Flash BMP® : Calibration for the Biochemical Methane Potential of solid organic waste using Near Infrared Spectroscopy (NIRS)

Significance of the Topic

Biochemical Methane Potential (BMP) assessment is essential for optimizing biogas yield from organic waste streams. Rapid and accurate measurement of BMP informs feedstock selection, process control, and waste management strategies in industrial anaerobic digesters.

Objectives and Study Overview

This work aims to replace the standard 30-day BMP fermentation test with a near-infrared spectroscopy (NIRS)–based approach, termed Flash BMP. Key objectives include:

• Developing a rapid calibration model for BMP prediction.
• Reducing analysis time from over 30 days to less than 2 days.
• Validating model performance across diverse solid waste matrices.

Methodology and Instrumentation

Solid waste samples were freeze-dried and ground to a uniform powder. A reference BMP assay following a 30-day batch fermentation protocol provided methane yield values (ml CH₄/g VS). Near-infrared spectra of each sample were collected using a benchtop NIR spectrometer. Multivariate calibration methods correlated spectral features to reference BMP values. The dataset comprised 500 samples spanning green waste, agricultural residues, energy crops, agro-industrial by-products, municipal solid waste, and sludge.

Main Results and Discussion

Flash BMP delivered methane potential estimates in under 2 days of sample preparation. The calibration model covered a range of 20–700 ml CH₄/g VS with prediction errors of 15–20%, comparable to standard BMP variability. The model maintained accuracy across all waste categories, demonstrating robust generalization. Instantaneous NIR measurement eliminated the need for chemical reagents and extended incubation.

Benefits and Practical Applications

Key advantages of the NIRS-based BMP method include:

• Rapid turnaround supporting process control and feedstock screening.
• Cost savings by removing lengthy fermentation and consumables.
• High representativeness through homogeneous sample preparation.
• Applicability to diverse organic residues in industrial settings.

Future Trends and Potential Applications

Emerging directions for Flash BMP and similar NIR-based assays involve:

• Integration into online monitoring systems for real-time digester control.
• Expansion of calibration libraries to new waste types and geographical regions.
• Coupling with machine learning algorithms for enhanced predictive accuracy.
• Combining NIR with complementary sensors (e.g., MIR, Raman) for multi-parameter characterization.

Conclusion

The Flash BMP approach successfully accelerates BMP determination using NIRS, matching the performance of the traditional 30-day test. Its rapid, reagent-free workflow supports improved decision-making in biogas production and organic waste valorization.

Used Instrumentation

Near-infrared spectrometer equipped for diffuse reflectance measurements, combined with standard sample grinding and freeze-drying equipment.

References

Angelidaki I., Alves M., Bolzonella D., Borzacconi L., Campos J. L., Guwy A. J., Kalyuzhnyi S., Jenicek P., van Lier J. B. Defining the biomethane potential (BMP) of solid organic wastes and energy crops: a proposed protocol for batch assays. Water Sci. Technol. 59(5):927–934, 2009.
Lesteur M., Bellon-Maurel V., Gonzalez C., Latrille E., Roger J. M., Junqua G., Steyer J. P. Alternative methods for determining anaerobic biodegradability: A review. Process Biochem. 45(4):431–440, 2010.