Hydrogen Sulfide Evolution from Colorado Oil Shale

Because traditional oil resources are declining, new-found attention is being focused on oil shale, coal, and oil sand as potential supplies of future energy. Unfortunately, extensive use of coal and oil shale could cause severe environmental problems. For example, oil shale retorting produces significant amounts of hydrogen sulfide and other gaseous sulfur species, e.g., 1.3 g H 2 S/100 g shale oil ( 1 ). In addition, evolution of H 2 S from oil shale retorted in the presence of steam is greater than in other gas environments ( 2 ). In our study, we have measured the dependence of H 2 S evolution on gas atmosphere. The gas environments used were argon, autogenous (self-generated), and steam-argon mixtures, all at atmospheric pressure. The samples used in these experiments were Green River oil shale from Colorado. In Green River oil shale, sulfur occurs in both inorganic and organic combinations. According to Smith et al. ( 3 ), the Green River oil shale rocks