Liquified petroleum gas
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 emissionss. 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.
| Table of contents |
|
2 See also 3 External links |
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