China
Africa
Explore chapters and articles related to this topic
Other Feedstocks—Coal, Oil Shale, and Biomass
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
Depending on the depth and other characteristics of the target oil shale deposits, either surface mining or underground mining methods may be used. Each method, in turn, can be further categorized according to the method of heating. Another way in which the various retorting processes differ is the manner by which heat is provided to the shale by hot gas—(i) by a solid heat carrier or (ii) by conduction through a heated wall. After mining, the oil shale is transported to a facility for retorting after which the oil must be upgraded by further processing before it can be sent to a refinery, and the spent shale must be disposed, often by putting it back into the mine. Eventually, the mined land is reclaimed. Both mining and processing of oil shale involve a variety of environmental impacts, such as global warming and greenhouse gas emissions, disturbance of mined land, disposal of spent shale, use of water resources, and impacts on air and water quality.
Environmental Considerations
Published in G. Daniel Brewer, Hydrogen Aircraft Technology, 2017
Oil shale is another very plentiful resource which can be used for production of jet fuels. Oil shale occurs as a rock-like substance which must be crushed and heated to release the kerogen which is then treated and refined to fuel specifications. Both aboveground and in situ conversion processes have been developed. The aboveground process requires a mining operation and transport of the shale to the retort. The shale is crushed and fed into the retort where it is mixed with air and burned. The oil mist that is produced is captured and condensed, forming a heavy oil that can be processed in a conventional refinery. The environmental problems which are created include the disturbance of the countryside due to the mining operation, plus the need to dispose of the crushed rock remaining after the kerogen has been removed. The rubble occupies substantially more volume than the shale in its original state. Disposal of the spent shale rubble also poses a problem because it must be prevented from leaching into groundwater supplies. Carbon dioxide and the usual tars and hydrocarbons associated with refinery operations will be present.
Nonrenewable Energy Resources
Published in Julie Kerr, Introduction to Energy and Climate, 2017
Oil shale can be mined using one of two methods: underground mining using the room-and-pillar method or surface mining. Room and pillar mining is a system in which the mined material is extracted across a horizontal plane, creating horizontal arrays of rooms and pillars. The pillars support the ceiling and the material is extracted from the “room.” After mining, the oil shale is transported to a facility for retorting, a heating process that separates the oil fractions of oil shale from the mineral fraction. The vessel in which retorting takes place is known as a retort. After retorting, the oil must be upgraded by further processing before it can be sent to a refinery, and the spent shale must be disposed of. Spent shale may be disposed of in surface impoundments, or as fill in graded areas; it may also be disposed of in previously mined areas. Eventually, the mined land needs to be reclaimed.
Economic geology value of oil shale deposits: Ethiopia (Tigray) and Jordan
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2018
Yohannes Yihdego, Hilmi S. Salem, Bediaku G. Kafui, Zarko Veljkovic
Shale oil refers to synthetic oil obtained by heating the organic material (kerogen) contained in the oil shale to a temperature, which will separate it into oil, combustible gas, and the residual carbon that remains in the spent shale rock. The kerogen’s content of oil shale deposits differs widely, and the economic feasibility of its extraction is highly dependent on international and local costs of the conventional hydrocarbons (crude oil and natural gas) (Yihdego and Al-Weshah 2016a, 2016b). This means that if the price of crude oil per barrel is higher than the production price of shale oil per barrel, then the extraction of shale oil is economic, and if the price of crude oil per barrel is less than the production price of shale oil per barrel, then the extraction of shale oil is uneconomic.