Abstract

New and rapid techniques for estimating the stable fraction of organic carbon (C_org) in biochar are needed for carbon (C) sequestration accounting. In this study, 25 biochar samples produced from different feedstocks and pyrolysis temperatures were scanned using visible near infrared (NIR) spectroscopy and analysed using standard laboratory methods for reference data. Principal component analysis and linear discriminant analysis of preprocessed spectral data were used to extract relevant information and discriminate among biochars, respectively. Partial least squares regression was used to build calibration models between preprocessed spectral data and reference data, and the accuracy of calibration models in predicting biochar properties was then tested using a cross-validation procedure. Biochar indices related to C stability, such as aromatic C, fixed C, atomic H/C_org ratio and the fraction of total C that is aromatic(fa) were successfully predicted (R²_CV 0.92–0.94, RPD_CV 3.26–4.22) using the NIR spectroscopy technique (NIR bands, 780–2500 nm). Aromatic C and fixed C could be predicted independently from fa. Other biochar properties, such as C_org, H and O content, and atomic O/C_org ratio, were predicted with an accuracy ranging from moderate to very high (R²_CV 0.80–0.96, RPD_CV 2.24–4.66). The study illustrates the potential of this rapid and low-cost technique for measuring biochar stability indices in routine analysis if accurate calibration models for each index are available.

© 2014 IM Publications LLP

Rapid detection of carbon-nitrogen ratio for anaerobic fermentation feedstocks using near-infrared spectroscopy combined with BiPLS and GSA

Jinming Liu, Nan Li, Feng Zhen, Yonghua Xu, Wenzhe Li, and Yong Sun
Appl. Opt. 58(18) 5090-5097 (2019)

Nondestructive determination of SSC in an apple by using a portable near-infrared spectroscopy system

Yizhe Zhang, Jipeng Huang, Qiulei Zhang, Jinwei Liu, Yanli Meng, and Yan Yu
Appl. Opt. 61(12) 3419-3428 (2022)

Laser depolarization ratio measurement of corn leaves from the biochar and non-biochar applied plots

Songxin Tan, Shannon Johnson, and Zhengrong Gu
Opt. Express 26(11) 14295-14306 (2018)

Using cross-correlation analysis of multi-channel near infrared spectroscopy to assess the hemodynamic response to cupping therapy

Ben-Yi Liau, Chi-Wen Lung, Manuel E. Hernandez, Pu-Chun Mo, Yameng Li, Jiaqi Guo, and Yih-Kuen Jan
Biomed. Opt. Express 14(9) 4455-4467 (2023)

Spark-induced breakdown spectroscopy and multivariate analysis applied to the measurement of total carbon in soil

Morgan S. Schmidt, Kellen J. Sorauf, Keith E. Miller, David Sonnenfroh, Richard Wainner, and Amy J. R. Bauer
Appl. Opt. 51(7) B176-B182 (2012)