Removal of Sulfur from Illinois Coals via Charring and Partial Oxidation

摘要

Illinois coals with different ash and sulfur compositions were charred and partially oxidized under various conditions of time and temperature (up to 900C). A specially designed charring-combustion apparatus was utilized. The following parameters affected sulfur removal during both charring and partial oxidation: the ratio of pyrite to organic sulfur, rates of increase and holding times of temperatures, final temperatures, and particle sizes. The main conclusions are (1) regardless of conditions, the total range of sulfur removal is fairly narrow and pyritic sulfur is definitely lost in the charring step; (2) the parameters that maintain optimum charring and post-oxidation conditions are numerous, interrelated, and complex; and (3) in post-charring, partial-oxidation experiments, maximum loss of sulfur and minimum loss of carbon occurred when the temperature was initially dropped to about 240C rather than maintained at 650C, and pyrite-rich coals were more readily desulfurized with less loss of carbon than organic-sulfur-rich coals.