Methane leak

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Methane plume over Turkmenistan, 2020 image from the Sentinel-5 Precursor satellite TKM TROPOMI Methane.png
Methane plume over Turkmenistan, 2020 image from the Sentinel-5 Precursor satellite

A methane leak comes from an industrial facility or pipeline and means a significant natural gas leak: the term is used for a class of methane emissions. Satellite data enables the identification of super-emitter events that produce methane plumes. Over 1,000 methane leaks of this type were found worldwide in 2022. [1] As with other gas leaks, a leak of methane is a safety hazard: coalbed methane in the form of fugitive gas emission has always been a danger to miners. Methane leaks also have a serious environmental impact. Natural gas can contain some ethane and other gases, but from both the safety and environmental point of view the methane content is the major factor.

Contents

As a greenhouse gas and climate change contributor, methane ranks second, following carbon dioxide. Fossil fuel exploration, transportation and production is responsible for about 40% of human-caused methane emissions. [1] Smaller leaks than can be spotted from space comprise a long tail of emissions. They can be identified from planes flying at 900 meters (3,000 ft). [2] According to Fatih Birol of the International Energy Agency, "Methane emissions are still far too high, especially as methane cuts are among the cheapest options to limit near-term global warming". [1]

Examples of methane leaks

Individual methane leaks as reported are specific events, with a large quantity of gas released. An example followed the 2022 Nord Stream pipeline sabotage. Following early reports that the escape might exceed 105 tonnes, The International Methane Emissions Observatory of the United Nations Environment Programme analysed the release. In February 2023 it put the mass of methane gas in the range 7.5 to 23.0 x 104 tonnes. In terms of overall human-made methane emissions, these figures are under 0.1% of the annual total. [3] [4]

Satellite data detection has shown that methane super emitter sites in Turkmenistan, USA and Russia are responsible for the biggest number of events from fossil fuel facilities. Equipment failures are normally responsible for the releases, which can last for weeks. [5]

The Aliso Canyon gas leak of 2015 has been quantified as at least 1.09 x 105 tonnes of methane. [6] Satellite data for the Raspadskaya coal mine, Kemerovo Oblast, Russia indicated in 2022 an hourly methane leakage rate of 87 tonnes; [7] this compares to 60 tonnes per hour of natural gas leaking from the Aliso Canyon incident, considered among the worst recorded leak events. [8]

Spain's Technical University of Valencia, in a study published in 2022, found that a super emitter event at a gas and oil platform in the Gulf of Mexico released around 4 x 104 tonnes of methane during a 17-day time period in December 2021 (hourly rate around 98 tonnes). [9] Another major event in 2022 was a leak of 427 tonnes an hour in August, near Turkmenistan's Caspian coast and a major pipeline. [5]

Units

Quantitative reports of methane leaks often use the standard cubic foot (scf) of the United States customary system. Applied to natural gas, a complex mixture of uncertain proportions, and depending on pressure and temperature conditions, the accuracy of calculations converting scf to metric units of mass is subject to limitations. A conversion figure given is 5 x 104 scf of natural gas as 1.32 short tons (1.20 t). [10]

For detection sensitivity, quantitative criteria are typically stated in units of standard cubic feet per hour (scf/h, "skiff", US), or thousand standard cubic feet per day (Mscf/d); or with metric units kilograms per hour (kg/hr), cubic meters per day (m3/d). [11]

To describe the mass balance of methane in the atmosphere, mass rates are described in units of Tg/yr, i.e. teragrams per year where a teragram is 106 tonnes (megagrams). [12] The methane leak from the Permian Basin, a significant region of the Mid-Continent Oil Producing Area, was estimated for 2018/9 from satellite data as 2.7 Tg/yr. Quoted in terms of the proportion of the mass of extracted gas, the leakage comes to 3.7%. [13] The 2021 Carbon Mapper project, a collaboration of the Jet Propulsion Laboratory and academia, detected 533 methane super-emitters in the Permian Basin. [14]

Related Research Articles

<span class="mw-page-title-main">Global warming potential</span> Potential heat absorbed by a greenhouse gas

Global warming potential (GWP) is a measure of how much infrared thermal radiation a greenhouse gas added to the atmosphere would absorb over a given time frame, as a multiple of the radiation that would be absorbed by the same mass of added carbon dioxide. GWP is 1 for CO2. For other gases it depends on how strongly the gas absorbs infrared thermal radiation, how quickly the gas leaves the atmosphere, and the time frame being considered. The carbon dioxide equivalent is calculated from GWP. For any gas, it is the mass of CO2 that would warm the earth as much as the mass of that gas. Thus it provides a common scale for measuring the climate effects of different gases. It is calculated as GWP times mass of the other gas.

<span class="mw-page-title-main">Natural gas</span> Gaseous fossil fuel

Natural gas is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon dioxide, nitrogen, hydrogen sulfide, and helium are also usually present. Methane is colorless and odorless, and the second largest greenhouse gas contributor to global climate change after carbon dioxide. Because natural gas is odorless, odorizers such as mercaptan are commonly added to it for safety so that leaks can be readily detected.

<span class="mw-page-title-main">Methane clathrate</span> Methane-water lattice compound

Methane clathrate (CH4·5.75H2O) or (8CH4·46H2O), also called methane hydrate, hydromethane, methane ice, fire ice, natural gas hydrate, or gas hydrate, is a solid clathrate compound (more specifically, a clathrate hydrate) in which a large amount of methane is trapped within a crystal structure of water, forming a solid similar to ice. Originally thought to occur only in the outer regions of the Solar System, where temperatures are low and water ice is common, significant deposits of methane clathrate have been found under sediments on the ocean floors of the Earth. Methane hydrate is formed when hydrogen-bonded water and methane gas come into contact at high pressures and low temperatures in oceans.

<span class="mw-page-title-main">Coalbed methane</span> Form of natural gas extracted from coal beds

Coalbed methane, coalbed gas, or coal seam gas (CSG) is a form of natural gas extracted from coal beds. In recent decades it has become an important source of energy in United States, Canada, Australia, and other countries.

<span class="mw-page-title-main">Southern California Gas Company</span> Natural gas utility company in California

The Southern California Gas Company is a utility company based in Los Angeles, California, and a subsidiary of Sempra. It is the primary provider of natural gas to Los Angeles and Southern California.

A gas leak refers to a leak of natural gas or another gaseous product from a pipeline or other containment into any area where the gas should not be present. Gas leaks can be hazardous to health as well as the environment. Even a small leak into a building or other confined space may gradually build up an explosive or lethal concentration of gas. Natural gas leaks and the escape of refrigerant gas into the atmosphere are especially harmful, because of their global warming potential and ozone depletion potential.

<span class="mw-page-title-main">Clathrate gun hypothesis</span> Meteorological hypothesis

The clathrate gun hypothesis is a proposed explanation for the periods of rapid warming during the Quaternary. The hypothesis is that changes in fluxes in upper intermediate waters in the ocean caused temperature fluctuations that alternately accumulated and occasionally released methane clathrate on upper continental slopes. This would have had an immediate impact on the global temperature, as methane is a much more powerful greenhouse gas than carbon dioxide. Despite its atmospheric lifetime of around 12 years, methane's global warming potential is 72 times greater than that of carbon dioxide over 20 years, and 25 times over 100 years. It is further proposed that these warming events caused the Bond Cycles and individual interstadial events, such as the Dansgaard–Oeschger interstadials.

<span class="mw-page-title-main">Greenhouse gas emissions</span> Sources and amounts of greenhouse gases emitted to the atmosphere from human activities

Greenhouse gas emissions from human activities strengthen the greenhouse effect, contributing to climate change. Carbon dioxide, from burning fossil fuels such as coal, oil, and natural gas, is one of the most important factors in causing climate change. The largest emitters are China followed by the US, although the United States has higher emissions per capita. The main producers fueling the emissions globally are large oil and gas companies. Human-caused emissions have increased atmospheric carbon dioxide by about 50% over pre-industrial levels. The growing levels of emissions have varied, but have been consistent among all greenhouse gases. Emissions in the 2010s averaged 56 billion tons a year, higher than any decade before. Total cumulative emissions from 1870 to 2017 were 425±20 GtC from fossil fuels and industry, and 180±60 GtC from land use change. Land-use change, such as deforestation, caused about 31% of cumulative emissions over 1870–2017, coal 32%, oil 25%, and gas 10%.

<span class="mw-page-title-main">Greenhouse gas emissions by the United States</span> Climate changing gases from the North American country

The United States produced 5.2 billion metric tons of carbon dioxide equivalent greenhouse gas (GHG) emissions in 2020, the second largest in the world after greenhouse gas emissions by China and among the countries with the highest greenhouse gas emissions per person. In 2019 China is estimated to have emitted 27% of world GHG, followed by the United States with 11%, then India with 6.6%. In total the United States has emitted a quarter of world GHG, more than any other country. Annual emissions are over 15 tons per person and, amongst the top eight emitters, is the highest country by greenhouse gas emissions per person. However, the IEA estimates that the richest decile in the US emits over 55 tonnes of CO2 per capita each year. Because coal-fired power stations are gradually shutting down, in the 2010s emissions from electricity generation fell to second place behind transportation which is now the largest single source. In 2020, 27% of the GHG emissions of the United States were from transportation, 25% from electricity, 24% from industry, 13% from commercial and residential buildings and 11% from agriculture. In 2021, the electric power sector was the second largest source of U.S. greenhouse gas emissions, accounting for 25% of the U.S. total. These greenhouse gas emissions are contributing to climate change in the United States, as well as worldwide.

<span class="mw-page-title-main">Gas-fired power plant</span> One or more generators which convert Natural gas into electricity

A gas-fired power plant, sometimes referred to as gas-fired power station or natural gas power plant, is a thermal power station that burns natural gas to generate electricity. Gas-fired power plants generate almost a quarter of world electricity and are significant sources of greenhouse gas emissions. However, they can provide seasonal, dispatchable energy generation to compensate for variable renewable energy deficits, where hydropower or interconnectors are not available.

<span class="mw-page-title-main">Methane</span> Hydrocarbon compound (CH₄); main component of natural gas

Methane is a chemical compound with the chemical formula CH4. It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it poses technical challenges due to its gaseous state under normal conditions for temperature and pressure.

Fugitive emissions are leaks and other irregular releases of gases or vapors from a pressurized containment – such as appliances, storage tanks, pipelines, wells, or other pieces of equipment – mostly from industrial activities. In addition to the economic cost of lost commodities, fugitive emissions contribute to local air pollution and may cause further environmental harm. Common industrial gases include refrigerants and natural gas, while less common examples are perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride.

<span class="mw-page-title-main">Aliso Canyon gas leak</span> Massive natural gas leak in southern California

The Aliso Canyon gas leak was a massive methane leak in the Santa Susana Mountains near the neighborhood of Porter Ranch in the city of Los Angeles, California. Discovered on October 23, 2015, gas was escaping from a well within the Aliso Canyon underground storage facility. This second-largest gas storage facility of its kind in the United States belongs to the Southern California Gas Company, a subsidiary of Sempra Energy. On January 6, 2016, Governor Jerry Brown issued a state of emergency. On February 11, the gas company reported that it had the leak under control. On February 18, state officials announced that the leak was permanently plugged.

<span class="mw-page-title-main">Aliso Canyon Oil Field</span> Oil field in Los Angeles County, California

The Aliso Canyon Oil Field is an oil field and natural gas storage facility in the Santa Susana Mountains in Los Angeles County, California, north of the Porter Ranch neighborhood of the City of Los Angeles. Discovered in 1938 and quickly developed afterward, the field peaked as an oil producer in the 1950s, but has remained active since its discovery. One of its depleted oil and gas producing formations, the Sesnon-Frew zone, was converted into a gas storage reservoir in 1973 by the Southern California Gas Company, the gas utility servicing the southern half of California. This reservoir is the second-largest natural gas storage site in the western United States, with a capacity of over 86 billion cubic feet of natural gas. Currently it is one of four gas storage facilities owned by Southern California Gas, the others being the La Goleta Gas Field west of Santa Barbara, Honor Rancho near Newhall, and Playa del Rey.

Increasing methane emissions are a major contributor to the rising concentration of greenhouse gases in Earth's atmosphere, and are responsible for up to one-third of near-term global heating. During 2019, about 60% of methane released globally was from human activities, while natural sources contributed about 40%. Reducing methane emissions by capturing and utilizing the gas can produce simultaneous environmental and economic benefits.

The Canadian province of Alberta faces a number of environmental issues related to natural resource extraction—including oil and gas industry with its oil sands—endangered species, melting glaciers in banff, floods and droughts, wildfires, and global climate change. While the oil and gas industries generates substantial economic wealth, the Athabasca oil sands, which are situated almost entirely in Alberta, are the "fourth most carbon intensive on the planet behind Algeria, Venezuela and Cameroon" according to an August 8, 2018 article in the American Association for the Advancement of Science's journal Science. This article details some of the environmental issues including past ecological disasters in Alberta and describes some of the efforts at the municipal, provincial and federal level to mitigate the risks and impacts.

<span class="mw-page-title-main">Greenhouse gas emissions by Russia</span> Greenhouse gas emissions originating from Russia and efforts to reduce them

Greenhouse gas emissionsbyRussia are mostly from fossil gas, oil and coal. Russia emits 2 or 3 billion tonnes CO2eq of greenhouse gases each year; about 4% of world emissions. Annual carbon dioxide emissions alone are about 12 tons per person, more than double the world average. Cutting greenhouse gas emissions, and therefore air pollution in Russia, would have health benefits greater than the cost. The country is the world's biggest methane emitter, and 4 billion dollars worth of methane was estimated to leak in 2019/20.

<span class="mw-page-title-main">Routine flaring</span> Disposal of unwanted gas during extraction

Routine flaring, also known as production flaring, is a method and current practice of disposing of large unwanted amounts of associated petroleum gas (APG) during crude oil extraction. The gas is first separated from the liquids and solids downstream of the wellhead, then released into a flare stack and combusted into earth's atmosphere. Where performed, the unwanted gas has been deemed unprofitable, and may be referred to as stranded gas, flare gas, or simply as "waste gas". Routine flaring is not to be confused with safety flaring, maintenance flaring, or other flaring practices characterized by shorter durations or smaller volumes of gas disposal.

<span class="mw-page-title-main">Valley Generating Station</span> Natural gas-fired power station in Los Angeles, California

The Valley Generating Station is a natural gas-fired power station located in Sun Valley, Los Angeles, California.

<span class="mw-page-title-main">2022 Nord Stream pipeline sabotage</span> Gas pipe explosions in the Nord Stream pipelines

On 26 September 2022, a series of clandestine bombings and subsequent underwater gas leaks occurred on the Nord Stream 1 and Nord Stream 2 natural gas pipelines. Both pipelines were built to transport natural gas from Russia to Germany through the Baltic Sea, and are majority owned by the Russian majority state-owned gas company, Gazprom. The perpetrators' identities and the motives behind the sabotage remain debated.

References

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  5. 1 2 "How secretive methane leaks are driving climate change". UNEP. 19 July 2022.
  6. "Aliso Canyon Natural Gas Leak, California Air Resources Board". ww2.arb.ca.gov.
  7. Fountain, Henry (14 June 2022). "One Site, 95 Tons of Methane an Hour". The New York Times.
  8. Milman, Oliver (26 February 2016). "LA gas leak: worst in US history spewed as much pollution as 600,000 cars". The Guardian.
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  13. Gramling, Carolyn (22 April 2020). "Permian Basin is leaking twice as much methane as once thought, Science News".
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