Desulfurization of Illinois coals with hydroperoxides of vegetable oils and alkali. Final technical report, September 1, 1995--August 31, 1996

The goal of this project is to develop an inexpensive method to remove organic sulfur from pyrite-free and mineral-free coal using base, air, and readily available farm products. This is accomplished by treating coals with impregnating coals with polyunsaturated offs, converting the oils to their hydroperoxides, and heating. Since these oils are relatively inexpensive and easily applied, this project could lead to a cost effective method for removing organic sulfur from coals. Moreover, the oils are environmentally safe; they produce no noxious products and improve burning qualities of the solid products. IBC-108 coal, (contains only 0.4% pyrite and 2.7% organic sulfur) was first treated with Na{sub 4}OH at two different concentrations and four different times, and with NH{sub 4}OH at two different concentrations and two different temperatures. Pretreating IBC-108 coal with bases removes 13% to 23% of the sulfur, and NaOH is a better treatment than NH{sub 4}OH in most of the experiments. Higher temperatures, higher base concentrations, and longer treatment times remove more sulfur. Na{sub 2}CO{sub 3} is more effective than NaOH for oil extraction after the oil treatment. To test for effectiveness of sulfur removal, eight coal samples were treated with NaOH (two concentrations at four different times) were further treated with linseed oil at three temperatures, four different times, and two oil to coal ratios. The combination of NaOH pretreatment, then oil treatment, followed by Na{sub 2}CO{sub 3} extraction, removes 23% to 50% of the sulfur. The best result is achieved by pretreating with 5% NaOH for 20 hr (23% sulfur removal) followed by oil treatment at 100{degrees}C for 5 hr with a 1:1 oil to coal ratio (50% sulfur removal in total). More sulfur is removed with a 1:1 oil to coal ratio than a 1:10 ratio under most conditions