Inline monitoring of fermentation processes

Significance of the Topic

Inline, real-time monitoring of fermentation parameters is critical for optimizing bioethanol production, ensuring high yields, consistent quality, and reduced operational costs.

Objectives and Study Overview

This study demonstrates the application of near-infrared spectroscopy (NIRS) directly in the fermentation tank to track ethanol, sugars, organic acids, moisture, and solids simultaneously, enabling dynamic process control.

Methodology and Instrumentation

Measurements were performed using the Metrohm 2060 The NIR Analyzer equipped with dedicated immersion probes and microbundle fibers. In systems with bypass loops, flow cells were used to manage particulate content. Calibration models were developed by comparing NIR spectra with reference analyses such as HPLC and Karl Fischer titration.

Main Results and Discussion

The inline NIRS approach provided updates every 30 seconds, accurately measuring ethanol (0–15 %), glucose (0–8 %), maltose (0–7 %), DP3 & DP4 sugars (0–15 %), acetic acid (0–0.5 %), glycerol (0–1 %), and lactic acid (0–0.25 %). Tight monitoring of sugar breakdown pathways enabled optimized enzyme and yeast dosing, reducing fermentation time and increasing batch throughput.

Benefits and Practical Applications

• Enhanced process safety and operator protection through reagent-free analysis
• Improved product quality and consistency via real-time adjustments
• Increased productivity and cost savings by minimizing downtime and optimizing fermentation cycles

Future Trends and Opportunities

Emerging developments include integration of multiplexed probe configurations, advanced chemometric algorithms, and AI-driven predictive control to further refine fermentation processes and extend applications to other biomanufacturing contexts.

Conclusion

Inline NIRS with the Metrohm 2060 system offers a robust, rapid, and reliable solution for comprehensive fermentation monitoring, driving efficiency and profitability in bioethanol production.

References

1. Statista, Global ethanol production for fuel use 2022.
2. Chang Y.-H. et al., Fermentation (2018), 4(2), 45.
3. Devantier R. et al., Appl. Microbiol. Biotechnol. (2005), 68(5), 622–629.