TOWARD ORGANIC DESULFURIZATION - THE TREATMENT OF BITUMINOUS COALS WITH STRONG BASES

The removal of organic sulfur from several Illinois Basin coals and Rasa coal by strongly basic reagents under mild conditions was investigated. The strength of the base was an important factor, and Lochmann's base (BASE), an equimolar mixture of n-butyllithium and potassium tert-butoxide, removed more organic sulfur than amides or alkoxides. The sulfur content of whole Illinois No. 6 coal (APCSP 3) was decreased from 4.9 to 1.6%, a reduction of 67%. The organic sulfur content of pyrite-free Illinois No. 6 coal was decreased by 31% from 1.8 to 1.25% by BASE. The degree of sulfur removal from the other pyrite-free coals ranged from 1 to 26%. Reactions with pure sulfur compounds and other observations suggest that BASE selectively removes sulfidic sulfur from Illinois No. 6 coal.