Prediction of biochemical methane potential of urban organic waste using Fourier transform mid-infrared photoacoustic spectroscopy and multivariate analysis

Abstract

Biochemical methane potential (BMP) assays are widely used to assess feedsocks in oder to control the process of biogas production. However, the continuous evaluation of feedstocks using a BMP assay is expensive, time-consuming and challenging. In this study, Fourier transform mid-infrared photoacoustic spectroscopy (FTIR-PAS) was used to predict the BMP values of 87 urban organic waste (UOW) samples derived from different sources in Denmark. The developed model of BMP prediction showed a coefficient of determination (R²) of 0.86 and a root mean square error (RMSE) of 59.3 mL CH₄/g VS in prediction. The interpretation of the regression coefficients used in the calibration showed a positive correlation with BMP for relatively easily degradable compounds, such as aliphatics, most likely lipids and amides most likely in proteins, while a negative correlation was found with lignin and hemicellulose.

Keywords: Anaerobic digestion; Biochemical methane potential (BMP); FTIR-PAS; PLSR modeling; Urban organic waste.