Dictionary of Meaning

<<Back
Please select a letter:
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | 0-9

Liquid Fuels

*** Shopping-Tip: Liquid Fuels
'''Liquid fuels''' are those combustible or energy-generating molecules which can be harnessed to create mechanical energy, usually producing kinetic energy, and which also must take the shape of their container. Most liquid fuels in widespread use are or are dervied from fossil fuels; however, there are several types, such as hydrogen fuel (for automotive use), that are also categorized as liquid fuels. This article deals primarily with the concept of liquid fuels in relation to ground transport. However, others such as rocket fuel also play an important role in the economy.

Fossil fuels
''Main Article: Fossil Fuel'' '''Fossil fuels''' which are also liquid fuels come from dead animals and plants which died many millions of years ago. The most notable of these is gasoline.

Gasoline
''Main Article: Gasoline'' '''Gasoline''' is the most widely used liquid fuel. Gasoline, as it's known in United States and Canada, (known as '''petrol''' in Britain, Australia, New Zealand, and many English-speaking countries) is made of hydrocarbon molecules forming aliphatic compounds, or chains of carbons with hydrogen atoms attached. However, many aromatic compounds (carbon chains forming rings) such as benzene are found naturally in gasoline and cause the health risks associated with prolonged exposure to the fuel. Production of gasoline is achieved by distillation of crude oil. The desirable liquid is separated from the crude oil in refineries. Crude oil is extracted from the ground in several processes, the most commonly seen may be beam pumps. To create gasoline, petroleum must first be removed from crude oil. Gasoline itself is actually not burned, but the fumes it creates ignite, causing the remaining liquid to evaporate. Gasoline is extremely volatile and easily combusts, making any leakage extremely dangerous. Gasoline for sale in most countries carries an octane rating. Octane is a measure of the resistance of gasoline to combusting prematurely, known as engine knocking knocking. The higher the octane rating, the harder it is to burn the fuel, which allows for a higher compression ratio. Engines with a higher compression ratio produce more power (such as in race car engines). However, such engines actually ''require'' a higher octane fuel.

Diesel
''Main Article: Diesel'' Conventional '''diesel''' is similar to gasoline in that it is a mixture of aliphatic hydrocarbons extracted from petroleum. Diesel may cost more or less than gasoline, but generally costs less to produce because the extraction processes used are simpler. Many countries (particularly in Europe) also have lower tax rates on diesel fuels. After distillation, the diesel fraction is normally processed to reduce the amount of sulfur in the fuel. Sulphur causes corrosion in vehicles, acid rain and higher emissions of soot from the tail pipe (exhaust pipe). In Europe, lower sulfur levels than in the United States are legally required. However, recent US legislation will reduce the maximum sulphur content of diesel from 3,000 ppm to 500 ppm by 2007, and 15 ppm by 2010. Similar changes are also underway in Australia, New Zealand and several Asian countries. A diesel engine is a type of internal combustion engine which ignites fuel by compressing it (which in turn raises the temperature) as opposed to using an outside source, such as a spark plug.

Alcohols
Alcohols are a useful type of liquid fuel because they combust rapidly (too rapidly for fossil fuel replacement) and are often cheap to produce. However, their acceptance is hampered by the fact that their production often requires as much or even more fossil fuel than they replaced. In this sense, alcohols are a chemical substance; they are similar chemically, but not identical to, the depressant of the same name (alcoholic beverages).

Butanol
''Main Articles: Butanol, Clostridium acetobutylicum, alcohol as a fuel'' '''Butanol''' is an alcohol which may be used as a fuel with the normal combustion engine, typically as a product of the ferment of biomass with the bacterium ''clostridium acetobutylicum'' (also known as the Weizmann organism). This process was first delineated by Chaim Weizmann in 1916 for the production of acetone from starch for making trinitrotoluene TNT. The advantages of butanol are its high octane rating (over 100) and high energy content, only about 10% lower than gasoline, and subsequently about 50% more energy-dense than ethanol, 100% more so than methanol. Butanol's only major disadvantages are its high flashpoint (95 °F or 35 °C), toxicity (note that toxicity levels exist but are not precisely confirmed to my knowledge), and the fact that the fermentation process for renewable butanol emits a foul odour. NOTE: Making butanol from oil produces no such odour, but the limited supply and environmental impact of oil usage defeats the purpose of alternative fuels. The cost of butanol is about $0.57-$0.58 per pound ($1250-$1320 per ton or $8 approx. per gallon) - so another drawback is its high cost in proportion to ethanol (approx. $1.50 per gallon) and methanol.

Ethanol
''Main Article: Ethanol, Ethanol fuel'' '''Ethanol''', also known as grain alcohol or ethyl alcohol, is most commonly used in alcoholic beverages. However, it may also be used as a fuel, most often in combination with gasoline. For the most part, it is used in a 9:1 ratio of gasoline to ethanol to reduce the negative environmental effects of gasoline. There is increasing interest in the use of a blend of 85% fuel ethanol blended with 15% gasoline. This fuel blend called E85, has a higher fuel octane than premium gasoline, allowing in properly optimized engines increases in both power and fuel economy over gasoline. When used in modern FFV (flexible fuel vehicles) it delivers preformance similar to the gasoline it replaces. [http://en.wikipedia.org/wiki/E85] Ethanol for use in gasoline and industrial purposes may be called a fossil fuel because it is synthesised from the petroleum product ethylene, which is cheaper than production from fermentation of cereal grains or sugarcane.

Methanol
''Main Article: Methanol, Methanol fuel'' '''Methanol''' is the lightest and simplest alcohol, produced from the natural gas component methane. Its application is limited due to its toxicity. Small amounts are used in some gasolines to increase the octane rating. Methanol-based fuels are used in some race cars and model airplanes. Methanol is also called ''methyl alcohol'' or ''wood alcohol'', the latter because it was formerly produced from the distillation of wood.

Hydrogen
''Main Article: Hydrogen car'' '''Hydrogen''' as a fuel is a feasible option for future use as a fuel. Liquid hydrogen is an important consideration because it has a higher density than its gaseous counterpart. Liquid hydrogen would be stored in cryogenic tanks. Its application would be most useful in fuel cells where hydrogen would react with oxygen (obviously this is readily available in the air) to create electricity which would power the vehicle. Unfortunately, widespread use of liquid hydrogen is several decades away. Their application is plagued with several serious problems including production, which may still involve fossil fuels, durability of the fuel cells to common roadway conditions such as bumps, the impracticability of conversion of older cars and difficulties with storage and handling. For a more detailed explanation see the Hydrogen car article.

See also
*Rocket fuel *E85 Category:Fuels see Liquid fuels

*** Shopping-Tip: Liquid Fuels