Oil shale industry

File:Stuart oil shale processing plant.jpg

Stuart oil shale pilot plant

Oil shale industry is developed in Brazil, China, Estonia and to some extent in Germany, Israel and Russia. Several other countries are currently researching their oil shale reserves and production methods to improve efficiency and recovery. Australia though has halted their pilot projects due to environmental concerns. Estonia accounts for about 70 % of the world's oil shale production.

Oil shale has been used in industry 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. Power generation is not particularly wide spread, however it is present in countries that have significant oil shale deposits, and little in the way of other hydrocarbon deposits. Similarly, oil shales are being seen as a solution to increase domestic production of oil in countries that are reliant on imports.

History

Main article: History of the oil shale industry

File:Production of oil shale.PNG

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.

Oil shale has been used since ancient times. The modern industrial oil shale mining began in 1837 at the Autun mines in France, followed by Scotland, Germany and several other countries. The first oil shale retort was constructed in the United States in 1855. The second wave of oil shale industry started just before the World War I, but was phased-out in most of countries after the World War II because of high processing costs and the discovery of large supplies of easily accessible crude oil. The oil shale production continued to grow only in Estonia, Russia and China. Due the 1973 oil crisis, oil shale industry was restarted in several countries, but was mainly shut down in mid of 1980s. The global oil shale industry started to increase slightly only in mid of 1990s. In 2003, the oil shale development program was initiated in the United States, and the commercial leasing program for oil shale and tar sands was introduced in 2005.

Mining

The oil shale is mined either by traditional underground mining or surface mining techniques. There are several mining methods, but the aim of all of them is the fragmenting of oil shale deposit to enable the transport of shale fragments to a power plant or retorting facility. Main methods of surface mining are open pit mining and strip mining. The main sub-surface mining method is the room-and-pillar method. The largest oil shale mine in the world is the Estonia underground mine in Estonia, operated by Eesti Põlevkivi.

Power generation

Oil shale could be used as a fuel for thermal power plants, where the shale is burned like coal to drive steam turbines. In 1924, the Tallinn Power Plant was witched to oil shale firing as a first power plant in the world. Currently there are oil shale-fired power plants in Estonia with an installation capacity of 2967 megawatts, Israel (12.5 MW), China (12 MW), and Germany (9.9 MW). While some countries have closed their oil shale-fired power plants (e.g. Romania) or converted to other fuels (e.g. Russia), some other countries are looking for construction of these power plants (e.g. Jordan and Egypt), or burn oil shale at the power plants together with coal (e.g. Canada and Turkey).

There are four technologies for combustion:

• Pulverized Combustion (PC)—used in the older units of oil shale-fired power plants in Estonia;
• Fluidized Bed Combustion (FBC)—used by Rohrbach Zement in Dotternhausen, Germany;
• Circulated Fluidized Bed (CFBC)—used in two new units at Narva Power Plants in Estonia, Huadian Power Plant in China, and PAMA power plant at Mishor Rotem in Israel;
• Pressurized fluidized-bed combustion (PFBC)—more advanced and efficient, but premature technology.

The most modern used technology of a combustion of oil shale in power plants is a pressurized fluidized-bed combustion (PFBC). The most modern used technology of a combustion of oil shale in power plants is a bubbling fluidized bed (BFB) or circulating fluidized bed (CFB) process, while the traditional way of burning oil shale is through pulverized combustion.

Oil extraction

Main article: Oil shale extraction

At present, the major shale oil producers are Estonia, Brazil and China, while Australia, USA, Canada and Jordan have planned to start or restart shale oil production. Although there are several oil shale retorting technologies, only five technologies are currently in commercial use, which are Kiviter, Galoter, Fushun, Petrosix, and Alberta Taciuk. The two main methods of extracting oil from shale are ex-situ and in-situ.

Other industrial uses

Oil shale is or could be used for production of different products like specialty carbon fibers, adsorbent carbons, carbon black, phenols, resins, glues, tanning agents, mastic, road bitumen, cement, bricks, construction and decorative blocks, soil additives, fertilizers, rock wool insulation, glass, and pharmaceutical products. However, oil shale usage for production of these products are still small or even in experimental stages only.

Some oil shales are suitable for sulfur, ammonia, alumina, soda ash, and nahcolite production as shale oil extraction byproducts. Some oil shales could be used for uranium and other rare chemical element production. In 1946-1952, a marine type of Dictyonema shale was used for uranium production in Sillamäe, Estonia, and in 1950-1989 alum shale was used in Sweden for the same purpose. Oil shale gas could be used as a substitute for natural gas, however at the current price level this is not economically feasible.

Economics

Main article: Oil shale economics

Medium-term prices for light-sweet crude oil in US dollars, 2005-2007 (not adjusted for inflation).

The various attempts to develop the world's oil shale deposits, over a period of over 150 years, have experienced successes when the cost of shale oil production in a given region was less than the price of crude oil or its other substitutes. According to a survey conducted by the RAND Corporation, a surface retorting complex (comprising a mine, retorting plant, upgrading plant, supporting utilities, and spent shale reclamation) is unlikely to be profitable in the United States until crude oil prices range between US$70 to US$95 per barrel (in 2005 dollars). Once commercial plants are in operation and experience-based learning takes place, costs are expected to decline in 12 years to US$35–US$48 per barrel. After production of 1,000 million barrels, costs are estimated to decline further to US$30 – US$40 per barrel. Royal Dutch Shell has announced that its in-situ extraction technology in Colorado could be competitive at prices over US$30 per barrel, while other technologies at full-scale production assert profitability at oil prices even lower than US$20 per barrel. To increase the efficiency of oil shale retorting, several co-pyrolysis processes have been proposed and tested.

A critical measure of the viability of oil shale as an energy source is 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. Royal Dutch Shell has reported an EROEI of three to four on its in-situ development, Mahogany Research Project. An additional economic consideration is the water needed in the oil shale retorting process, which may pose a problem in areas with water scarcity.

Environmental considerations

Main article: Environmental effects of oil shale industry

The oil shale industry can have a negative impact on the surrounding environments, if the risks associated with it are not managed correctly. Environmental concerns raised over the extraction of shale oil have caused the oil shale industry in some countries to come to a halt. Opposition to the proposed Stuart Oil Shale Project in Australia resulted in its being put on hold in 2004.

Surface-mining of oil shale deposits has the same environmental impacts as those of open-pit mining. In addition, combustion and thermal processing generate waste material, and the atmospheric emissions include carbon dioxide, a major greenhouse gas. 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.

See also

• Oil shale economics
• Oil shale reserves

References

• Survey of energy resources (PDF) (20 ed.). World Energy Council (WEC). 2004. ISBN 9780080444109. Retrieved 2007-07-20.