EVALUATING BYPRODUCTS OF ENVIRONMENTAL CONCERN IN WATER GENERATED DURING HYDROUS PYROLYSIS OF OIL SHALE

Development of major oil shale deposits throughout the world has the potential for generation and release of pollutants into the environment. There is particular concern regarding the contamination of fragile water supplies, particularly in areas under recurring or ongoing water stress. In order to assess differences in hazardous substance generation potential for various types of oil shale, we have performed hydrous pyrolysis (HP) experiments at 360°C for 72 h on 12 oil shales from different locations around the world. While hydrous pyrolysis conditions may not be representative of the retorting and reclamation processes likely to be used by the oil shale industry, it does provide a conservative baseline for comparison of pollutant yields in waters generated during the production of shale oil. In this study, we assess and compare organic and inorganic byproducts of environmental concern present in the recovered waters following HP and evaluate if and how organic matter type and rock mineralogy determine the extent of hazardous substances generation. Aqueous concentrations of regulated pollutants generated during the HP experiments are evaluated relative to water quality standards (RCRA and EPA) in order to place the results in context. In addition, results from closed system retorting under dry conditions followed by high temperature water extraction of the spent shale will be contrasted with the HP results.