Natural gas as source of energy
ACKNOWLEDGEMENT
I Munish kumar of B.Tech MBA (IT) want to express my intense feeling and experienced that I had while making this term paper.
I am really thankful to our Chemistry Mam ‘Mrs. Sonika’ who not only give us this term paper to do but also widen our view in respective topic.
Last but not the least, I would like to thanks my friends who not only encourage me but also helped in completing this term paper.
Introduction to Natural gas : as a source of energy
It is a mixture of hydrocarbons (molecules that contain only carbon and hydrogen and gases (most notably methane, ethane, propane, and butane) that exist naturally in rocks beneath the surface of the earth. it is widely used as a heating source, and in some cases specific portions of the natural gas are used as starting materials in industrial processes. natural gas is the product of the decaying of living matter over millions of years. specific conditions (including low oxygen levels) are necessary for this to occur. the hydrogen gases are trapped in geological formations known as anticlines. each of the major hydrocarbon components of natural gas is used as a fuel source.before natural gas can be used as a fuel, it must undergo extensive 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, and sometimes helium and nitrogen.natural gas is a versatile source of energy, which can be used by different actors. heating and electricity generation have been the main traditional uses.
Description/technical characteristics
Natural gas is colourless, odourless, tasteless, shapeless and lighter than air. it is gaseous at any temperature over -161° c. when it is at its natural state, it is not possible to see or smell natural gas. for safety reasons, a chemical odorant that smells a little like rotten eggs, mercaptan, is added to natural gas so that it can be smelled if there is a gas leak.
Natural gas is a mixture of light hydrocarbons including methane, ethane, propane, butanes and pentanes. Other compounds found in natural gas include co2, helium, hydrogen sulphide and nitrogen. the composition of natural gas is never constant, however, the primary component of natural gas is methane (typically, at least 90%), which has a simple hydrocarbon structure composed of one carbon atom and four hydrogen atoms (ch4). methane is highly flammable, burns easily and almost completely, while it emits very little air pollution. natural gas is neither corrosive nor toxic, its ignition temperature is high, and it has a narrow flammability range, making it an inherently safe fossil fuel compared to other fuel sources. in addition, because of its specific gravity of 0.60, lower than that of air (1.00), natural gas rises if escaping, thus dissipating from the site of any leak.
The carbon and hydrogen in natural gas are thought to have originated from the remains of plants and animals that were accumulated at the bottom of lakes and oceans over millions of years. After having been buried under huge layers of other sediments, the organic material is transformed into crude oil and natural gas as a result of the high pressure from the layers of sediments and the heat from the earth’s core. The oil and gas are then squeezed out of the marine shales in which they were deposited, and from there go into porous sedimentary rocks. oil and gas migrates upward through the porous rock, as it is less dense than the water, which fills the pores. Several different types of oil and gas “traps” exist.
Occurance of natural gas
Natural gas is found throughout the world in reservoirs deep beneath the surface of the earth and floor of the oceans. It forms as pockets of gas over crude oil deposits or is trapped in porous rock formations. Natural gas can be found in oil deposits, as associated natural gas, although non-associated natural gas is often found without the presence of oil.
When natural gas is cooled to a temperature of approximately -260°f at atmospheric pressure, it condenses to a liquid called liquefied natural gas (lng). One volume of this liquid takes up about 1/600th the volume of natural gas. lng weighs less than one-half that of water, actually about 45% as much. lng is odourless, colourless, non-corrosive, and non-toxic. When vaporized it burns only in concentrations of 5% to 15% when mixed with air. Neither lng, nor its vapour, can explode in an unconfined environment. Since lng takes less volume and weight, natural gas is liquefied for ease of storing and transporting.
Natural gas is considered as a clean fuel because of its environmentally friendly properties: commercialised natural gas is practically sulphur free and thus it produces virtually no sulphur dioxide (so2), natural gas emits lower levels of nitrogen oxides (nox) emissions than oil or coal and emissions of carbon dioxide (co2) are less than those of other fossil fuels (according to eurogas 40-50% less than coal and 25-30% less than oil).1]
Natural gas – chemical composition.
The primary component of natural gas is methane (ch4), the shortest and lightest hydrocarbon molecule. it may also contain heavier gaseous hydrocarbons such as ethane (c2h6), propane (c3h8) and butane (c4h10), as well as other sulphur containing gases, in varying amounts, see also natural gas condensate
Natural gas is used to produce steel, glass, paper, clothing, brick, electricity and as an essential raw material for many common products. Some products that use natural gas as a raw material are: paints, fertilizer, plastics, antifreeze, dyes, photographic film, medicines, and explosives.
Slightly more than half of the homes in the United States use natural gas as their main heating fuel. Natural gas is also used in homes to fuel stoves, water heaters, clothes dryers, and other household appliances.
The major consumers of natural gas in the United States in 2008 included:
- Electric power sector – 6.7 trillion cubic feet (Tcf)
- Industrial sector – 7.9 Tcf
- Residential sector – 4.9 Tcf
- Commercial sector – 3.1 Tcf
Storage of natural gas
in smaller fueling locations and on vehicles, natural gas is stored in thick-walled steel, aluminum, or composite tanks built to last more than 20 years.
Fossil fuel
A fuel that is derived from the decay of plant or animal life; coal, oil, and natural gas are the fossile fuel. fossil fuels are non renewable energy.because they take millions of years to form and reserves are being depleted much faster than new ones are being formed. concern about fossil fuel supplies is one of the causes of regional and global conflicts. the production and use of fossil fuels raise environmental concerns. a global movement toward the generation of renewable energy is therefore under way to help meet increased energy needs. 3]
Liquefied natural gas & uses as source of energy
The ability to liquefy the components of natural gas (either as a mixture or in isolation) has made natural gas much more practical as a energy source.. the liquefaction of natural gas’s components of the different boiling points of methane, ethane, and other gases as a way of purifying each substance. a combination of refrigeration and increased pressure allows the individual gases to be stored and transported conveniently. at one time, the natural gas which often accompanied petroleum.in the ground was simply burned off as a means of getting rid of it. recently, however, this gas has been collected, liquefied and used along with the petroleum.4]
Residential uses as source of energy
Residential applications are the most commonly known use of natural gas. it can be used for cooking, washing and drying, water warming, heating and air conditioning. domestic appliances are increasingly improved in order to use natural gas more economically and safely. operating costs of natural gas equipment are generally lower than those of other energy sources.
Commercial uses as source of energy
Main commercial uses of natural gas are food service providers, hotels, healthcare facilities or office buildings. commercial applications include cooling (space conditioning and refrigeration), cooking or heating.
Compressed natural gas as a source of energy
Compressed natural gas (cng) is a fossil fuel substitute for gasoline (petrol), diesel, or propane fuel. cng is made by compressing natural gas (which is mainly composed of methane [ch4]), to less than 1% of its volume at standard atmospheric pressure. it is stored and distributed in hard containers, at a normal pressure of 200-220 bar (2900-3200 psi), usually in cylindrical or spherical shapes.CNG is used in traditional gasoline internal combustion engine cars that have been converted into bi-fuel vehicles.
Uses as source of energy for transportation
Natural gas vehicles (ngvs)
NGVS are natural gas powered vehicles. natural gas can be used as a motor vehicle fuel in two ways: as compressed natural gas (CNG), which is the most common form, and as liquefied natural gas. natural gas vehicles fleet accounts for about one and a half million vehicles worldwide (according to the international natural gas vehicles association). concerns about air quality in most parts of the world are increasing the interest in using natural gas as a fuel for vehicles. cars using natural gas are estimated to emit 20% less greenhouse gases than gasoline or diesel cars. these vehicles are not a new technology since they have been used since the 1930s. in many countries ngvs are introduced to replace buses, taxis and other public vehicle fleets. natural gas in vehicles is inexpensive and convenient.
Rating in world in transportation fuel
Compressed natural gas (methane) is a cleaner alternative to other automobile fuels such as gasoline (petrol) and diesel. as of 2008 there were 9,6 million natural gas vehicles worldwide, led by pakistan (2.0 million), argentina (1.7 million), brazil (1.6 million), iran (1.0 million), and india (650 thousand).[12][13] 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%). cng-specific engines, however, use a higher compression ratio due to this fuel’s higher octane number of 120-130.
Hydrates
Hydrateshuge 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). however, as of 2009[update] no technology has been developed to produce natural gas economically from hydrates.
Domestic use as a source of energy
Natural gas is supplied to homes, where it is used for such purposes as cooking in natural gas-powered ranges and/or ovens, natural gas-heated clothes dryers, heating/cooling and central heating. home or other building heating may include boilers, furnaces, and water heaters. cng is used in rural homes without connections to piped-in public utility services, or with portable grills. however, due to cng being less economical than lpg, lpg (propane) is the dominant source of rural gas5].
Biogas part of natural gas
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). sources of biogas include swamps, marshes, and landfills (see landfill gas), as well as sewage sludge and manure[4] by way of anaerobic digesters, in addition to enteric fermentation particularly in cattle.
Town gas
Town gas is a 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. this is a historic 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
POWER GENRATION
Power generation electric utilities and independent power producers are increasingly using natural gas to provide energy for their power plants. in general, gas fuelled power plants have lower capital costs, are built faster, work more efficiently and emit less pollution than other fossil fuel power plants. technological improvements in design, efficiency and operation of combined cycle gas turbines and co-generation processes are favouring the use of natural gas in power generation. a combined-cycle power plant uses waste heat to produce more electricity, while natural gas co-generation, also called combined heat and power, produces power and heat that is useful for industry as well as commercial users. this cogeneration reduces pollution emission considerably.
Fuel cells
A fuel cell is an electrochemical device that combines hydrogen fuel and oxygen from the air to produce electricity, heat and water. fuel cells operate without combustion, so they are virtually pollution free. since the fuel is converted directly to electricity, a fuel cell can operate at much higher efficiencies than internal combustion engines, extracting more electricity from the same amount of fuel. the fuel cell itself has no moving parts, making it a quiet and reliable source of power. natural gas is one of the multiple fuels on which fuel cells can operate.
In industries as a source of energy
natural gas is used as an input to manufacture pulp and paper, metals, chemicals, stone, clay, glass, and to process certain foods. gas is also used to treat waste materials, for incineration, drying, dehumidification, heating and cooling, and cogeneration.
Advantages of natural gase
Natural gas is more environmentally friendly that coal or oil. it is composed of methane, which has just one carbon, producing very low carbon emissions. natural gas emits an estimated 70% less carbon dioxide that other fuels. natural gas burns cleaner than heating oil, and does not leave product, like ash, behind.
Natural gas is very popular, and the major source of energy for most consumers. it is conveniently pumped to homes across the country through a network of underground pipeline. it is provided through a local providers and utility companies. 6]
Cost-effective
Natural gas is more cost-effective because it is in abundant supply in the united states. this is further proven because natural gas, as opposed to oil, is not required for import from foreign countries.
Disadvantages
One disadvantage, credited as an advantage as well, is the environmental impact. experts on both sided argue these facts. it is cleaner to burn. however, natural gas is also a non-renewable resource. its use and availability is finite, as opposed to coal or oil. many critics also say natural gas extraction is leaving large craters within the earth.
Combustible
Due to its make-up, natural gas is combustible and easily explosive if handled improperly. with a leak, the gas builds up within a room or structure. when that gas is ignited it causes an explosion. the severity of the explosion depends upon the amount of the leak.
Natural gas is toxic if inhaled, leading to severe health risk or even death.
BIBILOGRAPHY:-
- www.ehow.com
- www.naturalgas.org
- http://tonto.eia.doe.gov/kids/energy.cfm?page=natural_gas_home-basics
- http://www.energyquest.ca.gov/story/chapter08.html
- http://en.wikipedia.org/wiki/Natural_gas
- http://www.consumerenergycenter.org/transportation/afvs/cng.html
- www.ornl.gov/reporter/no16/methane.htm
- http://www.getenergyaware.org/energy-natural-gas.asp
- http://www.kidzworld.com/article/1423-fossil-fuel-energy