, Brazil.
ACS Omega
|July 28, 2026
Summary
Extractive fermentation using vacuum-assisted gas stripping significantly boosts ethanol productivity from sorghum hydrolysate. This process intensification overcomes ethanol inhibition, enhancing bioethanol production efficiency.
Area of Science:
- Biotechnology
- Biochemical Engineering
- Renewable Energy
Background:
- Ethanol production from starch-based substrates is often limited by product inhibition, where high ethanol concentrations harm yeast.
- Extractive fermentation, removing ethanol during production, offers a solution to overcome these limitations.
- Process intensification strategies are crucial for improving the economic viability of bioethanol production.
Purpose of the Study:
- To model and experimentally validate extractive separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes.
- To assess the effectiveness of vacuum-assisted gas stripping for in situ ethanol removal.
- To demonstrate process intensification for enhanced ethanol productivity.
Main Methods:
- Kinetic parameter determination for saccharification and fermentation.
- Development and validation of a mathematical model for SHF and SSF processes.
- Experimental implementation of extractive SHF and SSF using vacuum-assisted gas stripping in a bubble column bioreactor.
Main Results:
- The developed model accurately predicted ethanol production in both conventional and extractive fermentations (R² > 0.99).
- Vacuum-assisted gas stripping effectively removed ethanol, mitigating product inhibition.
- Ethanol productivity was increased by up to 60% through this extractive fermentation strategy.
Conclusions:
- Extractive fermentation with vacuum-assisted gas stripping is a highly effective strategy for process intensification in bioethanol production.
- This method significantly enhances ethanol productivity from sorghum hydrolysate by overcoming product inhibition.
- The validated model provides a robust tool for designing and optimizing similar fermentation processes.
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