Overreliance on nonrenewable resources over the past few centuries has revealed their inherent vulnerabilities. In the past few decades, mounting environmental problems, increasing worry over secure supply chains, and economic instability due to volatile energy prices have routinely plagued industrialized and developing nations as they strive to meet ever-growing energy demands. Although there are still technological hurdles to clear before renewable energy can be efficiently exploited, the economic and environmental benefits of renewables suggest that this is a sound area of investment.
Shale gas Shale gas is natural gas produced from shale. Because shale has matrix permeability too low to allow gas to flow in economical quantities, shale gas wells depend on fractures to allow the gas to flow.
Early shale gas wells depended on natural fractures through which gas flowed; almost all shale gas wells today require fractures artificially created by hydraulic fracturing.
Sinceshale gas has become a major source of natural gas in the United States and Canada. History of manufactured gas Town gas is a flammable gaseous fuel made by the destructive distillation of coal. It contains a variety of calorific gases including hydrogencarbon monoxidemethaneand other volatile hydrocarbonstogether with small quantities of non-calorific gases such as carbon dioxide and nitrogenand is used in a similar way to natural gas.
This is a historical technology and is not usually economically competitive with other sources of fuel gas today. Most town "gashouses" located in the eastern US in the late 19th and early 20th centuries were simple by-product coke ovens that heated bituminous coal in air-tight chambers.
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. The coal tar or asphalt that collected in the bottoms of the gashouse ovens was often used for roofing and other waterproofing purposes, and when mixed with sand and gravel was used for paving streets.
Biogas Methanogenic archaea are responsible for all biological sources of methane. Some live in symbiotic relationships with other life forms, including termitesruminantsand cultivated crops. Other sources of methanethe principal component of natural gas, include landfill gasbiogas, and methane hydrate.
When methane-rich gases are produced by the anaerobic decay of non-fossil organic matter biomassthese are referred to as biogas or natural biogas.
Sources of biogas include swampsmarshesand landfillsas well as agricultural waste materials such as sewage sludge and manure by way of anaerobic digesters in addition to enteric fermentationparticularly in cattle.
Landfill gas is created by decomposition of waste in landfill sites.
Excluding water vaporabout half of landfill gas is methane and most of the rest is carbon dioxidewith small amounts of nitrogenoxygenand hydrogenand variable trace amounts of hydrogen sulfide and siloxanes. 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.
The gas can be vented to the atmosphere, flared or burned to produce electricity or heat. Biogas can also be produced by separating organic materials from waste that otherwise goes to landfills. This method is more efficient than just capturing the landfill gas it produces. 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.
Consequently, it may be more economical to burn 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 burned 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.
Other non-methane components may also be removed to meet emission standardsto prevent fouling of the equipment or for environmental considerations.
Co-firing landfill gas with natural gas improves combustion, which lowers emissions. Biogas, and especially landfill gas, are already used in some areas, but their use could be greatly expanded. Experimental systems were being proposed[ when? Gas generated in sewage treatment plants is commonly used to generate electricity.NATNUT Natural Animal Nutrition Unit Purpose This Unit covers the principles of small animal nutrition, including prepared pet foods, alternative.
Energy that is an alternative to the world's most used resources- fossil fuels. It is important because some day we will run out of fossil fuels and because some of the fossil fuels are harmful to our environment.
Introduction. Maintaining or improving soil health is essential for sustainable and productive agriculture. ‘Healthy’ soil will help to push sustainable agricultural productivity close to the limits set by soil type and climate. Key aspects of .
Since Beverley Paine has steadfastly promoted and supported home education as an educational choice for Australia families. Her books and websites aim to demystify education, gently deschooling families so that they may meet their children's individual and unique educational and developmental needs.
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