Fossil fuels methane

As previously discussed, methane is a powerful greenhouse gas, so why would we wish to extract it, perhaps risking its escape to the atmosphere, for purposes of using it as a fuel The primary environmental reason is that methane is considerably less polluting than other fossil fuels. Methane has the highest hydrogen-to-carbon ratio of all fossil fuels (4 1), and therefore, its combustion... 

Calculate AG° for the complete combustion of one mole of the following fossil fuels methane (CH4), ethane (C2H ), propane (C3H8), and -butane (C4H10). Identify any trends that are apparent from these calculations. 

A high-nickel alloy is used for increased strength at elevated temperature, and a chromium content in excess of 20% is desired for corrosion resistance. An optimum composition to satisfy the interaction of stress, temperature, and corrosion has not been developed. The rate of corrosion is directly related to alloy composition, stress level, and environment. The corrosive atmosphere contains chloride salts, vanadium, sulfides, and particulate matter. Other combustion products, such as NO, CO, CO2, also contribute to the corrosion mechanism. The atmosphere changes with the type of fuel used. Fuels, such as natural gas, diesel 2, naphtha, butane, propane, methane, and fossil fuels, will produce different combustion products that affect the corrosion mechanism in different ways. 

Methane from renewable biological sources will never be a major energy resource, yet it can be a valuable addition to the energy supply mix. Nevertheless, whether methane comes from fossil fuel reservoirs or from bioconversions, it is certain to provide useful energy for many years to come. 

See also Climatic Effects Fossil Fuels Gasoline and Additives Governmental Inteiwention in Energy Markets Liquefied Petroleum Gas Methane Natural Gas, Processing and Conversion of Natural Gas, Transportation, Distribution, and Storage of Oil and Gas, Exploration for Oil and Gas, Production of Risk Assesment and Management. 

Gas hydrates are an ice-like material which is constituted of methane molecules encaged in a cluster of water molecules and held together by hydrogen bonds. This material occurs in large underground deposits found beneath the ocean floor on continental margins and in places north of the arctic circle such as Siberia. It is estimated that gas hydrate deposits contain twice as much carbon as all other fossil fuels on earth. This source, if proven feasible for recovery, could be a future energy as well as chemical source for petrochemicals. 

Alternatives to fossil fuels, such as hydrogen, are explored in Box 6.2 and Section 14.3. Coal, which is mostly carbon, can be converted into fuels with a lower proportion of carbon. Its conversion into methane, CH4, for instance, would reduce C02 emissions per unit of energy. We can also work with nature by accelerating the uptake of carbon by the natural processes of the carbon cycle. For example, one proposed solution is to pump C02 exhaust deep into the ocean, where it would dissolve to form carbonic acid and bicarbonate ions. Carbon dioxide can also be removed from power plant exhaust gases by passing the exhaust through an aqueous slurry of calcium silicate to produce harmless solid products ... 

In the United States, methane is a major energy source used in many homes for cooking and heating of water and indoor air and water. It is commonly known that some power plants and industries use natural gas as a source of energy for generation of electricity and process heat and that this methane is a fossil fuel obtained from gas wells and transmitted throughout the country by gas pipelines. Most people also know that methane bubbles up from polluted swamps where sedimented plant matter is undergoing decomposition. Because of odors from swamps, and the odor due to natural gas additives, methane is incorrectly considered malodorous. 

What has changed in the last few hundred years is the additional release of carbon dioxide by human activities. Fossil fuels burned to run cars and trucks, heat homes and businesses, and power factories are responsible for about 98% of carbon dioxide emissions, 24% of methane emissions, and 18% of nitrous oxide emissions. Increased agriculture, deforestation, landfills, industrial production, and mining also contribute a significant share of emissions (5). For example, in 1997, the United States emitted about one-fifth of total global greenhouse gases. 

Develop technologies for the improved extraction of conventional fossil fuels, including unconventional sources such as oil shale, tar sands, and deep-sea methane hydrates. 

Muradov, N., Hydrogen via methane decomposition An application to decarbonization of fossil fuels, Int. J. Hydrogen Energ., 26,1165, 2001. 

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