Abstract |
Bench-scale and laboratory tests were conducted for chemical removal of sulfur (S) from coal to produce a low sulfur coal to meet air quality standards. The method used was the Meyer's process in which pyritic sulfur is oxidized by ferric compounds to a water soluble form. Approximately 100% of pyritic S was removed, using aqueous ferric salt solutions which, for the four coals tested, corresponded to an absolute removal of 1-3.5% by coal weight of S. The heat content of the coal increased and the ash content decreased as a result of pyrite removal. The pyritic S was removed from the coal as elemental S (40 mole %) and iron sulfate (60 mole %). Process operating temperatures of 50-130C, pressures of 1-10 atm, residence times of 1-16 hrs, and coal top sizes from 1/4-in. to 100 mesh were evaluated. Preliminary process design and cost estimation for a 100-ton/hr coal desulfurization plant are given. |