The term " thermal energy " is often used ambiguously in physics and engineering. It can denote several different physical concepts, including:
77-476: A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work . The concept was originally applied solely to those materials capable of releasing chemical energy but has since also been applied to other sources of heat energy, such as nuclear energy (via nuclear fission and nuclear fusion ). The heat energy released by reactions of fuels can be converted into mechanical energy via
154-756: A heat engine . Other times, the heat itself is valued for warmth, cooking , or industrial processes, as well as the illumination that accompanies combustion . Fuels are also used in the cells of organisms in a process known as cellular respiration , where organic molecules are oxidized to release usable energy. Hydrocarbons and related organic molecules are by far the most common source of fuel used by humans, but other substances, including radioactive metals, are also utilized. Fuels are contrasted with other substances or devices storing potential energy , such as those that directly release electrical energy (such as batteries and capacitors ) or mechanical energy (such as flywheels , springs, compressed air, or water in
231-400: A nuclear fission reactor ; nuclear fuel can refer to the material or to physical objects (for example fuel bundles composed of fuel rods ) composed of the fuel material, perhaps mixed with structural, neutron moderating , or neutron reflecting materials. When some of these fuels are struck by neutrons, they are in turn capable of emitting neutrons when they break apart. This makes possible
308-474: A price on carbon reflecting its cost for flood, cyclone, hurricane, drought, and related extreme weather expenses. Excluding subsidies, the levelised cost of electricity from new large-scale solar power in India and China has been below existing coal-fired power stations since 2021. A study by Rice University Center for Energy Studies suggested the following steps for countries: Energy efficiency
385-423: A transportation fuel. There are, however, a number of possible alternatives. Among the biofuels the use of bioethanol and biodiesel is already established to some extent in some countries. The use of hydrogen fuel is another alternative under development in various countries, alongside, hydrogen vehicles though hydrogen is actually an energy storage medium, not a primary energy source, and consequently
462-501: A body can change in a process in which chemical potential energy is converted into non-chemical energy. In such a process, the thermodynamic system can change its internal energy by doing work on its surroundings, or by gaining or losing energy as heat. It is not quite lucid to merely say that "the converted chemical potential energy has simply become internal energy". It is, however, sometimes convenient to say that "the chemical potential energy has been converted into thermal energy". This
539-403: A mixture of propane and butane , both of which are easily compressible gases under standard atmospheric conditions. It offers many of the advantages of compressed natural gas (CNG) but is denser than air, does not burn as cleanly, and is much more easily compressed. Commonly used for cooking and space heating, LP gas and compressed propane are seeing increased use in motorized vehicles. Propane
616-418: A net increase in global emissions. In developed countries, energy costs are low and heavily subsidised , whereas in developing countries, the poor pay high costs for low-quality services. In 2009, studies have put forward a plan to power 100% of the world's energy with wind , hydroelectric , and solar power by the year 2030. It recommends transfer of energy subsidies from fossil fuel to renewable, and
693-435: A pivotal part of our contemporary society, with most countries in the world burning fossil fuels in order to produce power, but are falling out of favor due to the global warming and related effects that are caused by burning them. Currently the trend has been towards renewable fuels, such as biofuels like alcohols. Chemical fuels are substances that release energy by reacting with substances around them, most notably by
770-555: A quarter of the world's primary energy and about 40% of the greenhouse gas emissions from fossil fuels. Phasing out coal has short-term health and environmental benefits which exceed the costs, and without it the 2 °C target in the Paris Agreement cannot be met; but some countries still favour coal, and there is much disagreement about how quickly it should be phased out. As of 2018 , 30 countries and many sub-national governments and businesses had become members of
847-439: A report highlighting the need for an active phase-out of coal-fired generation across Europe. Their analysis derived from a database of 280 coal plants and included emissions data from official EU registries. A 2016 report by Oil Change International, concludes that the carbon emissions embedded in the coal, oil, and gas in currently working mines and fields, assuming that these run to the end of their working lifetimes, will take
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#1732783374335924-424: A reservoir). The first known use of fuel was the combustion of firewood by Homo erectus nearly two million years ago. Throughout most of human history only fuels derived from plants or animal fat were used by humans. Charcoal , a wood derivative, has been used since at least 6,000 BCE for melting metals. It was only supplanted by coke , derived from coal, as European forests started to become depleted around
1001-915: A self-sustaining chain reaction that releases energy at a controlled rate in a nuclear reactor , or at a very rapid uncontrolled rate in a nuclear weapon . The most common fissile nuclear fuels are uranium-235 (U) and plutonium-239 (Pu). The actions of mining, refining, purifying, using, and ultimately disposing of nuclear fuel together make up the nuclear fuel cycle . Not all types of nuclear fuels create energy from nuclear fission. Plutonium-238 and some other elements are used to produce small amounts of nuclear energy by radioactive decay in radioisotope thermoelectric generators and other types of atomic batteries . In contrast to fission, some light nuclides such as tritium (H) can be used as fuel for nuclear fusion . This involves two or more nuclei combining into larger nuclei. Fuels that produce energy by this method are currently not utilized by humans, but they are
1078-572: A significant proportion of the population lacks access to electricity. The report concludes that, on the whole, building coal-fired power plants does little to help the poor and may make them poorer. Moreover, wind and solar generation are beginning to challenge coal on cost. A 2018 study in Nature Energy , suggests that 10 countries in Europe could completely phase out coal-fired electricity generation with their current infrastructure, whilst
1155-415: A society can be maintained, and may affect the population capacity of the planet. The most effective method of mitigating peak oil is to use renewable or alternative energy sources in place of petroleum. Because most oil is consumed for transportation most mitigation discussions revolve around transportation issues. Due to its high energy density and ease of handling , oil has a unique role as
1232-465: A source of energy. The International Energy Agency (IEA) predicts that fossil fuel prices will decline, with oil stabilizing around $ 75 to $ 80 per barrel as electric vehicle adoption surges and renewable energy expands. Additionally, the IEA anticipates a notable increase in liquefied natural gas capacity, enhancing Europe’s energy diversification. The amount of energy from different types of fuel depends on
1309-513: A timetable to stop burning fossil gas has not yet been agreed. Current efforts in fossil fuel phase-out involve replacing fossil fuels with sustainable energy sources in sectors such as transport and heating. Alternatives to fossil fuels include electrification , green hydrogen and biofuel . Phase-out policies include both demand-side and supply-side measures. Whereas demand-side approaches seek to reduce fossil-fuel consumption, supply-side initiatives seek to constrain production to accelerate
1386-464: A way to make heavy oil fractions usable as liquid fuels. Many liquid fuels play a primary role in transportation and the economy. Some common properties of liquid fuels are that they are easy to transport and can be handled easily. They are also relatively easy to use for all engineering applications and in home use. Fuels like kerosene are rationed in some countries, for example in government-subsidized shops in India for home use. Conventional diesel
1463-471: Is energy in transfer to or from a thermodynamic system by mechanisms other than thermodynamic work or transfer of matter, such as conduction, radiation, and friction. Heat refers to a quantity in transfer between systems, not to a property of any one system, or "contained" within it; on the other hand, internal energy and enthalpy are properties of a single system. Heat and work depend on the way in which an energy transfer occurs. In contrast, internal energy
1540-471: Is a property of the state of a system and can thus be understood without knowing how the energy got there. In addition to the microscopic kinetic energies of its molecules, the internal energy of a body includes chemical energy belonging to distinct molecules, and the global joint potential energy involved in the interactions between molecules and suchlike. Thermal energy may be viewed as contributing to internal energy or to enthalpy. The internal energy of
1617-406: Is also a major source of carbon dioxide emissions. Leaks are also a large source of atmospheric methane . In some countries natural gas is being used as a temporary "bridge fuel" to replace coal, in turn to be replaced by renewable sources or a hydrogen economy . However this "bridge fuel" may significantly extend the use of fossil fuel or strand assets , such as gas-fired power plants built in
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#17327833743351694-554: Is complementary to the use of sustainable energy sources, when phasing-out fossil fuels. Many countries and cities have introduced bans on the sales of new internal combustion engine (ICE) vehicles, requiring all new cars to be electric vehicles or otherwise powered by clean, non-emitting sources. Such bans include the United Kingdom by 2035 and Norway by 2025. Many transit authorities are working to purchase only electric buses while also restricting use of ICE vehicles in
1771-424: Is decreasing as heating technology and the availability of good quality fuel improves. In some areas, smokeless coal is often the only solid fuel used. In Ireland, peat briquettes are used as smokeless fuel. They are also used to start a coal fire. Liquid fuels are combustible or energy-generating molecules that can be harnessed to create mechanical energy , usually producing kinetic energy . They must also take
1848-475: Is easily mechanized, and thus less laborious. As there is a general movement towards a low carbon economy, the use of liquid fuels such as hydrocarbons is coming under scrutiny. Thermal energy Mark Zemansky (1970) has argued that the term “thermal energy” is best avoided due to its ambiguity. He suggests using more precise terms like “internal energy” and “heat” to avoid confusion. The term is, however, used in some textbooks. In thermodynamics , heat
1925-459: Is equivalent to 44 ⁄ 12 (this is the ratio of the molecular/atomic weights) or 3.7 tonnes of CO 2 . Carbon dioxide is one of the greenhouse gases that enhances radiative forcing and contributes to global warming , causing the average surface temperature of the Earth to rise in response, which the vast majority of climate scientists agree will cause major adverse effects . Fuels are
2002-401: Is expressed in ordinary traditional language by talking of 'heat of reaction' . In a body of material, especially in condensed matter, such as a liquid or a solid, in which the constituent particles, such as molecules or ions, interact strongly with one another, the energies of such interactions contribute strongly to the internal energy of the body. Still, they are not immediately apparent in
2079-415: Is part of the ongoing renewable energy transition , but is being hindered by fossil fuel subsidies . Many countries are shutting down coal-fired power stations , and fossil-fuelled electricity generation is thought to have peaked. But electricity generation is not moving off coal fast enough to meet climate goals. Many countries have set dates to stop selling petrol and diesel cars and trucks , but
2156-399: Is similar to gasoline in that it is a mixture of aliphatic hydrocarbons extracted from petroleum . Kerosene is used in kerosene lamps and as a fuel for cooking, heating, and small engines. Natural gas , composed chiefly of methane , can only exist as a liquid at very low temperatures (regardless of pressure), which limits its direct use as a liquid fuel in most applications. LP gas is
2233-551: Is supported by the European Bank for Reconstruction and Development . In 2019 the UN Secretary General said that countries should stop building new coal power plants from 2020 or face 'total disaster'. In 2020, although China built some plants, globally more coal power was retired than built: the UN Secretary General has said that OECD countries should stop generating electricity from coal by 2030 and
2310-409: Is the third most commonly used motor fuel globally. Fuel gas is any one of a number of fuels that are gaseous under ordinary conditions. Many fuel gases are composed of hydrocarbons (such as methane or propane ), hydrogen , carbon monoxide , or mixtures thereof. Such gases are sources of potential heat energy or light energy that can be readily transmitted and distributed through pipes from
2387-411: Is this kinetic motion that is the source and the effect of the transfer of heat across a system's boundary. For a gas that does not have particle interactions except for instantaneous collisions, the term "thermal energy" is effectively synonymous with " internal energy ". In many statistical physics texts, "thermal energy" refers to k T {\displaystyle kT} , the product of
Fuel - Misplaced Pages Continue
2464-1006: Is widespread public debate about how carbon neutral these fuels are. Fossil fuels are hydrocarbons , primarily coal and petroleum ( liquid petroleum or natural gas ), formed from the fossilized remains of ancient plants and animals by exposure to high heat and pressure in the absence of oxygen in the Earth's crust over hundreds of millions of years. Commonly, the term fossil fuel also includes hydrocarbon-containing natural resources that are not derived entirely from biological sources, such as tar sands . These latter sources are properly known as mineral fuels . Fossil fuels contain high percentages of carbon and include coal, petroleum, and natural gas. They range from volatile materials with low carbon: hydrogen ratios like methane , to liquid petroleum to nonvolatile materials composed of almost pure carbon, like anthracite coal. Methane can be found in hydrocarbon fields, alone, associated with oil, or in
2541-592: The Boltzmann constant and the absolute temperature , also written as k B T {\displaystyle k_{\text{B}}T} . When there is no accompanying flow of matter, the term "thermal energy" is also applied to the energy carried by a heat flow. Fossil fuel phase-out Fossil fuel phase-out is the gradual reduction of the use and production of fossil fuels to zero, to reduce deaths and illness from air pollution , limit climate change , and strengthen energy independence . It
2618-737: The International Monetary Fund estimated that fossil fuel subsidies were $ 5.2 trillion in 2017, which was 6.4% of global GDP. Some fossil fuel companies lobby governments. Phasing out fossil fuel subsidies is crucial to address the climate crisis. It must however be done carefully to avoid protests and making poor people poorer. In most cases, however, low fossil fuel prices benefit wealthier households more than poorer households. So to help poor and vulnerable people, other measures than fossil fuel subsidies would be more targeted. This could in turn increase public support for subsidy reform. Economic theory indicates that
2695-516: The Powering Past Coal Alliance , each making a declaration to advance the transition away from unabated (abated means with carbon capture and storage (CCS), but almost all power plants are unabated as CCS is so expensive) coal power generation. As of 2019 , however, the countries which use the most coal have not joined, and some countries continue to build and finance new coal-fired power stations. A just transition from coal
2772-579: The circular economy and biobased economy (e.g. bioplastics ) are being developed to reduce plastic pollution , the fossil fuel phase out specifically aims to end the burning of fossil fuels and the consequent production of greenhouse gases. Therefore, attempts to reduce the use of oil and gas in the plastic industry do not form part of fossil fuel phase-out or reduction plans. To meet the Paris Agreement target of keeping global warming to well below 2 °C (3.6 °F), coal use needs to halve from 2020 to 2030. However, as of 2017 , coal supplied over
2849-441: The stoichiometric ratio , the chemically correct air and fuel ratio to ensure complete combustion of fuel, and its specific energy , the energy per unit mass. 1 MJ ≈ 0.28 kWh ≈ 0.37 HPh . (The fuel-air ratio (FAR) is the reciprocal of the air-fuel ratio (AFR).) λ is the air-fuel equivalence ratio, and λ =1 means that it is assumed that the fuel and the oxidising agent (oxygen in air) are present in exactly
2926-466: The 18th century. Charcoal briquettes are now commonly used as a fuel for barbecue cooking. Crude oil was distilled by Persian chemists , with clear descriptions given in Arabic handbooks such as those of Muhammad ibn Zakarīya Rāzi . He described the process of distilling crude oil/petroleum into kerosene , as well as other hydrocarbon compounds, in his Kitab al-Asrar ( Book of Secrets ). Kerosene
3003-480: The 1970s have had no effect on curbing the oil consumption until 2007. In the United States, oil consumption declines in reaction to high prices. Key questions for mitigation are the viability of methods, the roles of government and private sector and how early these solutions are implemented. The responses to such questions and steps taken towards mitigation may determine whether or not the lifestyle of
3080-502: The 2020s, as the average plant life is 35 years. Although natural gas assets are likely to be stranded later than oil and coal assets, perhaps not until 2050, some investors are concerned by reputational risk . Fossil gas phase-out has progressed in some regions, for example with increasing use of hydrogen by the European Network of Transmission System Operators for Gas (ENTSOG) and changes to building regulations to reduce
3157-467: The Paris goal of substantially less than 2 °C. The actual effects of removing fossil fuel subsidies would depend heavily on the type of subsidy removed and the availability and economics of other energy sources. There is also the issue of carbon leakage , where removal of a subsidy to an energy-intensive industry could lead to a shift in production to another country with less regulation, and thus to
Fuel - Misplaced Pages Continue
3234-716: The United States and Russia could phase out at least 30%. In 2020, the Fossil Fuel Cuts Database provided the first global account of supply-side initiatives to constrain fossil fuel production. The latest update of the database recorded 1967 initiatives implemented between 1988 and October 2021 in 110 countries across seven major types of supply-side approaches (Divestment, n=1201; Blockades, n= 374; Litigation, n= 192; Moratoria and Bans, n= 146; Production subsidies removal, n=31; Carbon tax on fossil fuel production, n=16; Emissions Trading Schemes, n= 7). The GeGaLo index of geopolitical gains and losses assesses how
3311-561: The absorption of a proton or neutron . In most stars the fuel is provided by hydrogen, which can combine to form helium through the proton-proton chain reaction or by the CNO cycle . When the hydrogen fuel is exhausted, nuclear fusion can continue with progressively heavier elements, although the net energy released is lower because of the smaller difference in nuclear binding energy. Once iron-56 or nickel-56 nuclei are produced, no further energy can be obtained by nuclear fusion as these have
3388-513: The area around modern Baku , Azerbaijan . These fields were described by the Arab geographer Abu al-Hasan 'Alī al-Mas'ūdī in the 10th century, and by Marco Polo in the 13th century, who described the output of those wells as hundreds of shiploads. With the development of the steam engine in the United Kingdom in 1769, coal came into more common use, the combustion of which releases chemical energy that can be used to turn water into steam. Coal
3465-465: The city center to limit air pollution. Many US states have a zero-emissions vehicle mandate, incrementally requiring a certain per cent of cars sold to be electric. The German term Verkehrswende ("traffic transition" analogous to Energiewende , energetic transition) calls for a shift from combustion powered road transport to bicycles, walking and rail transport and the replacement of remaining road vehicles with electric traction. Biofuels , in
3542-600: The correct proportions so that they are both fully consumed in the reaction. Nuclear fuel is any material that is consumed to derive nuclear energy . In theory, a wide variety of substances could be a nuclear fuel, as they can be made to release nuclear energy under the right conditions. However, the materials commonly referred to as nuclear fuels are those that will produce energy without being placed under extreme duress. Nuclear fuel can be "burned" by nuclear fission (splitting nuclei apart) or fusion (combining nuclei together) to derive nuclear energy. "Nuclear fuel" can refer to
3619-591: The earliest fuel employed by humans is wood. Evidence shows controlled fire was used up to 1.5 million years ago at Swartkrans , South Africa. It is unknown which hominid species first used fire, as both Australopithecus and an early species of Homo were present at the sites. As a fuel, wood has remained in use up until the present day, although it has been superseded for many purposes by other sources. Wood has an energy density of 10–20 MJ / kg . Recently biofuels have been developed for use in automotive transport (for example bioethanol and biodiesel ), but there
3696-536: The first time on 1 February 2008. At that stage Boeing also had plans to use alternative fuel on the 747 . Because some biofuels such as ethanol contains less energy, more "tankstops" might be necessary for such planes. The US Air Force is currently in the process of certifying its entire fleet to run on a 50/50 blend of synthetic fuel derived from the Fischer–Tropsch process and JP-8 jet fuel. In 2015, Greenpeace and Climate Action Network Europe released
3773-522: The form of liquid fuels derived from plant materials, are entering the market. However, many of the biofuels that are currently being supplied have been criticised for their adverse impacts on the natural environment , food security , and land use . The mitigation of peak oil is the attempt to delay the date and minimize the social and economic effects of peak oil by reducing the consumption of and reliance on petroleum . By reducing petroleum consumption, mitigation efforts seek to favorably change
3850-645: The form of methane clathrates . Fossil fuels formed from the fossilized remains of dead plants by exposure to heat and pressure in the Earth's crust over millions of years. This biogenic theory was first introduced by German scholar Georg Agricola in 1556 and later by Mikhail Lomonosov in the 18th century. It was estimated by the Energy Information Administration that in 2007 primary sources of energy consisted of petroleum 36.0%, coal 27.4%, natural gas 23.0%, amounting to an 86.4% share for fossil fuels in primary energy consumption in
3927-420: The fuel itself, or to physical objects (for example bundles composed of fuel rods ) composed of the fuel material, mixed with structural, neutron moderating , or neutron-reflecting materials. Nuclear fuel has the highest energy density of all practical fuel sources. The most common type of nuclear fuel used by humans is heavy fissile elements that can be made to undergo nuclear fission chain reactions in
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#17327833743354004-431: The generation of renewable energy is therefore under way to help meet increased energy needs. The burning of fossil fuels produces around 21.3 billion tonnes (21.3 gigatonnes ) of carbon dioxide (CO 2 ) per year, but it is estimated that natural processes can only absorb about half of that amount, so there is a net increase of 10.65 billion tonnes of atmospheric carbon dioxide per year (one tonne of atmospheric carbon
4081-487: The goals of the Paris Agreement, the phase-out of fossil fuels would need to "move four times faster". To achieve the goal of limiting global warming to 1.5 °C above pre-industrial levels , the vast majority of fossil fuel reserves owned by countries and companies as of 2021 would have to remain in the ground. The renewable energy transition can create jobs through the construction of new power plants and
4158-846: The government announced an ambitious plan to expand nuclear power which by the end of the 1980s had shifted France's electricity sector almost entirely away from coal gas and oil and towards nuclear power. The trend towards encouraging cycling in the Netherlands and Denmark also coincided with the 1973 oil crisis and aimed in part at reducing the need for oil imports in the transportation sector. Significant fossil fuel subsidies are present in many countries. Fossil fuel subsidies in 2019 for consumption totalled US$ 320 billion spread over many countries. As of 2019 governments subsidise fossil fuels by about $ 500 billion per year: however using an unconventional definition of subsidy which includes failing to price greenhouse gas emissions,
4235-511: The health benefits of phasing out fossil fuels measured in money (estimated by economists using the value of life for each country) are substantially more than the cost of achieving the 2 °C goal of the Paris Agreement. Fossil-fuel phase-out is the largest part of limiting global warming as fossil fuels account for over 70% of greenhouse gas emissions . In 2020, the International Energy Agency said that to meet
4312-454: The highest nuclear binding energies. Any nucleii heavier than Fe and Ni would thus absorb energy instead of giving it off when fused. Therefore, fusion stops and the star dies. In attempts by humans, fusion is only carried out with hydrogen (H (deuterium) or H (tritium)) to form helium-4 as this reaction gives out the most net energy. Electric confinement ( ITER ), inertial confinement (heating by laser) and heating by strong electric currents are
4389-436: The kinetic energies of molecules, as manifest in temperature. Such energies of interaction may be thought of as contributions to the global internal microscopic potential energies of the body. In a statistical mechanical account of an ideal gas , in which the molecules move independently between instantaneous collisions, the internal energy is just the sum total of the gas's independent particles' kinetic energies , and it
4466-468: The main source of fuel for stars . Fusion fuels are light elements such as hydrogen whose nucleii will combine easily. Energy is required to start fusion by raising the temperature so high that nuclei can collide together with enough energy that they stick together before repelling due to electric charge. This process is called fusion and it can give out energy. In stars that undergo nuclear fusion, fuel consists of atomic nuclei that can release energy by
4543-435: The manufacturing of the equipment that they need, as was seen in the case of Germany and the wind power industry. Countries which lack fossil fuel deposits, particularly coal but also petroleum and natural gas, often cite energy independence in their shift away from fossil fuels. In Switzerland the decision to electrify virtually the entire railway network was taken in light of the two world wars (during which Switzerland
4620-496: The optimal policy would be to remove coal mining and burning subsidies and replace them with optimal taxes. Global studies indicate that even without introducing taxes, subsidy and trade barrier removal at a sectoral level would improve efficiency and reduce environmental damage. Removal of these subsidies would substantially reduce greenhouse gas emissions and create jobs in renewable energy. The IMF estimated in 2023 that removal of fossil fuel subsidies would limit global heating to
4697-541: The pace of energy transition and reduction in emissions. It has been suggested that laws should be passed to make fossil fuel companies bury the same amount of carbon as they emit. The International Energy Agency estimates that in order to achieve carbon neutrality by the middle of the century, global investments in renewable energy must triple by 2030, reaching over $ 4 trillion annually. While crude oil and natural gas are also being phased out in chemical processes (e.g. production of new building blocks for plastics) as
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#17327833743354774-452: The point of origin directly to the place of consumption. Fuel gas is contrasted with liquid fuels and from solid fuels, though some fuel gases are liquefied for storage or transport. While their gaseous nature can be advantageous, avoiding the difficulty of transporting solid fuel and the dangers of spillage inherent in liquid fuels, it can also be dangerous. It is possible for a fuel gas to be undetected and collect in certain areas, leading to
4851-509: The popular methods. Most transportation fuels are liquids, because vehicles usually require high energy density . This occurs naturally in liquids and solids. High energy density can also be provided by an internal combustion engine . These engines require clean-burning fuels. The fuels that are easiest to burn cleanly are typically liquids and gases. Thus, liquids meet the requirements of being both energy-dense and clean-burning. In addition, liquids (and gases) can be pumped, which means handling
4928-779: The process of combustion . Chemical fuels are divided in two ways. First, by their physical properties, as a solid, liquid or gas. Secondly, on the basis of their occurrence: primary (natural fuel) and secondary (artificial fuel) . Thus, a general classification of chemical fuels is: Solid fuel refers to various types of solid material that are used as fuel to produce energy and provide heating , usually released through combustion. Solid fuels include wood , charcoal , peat , coal , hexamine fuel tablets , and pellets made from wood (see wood pellets ), corn , wheat , rye and other grains . Solid-fuel rocket technology also uses solid fuel (see solid propellants ). Solid fuels have been used by humanity for many years to create fire . Coal
5005-433: The rest of the world by 2040. Crude oil is refined into fuel oil , diesel and petrol. The refined products are primarily for transportation by conventional cars, trucks, trains, planes and ships. Popular alternatives are human-powered transport , public transport, electric vehicles , and biofuels . Natural gas is widely used to generate electricity and has an emission intensity of about 500 g/kWh. Heating
5082-575: The risk of a gas explosion . For this reason, odorizers are added to most fuel gases so that they may be detected by a distinct smell. The most common type of fuel gas in current use is natural gas . Biofuel can be broadly defined as solid, liquid, or gas fuel consisting of, or derived from biomass . Biomass can also be used directly for heating or power—known as biomass fuel . Biofuel can be produced from any carbon source that can be replenished rapidly e.g. plants. Many different plants and plant-derived materials are used for biofuel manufacture. Perhaps
5159-441: The shape of Hubbert curve. For the most part, mitigation involves fuel conservation , and the use of alternative and renewable energy sources. The development of unconventional oil resources can extend the supply of petroleum, but does not reduce consumption. Historically, world oil consumption data show that mitigation efforts during the 1973 and 1979 oil shocks lowered oil consumption, while general recessions since
5236-551: The shape of the Hubbert curve , which is the graph of real oil production over time predicted by Hubbert peak theory . The peak of this curve is known as peak oil, and by changing the shape of the curve, the timing of the peak in oil production is affected. An analysis by the author of the Hirsch report showed that while the shape of the oil production curve can be affected by mitigation efforts, mitigation efforts are also affected by
5313-499: The shape of their container; the fumes of liquid fuels are flammable, not the fluids. Most liquid fuels in widespread use are derived from the fossilized remains of dead plants and animals by exposure to heat and pressure inside the Earth's crust. However, there are several types, such as hydrogen fuel (for automotive uses), ethanol , jet fuel and bio-diesel , which are all categorized as liquid fuels. Emulsified fuels of oil in water, such as orimulsion , have been developed as
5390-461: The use of a non-petroleum source would be required to extract the hydrogen for use. Though hydrogen is currently outperformed in terms of cost and efficiency by battery powered vehicles , there are applications where it would come in useful. Short haul ferries and very cold climates are two examples. Hydrogen fuel cells are about a third as efficient as batteries and double the efficiency of petrol vehicles. An Airbus A380 flew on alternative fuel for
5467-511: The use of gas heating. Commonly cited reasons for phasing out fossil fuels are to: Most of the millions of premature deaths from air pollution are due to fossil fuels. Pollution may be indoors e.g. from heating and cooking, or outdoors from vehicle exhaust . One estimate is that the proportion is 65% and the number 3.5 million each year. According to Professor Sir Andy Haines at the London School of Hygiene and Tropical Medicine
5544-512: The world to just beyond the 2 °C limit contained in the 2015 Paris Agreement and even further from the 1.5 °C goal. The report observes that "one of the most powerful climate policy levers is also the simplest: stop digging for more fossil fuels". In 2016, the Overseas Development Institute (ODI) and 11 other NGOs released a report on the impact of building new coal-fired power plants in countries where
5621-548: The world. Non-fossil sources in 2006 included hydroelectric 6.3%, nuclear 8.5%, and others ( geothermal , solar , tidal , wind , wood , waste ) amounting to 0.9%. World energy consumption was growing about 2.3% per year. Fossil fuels are non-renewable resources because they take millions of years to form, and reserves are being depleted much faster than new ones are being made. So we must conserve these fuels and use them judiciously. The production and use of fossil fuels raise environmental concerns. A global movement toward
5698-437: Was also produced during the same period from oil shale and bitumen by heating the rock to extract the oil, which was then distilled. Rāzi also gave the first description of a kerosene lamp using crude mineral oil, referring to it as the "naffatah". The streets of Baghdad were paved with tar , derived from petroleum that became accessible from natural fields in the region. In the 9th century, oil fields were exploited in
5775-604: Was later used to drive ships and locomotives . By the 19th century, gas extracted from coal was being used for street lighting in London. In the 20th and 21st centuries, the primary use of coal is to generate electricity , providing 40% of the world's electrical power supply in 2005. Fossil fuels were rapidly adopted during the Industrial Revolution , because they were more concentrated and flexible than traditional energy sources, such as water power. They have become
5852-406: Was neutral) when coal imports became increasingly difficult. As Switzerland has ample hydropower resources, electric trains (as opposed to those driven by steam locomotives or diesel) could be run on domestic energy resources, reducing the need for coal imports. The 1973 oil crisis also led to a shift in energy policy in many places to become (more) independent of fossil fuel imports. In France
5929-409: Was the fuel source which enabled the Industrial Revolution , from firing furnaces , to running steam engines . Wood was also extensively used to run steam locomotives . Both peat and coal are still used in electricity generation today. The use of some solid fuels (e.g. coal) is restricted or prohibited in some urban areas, due to unsafe levels of toxic emissions. The use of other solid fuels as wood
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