Material balance in coal. 2. Oxygen determination and stoichiometry of 33 coals

✍ Scribed by Alexis Volborth; George E. Miller; Claudia K. Garner; Paul A. Jerabek

• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 980 KB
• Volume: 57
• Category: Article
• ISSN: 0016-2361
• DOI: 10.1016/0016-2361(78)90091-1

✦ Synopsis

Chemical coal analysis can be supplemented by the determination of oxygen in high-and lowtemperature ash, in coal as received, and in dried coal at 105°C. The rapid method utilizes fastneutron activation. The reaction 160(np)16N and counting of the 6.1 and 7.1 MeV gamma radiation of 7.3 s half-life are used. A specially designed dual transfer and simultaneous counting system gives very accurate results. Oxygen in 33 coals ranging from lignite to low-volatile bituminous coal has been determined and results are compared with 'oxygen by difference'. Considerable discrepancies are observed. Better stoichiometric results are obtained if oxygen in coal ash, in wet coal and the dried coal is determined. This permits the estimation of the true material balances in fuels using data of the ultimate and the proximate coal analysis. The oxygen determination provides the coal chemist with an accurate basis and can be used to rank coal. The summation of the percent of carbon, nitrogen, hydra. gen, sulphur and oxygen becomes more meaningful, some errors can be detected, and the state of completeness of coal analysis can be evaluated. Total sulphur can be estimated and oxidation effects during drying can be detected. These affect the moisture determination. It appears that after more data have been collected the interpretation of solid fuel analyses may be facilitated and will be made stoichiometrically more meaningful; the ranks of different coals and other properties such as O/C plots will become better defined. This approach may help the coal industry in general to quantize further the energy generating processes, It may be possible to simplify the present time-consuming methods of coal analysis. A brief overview of coal analysis methods in relation to direct determination of oxygen is giveni.