Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.13/24652
- The heterogeneity of coal chemical properties derived from a reflectogram
Wall, Terry Fitzgerald;
- Proximate and ultimate analyses of a coal are regarded as sufficient to describe its chemical composition, and they have been widely used for practical applications. However, coal is actually a heterogeneous substance and is composed of different materials (macerals); therefore, the corresponding chemical compositions are average values of the individual composition of the macerals present in the coal. The reflectance distribution of a coal (the reflectogram), which shows the heterogeneity of the coal, can be represented by several reflectance bins. In this paper, the variation of chemical properties of a coal is differentiated by the difference in reflectance. The main focus of this paper is to establish correlations between chemical properties of a single reflectance bin and its reflectance from a maceral-independent approach and maceral-dependent approach. The bulk chemical properties (volatile matter (VM) content, ratio of hydrogen to carbon (H/C), etc.) of a coal then can be obtained by adding the properties of each individual reflectance bin together. Proximate and ultimate analyses with reflectogram analyses were conducted for 29 coal samples. A least-squares fit strategy was applied to derive the correlations, which were then used to predict the bulk properties of another eight samples. The relative error of the estimated VM from the maceral-dependent approach is 3.9%, whereas the relative error from the maceral-independent approach is 7.9%. No single reflectance bin data are available in the literature; therefore, comparisons between the properties of single reflectance bin from maceral-dependent approach and bulk properties of maceral-rich fractions (bulk VM content versus mean maceral reflectance) in the literature have been made, and both show similar qualitative trends.
- Energy & Fuels Vol. 19, no. 1, p. 130-137
- American Chemical Society
- Resource Type
- journal article