Analyses coals

Coal analyses are reported on severalbases, and it is customaiy to select the basis best suited to the application. The as-received basis represents the weight percentage of each constituent in the sample as received in the laboratoiy. The sample itself may be coal as fired, as mined, or as prepared for a particular use. The moisture-free (diy) basis is generally the most useful basis because performance calculations can be easily corrected for the ac tual moisture content at the point of use. The dry, ash-free basis is frequently used to approximate... 

The two coals used for the experiments were blends of West Kentucky 9 and 14 seam coals. One blend contained 0.39 weight percent more organic sulfur than the other. Both coals were significantly oxidized before they were received as shown by the appreciable sulfate sulfur contents. Coal analyses are shown in Table 1. 

Each of these is reported in the proximate analysis. Coal analyses can be reported on several bases as-received, moisture-free (or dry), and mineral-matter-free (or ash-free). 

Mineral matter characterization in coal has received considerable attention. Given and Yarzab (1) discussed the problems posed by mineral matter in various coal analyses. Furthermore, mineral matter complicates the chemical treatment of coal. It also has many adverse effects on commercial coal utilization. Coal consumers pay to ship mineral matter, to accommodate its impact on capital equipment and operations, and to dispose of the resultant ash. The impact of coal minerals on utilization motivated Consol s initial interest in mineralogy (2). The results reported here are from a second phase of the FTIR method development, in which extensive improvements were made to the methods. 

Nearly all the Antarctic coal analyses are based upon determinations of the U.S. Bureau of Mines Coal Analysis Section under the supervision of Forrest E. Walker. Sources of other analytic data and sources of collections upon which they are based are cited in the locality listing of respective analyses tabulated. Ultimate values as well as results of proximate determination are given whenever available. 

Materials. Analyses. The coal analyses are given in Table II both black durain and cannel coals are rich in sporinite material while the remainder are highly vitrainous. Two experiments were also carried out with material other than coal one with Neospectra carbon black and the other with a soot residue formed by the reaction of coal (CRC 802) in the plasma. The analysis (% daf basis) of the Neospectra carbon black was as follows C, 92.0 H, 0.8 N, 0.05 O by difference, 7.2 volatile matter, 9.2. All the materials were vacuum dried at 110°C. for several hours prior to use. 

Table 5.1 Arsenic in coal utilization byproducts. Compare with coal analyses in Table 3.22. 

The data obtained from coal analyses (Table 1.1) establish the price of the coal by allocation of production costs as well as to control mining and cleaning operations and to determine plant efficiency. However, the limitations of the analytical methods must be recognized (Rees, 1966). In commercial operations, the price of coal not only reflects the quantity of coal but also invariably reflects the relationship of a desirable property or even a combination of properties to performance of coal under service conditions (Vorres, 1993). 

Quite often, a variation of a proximate analysis or an ultimate analysis is requested, together with one or more of the miscellaneous analyses or tests discussed in this chapter. Restrictions that have been placed on the coal used in coal-fired power plants and other coal-burning facilities have created a need for more coal analyses as well as a need for more accurate and faster methods of analysis. This trend will continue, and more testing will be required with increased use of coal in liquefaction and gasification plants. 

Coal analyses are generally reported in tabular form (Tables 1.4 and 1.5) and the data can be represented graphically as in these EIA coal data from the U.S. Department of Energy ... 

Rees, O. W. 1966. Chemistry, Uses and Limitations of Coal Analyses. Report of Investigations 220. Illinois State Geological Survey, Urbana, IL. 

The major forms of sulfur in coal are pyritic, organic, and sulfate. Pyritic and organic sulfur generally account for the bulk of sulfur in coal. Elemental sulfur also occurs in coal, but only in trace to minor amounts it is not determined in routine coal analyses. 

As a result, there is an optimum time for each coal for maximizing liquid yield. An approximate explanation of these yields based on the coal analyses shown in Table 1 can be made. Higher yields correlate with high volatile matter, sulfur content, and reactive fractions and are, of course, inversely proportional to ash content. 

The physical property system is supported by a data file on both conventional compounds and on typical coal analyses and data. The data bank contains correlation constants for over 400 conventional compounds and extensive data for thirteen characteristic coals. A Data File Management system permits a user to modify the data files, to create his own private data files, and... 

The two most common coal analyses are the proximate analysis and the ultimate analysis. In addition, there are a number of miscellaneous analyses. Many of these tests are empirical, requiring strict adherence to specified conditions. In the United States, the American Society for Testing and Materials (ASTM) standardizes these methods. International standards are developed by the International Organization for Standardization. 

Experiments of burning have been conducted for different kinds of coal, including bituminous coal (No. 1), sub-bituminous coal (No. 2), caking coal (No. 3) and low-grade coal (No. 4). Proximate and ultimate coal analyses are listed in Table V. The operating behavior of this combustor will be briefly summarized below. 

The authors would like to thank Art Ruud for the extensive coal analyses he and his group carried out. Thanks also to John Diehl for running the capillary GC profiles of the seven coal extracts. 

Coal analyses were performed by Commercial Testing and Engineering Co., Chicago, 111. Data handling and curve fitting were done on the TRW Timeshare/CDC 6500 computer system. 

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