Natural gas

Natural gas is a gas consisting primarily of methane, typically with 0–20% higher hydrocarbons[1] (primarily ethane). It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock forfertilizers.Sony VAIO VGN-SR41M/P Battery

Most natural gas is created by two mechanisms: biogenic and thermogenic. Biogenic gas is created by methanogenic organisms in marshes, bogs, landfills, and shallow sediments. Deeper in the earth, at greater temperature and pressure, thermogenic gas is created from buried organic material.Sony VAIO VGN-SR41M/S Battery

Before natural gas can be used as a fuel, it must undergo processing to remove almost all materials other than methane. The by-products of that processing include ethane, propane,butanes, pentanes, and higher molecular weight hydrocarbons, elemental sulfur, carbon dioxide,water vapor, and sometimes helium and nitrogen.Sony VAIO VGN-SR49VN/H Battery

Natural gas is often informally referred to as simply gas, especially when compared to other energy sources such as oil or coal.

Natural gas

In the 19th century, natural gas was usually obtained as a byproduct of producing oil, since the small, Sony VAIO VGN-SR51B/P Battery

light gas carbon chains came out of solution as the extracted fluids underwent pressure reduction from the reservoir to the surface, similar to uncapping a bottle of soda pop where the carbon dioxide effervesces. Unwanted natural gas was a disposal problem in the active oil fields. Sony VAIO VGN-SR51B/S Battery

If there was not a market for natural gas near the wellhead it was virtually valueless since it had to be piped to the end user. In the 19th century and early 20th century, such unwanted gas usually was burned off in the oil fields. Today, unwanted gas (or 'stranded' gas without a market)Sony VAIO VGN-SR51MF Battery

associated with oil extraction often is returned to the reservoir with 'injection' wells while awaiting a possible future market or to repressurize the formation, which can enhance extraction rates from other wells. In regions with a high natural gas demand (such as the US), pipelines are constructed when economically feasible to move the gas from the wellsite to the end consumer.Sony VAIO VGN-SR51MF/P Battery

Another solution is to export the natural gas as a liquid. Gas-to-liquids (GTL) is a developing technology that converts stranded natural gas into synthetic gasoline, diesel or jet fuel through the Fischer-Tropsch process developed in WWII Germany. Such fuel can be transported to users through conventional pipelines and tankers. Sony VAIO VGN-SR51MF/S Battery

Proponents claim GTL burns cleaner than comparable petroleum fuels. Most major international oil companies are in an advanced stage of GTL production, with a world-scale (140,000 barrels (22,000 m3) a day) GTL plant in Qatar scheduled to be in production before 2010.Sony VAIO VGN-SR51MF/W Battery

Natural gas can be "associated" (found in oil fields) or "non-associated" (isolated in natural gas fields), and is also found in coal beds (as coalbed methane). It sometimes contains significant amounts of ethane, propane, butane, and pentane—heavier hydrocarbons removed for commercial use prior to the methane being sold as a consumer fuel or chemical plant feedstock.Sony VAIO VGN-SR51MR Battery

Non-hydrocarbons such ascarbon dioxide, nitrogen, helium (rarely), and hydrogen sulfide must be removed also before the natural gas can be transported.

Natural gas is commercially extracted from oil fields and natural gas fields. Gas extracted from oil wells is called casinghead gas or associated gas. Sony VAIO VGN-SR59VG Battery

The natural gas industry is extracting gas from increasingly more challenging resource types: sour gas, tight gas, shale gas, and coalbed methane.

The world's largest proven gas reserves are located in Russia, with 4.757×1013 m³ (1.68×1015 cubic feet). Sony VAIO VGN-SR59VG/H Battery

With the Gazprom company, Russia is frequently the world's largest natural gas extractor. Major proven resources (in billion cubic meters) are world 175,400 (2006), Russia 47,570 (2006), Iran 26,370 (2006), Qatar 25,790 (2007), Saudi Arabia 6,568 (2006) and United Arab Emirates 5,823 (2006).Sony VAIO VGN-SR70B/S Battery

It is estimated that there are about 900 trillion cubic meters of "unconventional" gas such as shale gas, of which 180 trillion may be recoverable.[4]In turn, many studies from MIT, Black & Veatch and the DOE -- see natural gas will account for a larger portion of electricity generation and heat in the future. Sony VAIO VGN-SR72B/P Battery

The world's largest gas field is Qatar's offshore North Field, estimated to have 25 trillion cubic meters[6] (9.0×1014cubic feet) of gas in place—enough to last more than 420 years at optimum extraction levels. The second largest natural gas field is the South Pars Gas Field in Iranian waters in the Persian Gulf. Sony VAIO VGN-SR72B/S Battery

Located next to Qatar's North Field, it has an estimated reserve of 8 to 14 trillion cubic meters[7] (2.8×1014 to 5.0×1014 cubic feet) of gas.

Because natural gas is not a pure product, as the reservoir pressure drops when non-associated gas is extracted from a field under supercritical(pressure/temperature) conditions, Sony VAIO VGN-SR73JB/S Battery

the higher molecular weight components may partially condense upon isothermic depressurizing—an effect called retrograde condensation. The liquid thus formed may get trapped as the pores of the gas reservoir get deposited. Sony VAIO VGN-SR74FB/S Battery

One method to deal with this problem is to re-inject dried gas free of condensate to maintain the underground pressure and to allow re-evaporation and extraction of condensates. More frequently, the liquid condenses at the surface, and one of the tasks of the gas plant to collect this condensate. Sony VAIO VGN-SR90FS Battery

The resulting liquid is called natural gas liquid (NGL) and has commercial value.

Town gas

Town gas is a synthetically produced mixture of methane and other gases, mainly the highly toxic carbon monoxide, that can be used in a similar way to natural gas and can be produced by treating coal chemically. Sony VAIO VGN-SR90NS Battery

This is a historical technology, still used as 'best solution' in some local circumstances, although coal gasification is not usually economic at current gas prices. However, depending upon infrastructure considerations, it remains a future possibility.

Most town "gashouses" located in the eastern US in the late 19th and early 20th centuries were simple by-product coke ovens which heated bituminous coal in air-tight chambers. Sony VAIO VGN-SR90S Battery

The gas driven off from the coal was collected and distributed through networks of pipes to residences and other buildings where it was used for cooking and lighting. (Gas heating did not come into widespread use until the last half of the 20th century.) Sony VAIO VGN-SR90US Battery

The coal tar (or asphalt) that collected in the bottoms of the gashouse ovens was often used for roofing and other water-proofing purposes, and when mixed with sand and gravel was used for paving streets.

Biogas

When methane-rich gases are produced by the anaerobic decay of non-fossil organic matter (biomass), these are referred to as biogas (or natural biogas). Sony VAIO VGN-SR91NS Battery

Sources of biogas include swamps, marshes, and landfills (see landfill gas), as well as sewage sludge and manure[8] by way of anaerobic digesters, in addition to enteric fermentation particularly in cattle.

Methanogenic archaea are responsible for all biological sources of methane, some in symbiotic relationships with other life forms, including termites, ruminants, and cultivated crops. Sony VAIO VGN-SR91PS Battery

Methane released directly into the atmosphere would be considered a pollutant. However, methane in the atmosphere is oxidized, producing carbon dioxide and water. Methane in the atmosphere has a half life of seven years, meaning that if a tonne of methane were emitted today, 500 kilograms would have broken down to carbon dioxide and water after seven years.Sony VAIO VGN-SR91S Battery

Other sources of methane, the principal component of natural gas, include landfill gas, biogas and methane hydrate. Biogas, and especially landfill gas, are already used in some areas, but their use could be greatly expanded. Landfill gas is a type of biogas, but biogas usually refers to gas produced from organic material that has not been mixed with other waste.Sony VAIO VGN-SR91US Battery

Landfill gas is created from the decomposition of waste in landfills. If the gas is not removed, the pressure may get so high that it works its way to the surface, causing damage to the landfill structure, unpleasant odor, vegetation die-off and an explosion hazard.Sony VAIO VGN-SR92NS Battery

The gas can be vented to the atmosphere, flared or burned to produce electricity or heat. Experimental systems were being proposed for use in parts Hertfordshire, UK andLyon in France.

Once water vapor is removed, about half of landfill gas is methane. Almost all of the rest is carbon dioxide, but there are also small amounts of nitrogen, oxygen and hydrogen. Sony VAIO VGN-SR92PS Battery

There are usually trace amounts of hydrogen sulfide and siloxanes, but their concentration varies widely. Landfill gas cannot be distributed through utility natural gas pipelines unless it is cleaned up to less than 3% CO2, and a few parts per million H2S, because CO2 and H2S corrode the pipelines.Sony VAIO VGN-SR92S Battery

It is usually more economical to combust the gas on site or within a short distance of the landfill using a dedicated pipeline. Water vapor is often removed, even if the gas is combusted on site. If low temperatures condense water out of the gas, siloxanes can be lowered as well because they tend to condense out with the water vapor.Sony VAIO VGN-SR92US Battery

Other non-methane components may also be removed in order to meet emission standards, to prevent fouling of the equipment or for environmental considerations. Co-firing landfill gas with natural gas improves combustion, which lowers emissions.

Gas generated in sewage treatment plants is commonly used to generate electricity. Sony VAIO VGN-SR93DS Battery

For example, the Hyperion sewage plant in Los Angeles burns 8 million cubic feet (230,000 m3) of gas per day to generate powerNew York City utilizes gas to run equipment in the sewage plants, to generate electricity, and in boilers.[11]Using sewage gas to make electricity is not limited to large cities. Sony VAIO VGN-SR93JS Battery

The city of Bakersfield, California uses cogeneration at its sewer plants.[12] California has 242 sewage wastewater treatment plants, 74 of which have installed anaerobic digesters. The total biopower generation from the 74 plants is about 66 MW.

Biogas is usually produced using agricultural waste materials, such as otherwise unusable parts of plants and manure. Sony VAIO VGN-SR93PS Battery

Biogas can also be produced by separatingorganic materials from waste that otherwise goes to landfills. Such method is more efficient than just capturing the landfill gas it produces. Using materials that would otherwise generate no income, or even cost money to get rid of, improves the profitability and energy balance of biogas production.Sony VAIO VGN-SR93YS Battery

Anaerobic lagoons produce biogas from manure, while biogas reactors can be used for manure or plant parts. Like landfill gas, biogas is mostly methane and carbon dioxide, with small amounts of nitrogen, oxygen and hydrogen. However, with the exception of pesticides, there are usually lower levels of contaminants.Sony VAIO VGN-SR94FS Battery

Crystallized natural gas – hydrates

Huge quantities of natural gas (primarily methane) exist in the form of hydrates under sediment on offshore continental shelves and on land in arctic regions that experience permafrost such as those in Siberia (hydrates require a combination of high pressure and low temperature to form). Sony VAIO VGN-SR94GS Battery

However, as of 2010 no technology has been developed to extract natural gas economically from hydrates.

In 2010, using current technology, the cost of extracting natural gas from crystallized natural gas is estimated to 100%–200% the cost of extracting natural gas from conventional sources, and even higher from offshore deposits.Sony VAIO VGN-SR94HS Battery

Natural gas processing

The image below is a schematic block flow diagram of a typical natural gas processing plant. It shows the various unit processes used to convert raw natural gas into sales gas pipelined to the end user markets.Sony VAIO VGN-SR94VS Battery

The block flow diagram also shows how processing of the raw natural gas yields byproduct sulfur, byproduct ethane, and natural gas liquids (NGL) propane, butanes and natural gasoline (denoted as pentanes +).

Power generation

Natural gas is a major source of electricity generation through the use of gas turbines and steam turbines.Sony VAIO VGN-SZ35B/B Battery

Most grid peaking power plants and some off-grid engine-generators use natural gas. Particularly high efficiencies can be achieved through combining gas turbines with a steam turbine in combined cycle mode. Natural gas burns more cleanly than other Hydrocarbon fuels, such as oil and coal, and produces less carbon dioxide per unit of energy released.Sony VAIO VGN-SZ54B/B Battery

For an equivalent amount of heat, burning natural gas produces about 30% less carbon dioxide than burning petroleum and about 45% less than burning coal.Combined cycle power generation using natural gas is thus the cleanest source of power available using hydrocarbon fuels, and this technology is widely used wherever gas can be obtained at a reasonable cost.Sony VAIO VGN-SZ55B/B Battery

Fuel cell technology may eventually provide cleaner options for converting natural gas into electricity, but as yet it is not price-competitive.

Domestic use

Natural gas dispensed from a simple stovetop can generate heat in excess of 2000°F (1093°C) making it a powerful domestic cooking and heating fuel.Sony VAIO VGN-SZ55GN/B Battery

In much of the developed world it is supplied to homes via pipes where it is used for many purposes including natural gas-powered ranges and ovens, natural gas-heated clothes dryers, heating/cooling and central heating. Home or other building heating may include boilers, furnaces, and water heaters. Sony VAIO VGN-SZ56 Battery

Compressed natural gas (CNG) is used inrural homes without connections to piped-in public utility services, or with portable grills. Natural gas is also supplied by independent natural gas suppliers through Natural Gas Choice programs throughout the United States. However, due to CNG being less economical than LPG, LPG (propane) is the dominant source of rural gas.Sony VAIO VGN-SZ561N Battery

Transportation

CNG is a cleaner alternative to other automobile fuels such as gasoline (petrol) and diesel. As of 2008 there were 9.6 millionnatural gas vehicles worldwide, led by Pakistan (2.0 million), Argentina (1.7 million), Brazil (1.6 million), Iran (1.0 million), and India (650,000).Sony VAIO VGN-SZ562N Battery

The energy efficiency is generally equal to that of gasoline engines, but lower compared with modern diesel engines. Gasoline/petrol vehicles converted to run on natural gas suffer because of the low compression ratio of their engines, resulting in a cropping of delivered power while running on natural gas (10%–15%). Sony VAIO VGN-SZ57N Battery

CNG-specific engines, however, use a higher compression ratio due to this fuel's higher octane number of 120–130.

Fertilizers

Natural gas is a major feedstock for the production of ammonia, via the Haber process, for use in fertilizer production.Sony VAIO VGN-SZ58GN Battery

Aviation

Russian aircraft manufacturer Tupolev is currently running a development program to produce LNG- and hydrogen-powered aircraft.[26] The program has been running since the mid-1970s, and seeks to develop LNG and hydrogen variants of the Tu-204 and Tu-334 passenger aircraft, and also the Tu-330 cargo aircraft. Sony VAIO VGN-SZ58GN/C Battery

It claims that at current market prices, an LNG-powered aircraft would cost 5,000 roubles (~ $218/ £112) less to operate per ton, roughly equivalent to 60%, with considerable reductions to carbon monoxide, hydrocarbon and nitrogen oxide emissions.Sony VAIO VGN-SZ58N Battery

The advantages of liquid methane as a jet engine fuel are that it has more specific energy than the standard kerosene mixes do and that its low temperature can help cool the air which the engine compresses for greater volumetric efficiency, in effect replacing an intercooler. Alternatively, it can be used to lower the temperature of the exhaust.Sony VAIO VGN-SZ61MN/B Battery

Hydrogen

Natural gas can be used to produce hydrogen, with one common method being the hydrogen reformer. Hydrogen has many applications: it is a primary feedstock for the chemical industry, a hydrogenating agent, an important commodity for oil refineries, and the fuel source in hydrogen vehicles.Sony VAIO VGN-SZ61VN/X Battery

Other

Natural gas is also used in the manufacture of fabrics, glass, steel, plastics, paint, and other products.

Storage and transport

Because of its low density, it is not easy to store natural gas or transport by vehicle. Natural gas pipelines are impractical acrossoceans.Sony VAIO VGN-SZ61WN/C Battery

Many existing pipelines in America are close to reaching their capacity, prompting some politicians representing northern states to speak of potential shortages. In Europe, the gas pipeline network is already dense in the West. New pipelines are planned or under construction in Eastern Europe and between gas fields in Russia, Near East and Northern Africa and Western Europe. Sony VAIO VGN-SZ640N/B Battery

See also List of natural gas pipelines.

LNG carriers transport liquefied natural gas (LNG) across oceans, while tank trucks can carry liquefied or compressed natural gas (CNG) over shorter distances. Sea transport using CNG carrier ships that are now under development may be competitive with LNG transport in specific conditions.Sony VAIO VGN-SZ645P3 Battery

Gas is turned into liquid at a liquefaction plant, and is returned to gas form at regasification plant at the terminal. Shipborne regasification equipment is also used. LNG is the preferred form for long distance, high volume transportation of natural gas, whereas pipeline is preferred for transport for distances up to 4,000 km over land and approximately half that distance offshore.Sony VAIO VGN-SZ650N/C Battery

CNG is transported at high pressure, typically above 200 bars. Compressors and decompression equipment are less capital intensive and may be economical in smaller unit sizes than liquefaction/regasification plants. Natural gas trucks and carriers may transport natural gas directly to end-users, or to distribution points such as pipelines.Sony VAIO VGN-SZ660N/C Battery

In the past, the natural gas which was recovered in the course of recovering petroleum could not be profitably sold, and was simply burned at the oil field in a process known as flaring. Flaring is now illegal in many countries. Additionally, companies now recognize that gas may be sold to consumers in the form of LNG or CNG, or through other transportation methods. Sony VAIO VGN-SZ670N/C Battery

The gas is now re-injected into the formation for later recovery. The re-injection also assists oil pumping by keeping underground pressures higher.

A "master gas system" was invented in Saudi Arabia in the late 1970s, ending any necessity for flaring. Satellite observation, however, shows that flaring[29] and venting[30] are still practiced in some gas-extracting countries.Sony VAIO VGN-SZ680ND Battery

Natural gas is used to generate electricity and heat for desalination. Similarly, some landfills that also discharge methane gases have been set up to capture the methane and generate electricity.

Natural gas is often stored underground inside depleted gas reservoirs from previous gas wells, salt domes, or in tanks asliquefied natural gas. Sony VAIO VGN-SZ691N/X Battery

The gas is injected in a time of low demand and extracted when demand picks up. Storage nearby end users helps to meet volatile demands, but such storage may not always be practicable.

With 15 countries accounting for 84% of the worldwide extraction, access to natural gas has become an important issue in international politics, and countries vie for control of pipelines.Sony VAIO VGN-SZ71E/B Battery

In the first decade of the 21st century, Gazprom, the state-owned energy company in Russia, engaged in disputes with Ukraine and Belarus over the price of natural gas, which have created worries that gas deliveries to parts of Europe could be cut off for political reasons.Sony VAIO VGN-SZ71VN/X Battery

Floating Liquefied Natural Gas (FLNG) is an innovative technology designed to enable the development of offshore gas resources that would otherwise remain untapped because due to environmental or economic factors it is nonviable to develop them via a land-based LNG operation. Sony VAIO VGN-SZ71WN/C Battery

FLNG technology also provides a number of environmental and economic advantages:

• Environmental – Because all processing is done at the gas field, there is no requirement for long pipelines to shore, compression units to pump the gas to shore, dredging and jetty construction, and onshore construction of an LNG processing plant, which significantly reduces the environmental footprint.Sony VAIO VGN-SZ74B/B Battery
• Avoiding construction also helps preserve marine and coastal environments. In addition, environmental disturbance will be minimised during decommissioning because the facility can easily be disconnected and removed before being refurbished and re-deployed elsewhere.Sony VAIO VGN-SZ750N/C Battery
• Economic – Where pumping gas to shore can be prohibitively expensive, FLNG makes development economically viable. As a result, it will open up new business opportunities for countries to develop offshore gas fields that would otherwise remain stranded, such as those offshore East Africa.Sony VAIO VGN-SZ75B/B Battery

Many gas and oil companies are considering the economic and environmental benefits of Floating Liquefied Natural Gas (FLNG)However, for the time being, the only FLNG facility now in development is being built by Shell,[35] due for completion in around 2017.Sony VAIO VGN-SZ76 Battery

CO2 emissions

Natural gas is often described as the cleanest fossil fuel, producing less carbon dioxide per joule delivered than either coal or oil and far fewer pollutants than other hydrocarbon fuels. However, in absolute terms, it does contribute substantially to global carbon emissions, and this contribution is projected to grow. Sony VAIO VGN-SZ770N/C Battery

According to the IPCC Fourth Assessment Report (Working Group III Report, chapter 4), in 2004, natural gas produced about 5.3 billion tons a year of CO2 emissions, while coal and oil produced 10.6 and 10.2 billion tons respectively (figure 4.4). Sony VAIO VGN-SZ77N Battery

According to an updated version of the SRES B2 emissions scenario, however, by the year 2030, natural gas would be the source of 11 billion tons a year, with coal and oil now 8.4 and 17.2 billion respectively because demand is increasing 1.9% a year (Total global emissions for 2004 were estimated at over 27,200 million tons)Sony VAIO VGN-SZ780 Battery

In addition, natural gas itself is a greenhouse gas more potent than carbon dioxide when released into the atmosphere, although natural gas is released in much smaller quantities. However, methane is oxidized in the atmosphere, and hence natural gas has a residence lifetime in the atmosphere for approximately 12 years,Sony VAIO VGN-SZ78N Battery

compared to CO2, which is already oxidized, and has an effect for 100 to 500 years. Natural gas is mainly composed of methane, which has a radiative forcing twenty times greater than carbon dioxide. Based on such composition, a ton of methane in the atmosphere traps in as much radiation as 20 tons of carbon dioxide;Sony VAIO VGN-SZ791N/X Battery

however, it remains in the atmosphere for a 8–40 times shorter time. Carbon dioxide still receives the lion's share of attention over greenhouse gases because it is released in much larger amounts. Still, it is inevitable when natural gas is used on a large scale that some of it will leak into the atmosphere.Sony VAIO VGN-SZ84NS Battery

(Coal methane not captured by coal bed methane extraction techniques is simply lost into the atmosphere; however, most methane in the atmosphere is currently from animals and bacteria, not from industrial leaks .) Current estimates by the EPA place global emissions of methane at 3 trillion cubic feet (85 km3) annually, or 3.2% of global production.Sony VAIO VGN-SZ84PS Battery

Direct emissions of methane represented 14.3% of all global anthropogenic greenhouse gas emissions in 2004.

Other pollutants

Natural gas produces far lower amounts of sulfur dioxide and nitrous oxides than any other hydrocarbon fuel.Sony VAIO VGN-SZ84S Battery

Carbon dioxide produced is 117,000 ppm vs 208,000 for burning coal. Carbon monoxide produced is 40 ppm vs 208 for burning coal[citation needed]. Nitrogen oxides produced is 92 ppm vs 457 for burning coal. Sulfur dioxide is 1 ppm vs 2,591 for burning coal. Mercury is 0 vs .016 for burning coal.Sony VAIO VGN-SZ84US Battery

Particulates are also a major contribution to global warming. Natural gas has 7ppm vs coal's 2,744ppm.

Extraction

The practice of hydraulic fracturing, the process of using a combination of chemicals ranging from harmless to toxic to force natural gas to the surface from reservoirs with low permeability, has come under scrutiny internationally due to concerns about environmental and health safety, and has been suspended or banned in some countries.Sony VAIO VGN-SZ85NS Battery

Production

In mines, where methane seeping from rock formations has no odor, sensors are used, and mining apparatus such as the Davy lamp has been specifically developed to avoid ignition sources.

Some gas fields yield sour gas containing hydrogen sulfide (H2S). This untreated gas is toxic. Amine gas treating, an industrial scale process which removes acidic gaseous components, is often used to remove hydrogen sulfide from natural gas. Sony VAIO VGN-SZ85S Battery

Extraction of natural gas (or oil) leads to decrease in pressure in the reservoir. Such decrease in pressure in turn may result insubsidence, sinking of the ground above. Subsidence may affect ecosystems, waterways, sewer and water supply systems, foundations, and so on.Sony VAIO VGN-SZ85US Battery

Releasing the gas from low-permeability reservoirs is accomplished by a process called hydraulic fracturing or "hydrofracking". To allow the natural gas to flow out of the shale, oil operators force one to 9 million US gallons (34,000 m3) of water mixed with a variety of chemicals through the wellbore casing into the shale.Sony VAIO VGN-SZ94NS Battery

The high pressure water breaks up or "fracks" the shale, which releases the trapped gas. Sand is added to the water as a proppant to keep the fractures in the shale open, thus enabling the gas to flow into the casing and then to the surface. The chemicals are added to the frack fluid to reduce friction and combat corrosion. Sony VAIO VGN-SZ94PS Battery

During the extracting life of a gas well, other low concentrations of other chemical substances may be used, such as biocides to eliminate fouling, scale and corrosion inhibitors, oxygen scavengers to remove a source of corrosion, and acids to clean the perforations in the pipe.Sony VAIO VGN-SZ94S Battery

Dealing with fracking fluid can be a challenge. Along with the gas, 30% to 70% of the chemically-laced frack fluid, or flow back, returns to the surface. Additionally, a significant amount of salt and other minerals, once a part of the rock layers that were under prehistoric seas, may be incorporated in the flow back as they dissolve in the frack fluid.Sony VAIO VGN-SZ94US Battery

Use

In order to assist in detecting leaks, a minute amount of odorant is added to the otherwise colorless and almost odorless gas used by consumers. The odor has been compared to the smell of rotten eggs, due to the added butyl mercaptan. Sometimes a related compound, thiophane may be used in the mixture.Sony VAIO VGN-SZ95NS Battery

Explosions caused by natural gas leaks occur a few times each year. Individual homes, small businesses and other structures are most frequently affected when an internal leak builds up gas inside the structure. Frequently, the blast will be enough to significantly damage a building but leave it standing.Sony VAIO VGN-SZ95S Battery

In these cases, the people inside tend to have minor to moderate injuries. Occasionally, the gas can collect in high enough quantities to cause a deadly explosion, disintegrating one or more buildings in the process. The gas usually dissipates readily outdoors, but can sometimes collect in dangerous quantities if flow rates are high enough. Sony VAIO VGN-SZ95US Battery

However, considering the tens of millions of structures that use the fuel, the individual risk of using natural gas is very low.

Natural gas heating systems are a minor source of carbon monoxide deaths in the United States. Sony VAIO VGN-TZ121 Battery

According to the US Consumer Product Safety Commission (2008), 56% of unintentional deaths from non-fire CO poisoning were associated with engine-driven tools like gas-powered generators and lawn mowers. Natural gas heating systems accounted for 4% of these deaths. Sony VAIO VGN-TZ13 Battery

Improvements in natural gas furnace designs have greatly reduced CO poisoning concerns. Detectors are also available that warn of carbon monoxide and/or explosive gas (methane, propane, etc.).

Energy content, statistics and pricing

Quantities of natural gas are measured in normal cubic meters (corresponding to 0 °C at 101.325 kPa) or in standard cubic feet (corresponding to 60 °F (16 °C) and 14.73 psia). Sony VAIO VGN-TZ130N/B Battery

The gross heat of combustion of one cubic meter of commercial quality natural gas is around 39 megajoules (?10.8 kWh), but this can vary by several percent. This comes to about 49 megajoules (?13.5 kWh) for one kg of natural gas (assuming 0.8 kg/m^3, an approximate value).Sony VAIO VGN-TZ131 Battery

The price of natural gas varies greatly depending on location and type of consumer. In 2007, a price of $7 per 1,000 cubic feet (28 m3) was typical in the United States. The typical caloric value of natural gas is roughly 1,000 British thermal units (BTU) per cubic foot, depending on gas composition. Sony VAIO VGN-TZ132/N Battery

This corresponds to around $7 per million BTU, or around $7 per gigajoule. In April 2008, the wholesale price was $10 per 1,000 cubic feet (28 m3) ($10/MMBTU). The residential price varies from 50% to 300% more than the wholesale price. At the end of 2007, this was $12–$16 per 1,000 cu ft (28 m3).Sony VAIO VGN-TZ132N Battery

Natural gas in the United States is traded as a futures contract on the New York Mercantile Exchange. Each contract is for 10,000 MMBTU (~10,550 gigajoules), or 10 billion BTU. Thus, if the price of gas is $10 per million BTUs on the NYMEX, the contract is worth $100,000.Sony VAIO VGN-TZ150N/B Battery

European Union

As one of the world's largest importers of natural gas, the EU is a major player on the international gas market.

Gas prices for end users vary greatly across the EU. A single European energy market, one of the key objectives of the European Union, should level the prices of gas in all EU member states.Sony VAIO VGN-TZ150N/N Battery

United States

In US units, one standard cubic foot of natural gas produces around 1,028 British thermal units (BTU). The actual heating value when the water formed does not condense is the net heat of combustion and can be as much as 10% less.

In the United States, retail sales are often in units of therms (th); 1 therm = 100,000 BTU. Sony VAIO VGN-TZ160CB Battery

Gas meters measure the volume of gas used, and this is converted to therms by multiplying the volume by the energy content of the gas used during that period, which varies slightly over time. Wholesale transactions are generally done in decatherms (Dth), or in thousand decatherms (MDth), or in million decatherms (MMDth).Sony VAIO VGN-TZ160N/B Battery

A million decatherms is roughly a billion cubic feet of natural gas. Gas sales to domestic consumers may be in units of 100 standard cubic feet (Ccf).

As of 2009, the Potential Gas Committee estimated that the United States has total future recoverable natural gas resources approximately 100 times greater than current annual consumption.Sony VAIO VGN-TZ16GN/B Battery

Canada

Canada uses metric measure for internal trade of petrochemical products. Consequently, natural gas is sold by the Gigajoule, a measure approximately equal to 1/2 of a barrel (250lbs) of oil, or 1 million BTUs, or 1000 cu ft of gas, or 100cu metres of gas.Sony VAIO VGN-TZ16N Battery

Elsewhere

In the rest of the world, Natural gas is sold in Gigajoule retail units. LNG (liquefied natural gas) and LPG (liquefied petroleum gas) are traded in metric tons or mmBTU as spot deliveries. Long term Natural gas distribution contracts are signed in cubic metres, and LNG contracts are in metric tonnes (1,000kg). Sony VAIO VGN-TZ16N/B Battery

The LNG and LPG is transported by specialized transport ships, as the gas is liquified at cryogenic temperatures. The specification of each LNG/LPG cargo will usually contain the energy content, but this information is in general not available to the public.

In the Russian Federation, Gazprom sold approximately 250 billion cubic metres of natural gas in 2008.Sony VAIO VGN-TZ17/N Battery

Energy development is the effort to provide sufficient primary energy sources and secondary energy forms for supply, cost, impact on air pollution and water pollution, mitigation of climate change with renewable energy.

Technologically advanced societies have become increasingly dependent on external energy sources for transportation, the production of many manufactured goods, and the delivery of energy services. Sony VAIO VGN-TZ170N/B Battery

This energy allows people who can afford the cost to live under otherwise unfavorable climatic conditions through the use of heating, ventilation, and/or air conditioning. Level of use of external energy sources differs across societies, as do the climate, convenience, levels of traffic congestion, pollutionand availability of domestic energy sources.Sony VAIO VGN-TZ170N/N Battery

Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which arerenewable (naturally replenished.) Renewable energy is an alternative to fossil fuels and nuclear power, and was commonly calledalternative energy in the 1970s and 1980s. Sony VAIO VGN-TZ17GN/B Battery

In 2008, about 19% of global final energy consumption came from renewables, with 13% coming from traditional biomass, which is mainly used for heating, and 3.2% from hydroelectricity.[1] New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 2.7% and are growing very rapidly.Sony VAIO VGN-TZ17N Battery

The share of renewables in electricity generation is around 18%, with 15% of global electricity coming from hydroelectricity and 3% from new renewables.

Wind power is growing at the rate of 30% annually, with a worldwide installed capacity of 158 gigawatts (GW) in 2009, and is widely used in Europe, Asia, and the United States.Sony VAIO VGN-TZ18/N Battery

At the end of 2009, cumulative global photovoltaic (PV) installations surpassed 21 GW[6][7][8] and PV power stations are popular in Germany and Spain.[9] Solar thermal power stations operate in the USA and Spain, and the largest of these is the 354 megawatt (MW) SEGS power plant in the Mojave Desert.Sony VAIO VGN-TZ180N/RC Battery

The world's largestgeothermal power installation is The Geysers in California, with a rated capacity of 750 MW. Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugar cane, and ethanol now provides 18% of the country's automotive fuel.[11] Ethanol fuel is also widely available in the USA.Sony VAIO VGN-TZ185N/WC Battery

Climate change concerns, coupled with high oil prices, peak oil, and increasing government support, are driving increasing renewable energy legislation, incentives and commercialization. New government spending, regulation and policies helped the industry weather the global financial crisis better than many other sectors.Sony VAIO VGN-TZ18GN/X Battery

Scientists have advanced a plan to power 100% of the world's energy with wind, hydroelectric, and solar power by the year 2030,recommending renewable energy subsidies and a price on carbon reflecting its cost for flood and related expenses.Sony VAIO VGN-TZ18N Battery

While many renewable energy projects are large-scale, renewable technologies are also suited to rural and remote areas, where energy is often crucial in human development. Globally, an estimated 3 million households get power from small solar PV systems.Sony VAIO VGN-TZ190N/B Battery

Micro-hydro systems configured into village-scale or county-scale mini-grids serve many areas.[17] More than 30 million rural households get lighting and cooking from biogas made in household-scale digesters. Biomass cookstoves are used by 160 million households.Sony VAIO VGN-TZ190N/BC Battery

Wind

Wind power harnesses the power of the wind to propel the blades of wind turbines. These turbines cause the rotation of magnets, which creates electricity. Wind towers are usually built together on wind farms.Sony VAIO VGN-TZ191N/XC Battery

Wind power is growing at the rate of 30% annually, with a worldwide installed capacity of 158 gigawatts (GW) in 2009, and is widely used in Europe, Asia, and theUnited States.

At the end of 2010, worldwide nameplate capacity of wind-powered generators was 197 gigawatts (GW).Sony VAIO VGN-TZ195N/XC Battery

Energy production was 430 TWh, which is about 2.5% of worldwide electricity usage. Several countries have achieved relatively high levels of wind power penetration, such as 21% of stationary electricity production in Denmark, 18% in Portugal, 16% in Spain, 14% inIreland and 9% in Germany in 2010.Sony VAIO VGN-TZ198N/RC Battery

As of 2011, 83 countries around the world are using wind power on a commercial basis.

Hydroelectric

In hydro energy, the gravitational descent of a river is compressed from a long run to a single location with a dam or a flume. Sony VAIO VGN-TZ250N/B Battery

This creates a location where concentrated pressure and flow can be used to turn turbines or water wheels, which drive a mechanical mill or an electric generator.

In some cases with hydroelectric dams, there are unexpected results. Sony VAIO VGN-TZ250N/N Battery

One study shows that a hydroelectric dam in the Amazon has 3.6 times larger greenhouse effect per kW•h than electricity production from oil, due to large scale emission of methane from decaying organic material, though this is most significant as river valleys are initially flooded, and are of much less consequence for more boreal dams.Sony VAIO VGN-TZ250N/P Battery

This effect applies in particular to dams created by simply flooding a large area, without first clearing it of vegetation. There are however investigations into underwater turbines that do not require a dam. And pumped-storage hydroelectricity can use water reservoirs at different altitudes to store wind and solar power.Sony VAIO VGN-TZ27/N Battery

Solar

Solar power involves using solar cells to convert sunlight into electricity, using sunlight hitting solar thermal panels to convert sunlight to heat water or air, using sunlight hitting a parabolic mirror to heat water (producing steam), or using sunlight entering windows for passive solar heating of a building. Sony VAIO VGN-TZ270N/B Battery

It would be advantageous to place solar panels in the regions of highest solar radiation.

At the end of 2009, cumulative global photovoltaic (PV) installations surpassed 21 GW and PV power stations are popular inGermany and Spain. Solar thermal power stations operate in the USA and Spain, and the largest of these is the 354 megawatt (MW)SEGS power plant in the Mojave Desert.Sony VAIO VGN-TZ27N Battery

China is increasing worldwide silicon wafer capacity for photovoltaics to 2,000 metric tons by July 2008, and over 6,000 metric tons by the end of 2010. Significant international investment capital is flowing into China to support this opportunity.Sony VAIO VGN-TZ28/N Battery

China is building large subsidized off-the-grid solar-powered cities in Huangbaiyu and Dongtan Eco City. Much of the design was done by Americans such as William McDonough.

Agricultural biomass

Biomass production involves using garbage or other renewable resources such as corn or othervegetation to generate electricity.Sony VAIO VGN-TZ285N/RC Battery

When garbage decomposes, the methane produced is captured in pipes and later burned to produce electricity. Vegetation and wood can be burned directly to generate energy, like fossil fuels, or processed to form alcohols. Brazil has one of the largest renewable energy programs in the world, Sony VAIO VGN-TZ28N Battery

involving production of ethanol fuel from sugar cane, and ethanol now provides 18% of the country's automotive fuel.Ethanol fuel is also widely available in the USA.

Vegetable oil is generated from sunlight, H2O, and CO2 by plants. It is safer to use and store than gasoline or diesel as it has a higher flash point. Sony VAIO VGN-TZ290EAB Battery

Straight vegetable oil works in diesel engines if it is heated first. Vegetable oil can also betransesterified to make biodiesel, which burns like normal diesel.

Geothermal

Geothermal energy harnesses the heat energy present underneath the Earth. Two wells are drilled. One well injects water into the ground to provide water. Sony VAIO VGN-TZ290EAN Battery

The hotrocks heat the water to produce steam. The steam that shoots back up the other hole(s) is purified and is used to drive turbines, which power electric generators. When the water temperature is below the boiling point of water a binary system is used. Sony VAIO VGN-TZ290EAP Battery

A low boiling point liquid is used to drive a turbine and generator in a closed system similar to a refrigeration unit running in reverse. There are also natural sources of geothermal energy: some can come from volcanoes, geysers, hot springs, and steam vents.The world's largest geothermal power installation is The Geysers in California, with a rated capacity of 750 MW.Sony VAIO VGN-TZ295N/XC Battery

Tidal

Tidal power can be extracted from Moon-gravity-powered tides by locating a water turbine in a tidal current, or by building impoundment pond dams that admit-or-release water through a turbine. Sony VAIO VGN-TZ298N/XC Battery

The turbine can turn an electrical generator, or a gas compressor, that can then store energy until needed. Coastal tides are a source of clean, free, renewable, and sustainable energy.

Fossil fuels

Fossil fuels sources burn coal or hydrocarbon fuels, which are the remains of the decomposition of plants and animals.Sony VAIO VGN-TZ33/B Battery

There are three main types of fossil fuels: coal, petroleum, and natural gas. Another fossil fuel, liquefied petroleum gas (LPG), is principally derived from the production of natural gas. Heat from burning fossil fuel is used either directly for space heating and process heating, or converted to mechanical energy for vehicles, industrial processes, or electrical power generation.Sony VAIO VGN-TZ33/N Battery

Greenhouse gas emissions result from fossil fuel-based electricity generation. Currently governments subsidize fossil fuels by an estimated $500 billion a year.

Nuclear power stations use nuclear fission to generate energy by the reaction of uranium-235 inside a nuclear reactor.Sony VAIO VGN-TZ33/W Battery

The reactor uses uranium rods, the atoms of which are split in the process of fission, releasing a large amount of energy. The process continues as a chain reaction with other nuclei. The energy heats water to create steam, which spins a turbine generator, producing electricity.Sony VAIO VGN-TZ350N/B Battery

Depending on the type of fission fuel considered, estimates for existing supply at known usage rates varies from several decades for the currently popular Uranium-235 to thousands of years for uranium-238. At the present rate of use, there are (as of 2007) about 70 years left of known uranium-235 reserves economically recoverable at a uranium price of US$ 130/kg.Sony VAIO VGN-TZ350N/N Battery

The nuclear industry argue that the cost of fuel is a minor cost factor for fission power, more expensive, more difficult to extract sources of uranium could be used in the future, such as lower-grade ores, and if prices increased enough, from sources such as granite and seawater.Sony VAIO VGN-TZ350N/P Battery

Increasing the price of uranium would have little effect on the overall cost of nuclear power; a doubling in the cost of natural uranium would increase the total cost of nuclear power by 5 percent. On the other hand, if the price of natural gas was doubled, the cost of gas-fired power would increase by about 60 percent.Sony VAIO VGN-TZ370N/B Battery

Opponents on the other hand argue that the correlation between price and production is not linear, but as the ores' concentration becomes smaller, the difficulty (energy and resource consumption are increasing, while the yields are decreasing) of extraction rises very fast, and that the assertion that a higher price will yield more uranium is overly optimistic;Sony VAIO VGN-TZ37N/G Battery

for example a rough estimate predicts that the extraction of uranium from granite will consume at least 70 times more energy than what it will produce in a reactor. As many as eleven countries have depleted their uranium resources, and only Canada has mines left that produce better than 1% concentration ore. Seawater seems to be equally dubious as a source.Sony VAIO VGN-TZ37N/P Battery

Nuclear meltdowns and other reactor accidents, such as the Fukushima I nuclear accident (2011), Three Mile Island accident (1979) and the Chernobyl disaster (1986), have caused much public concern. Research is being done to lessen the known problems of current reactor technology by developing automated and passively safereactors. Sony VAIO VGN-TZ37N/R Battery

Historically, however, coal and hydropower power generation have both been the cause of more deaths per energy unit produced than nuclear power generation.

Nuclear proliferation is the spread of nuclear technology which may happen from nation to nation or through other black market channels, including nuclear power plants and related technology including nuclear weapons.Sony VAIO VGN-TZ37N/X Battery

The long-term radioactive waste storage problems of nuclear power have not been solved. Several countries have considered using underground repositories. Nuclear waste takes up little space compared to wastes from the chemical industry which remain toxic indefinitely.[38] Spent fuel rods are now stored in concrete casks close to the nuclear reactors.Sony VAIO VGN-TZ38N/X Battery

The amounts of waste could be reduced in several ways. Both nuclear reprocessing and breeder reactors could reduce the amounts of waste.Subcritical reactors or fusion reactors could greatly reduce the time the waste has to be stored. Subcritical reactors may also be able to do the same to already existing waste. Sony VAIO VGN-TZ398U/XC Battery

The only long-term way of dealing with waste today is by geological storage.

At present, nuclear energy is in decline, according to a 2007 World Nuclear Industry Status Report presented by the Greens/EFA group in the European Parliament. Sony VAIO VGN-TZ50B Battery

The report outlines that the proportion of nuclear energy in power production has decreased in 21 out of 31 countries, with five fewer functioning nuclear reactors than five years ago. There are currently 32 nuclear power plants under construction or in the pipeline, 20 fewer than at the end of the 1990s.Sony VAIO VGN-TZ90HS Battery

Thorium can be used as fuel in a nuclear reactor. A thorium fuel cycle offers several potential advantages over a uranium fuel cycle including much greater abundanceon Earth, superior physical and nuclear properties of the fuel, enhanced proliferation resistance, and reduced nuclear waste production. Sony VAIO VGN-TZ90NS Battery

Nobel laureate Carlo Rubbiaat CERN (European Organization for Nuclear Research), has worked on developing the use of thorium as an alternative to uranium in reactors. Rubbia states that a tonne of thorium can produce as much energy as 200 tonnes of uranium, or 3,500,000 tonnes of coal.Sony VAIO VGN-TZ90S Battery

One of the early pioneers of the technology was U.S. physicistAlvin Weinberg at Oak Ridge National Laboratory in Tennessee, who helped develop a working nuclear plant using liquid fuel in the 1960s.

Fusion

Fusion power could solve many of the problems of fission power (the technology mentioned above) but, despite research having started in the 1950s, no commercial fusion reactor is expected before 2050.Sony VAIO VPC CW2MFX/PU Battery

Many technical problems remain unsolved. Proposed fusion reactors commonly use deuterium, an isotope of hydrogen, as fuel and in most current designs also lithium. Assuming a fusion energy output equal to the current global output and that this does not increase in the future,Sony VAIO VPC S11V9E/B Battery

then the known current lithium reserves would last 3000 years, lithium from sea water would last 60 million years, and a more complicated fusion process using only deuterium from sea water would have fuel for 150 billion years.

Cost by source

The following chart does not include the external, weather-related costs of using fossil fuels.Sony VAIO VPCB119GJ/B Battery

Large energy subsidies are present in many countries (Barker et al., 2001:567-568). Currently governments subsidize fossil fuels by $557 billion per year. Economic theory indicates that the optimal policy would be to remove coal mining and burning subsidies and replace them with optimal taxes.Sony VAIO VPCB11AGJ Battery

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 GHG emissions and stimulate economic growth.Sony VAIO VPCB11AVJ Battery

Increased energy efficiency

Energy efficiency is increasing by about 2% a year, and absorbs most of the requirements for energy development. New technology makes better use of already available energy through improved efficiency, such as more efficient fluorescent lamps, engines, and insulation. Sony VAIO VPCB11V9E Battery

Using heat exchangers, it is possible to recover some of the energy in waste warm water and air, for example to preheat incoming fresh water. Hydrocarbon fuel production from pyrolysis could also be in this category, allowing recovery of some of the energy in hydrocarbon waste.Sony VAIO VPCB11X9E Battery

Already existing power plants often can and usually are made more efficient with minor modifications due to new technology. New power plants may become more efficient with technology like cogeneration. New designs for buildings may incorporate techniques like passive solar. Sony VAIO VPCCW18FJ/P Battery

Light-emitting diodes are gradually replacing the remaining uses of light bulbs. Note that none of these methods allows perpetual motion, as some energy is always lost to heat.

Mass transportation increases energy efficiency compared to widespread conventional automobile use while air travel is regarded as inefficient. Sony VAIO VPCCW18FJ/R Battery

Conventional combustion engine automobiles have continually improved their efficiency and may continue to do so in the future, for example by reducing weight with new materials.Hybrid vehicles can save energy by allowing the engine to run more efficiently, regaining energy from braking, turning off the motor when idling in traffic, etc. Sony VAIO VPCCW18FJ/W Battery

More efficient ceramic or diesel engines can improve mileage. Electric vehicles such as Maglev, trolleybuses, and PHEVs are more efficient during use (but maybe not if doing a life cycle analysis) than similar current combustion based vehicles, reducing their energy consumption during use by 1/2 to 1/4.Sony VAIO VPCCW19FJ/W Battery

Microcars or motorcycles may replace automobiles carrying only one or two people. Transportation efficiency may also be improved by in other ways, see automated highway system.

Electricity distribution may change in the future. New small scale energy sources may be placed closer to the consumers so that less energy is lost during electricity distribution. Sony VAIO VPCCW1AFJ Battery

New technology like superconductivity or improved power factor correction may also decrease the energy lost. Distributed generation permits electricity "consumers," who are generating electricity for their own needs, to send their surplus electrical power back into the power grid.Sony VAIO VPCCW1AHJ Battery

Transmission

While new sources of energy are only rarely discovered or made possible by new technology, distribution technology continually evolves. The use of fuel cells in cars, for example, is an anticipated delivery technology.Sony VAIO VPCCW1S1E Battery

This section presents some of the more common delivery technologies that have been important to historic energy development. They all rely in some way on the energy sources listed in the previous section.

Fossil fuels

Shipping is a flexible delivery technology that is used in the whole range of energy development regimes from primitive to highly advanced. Sony VAIO VPCCW1S1E/B Battery

Currently, coal, petroleum and their derivatives are delivered by shipping via boat, rail, or road. Petroleum and natural gas may also be delivered via pipeline and coal via a Slurry pipeline. Refined hydrocarbon fuels such as gasoline and LPGmay also be delivered via aircraft. Sony VAIO VPCCW1S1E/L Battery

Natural gas pipelines must maintain a certain minimum pressure to function correctly.Ethanol's corrosive properties make it harder to build ethanol pipelines. The higher costs of ethanol transportation and storage are often prohibitive.Sony VAIO VPCCW1S1E/P Battery

Electricity

Electricity grids are the networks used to transmit and distribute power from production source to end user, when the two may be hundreds of kilometres away. Sources include electrical generation plants such as a nuclear reactor, coal burning power plant, etc.Sony VAIO VPCCW1S1E/R Battery

A combination of sub-stations, transformers, towers, cables, and piping are used to maintain a constant flow of electricity. Grids may suffer from transient blackouts and brownouts, often due to weather damage. During certain extreme space weather eventssolar wind can interfere with transmissions. Sony VAIO VPCCW1S1E/W Battery

Grids also have a predefined carrying capacity or load that cannot safely be exceeded. When power requirements exceed what's available, failures are inevitable. To prevent problems, power is then rationed.

Industrialised countries such as Canada, the US, and Australia are among the highest per capita consumers of electricity in the world, which is possible thanks to a widespread electrical distribution network. Sony VAIO VPCCW21FX/B Battery

The US grid is one of the most advanced, althoughinfrastructure maintenance is becoming a problem. CurrentEnergy provides a realtime overview of the electricity supply and demand for California, Texas, and the Northeast of the US. African countries with small scale electrical grids have a correspondingly low annual per capita usage of electricity. Sony VAIO VPCCW21FX/L Battery

One of the most powerful power grids in the world supplies power to the state of Queensland, Australia.

Storage

Methods of energy storage have been developed, which transform electrical energy into forms of potential energy.Sony VAIO VPCCW21FX/R Battery

A method of energy storage may be chosen on the basis of stability, ease of transport, ease of energy release, or ease of converting free energy from the natural form to the stable form.

Chemical

Some natural forms of energy are found in stable chemical compounds such as fossil fuels. Sony VAIO VPCCW21FX/W Battery

Most systems of chemical energy storage result from biological activity, which store energy in chemical bonds. Man-made forms of chemical energy storage include hydrogen fuel, synthetic hydrocarbon fuel, batteries and explosives such ascordite and dynamite.Sony VAIO VPCCW26EC Battery

Gravitational and hydroelectric

Dams can be used to store energy, by using pumped-storage hydroelectricity, excess energy to pump water into the reservoir. When electrical energy is required, the process is reversed. The water then turns a turbine, generating electricity. Sony VAIO VPCCW26FX/B Battery

Hydroelectric power is currently an important part of the world's energy supply, generating one-fifth of the world's electricity.

Thermal

There are several technologies to store heat. Thermal energy from the sun, for example, can be stored in a reservoir or in the ground for daily or seasonal use. Thermal energy for cooling can be stored in ice.Sony VAIO VPCCW28EC Battery

Many thermal power plants are set up near coal or oil fields. The thermal power plant is used since fuel is burnt to produce heat energy, which is converted into electrical energy .

Mechanical pressure

Energy may also be stored in pressurized gases or alternatively in a vacuum. Compressed air, for example, may be used to operate vehicles and power tools. Sony VAIO VPCCW28FJ/P Battery

Large-scale compressed air energy storage facilities are used to smooth out demands on electricity generation by providing energy during peak hours and storing energy during off-peak hours. Such systems save on expensive generating capacity since it only needs to meet average consumption rather than peak consumption. Sony VAIO VPCCW28FJ/R Battery

Electrical capacitance

Electrical energy may be stored in capacitors. Capacitors are often used to produce high intensity releases of energy (such as a camera's flash).

Hydrogen

Hydrogen can be manufactured at roughly 77 percent thermal efficiency by the method of steam reforming of natural gas.Sony VAIO VPCCW28FJ/W Battery

When manufactured by this method it is a derivative fuel like gasoline; when produced by electrolysis of water, it is a form of chemical energy storage as are storage batteries, though hydrogen is the more versatile storage mode since there are two options for its conversion to useful work:Sony VAIO VPCCW29FJ/W Battery

(1) a fuel cell can convert the chemicals hydrogen and oxygen into water, and in the process, produce electricity, or (2) hydrogen can be burned (less efficiently than in a fuel cell) in an internal combustion engine.

Batteries are used to store energy in a chemical form.Sony VAIO VPCCW2AFJ Battery

As an alternative energy, batteries can be used to store energy in battery electric vehicles. Battery electric vehicles can be charged from the grid when the vehicle is not in use. Because the energy is derived from electricity, battery electric vehicles make it possible to use other forms of alternative energy such as wind, solar,geothermal, nuclear, or hydroelectric.Sony VAIO VPCCW2AHJ Battery

The environmental movement emphasizes sustainability of energy use and development. Renewable energy is sustainable in its production; the available supply will not be diminished for the foreseeable future - millions or billions of years. "Sustainability" also refers to the ability of the environment to cope with waste products, especially air pollution.Sony VAIO VPCCW2S1E Battery

Sources which have no direct waste products (such as wind, solar, and hydropower) are seen as ideal in this regard.

Fossil fuels such as petroleum, coal, and natural gas are not renewable. For example, the timing of worldwide peak oil production is being actively debated but it has already happened in some countries.Sony VAIO VPCCW2S1E/B Battery

Fossil fuels also make up the bulk of the world's currentprimary energy sources. With global demand for energy growing, the need to adopt alternative energy sources is also growing. Fossil fuels are also a major source of greenhouse gas emissions, leading to concerns about global warming if consumption is not reduced.Sony VAIO VPCCW2S1E/L Battery

Energy conservation is an alternative or complementary process to energy development. It reduces the demand for energy by using it more efficiently.

Resilience

Some observers contend that the much talked about idea of “energy independence” is an unrealistic and opaque concept.Sony VAIO VPCCW2S1E/P Battery

They offer “energy resilience” as a more sensible goal and more aligned with economic, security and energy realities. The notion of resilience in energy was detailed in the 1982 book Brittle Power: Energy Strategy for National Security. Sony VAIO VPCCW2S1E/R Battery

The authors argued that simply switching to domestic energy would be no more secure inherently because the true weakness is the interdependent and vulnerable energy infrastructure of the United States. Key aspects such as gas lines and the electrical power grid are centralized and easily susceptible to major disruption.Sony VAIO VPCCW2S1E/W Battery

They conclude that a “resilient energy supply” is necessary for both national security and the environment. They recommend a focus on energy efficiency and renewable energy that is more decentralized.

More recently former Intel Corporation Chairman and CEO Andrew Grove has touted energy resilience, arguing that complete independence is infeasible given the global market for energy.Sony VAIO VPCCW2S5C CN1 Battery

He describes energy resilience as the ability to adjust to interruptions in the supply of energy. To this end he suggests the U.S. make greater use of electricity. Electricity can be produced from a variety of sources. A diverse energy supply will be less impacted by the disruption in supply of any one source. Sony VAIO VPCF112FX/B Battery

He reasons that another feature of electrification is that electricity is “sticky” – meaning the electricity produced in the U.S. is more likely to stay there because it cannot be transported overseas. According to Grove, a key aspect of advancing electrification and energy resilience will be converting the U.S. automotive fleet from gasoline-powered to electric-powered. Sony VAIO VPCF115FG/B Battery

This, in turn, will require the modernization and expansion of the electrical power grid. As organizations such as the Reform Institute have pointed out, advancements associated with the developing smart grid would facilitate the ability of the grid to absorb vehicles en masse connecting to it to charge their batteries. Sony VAIO VPCF116FGBI Battery

Future

Extrapolations from current knowledge to the future offer a choice of energy futures. Some predictions parallel the Malthusian catastrophe hypothesis. Numerous are complex models based scenarios as pioneered by Limits to Growth. Sony VAIO VPCF117FJ/W Battery

Modeling approaches offer ways to analyze diverse strategies, and hopefully find a road to rapid and sustainable development of humanity. Short term energy crises are also a concern of energy development. Some extrapolations lack plausibility, particularly when they predict a continual increase in oil consumption.Sony VAIO VPCF117HG/BI Battery

Energy production usually requires an energy investment. Drilling for oil or building a wind power plant requires energy. The fossil fuel resources (see above) that are left are often increasingly difficult to extract and convert. They may thus require increasingly higher energy investments. Sony VAIO VPCF118FJ/W Battery

If the investment is greater than the energy produced, then the fossil resource is no longer an energy source. This means that a large part of the fossil fuel resources and especially the non-conventional ones cannot be used for energy production today.Sony VAIO VPCF119FC Battery

Such resources may still be exploited economically in order to produce raw materials forplastics, fertilizers or even transportation fuel but now more energy is consumed than produced. (They then become similar to ordinary mining reserves, economically recoverable but not net positive energy sources.) Sony VAIO VPCF119FC/BI Battery

New technology may ameliorate this problem if it can lower the energy investment required to extract and convert the resources, although ultimately basic physics sets limits that cannot be exceeded.

Between 1950 and 1984, as the Green Revolution transformed agriculture around the globe, world grain production increased by 250%.Sony VAIO VPCF119FJ/BI Battery

The energy for the Green Revolution was provided by fossil fuels in the form of fertilizers (natural gas), pesticides (oil), andhydrocarbon fueled irrigation. The peaking of world hydrocarbon production (peak oil) may lead to significant changes, and require sustainable methods of production.Sony VAIO VPCF11AFJ Battery

Natural-gas condensate is a low-density mixture of hydrocarbon liquids that are present as gaseous components in the raw natural gas produced from many naturalgas fields.

It condenses out of the raw gas if the temperature is reduced to below the hydrocarbon dew point temperature of the raw gas.Sony VAIO VPCF11AGJ Battery

The natural gas condensate is also referred to as simply condensate, or gas condensate, or sometimes natural gasoline because it contains hydrocarbons within the gasoline boiling range. Raw natural gas may come from any one of three types of gas wells:Sony VAIO VPCF11AHJ Battery

• Crude oil wells—Raw natural gas that comes from crude oil wells is called associated gas. This gas can exist separate from the crude oil in the underground formation, or dissolved in the crude oil.
• Dry gas wells—These wells typically produce only raw natural gas that does not contain any hydrocarbon liquids. Such gas is called non-associated gas.Sony VAIO VPCF11JFX/B Battery
• Condensate wells—These wells produce raw natural gas along with natural gas liquid. Such gas is also non-associated gas and often referred to as wet gas.

Composition of natural-gas condensate

There are hundreds of wet gas fields worldwide and each has its own unique gas condensate composition. Sony VAIO VPCF11M1E Battery

However, in general, gas condensate has a specific gravityranging from 0.5 to 0.8 and may contain:

• Hydrogen sulfide (H2S)
• Thiols traditionally also called mercaptans (denoted as RSH, where R is an organic group such as methyl, ethyl, etc.)
• Carbon dioxide (CO2) Sony VAIO VPCF11M1E/H Battery
• Straight-chain alkanes having from 2 to 12 carbon atoms (denoted as C2 to C12)
• Cyclohexane and perhaps other naphthenes
• Aromatics (benzene, toluene, xylenes, and ethylbenzene) Sony VAIO VPCF11MFX/B Battery

Separating the condensate from the raw natural gas

There are literally hundreds of different equipment configurations for the processing required to separate natural gas condensate from a raw natural gas. The schematic flow diagram to the right depicts just one of the possible configurations.Sony VAIO VPCF11S1E Battery

The raw natural gas feedstock from a gas well or a group of wells is cooled to lower the gas temperature to below its hydrocarbon dew point at the feedstock pressure and that condenses a good part of the gas condensate hydrocarbons. Sony VAIO VPCF11S1E/B Battery

The feedstock mixture of gas, liquid condensate and water is then routed to a high pressure separator vessel where the water and the raw natural gas are separated and removed. The raw natural gas from the high pressure separator is sent to the main gas compressor.Sony VAIO VPCF11Z1E Battery

The gas condensate from the high pressure separator flows through a throttling control valve to a low pressure separator. The reduction in pressure across the control valve causes the condensate to undergo a partial vaporization referred to as a flash vaporization. Sony VAIO VPCF11Z1E/BI Battery

The raw natural gas from the low pressure separator is sent to a "booster" compressor which raises the gas pressure and sends it through a cooler and on to the main gas compressor. The main gas compressor raises the pressure of the gases from the high and low pressure separators to whatever pressure is required for the pipeline transportation of the gas to the raw natural gas processingplant.Sony VAIO VPCF11ZHJ Battery

The main gas compressor discharge pressure will depend upon the distance to the raw natural gas processing plant and it may require that a multi-stage compressor be used.

At the raw natural gas processing plant, the gas will be dehydrated and acid gases and other impurities will be removed from the gas.Sony VAIO VPCF127HGBI Battery

Then, the ethane (C2), propane(C3), butanes (C4), and pentanes (C5)—plus higher molecular weight hydrocarbons referred to as C5+—will also be removed and recovered as byproducts.

The water removed from both the high and low pressure separators will probably need to be processed to remove hydrogen sulfide (H2S) before the water can be disposed of or reused in some fashion.Sony VAIO VPCF137HG/BI Battery

Some of the raw natural gas may be re-injected into the gas wells to help maintain the gas reservoir pressures.

Drip gas

Drip gas is natural gas condensate, a naturally occurring form of gasoline found near many oil and natural gas wells, in natural gas pipelines, and as a byproduct of natural gas extraction.Sony VAIO VPCS111FM/S Battery

It is also known as "condensate," "natural gasoline," "casing head gas," "raw gas," "white gas," and "liquid gold." Drip gas has industrial uses as a cleaner and solvent, as a lantern and stove fuel, and as a denaturing additive for fuel alcohol.

Historical use in vehicles

Some very early internal combustion engines—such as the first types made by Karl Benz, and early Wright brothers aircraft engines—used natural gasoline, which could be either drip gas or a similar range of hydrocarbons distilled from crude oil.Sony VAIO VPCS115EC Battery

Natural gasoline has an octane rating of about 30 to 50, sufficient for the low-compression engines of the early 20th century. By 1930, improved engines and higher compression ratios required higher-octane, refined gasolines to produce power without knocking or detonation.Sony VAIO VPCS115FG Battery

Beginning in the Great Depression, drip gas was used as a replacement for commercial gasoline by people in oil-producing areas. "In the days of simple engines in automobiles and farm tractors it was not uncommon for anyone having access to a condensate well to fill his tank with 'drip,'" according to the Oklahoma Historical Society. Sony VAIO VPCS117GG Battery

Sometimes it worked fine. "At other times it might cause thundering backfires and clouds of foul-smelling smoke."

Woody Guthrie's autobiographical novel Seeds of Man begins with Woody and his uncle Jeff tapping a natural gas pipeline for drip gas. The gas also has a mention inBadlands, the Terrence Malick movie.Sony VAIO VPCS117GGB Battery

It was sold commercially at gas stations and hardware stores in North America until the early 1950's. The White gas sold today is a similar product but is produced at refineries with the benzene removed.

In 1975, the New Mexico State Police's drip gas detail – three men in pickup trucks – began patrolling oil and gas fields, catching thieves and recovering barrels of stolen gas. The detail stopped its work in 1987.Sony VAIO VPCS118EC Battery

The use of drip gas in cars and trucks is now illegal in many states. It is also harmful to modern engines due to its low octane rating, high heat of combustion and lack of additives. It has a distinctive smell when used as a fuel, which allowed police to catch people using drip gas illegally.Sony VAIO VPCS119FJ/B Battery

Composition

Under the United States Code of Federal Regulations, drip gas consists of butane, pentane, and hexane hydrocarbons. Within set ranges of distillation, drip gas may be extracted and used to denature fuel alcohol.Sony VAIO VPCS119GC Battery,Sony VAIO VPCS11AFJ Battery,Sony VAIO VPCS11AGJ Battery