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Updated: Jun 11, 2025

Author Spotlight: On-Site Biochar Production for Woody Debris Incineration in Forestry
Published on: January 5, 2024
Predicting Stability of Barley Straw-Derived Biochars Using Fourier Transform Infrared Spectroscopy
Monica A McCall1,2, Jonathan S Watson1, Mark A Sephton1
1Earth Science and Engineering, Imperial College London, Exhibition Rd, South Kensington, London SW7 2BX, United Kingdom.
Abstract:
In order to estimate the ability of biochar to sequester carbon as part of greenhouse gas removal technology, there is a need for rapid and accessible estimations of biochar stability. This study employs a novel method using Fourier transform infrared spectroscopy (FTIR) to predict common stability indicators, namely H:C and O:C molar ratios. Biochars derived from barley straw were produced at temperatures from 150 to 700 °C. The greatest compositional changes of the biochars occurred between 200 and 400 °C. All biochars produced at ≥400 °C achieved H:C < 0.7 and O:C < 0.4, indicative of biochars suitable for soil application. Regression models were built using FTIR data to predict H:C and O:C molar ratios. The H:C model produced a coefficient of determination (R 2) of 0.99, mean absolute percentage error (MAPE) 6.86%, and root-mean-square error (RMSE) of 0.07. The O:C model achieved the same R 2 (0.99), MAPE of 9.02%, and RMSE of 0.03. Our results demonstrate that combining FTIR data with modeling is a promising rapid and accessible method for attaining biochar stability data.
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