Aromaticity and degree of aromatic condensation of char |
| |
| Institution: | 1. State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China;2. Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA;3. Coastal Plains Soil, Water, and Plant Research Center, Agricultural Research Service, U.S. Department of Agriculture, 2611 West Lucas Street, Florence, SC 29501, USA;4. Leibniz Institute for Agricultural Engineering, Max-Eyth-Allee 100, 14469 Potsdam-Bornim, Germany |
| |
| Abstract: | The aromatic carbon structure is a defining property of chars and is often expressed with the help of two concepts: (i) aromaticity and (ii) degree of aromatic condensation. The varying extent of these two features is assumed to largely determine the relatively high persistence of charred material in the environment and is thus of interest for, e.g., biochar characterization or carbon cycle studies. Consequently, a variety of methods has been used to assess the aromatic structure of chars, which has led to interesting insights but has complicated the comparison of data acquired with different methods. We therefore used a suite of seven methods (elemental analysis, MIR spectroscopy, NEXAFS spectroscopy, 13C NMR spectroscopy, BPCA analysis, lipid analysis and helium pycnometry) and compared 13 measurements from them using a diverse sample set of 38 laboratory chars. Our results demonstrate that most of the measurements could be categorized either into those which assess aromaticity or those which assess the degree of aromatic condensation. A variety of measurements, including relatively inexpensive and simple ones, reproducibly captured the two aromatic features in question, and data from different methods could therefore be compared. Moreover, general patterns between the two aromatic features and the pyrolysis conditions were revealed, supporting reconstruction of the highest heat treatment temperature (HTT) of char. |
| |
| Keywords: | Pyrogenic organic matter Char Aromaticity Aromatic condensation Pyrolysis Stability Heat treatment temperature Biochar |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
