Coal characterization

Royce, A. Readyhough, P.J. Silveston, P.L. Plastic Ranee of Coking Coals Preprint, Coal Characterization for Conversion Processes Symprosium, Rolduc, Netherlands, May 22-25, 1989. 

The proximate analysis of coal is presented as a group of test methods (ASTM D-3172 ASTM D-3173 ASTM D-3174 ASTM D-3175 ASTM D-5142 ISO 1171) that has been used widely as the basis for coal characterization in connection with coal utilization. These analyses are in contrast to the ultimate analysis of coal, which provides information about the elemental composition. 

Guet, I. M. 1990. In Advanced Methodologies in Coal Characterization, H. Charcosset and B. Nickel-Pepin-Donat (Editors). Elsevier, Amsterdam, p. 103. 

Gupta, R. 2007. Advanced coal characterization A review. Energy and Fuels 21(2) 451—460. 

Iron bearing minerals in coal characterization using Moessbauer spectroscopy... 

Now we turn from model systems to the reduction of coal. Detailed mass balance considerations suggest the weight of tetrahydrofuran-derived products on coal after the reduction step to be in the range of 4% (48-hr reduction) to 7% (213-hr reduction). These numbers are consistent with results of Larsen and Hombach, who employed " C-labeled tetrahydrofuran (35). Of direct influence to the application of the Sternberg procedure to coal characterization is Larsen s further observation that 60% of the added tetrahydrofuran is bonded inextricably to the coal (35, 36). 

Pyrolysis results are very important for coal characterization, as all conversion processes of coal such as combustion, liquefaction, and gasification start with a pyrolytic step. For this reason, pyrolysis was frequently used for the analysis of coals [17,18). Pyrolysis data were correlated with coal composition, coal characterization and ranking [18a], prediction of coal reactivity as well as of other properties related to coal utilization. Techniques such as Py-MS, Py-GC/MS with different ionization modes, Py-FTIR, or evolved gas analysis (EGA) [19] were described for coal analysis. Programmed temperature pyrolysis is another technique that has been proposed [17] for a complete evaluation of the two types of molecules present in coal. 

Following an overview of this volume, the first section, which consists of three chapters, focuses on methodology and instrumentation. The next three sections consider characterization of vapor—polymer systems (4 chapters), polymer—polymer systems (4 chapters), and surfaces and interfaces (6 chapters). The final two sections cover analytical applications (2 chapters) and the application of IGC in coal characterization and food science (1 chapter each). 

Coal beneficiation involves a series of steps to separate the mineral matter from the combustible portion of the coal. Current coal characterization for beneficiation is usually limited to measurements of the particle specific gravity distribution (washability). It is further assumed that the properties of the coal feed stream and related mineral matter remain constant during the separation or cleaning process, but the compositions of the streams do change. These changes are important in understanding the lack of expected separations. The effects of specific mineral constituents on different unit operations are described. Better measurement and analytical systems will permit improved control of the processes and better separations. 

The primary function of the computer in FTIR instruments is to perform the Fourier transformation that converts an inter-ferogram to a recognizable spectrum. However, the availability of an on-line mini-computer has opened the door to routine data manipulations. In this section we will review procedures that have been or promise to be useful in coal characterization. Certain data analysis operations, such as numerical integration... 

Knowledge of coal properties is an important aspect of coal characterization and has been used as a means of determining the suitability of coal for commercial use for decades, perhaps even centuries. In fact, the molecular characterization of coal (Chapter 10) is seen to be of little, or no, by some consumers. 

The determination of the properties of coal as a means of coal evaluation and with the goal of predicting behavior during utilization is well documented (Chapters 8 and 9). However, there is another area of coal characterization that has been at least equally well documented, but perhaps less well recognized as a means of evaluation, which involves studies of the molecular constituents of coal. 

C. E. Romero, R. De Saro, J. Craparo, A. Weisberg, R. Moreno and Z. Yao, Laser-induced breakdown spectroscopy for coal characterization and assessing slagging propensity, Energ. Fuel., 2010, 24, 510-517. 

If coal is intended to serve as fuel for industrial gasification processes, it is smart to borrow know-how for coal characterization from combustion research because of its long and comprehensive history. Hence, well-known analysis methods and classification schemes will appear, which must be always reviewed in the light of gasification conditions that differ from combustion in terms of oxidant (oxygen and steam instead of air), operation pressure (20-100 bar), and overall reducing atmospheres (products are CO and H2 instead of CO2, H2O). 

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