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Spent Oil Shale
What is Oil Shale?
- Oil shale is a fine-grained sedimentary rock that can be heated, vaporized, cleaned and upgraded to form synthetic crude oil.
- This synthetic oil can be used as an alternative energy source for traditional crude oil.
EPA is clarifying that oil shale generated by above ground retorting or heating of oil shale operations is:
- not considered a Bevill waste excluded from the pertinent regulations under RCRA Subtitle C, and
- that studies indicate that spent oil shale from above ground heating is unlikely to express a hazardous waste characteristic, and so is not likely to be a hazardous waste.
Notice of Data Availability on Spent Oil Shale from Above Ground Retorting Operations | PDF Version (8 pp, 259K, about PDF) - December 24, 2008
The support materials for this rule and the public comments EPA received on the proposal are available for public review online, as explained below. Please note that final rule materials will not be available from Regulations.gov until the rule is published in the Federal Register
To use Regulation.gov:
- Select Docket Search.
- Select "Environmental Protection Agency" from the Agency drop-down menu.
- In the Docket ID box, type in the docket number (EPA-HQ-RCRA-2008-0645) and press the "Submit" button to receive search results.
Because the question has been raised about how RCRA applies to spent oil shale generated by above ground oil shale operations.
In 1980, Congress amended RCRA and directed the EPA to study wastes from the extraction, beneficiation and processing of ores and minerals and determine if those wastes should be exempted from regulation as hazardous wastes under RCRA Subtitle C.A list of “Bevill exempt” extraction, beneficiation and mineral processing wastes are noted at 40 CFR 261.4(b)(7).
December 31, 1985: EPA submits a Report to Congress on Wastes from the Extraction and Beneficiation of Metallic Ores, Phosphate Rock, Asbestos, Overburden from Uranium Mining, and Oil Shale (EPA530-SW-85-033).
July 3, 1986: EPA publishes the Final Regulatory Determination for Extraction and Beneficiation Waste (51 FR 24496) which determines that regulation of these wastes under RCRA Subtitle C is not warranted. These wastes continue to be excluded from the definition of hazardous waste.
March 3, 1989: EPA issues a letter to Region 8 classifying wastes from the mining, crushing, screening, and retorting of oil shale as an exempt extraction/beneficiation waste.
April 17, 1989: EPA issues a proposed rule (54 FR 15316) which for the first time dealt with the Court decisions mandating that the Agency clarify the line between extraction/beneficiation and mineral processing. Table 1 at 54 FR 15343 notes that shale oil retorting wastes are beneficiation wastes, although the proposed regulatory text did not include shale oil retort waste as a beneficiation waste.
September 1, 1989: EPA promulgates a Bevill final rule including a list of activities which generate exempt extraction/beneficiation wastes (see 40 CFR 261.4(b)(7). There was no discussion in the final rule on oil shale retort waste.
September 1, 1989 and January 23, 1990: EPA publishes in the Federal Register (54 FR 36592; September 1, 1989 and 55 FR 2322; January 23, 1990) the final boundaries of the Mining Waste Exclusion for mineral processing wastes, limiting the exclusion to 20 specific mineral processing wastes generated by 91 facilities located in 29 states, representing 12 mineral commodity sectors. None of the 20 Bevill-excluded mineral processing wastes include spent oil shale from above-ground retorting operations.
No. The Agency is restating the RCRA status of spent oil shale from above ground oil shale operations based on the final Bevill rulemakings issued on September 1, 1989 (54 FR 36592), on January 23, 1990 (55 FR 2323) and on June 13, 1991 (56 FR 27300).
The Bureau of Land Management defines oil shale as fine-grained sedimentary rock containing:
- Organic matter which was derived chiefly from aquatic organisms or waxy spores or pollen grains, which is only slightly soluble in ordinary petroleum solvents, and of which a large proportion is distillable into synthetic petroleum, and
- Inorganic matter, which may contain other minerals. This term is applicable to any argillaceous, carbonate, or siliceous sedimentary rock which, through destructive distillation, will yield synthetic petroleum.
BLM defines kerogen as the hydrocarbon in oil shale. Kerogen is a pyrobitumen, and oil is formed from kerogen by heating. It consists chiefly of low forms of plant life; chemically it is a complex mixture of hydrocarbon compounds of large molecules, containing hydrogen, carbon, oxygen, nitrogen, and sulfur. Kerogen is the chief source of oil in oil shales.
Nearly 62% of the world’s potentially recoverable oil shale resources are concentrated in the United States. The largest of the deposits is found in the Green River formation in Northwestern Colorado, Northeastern Utah and Southwestern Wyoming. The richest and most easily recoverable deposits are located in the Piceance Creek Basin in Western Colorado and the Uinta Basin in Eastern Utah. There are less productive oil shale deposits in the eastern US.
Organic kerogen within the oil shale rock can be heated at high temperatures to form synthetic gas and shale oil. The heating step is referred to as destructive distillation. Most surface operations utilize closed metal vessels where the oil shale is placed and internally or externally heated. When sufficient heat is applied to oil shale, hydrogen gas and oil are released from the oil shale. A recent study of oil shale production by the Congressional Research Service, “Oil Shale: History, Incentives, and Policy,” (April 13, 2006 RL33359), states “Oil derived from shale has been referred to as a synthetic crude oil and thus closely associated with synthetic fuel production.” After shale oil produced, it will be cleaned and upgraded to produce transportation fuels.
Spent oil shale, a waste of this process, is usually removed and disposed of in above ground disposal units or is placed back into mined out voids.
Based on the data we’ve evaluated and described in this notice, we believe spent oil shale is very unlikely to exhibit a hazardous characteristic under RCRA Subtitle C.
Shale oil flowing out of above ground operations must be cleaned of contaminants and/or be “upgraded” to make a range of products. Shale oil “cleaning” often involves the removal of sulfur. Shale oil upgrading generally includes additional processing equivalent to crude oil hydrocracking (required to convert oil-shale distillates to gasoline). Upgrading also removes arsenic and nitrogen using hydrotreating.
An upgrade facility could generate over 3,000 metric tons per year of spent catalysts, treatment chemicals, and sludges and byproduct wastes. Upgrade wastes of concern may include (at a 1 million tpd plant) 5400 tons per year of spent hydrotreater guard bed catalyst containing 20 percent arsenic and potentially hazardous API separator bottoms which may generate 7200 tons per year.
Wastes from the upgrade operations are not exempt from hazardous waste requirements, and may, in some cases, exhibit a hazardous characteristic. EPA is not addressing or seeking comment on those wastes, which are of much smaller volume relative to the spent oil shale.