'''Liquified Petroleum Gas''' (also called
Liquefied Petroleum Gas,
Liquid Petroleum Gas,
LPG,
LP Gas, or
autogas) is a mixture of
hydrocarbon gases used as a
fuel in heating appliances and vehicles, and increasingly replacing
fluorocarbons as an aerosol propellant and a refrigerant to reduce damage to the
ozone layer. Varieties of LPG bought and sold include mixes that are primarily
propane, mixes that are primarily
butanes, and mixes including both
propane and
butanes.
Propylene and butylenes are usually also present in small concentration. A powerful odorant,
ethanethiol, is added so that leaks can be detected easily. LPG is manufactured during the refining of crude oil, or extracted from oil or
gas streams as they emerge from the ground.
At normal temperatures and pressures, LPG will evaporate. Because of this, LPG is supplied in pressurised
steel bottles. In order to allow for thermal expansion of the contained liquid, these bottles should not be filled completely; typically, they are filled to between 80% and 85% of their capacity. The ratio between the volumes of the vaporised gas and the liquified gas varies depending on composition, pressure and temperature, but is typically around 250:1. The pressure at which LPG becomes liquid, called its
vapor pressure, likewise varies depending on composition and temperature; for example, it is approximately 2.2
bar for pure butane at 20 °C, and approximately 22
bar for pure propane at 55 °C.
LPG was first produced in 1910 by Dr. Walter Snelling, and the first commercial products appeared in 1912. It currently provides about 3% of the energy consumed in the
United States.
LPG is widely used as a "green"
fuel for
internal combustion engines as it decreases
exhaust emissions. It has a RON that is between 90 and 110 and an energy content (
HHV) that is between 25.5 megajoule/liter (for pure propane) and 28.7 megajoule/liter (for pure butane.)
Toyota made a number of LPG engines in their
1970s M,
R, and
Y engine families.
Currently, a number of
automobile manufacturers -
Citroën,
Daewoo,
Fiat,
Ford,
Hyundai,
Opel/
Vauxhall,
Peugeot,
Renault,
Saab and
Volvo- have
OEM bi-fuel models that will run equally well on both LPG and petrol.
LPG as cooking fuel
According to the 2004 Census of
India, of Indian households or 70.0 million Indian households used LPG as cooking fuel in 2004. 76.64% of such households were from urban India making up 48% of urban Indian households as compared to a usage of 5.7% only in
rural Indian households. LPG is subsidised by the government. Increase in LPG prices has been a politically sensitive matter in India as it potentially affects the
urban middle class voting pattern.
LPG was once a popular cooking fuel in
Hong Kong; however, the continued expansion of
town gas to buildings has reduced LPG usage to less than 24% of residential units.
See also
External links
Category:Petroleum
Category:Fuels
es:Gas licuado del petróleo
fr:Gaz de pétrole liquéfié
id:Elpiji
nl:LPG
ja:液化石油ガス
pl:LPG
pt:GPL (combustível)
zh:液化石油气