Environmental impact of the oil shale industry includes the consideration of issues such as

land use Land use involves the management and modification of natural environment or wilderness into built environment such as settlements and semi-natural habitats such as arable fields, pastures, and managed woods. Land use by humans has a long ...

waste management Waste management or waste disposal includes the processes and actions required to manage waste from its inception to its final disposal. This includes the collection, transport, treatment and disposal of waste, together with monitorin ...

, and

water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...

and

air pollution Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are many different typ ...

caused by the extraction and processing of

oil shale Oil shale is an organic-rich fine-grained sedimentary rock containing kerogen (a solid mixture of organic chemical compounds) from which liquid hydrocarbons can be produced. In addition to kerogen, general composition of oil shales constitut ...

. Surface mining of oil shale deposits causes the usual environmental impacts of

open-pit mining Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique of extracting rock or minerals from the earth from an open-air pit, sometimes known as a borrow. This form of mini ...

. In addition, the

combustion Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combus ...

and thermal processing generate waste material, which must be disposed of, and harmful atmospheric emissions, including

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

, a major greenhouse gas. Experimental in-situ conversion processes and

carbon capture and storage Carbon capture and storage (CCS) or carbon capture and sequestration is the process of capturing carbon dioxide (CO2) before it enters the atmosphere, transporting it, and storing it (carbon sequestration) for centuries or millennia. Usually th ...

technologies may reduce some of these concerns in future, but may raise others, such as the pollution of groundwater.

Surface mining and retorting

Land use and waste management

Surface mining and ''in-situ'' processing requires extensive land use. Mining, processing, and waste disposal require land to be withdrawn from traditional uses, and therefore should avoid high density population areas. Oil shale mining reduces the original ecosystem diversity with habitats supporting a variety of plants and animals. After mining the land has to be reclaimed, process takes time and cannot necessarily re-establish the original biodiversity. The impact of sub-surface mining on the surroundings will be less than for open pit mines. However, sub-surface mining may also cause subsidence of the surface due to the collapse of mined-out area and abandoned stone drifts. Disposal of mining wastes, spent oil shale (including semi-coke) and combustion ashes needs additional land use. According to the study of the European Academies Science Advisory Council, after processing, the waste material occupies a greater volume than the material extracted, and therefore cannot be wholly disposed underground. According to this, production of a barrel of

shale oil Shale oil is an unconventional oil produced from oil shale rock fragments by pyrolysis, hydrogenation, or thermal dissolution. These processes convert the organic matter within the rock (kerogen) into synthetic oil and gas. The resulting oil c ...

can generate up to 1.5 tonnes of semi-coke, which may occupy up to 25% greater volume than the original shale. This is not confirmed by the results of Estonia's oil shale industry. The mining and processing of about one billion tonnes of oil shale in Estonia has created about 360-370 million tonnes of solid waste, of which 90 million tonnes is a mining waste, 70–80 million tonnes is a semi-coke, and 200 million tonnes are combustion ashes. The waste material may consist of several pollutants including

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ...

s, heavy metals, and polycylic aromatic hydrocarbons (PAHs), some of which are

toxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subs ...

and

carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive subs ...

ic. To avoid contamination of the groundwater, the solid waste from the thermal treatment process is disposed in an

open dump Open or OPEN may refer to: Music * Open (band), Australian pop/rock band * The Open (band), English indie rock band * ''Open'' (Blues Image album), 1969 * ''Open'' (Gotthard album), 1999 * ''Open'' (Cowboy Junkies album), 2001 * ''Open'' (YF ...

( landfill or "heaps"), not underground where it could potentially reach clean ground water. As semi-coke consists of, in addition to minerals, up to 10% organics that may pose hazard to the environment owing to leaching of toxic compounds as well as to the possibility of self-ignition.

Water management

Mining influences the water runoff pattern of the area affected. In some cases it requires the lowering of

groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated ...

levels below the level of the oil shale strata, which may have harmful effects on the surrounding

arable land Arable land (from the la, arabilis, "able to be ploughed") is any land capable of being ploughed and used to grow crops.''Oxford English Dictionary'', "arable, ''adj''. and ''n.''" Oxford University Press (Oxford), 2013. Alternatively, for th ...

and forest. In Estonia, for each cubic meter of oil shale mined, 25 cubic meters of water must be pumped from the mine area. At the same time, the thermal processing of oil shale needs water for quenching hot products and the control of dust. Water concerns are a particularly sensitive issue in arid regions, such as the western part of the United States and Israel's Negev Desert, where there are plans to expand the oil shale industry. Depending on technology, above-ground retorting uses between one and five barrels of water per barrel of produced shale oil. ''In situ'' processing, according to one estimate, uses about one-tenth as much water. Water is the main transmitter of oil shale industry pollutants. One environmental issue is to prevent noxious materials leaching from spent shale into the water supply. The oil shale processing is accompanied by the formation of process waters and waste waters containing

phenols In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (— O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds are ...

tar Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. "a dark brown or black bi ...

and several other products, heavily separable and toxic to the environment. A 2008 programmatic environmental impact statement issued by the

United States Bureau of Land Management The Bureau of Land Management (BLM) is an agency within the United States Department of the Interior responsible for administering federal lands. Headquartered in Washington DC, and with oversight over , it governs one eighth of the country's la ...

stated that surface mining and retort operations produce of waste water per of processed oil shale.

Air pollution management

Main air pollution is caused by the oil shale-fired power plants. These factory plants provide the atmospheric emissions of gaseous products like nitrogen oxides, sulfur dioxide and

hydrogen chloride The compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colourless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride ga ...

, and the airborne particulate matter ( fly ash). It includes particles of different types (carbonaceous, inorganic ones) and different sizes. The concentration of air pollutants in

flue gas Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produc ...

depends primarily on the combustion technology and burning regime, while the emissions of solid particles are determined by the efficiency of fly ash-capturing devices. Open deposition of semi-coke causes distribution of pollutants in addition to aqueous vectors also via air (dust). There are possible links from being in an oil shale area to a higher risk of asthma and lung cancer than other areas.

Greenhouse gas emissions

Carbon dioxide emissions from the production of shale oil and shale gas are higher than conventional oil production and a report for the

European Union The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been de ...

warns that increasing public concern about the adverse consequences of global warming may lead to opposition to oil shale development. Emissions arise from several sources. These include released by the decomposition of the

kerogen Kerogen is solid, insoluble organic matter in sedimentary rocks. Comprising an estimated 1016 tons of carbon, it is the most abundant source of organic compounds on earth, exceeding the total organic content of living matter 10,000-fold. It ...

and

carbonate minerals Carbonate minerals are those minerals containing the carbonate ion, . Carbonate divisions Anhydrous carbonates *Calcite group: trigonal **Calcite CaCO3 **Gaspéite (Ni,Mg,Fe2+)CO3 **Magnesite MgCO3 **Otavite CdCO3 **Rhodochrosite MnCO3 **Sider ...

in the extraction process, the generation of the energy needed to heat the shale and in the other oil and gas processing operations, and fuel used in the mining of the rock and the disposal of waste. As the varying mineral composition and calorific value of oil shale deposits varies widely, the actual values vary considerably. At best, the direct combustion of oil shales produces carbon emissions similar to those from the lowest form of coal, lignite, at 2.15

moles Moles can refer to: * Moles de Xert, a mountain range in the Baix Maestrat comarca, Valencian Community, Spain * The Moles (Australian band) *The Moles, alter ego of Scottish band Simon Dupree and the Big Sound People *Abraham Moles, French engin ...

CO₂/ MJ, an energy source which is also politically contentious due to its high emission levels. For both power generation and oil extraction, the CO₂ emissions can be reduced by better utilization of

waste heat Waste heat is heat that is produced by a machine, or other process that uses energy, as a byproduct of doing work. All such processes give off some waste heat as a fundamental result of the laws of thermodynamics. Waste heat has lower utility ...

from the product streams.

''In-situ'' processing

Currently, the '' in-situ'' process is the most attractive proposition due to the reduction in standard surface environmental problems. However, ''in-situ'' processes do involve possible significant environmental costs to

aquifer An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials ( gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characteris ...

s, especially since ''in-situ'' methods may require ice-capping or some other form of barrier to restrict the flow of the newly gained oil into the groundwater aquifers. However, after the removal of the freeze wall these methods can still cause groundwater contamination as the hydraulic conductivity of the remaining shale increases allowing groundwater to flow through and leach salts from the newly toxic aquifer.

References

External links and further reading

Oil Shale and Tar Sands Draft Programmatic Environmental Impact Statement (EIS)
Concerning potential leases of Federal oil sands lands in Utah and oil shale lands in Utah, Wyoming, and Colorado {{DEFAULTSORT:Environmental Impact of the Oil Shale Industry Oil shale