ESL Lesson 1
Oil in Our Every Day Life
ESL Lesson 2
The History of Mining
ESL Lesson 3
Economic growth
ESL Lesson 4
Delivery Systems
ESL Lesson 5
Cities and Population Movement
ESL Lesson 6
Recycling
ESL Lesson 7
Rubber
ESL Lesson 8
Farming
Oil shale
Oil shale is a general term (common word) applied to (for) a group of rocks that has enough organic material [called kerogen] to produce petroleum upon distillation (process of removing oil from rock). The kerogen in oil shale can be converted (changed) to oil through the chemical process of pyrolysis. During pyrolysis the oil shale is heated to 445-500 °C in the absence of air (with no air) and the kerogen is converted (changed) to oil and separated out, a process called "retorting". Oil shale has also been burnt directly as a low-grade fuel (type of very polluting fuel). The United States Energy Information Administration (EIA) estimates the world supply of oil shale at 2.6 trillion barrels of recoverable oil, 1.0-1.2 trillion barrels of which are in the United States. Estonia, Russia, Brazil, and China currently mine oil shale; however production is declining due to (because of) economic and environmental factors.
Extraction
Mining
With mining, the oil shale is mined either by traditional underground mining or surface mining (strip mining) from the ground and then transported (moved) to a processing facility. At the facility, the shale is heated to 450-500 °C and enriched with hydrogen (hydrogen is added by adding superheated steam). The resulting oil is then separated from the waste material.
In-Situ
With in-situ processing, the shale is fractured (broken) and heated underground to release gases and oils. Most of these methods are still experimental. The Shell Oil Company has been developing a new method under the name the Mahogany Research Project that uses electrical heating in Colorado. A heating element (unit) is lowered into the well and allowed to heat the kerogen over a period of approximately four years, slowly converting it (turning it into) into oils and gases, which are then pumped to the surface. This greatly reduces the footprint (environmental damage) of extraction operations-to no more than a conventional oil well. It could also potentially (possibly) extract more oil from a given area of land, as the wells can reach much deeper than surface strip-mines can.
History
Oil shale has been used since ancient times and can be used directly as a fuel just like coal. The modern use of oil shale to produce oil dates to 1847 when Dr James Young prepared lighting oil, lubricating oil and wax from coal. In 1850 he patented the process of "cracking" oil into its constituent parts (basic parts). Oil from oil shale was produced in that region (area) from 1857 until 1962 when production was cancelled (stopped) due to the much lower cost of petroleum. Oil shales were not exploited (used frequently) until fuel shortages during World War I. Mining began in 1918 and has continued since, with the size of operation increasing with demand. Once heavily processed (large amount of chemicals and heat added), the oil produced will be suitable for production of low-emission (low-pollution) petrol. Two large power stations burning oil shales were opened, a 1,400 MW plant in 1965 and a 1,600 MW plant in 1973. Oil shale production peaked in 1980 at 31.35 million tonnes. In Australia from June 2001 through to March 2003 produced 703,000 barrels of oil, 62,860 barrels of light fuel oil, and 88,040 barrels of ultra-low sulphur naphtha (flammable liquid similar to oil, varnish is the most well known).
Reserves
Estimated Shale Oil Reserves (Millions of Tonnes)| Region | Shale Reserves | Kerogen Reserves | Kerogen in Place |
|---|---|---|---|
| Africa | 12,373 | 500 | 5,900 |
| Asia | 20,570 | 1,100 | - |
| Australia | 32,400 | 1,725 | 36,985 |
| Europe | 54,180 | 600 | 12,500 |
| Middle East | 35,360 | 4,600 | 24,600 |
| North America | 3,340,000 | 80,000 | 140,000 |
| South America | - | 400 | 9,600 |
Graph source: World Energy Council, WEC Survey of Energy Resources
Therefore, worldwide there are approximately 620 billion barrels of known recoverable kerogen. This compares with known worldwide petroleum reserves of 1200 billion barrels (Source: BP Statistical Review of World Energy, 2006).
Continue to: Economics
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Recycling
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Oil shale
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Economics
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Environmental Considerations
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Shale Oil Extraction Imminent
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