Alternative Fuels

The definition of Alternative Fuel varies according to the context of its usage. In the context of petroleum substitutes, the term 'alternative fuel' can imply any available fuel or energy source, and does not necessarily refer to a source of renewable energy. In the context of environmental sustainability, 'alternative fuel' often implies an ecologically benign renewable fuel. Alternative Fuels, also known as non-conventional fuels, are any materials or substances that can be used as a fuel, other than conventional fuels. Conventional fuels include: fossil fuels (petroleum (oil), coal, propane, and natural gas), and also in some instances nuclear materials such as uranium. Some well known alternative fuels include biodiesel, ethanol, butanol, chemically stored electricity (batteries and fuel cells), hydrogen, methane, natural gas, vegetable oil, biomass, and peanut oil.

Liquid hydrogen
Liquid hydrogen is the element hydrogen in the liquid state. It is a common liquid rocket fuel for rocket applications. In the aerospace industry, its name is often abbreviated to LH2. Hydrogen is found naturally in the molecular H2 form, thus the H2 part of the name.

Biomass
Biomass, in the energy production industry, refers to living and recently dead biological material which can be used as fuel or for industrial production. Most commonly, biomass refers to plant matter grown for use as biofuel, but it also includes plant or animal matter used for production of fibres, chemicals or heat. Biomass may also include biodegradable wastes that can be burnt as fuel. It excludes organic material which has been transformed by geological processes into substances such as coal or petroleum.

Ammonia
Liquid ammonia was used as the fuel of the rocket airplane, the X-15. Although not as powerful as other fuels, it left no soot in the reusable rocket engine, and has about the same density as the oxidizer, liquid oxygen, which simplified the aircraft's keeping the same center of gravity in flight. Anhydrous ammonia is a practical clean (CO2-free) and renewable fuel which can be and has been used to replace fossil fuel in powering internal combustion engines.[21] However, since the current, large scale methods of producing ammonia create CO2, it is debatable whether using ammonia as a fuel for internal combustion engines would reduce the overall global emissions of CO2.

Synthetic fuel
Synthetic fuel or synfuel is synfuel is any liquid fuel obtained from coal, natural gas, or biomass. It can sometimes refer to fuels derived from other solids such as oil shale, tar sand, waste plastics, or from the fermentation of biomatter. It can also (less often) refer to gaseous fuels produced in a similar way. The process of producing synfuels is often referred to as Coal-To-Liquids (CTL), Gas-To-Liquids (GTL) or Biomass-To-Liquids (BTL), depending on the initial feedstock. The best known synthesis process is the Fischer-Tropsch synthesis which was used on a large scale in Germany during World War II. Other processes include the Bergius process, the Mobil process and the Karrick process. An intermediate step in the production of synthetic fuel is often syngas, a stoichiometric mixture of carbon monoxide and hydrogen, which is sometimes directly used as an industrial fuel.



Natural gas
Natural Gas is a gaseous fossil fuel consisting primarily of methane but including significant quantities of ethane, butane, propane, carbon dioxide, nitrogen, helium and hydrogen sulfide. It is found in oil fields and natural gas fields, and in coal beds (as coalbed methane). When methane-rich gases are produced by the anaerobic decay of non-fossil organic material, these are referred to as biogas. Sources of biogas include swamps, marshes, and landfills (see landfill gas), as well as sewage sludge and manure by way of anaerobic digesters, in addition to enteric fermentation particularly in cattle. Natural gas is often informally referred to as simply gas, especially when compared to other energy sources such as electricity. 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.

Future energy development
Main article: Future energy development
Extrapolations from current knowledge to future energy development 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. 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.
Existing technologies for new energy sources, such as new renewable energy technologies, nuclear fission and fusion are promising, but need sustained research and development, including consideration of possible harmful side effects. Artificial Photosynthesis is another energy technology being researched and developed



Vocabulário:

approaches: aproximações;
coal: carvão;
decay: deteriorização;
harmfull: prejudicial;
knowledge: conhecimento;
landfil: aterrar;
manure: estrume;
sewage: esgoto;
sludge: lama;
soot: fuligem;
source: fonte;
swamp: pântano;
undergo: submeter-se.


Questões:


(1) Qual a constituição do gás natural?

(2) Qual a comum aplicação do hidrogênio líquido?

(3) Qual é o combustível que ocorre a partir da queima de desperdícios biodegradáveis?

(4) Segundo o texto quais as possíveis definições de combustíveis alternativos?

(5) De acordo com o texto de onde pode ser obtido o combustível sintético? Quais as ultizações citadas no texto desse combustível?




Nomes:
Priscila Fabiana, Raquel Ricciardi, Sellis Christine, Talita Dayane e Talita Rodrigues
N°
33, 34, 36, 39 e 40