Oil shale industry


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Stuart oil shale pilot plant

Oil shale industry is a industry of mining and processing of oil shale—a fine-grainedsedimentary rock, containing significant amounts of kerogen (a solid mixture of organicchemical compounds), from which liquid hydrocarbons can be manufactured. The industry has developed in Brazil, China, Estonia and to some extent in Germany,Israel and Russia. Several other countries are currently conducting research on their oil shale reserves and production methods to improve efficiency and recovery.[1] However,Australia has halted their pilot projects due to environmental concerns.[2] Estonia accounts for about 70 % of the world's oil shale production.[3]

Oil shale has been used for industrial purposes since the early 1600s, when it was mined for its minerals. Since the late 1800s, shale oil has also been used for its oil content and as a low grade fuel for power generation. However, barring countries having significant oil shale deposits, its use for power generation is not particularly widespread. Similarly, oil shale is a source for production of synthetic crude oil and it is seen as a solution towards increasing domestic production of oil in countries that are reliant on imports.

Contents

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[edit]History

Main article: History of the oil shale industry
Production of oil shale in millions of metric tons from Estonia (Estonia deposit), Russia (Leningrad and Kashpir deposits), United Kingdom (Scotland, Lothians), Brazil (Iratí Formation), China (Maoming and Fushun deposits), and Germany (Dotternhausen) from 1880 to 2000.[4]

Oil shale has been used since ancient times. Modern industrial oil shale mining began in 1837 at the Autun mines in France, followed by Scotland, Germany and several other countries.[5][6] The oil shale industry started growing just before World War Ibecause of the mass production of automobiles and trucks and the supposed shortage of gasoline for transportation needs. In 1924, the Tallinn Power Plant was the first power plant in the world to switch to oil shale firing.[7] However, following the end ofWorld War II, the oil shale industry was phased-out in most of countries due to high processing costs and the discovery of large supplies of easily accessible and cheaper crude oil.[4][6][5][8] Oil shale production however, continued to grow in Estonia, Russia and China. Following the 1973 oil crisis, the oil shale industry was restarted in several countries, but in the 1980s, when oil prices fell, many industries faced closure. The global oil shale industry mainly started growing during mid-1990s. In 2003, the oil shale development program was initiated in the United States, and in 2005, the commercial leasing program for oil shale and tar sands was introduced.[9][10]

As of May 2007, Estonia is actively engaged in exploitation of oil shale on a significant scale and accounts for 70 % of the world’s processed oil shale.[11] Estonia is unique in that its oil shale deposit account for just 17 % of total deposits in European Union but it generates 90 % of its power from oil shale. Oil shale industry in Estonia employs 7,500 people, which is about 1 % of national employment, accounting for 4 % of its gross domestic product.[12]

[edit]Mining

Oil shale is mined either by traditional underground mining or surface mining techniques. There are several mining methods available, but the common aim of all these methods is to fragment the oil shale deposits in order to enable the transport of shale fragments to a power plant or retorting facility. The main methods of surface mining are open pit mining and strip mining. An important method of sub-surface mining is theroom-and-pillar method.[13] In this method, the material is extracted across a horizontal plane while leaving "pillars" of untouched material to support the roof. These pillars reduce the likelihood of a collapse. Oil shale can also be obtained as a by-product of coal mining.[14]

The largest oil shale mine in the world is the Estonia Mine, operated by Eesti Põlevkivi.[15] In 2005, Estonia mined 14.8 million tonnes of oil shale.[12] During the same period, mining permits were issued for almost 24 million tonnes, with applications being received for mining an additional 26 million tonnes.[16] In 2008, the Estonian Parliament approved the "National Development Plan for the Use of Oil Shale 2008-2015", which limits the annual extraction of oil shale to 20 million tonnes.[17]

[edit]Power generation

Oil shale can be used as a fuel in thermal power plants, wherein the shale is burnt like coal to drive the steam turbines. As of 2008, there are oil shale-fired power plants in Estonia with a generating capacity of 2,967 megawatts (MW), Israel (12.5 MW), China (12 MW), and Germany (9.9 MW).[18][19] Also Romania and Russia have run oil shale-fired power plants, but have shut them down or switched to other fuels like natural gas. Jordan and Egypt have announced their plans to construct oil shale-fired power plants, while Canada and Turkey plan to burn oil shale at the power plants along with coal.[18][20][21]

Thermal power plants which use oil shale as a fuel mostly employ two types of combustion methods. The traditional method is Pulverized combustion (PC) which is used in the older units of oil shale-fired power plants in Estonia, while the more advanced method is Fluidized bed combustion (FBC), which is used by Holcim cement factory in Dotternhausen, Germany, and in PAMA power plant at Mishor Rotem in Israel. The main FBC technologies are Bubbling fluidized bed combustion (BFBC) and Circulating fluidized bed combustion (CFBC).[18][22] There are more than 60 power plants around the world, which are using CFBC technology for combustion of coal and lignite, but only two new units atNarva Power Plants in Estonia, and one at Huadian Power Plant in China use CFBC technology for combustion of oil shale.[19][20][23][24] The most advanced and efficient oil shale combustion technology is Pressurized fluidized-bed combustion (PFBC). However, this technology is still premature and is in its nascent stage.[25]

[edit]Oil extraction

Main article: Oil shale extraction

As of 2008, the major shale oil producers are Estonia, Brazil and China, while Australia, USA, Canada and Jordan have planned to setup or restart shale oil production.[18][20] In 2005, the global oil shale production was 684,000 tonnes. Although the largest shale oil producer in 2005 was Estonia, it is expected that as of 2007, China has overtaken the position of the largest producer in the world.[12][26]

Companies with shale oil production projects (operational or in the developmental phase)[27][4]
CompanyLocationMethodStatus
Ambre EnergyUtah, USAConduction through a wall (Staged electrically heated retort process (Oil-Tech process))Pilot project
American Shale Oil CorporationColorado, USATrue in-situ process (The EGL Oil Shale Process)Testing
Chevron Shale Oil CompanyColorado, USAModified in-situ process (CRUSH process)Testing
Eesti EnergiaNarva, EstoniaHot recycled solids (Galoter process)Operational
ExxonMobilColorado, USAModified in-situ process; reactive fluids (ExxonMobil Electrofrac)Testing
Fushun Mining GroupFushun, ChinaInternal combustion (Fushun process)Operational
Hom TovMishor Rotem, IsraelConduction through a wall (Hom Tov co-pyrolysis process)Testing
Independent Energy PartnersColorado, USATrue in-situ process (fuel cell process)Testing
Kiviõli KeemiatööstusKiviõli, EstoniaInternal combustion (Kiviter process)Operational
Mountain West EnergyUtah, USATrue in-situ process (IGE process)Testing
Oil Shale Exploration CompanyUtah, USAHot recycled solids (ATP); Externally generated hot gas (Petrosix process)Testing
PetrobrasSão Mateus do Sul,Paraná, BrazilExternally generated hot gas (Petrosix process)Operational
Queensland Energy ResourcesStuart Deposit,Queensland, AustraliaHot recycled solids (ATP)Pilot project, temporary suspended
Red Leaf ResourcesUtah, USAExternally generated hot gas (EcoShale In-Capsule Process)Testing
Shale Technologies LLCRifle, Colorado, USAInternal combustion (Paraho Direct process)Pilot project
Shell Frontier Oil and GasColorado, USATrue in-situ process (ICP)Pilot project
VKG OilKohtla-Järve, EstoniaInternal combustion (Kiviter process)Operational

Although there are several oil shale retorting technologies, only five technologies are currently in commercial use. These are Kiviter, Galoter,Fushun, Petrosix, and Alberta Taciuk.[28] The two main methods of extracting oil from shale are ex-situ and in-situ. In ex-situ method, the oil shale is mined and transported to the retort facility in order to extract the oil. The in-situ method converts the kerogen while it is still in the form of an oil shale deposit, and then extracts it via a well, where it rises up as normal petroleum.[29]

[edit]Other industrial uses

Oil shale is used for cement production by Kunda Nordic Cement in Estonia, by Holcim in Germany, and by Fushun cement factory in China.[30][14] Oil shale can also be used for production of different chemical products, construction materials, and pharmaceutical products.[20][12] However, use of oil shale for production of these products is still very rare and in experimental stages only.[4][21]

Some oil shales are suitable source for sulfur, ammonia, alumina, soda ash, and nahcolite which occur as shale oil extraction byproducts. Some oil shales can also be used for uranium and other rare chemical element production. During 1946–1952, a marine variety of Dictyonemashale was used for uranium production in Sillamäe, Estonia, and during 1950–1989 alum shale was used in Sweden for the same purpose.[4]Oil shale gas can also be used as a substitute for natural gas. After World War II, Estonian-produced oil shale gas was used in Leningrad and the cities in North Estonia.[31] However, at the current price level of natural gas, this is not economically feasible.[32][33]

[edit]Economics

Main article: Oil shale economics
Medium-term prices for light-sweet crude oil in US dollars, 2005–2007 (not adjusted for inflation)

During the early 20th century, the crude-oil industry expanded. Since then, the various attempts to develop oil shale deposits have succeeded only when the cost of shale-oil production in a given region comes in below the price of crude oil or its other substitutes.[34] According to a survey conducted by the RAND Corporation, the cost of producing a barrel of oil at a surface retorting complex in the United States (comprising a mine, retorting plant, upgrading plant, supporting utilities, and spent shale reclamation), would range between US$70–95 ($440–600/m3, adjusted to 2005 values). This estimate considers varying levels of kerogen quality and extraction efficiency. In order for the operation to be profitable, the price of crude oil would need to remain above these levels. The analysis also discusses the expectation that processing costs would drop after the complex was established. The hypothetical unit would see a cost reduction of 35–70% after its first 500 million barrels (79×106 m3) were produced. Assuming an increase in output of 25 thousand barrels per day (4.0×103 m3/d) during each year after the start of commercial production, the costs would then be expected to decline to $35–48 per barrel ($220–300/m3) within 12 years. After achieving the milestone of 1 billion barrels (160×106 m3), its costs would decline further to $30–40 per barrel ($190–250/m3).[13][12] A comparison of the proposed American oil shale industry to the Alberta tar-sands industry has been drawn (the latter enterprise generated over one million barrels of oil per day in late 2007), stating that "the first-generation facility is the hardest, both technically and economically".[35][36]

Royal Dutch Shell has announced that its in situ extraction technology in Colorado could become competitive at prices over $30 per barrel ($190/m3), while other technologies at full-scale production assert profitability at oil prices even lower than $20 per barrel ($130/m3).[37][38][39] To increase the efficiency of oil shale retorting, researchers have proposed and tested several co-pyrolysis processes.[40][41][42][43][44]

In a 1972 publication by the journal Pétrole Informations (ISSN 0755-561X), shale oil production was unfavorably compared to the liquefaction of coal. The article stated that coal liquefaction was less expensive, generated more oil, and created fewer environmental impacts than oil shale extraction. It cited a conversion ration of 650 litres (170 U.S. gal/140 imp gal) of oil per one ton of coal, as against 150 litres (40 U.S. gal/33 imp gal) per one ton of shale oil.[5]

A critical measure of the viability of oil shale as an energy source lies in the ratio of the energy produced by the shale to the energy used in its mining and processing, a ratio known as "Energy Returned on Energy Invested" (EROEI). A 1984 study estimated the EROEI of the various known oil shale deposits as varying between 0.7–13.3[45] although known oil shale extraction development projects assert an EROI between 3 to 10. Royal Dutch Shell has reported an EROEI of three to four on its in situ development, Mahogany Research Project.[37][46][47] The water needed in the oil shale retorting process offers an additional economic consideration: this may pose a problem in areas with water scarcity.

[edit]Environmental considerations

Main article: Environmental impact of oil shale industry

Oil shale mining involves a number of environmental impacts, more pronounced in surface mining than in underground mining. They include acid drainage induced by the sudden rapid exposure and subsequent oxidation of formerly buried materials, the introduction of metals into surface-water and groundwater, increased erosion, sulfur-gas emissions, and air pollution caused by the production of particulates during processing, transport, and support activities.[48][49] In 2002, about 97% of air pollution, 86% of total waste and 23% of water pollution in Estonia came from the power industry, which uses oil shale as the main resource for its power production.[50]

Oil shale extraction can damage the biological and recreational value of land and the ecosystem in the mining area. Combustion and thermal processing generate waste material. In addition, the atmospheric emissions from oil shale processing and combustion include carbon dioxide, agreenhouse gas. Environmentalists oppose production and usage of oil shale, as it creates even more greenhouse gases than conventional fossil fuels.[51] Section 526 of the Energy Independence And Security Act prohibits United States government agencies from buying oil produced by processes that produce more greenhouse gas emissions than would traditional petroleum.[52][53] Experimental in situ conversion processes and carbon capture and storage technologies may reduce some of these concerns in the future, but at the same time they may cause other problems, including groundwater pollution.[54]

Some commentators have expressed concerns over the oil shale industry's use of water. In 2002, the oil shale-fired power industry used 91% of the water consumed in Estonia.[50] Depending on technology, above-ground retorting uses between one and five barrels of water per barrel of produced shale-oil.[13][55][56][57][58] A 2007 programmatic environmental impact statement issued by the US Bureau of Land Managementstated that surface mining and retort operations produce two to ten US gallons (1.5–8 imperial gallons or 8–38 L) of wastewater per tonne of processed oil shale.[55] In situ processing, according to one estimate, uses about one-tenth as much water.[59]

Water concerns become particularly sensitive issues in arid regions, such as the western US and Israel's Negev Desert, where plans exist to expand the oil shale industry despite a water shortage.[60]

Environmental activists, including members of Greenpeace, have organized strong protests against the oil shale industry. In one result,Queensland Energy Resources put the proposed Stuart Oil Shale Project in Australia on hold in 2004.[48][61][62]

[edit]See also

[edit]Notes

  1. ^ WEC (2007), p. 93
  2. ^ Greenpeace Australia Pacific (2005-03-03). "Climate-changing shale oil industry stopped". Retrieved on 2007-06-28.
  3. ^ (2005). "Non-Nuclear Energy Research in Europe – A comparative study. Country Reports A – I. Volume 2" (PDF). European Commission. Directorate-General for Research. EUR 21614/2 Retrieved on 2007-06-29.
  4. ^ a b c d e Dyni, John R.. "Geology and resources of some world oil shale deposits. Scientific Investigations Report 2005–5294" (PDF). U.S. Department of the Interior. U.S. Geological Survey. Retrieved on 2007-07-09.
  5. ^ a b c Laherrère, Jean (2005). "Review on oil shale data" (PDF). Hubbert Peak. Retrieved on 2007-06-17.
  6. ^ a b WEC (2007), pp. 96-97
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  8. ^ Yin, Liang (2006-11-07). "Current status of oil shale industry in Fushun, China" (PDF)., International Oil Shale Conference. Retrieved on 2007-06-29.
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