Liquefied petroleum gas (LPG, LP gas, or condensate) is a gaseous fuel made from gasoline containing a flammable mixture of hydrocarbon gases, most commonly propane, butane, and propylene. However, the latter two usually make up 5% or less of the mix.
LPG is used as a gaseous fuel in heating, cooking equipment, and vehicles. It is increasingly being used as an aerosol and refrigerant fuel, replacing chlorofluorocarbons to reduce ozone depletion. If it is used specifically as a vehicle fuel, it is often referred to as LPG.
The LPG variants purchased and sold include blends that are primarily propane, primarily butane, and most often blends containing propane and butane. In winter, the Northern Hemisphere mix contains more propane, while in summer it contains more butane. There are two main types of LPG sold in the United States: commercial propane and HD-5. These specifications are published by the Gas Processors Association (GPA) and the American Society for Testing and Materials. Propane/butane blends are also listed in this specification.
Uses of LPG Gas
LPG has a wide range of applications in many different markets as an efficient fuel tank in the agricultural, recreational, hospitality, industrial, construction, marine, and fisheries sectors. It can be used as a fuel for cooking, central heating, and hot water, and is a very cheap and efficient way to heat a home off the grid. If you want to know about CNG Gas, then read this article.
LPG is used for cooking in many countries for reasons of economy, convenience, or because it is the preferred fuel source.
In India, nearly 8.9 million tonnes of LPG were consumed in households in the six months between April and September 2016, mainly for cooking. The number of domestic connections is 215 million (ie one connection for six people) with a circulation of more than 350 million LPG cylinders. Most of the LPG needs are imported. The supply of city gas pipelines in India has not yet been massively developed. LPG is subsidized by the Indian government for private customers. The increase in LPG prices is a sensitive political issue in India because it can affect the behavior of middle-class voters.
LPG was once the standard cooking fuel in Hong Kong; however, the continued expansion of city gas into new buildings has reduced LPG consumption to less than 24% of residential units. However, with the exception of electric, induction, or infrared stoves, LPG stoves are the only type available in most suburban villages and many public housing developments.
LPG is the most common cooking fuel in urban areas of Brazil and is used in almost all homes except for the cities of Rio de Janeiro and São Paulo, which have natural gas pipeline infrastructure. Since 2001, poor families have received government subsidies (“Vale Gás”) which are used specifically for the purchase of LPG. Since 2003, this subsidy has been part of the government’s main social assistance program (“Bolsa Família”). In addition, since 2005, the state oil company Petrobras has differentiated between LPG for cooking and LPG for other uses, setting lower prices for the former. This is the result of a directive from the Brazilian federal government, but its termination is currently under discussion.
Especially in Europe and rural areas in many countries, liquefied gas can be an alternative to electric heating, oil, or kerosene. LPG is most often used in areas that do not have direct access to natural gas pipelines.
LPG can be used as an energy source for combined heat and electricity (CHP) generation. CHP is the process of generating useful electrical power and heat from a single fuel source. This technology allows the use of propane-butane not only as a fuel for heating and cooking but also for decentralized power generation.
LPG can be stored in many ways. LPG, like other fossil fuels, can be combined with renewable energy sources to offer greater reliability while achieving reduced CO2 emissions. However, unlike renewable wind and solar power, LPG can be used as a self-sustaining source of electricity without the high cost of storing electrical energy.
In many climates, renewable sources such as solar and wind power still require the construction, installation, and maintenance of reliable primary energy sources such as LPG plants to provide year-round electricity. 100% wind/solar is possible, with the caveat that the cost of the additional generating capacity required to charge the battery plus the cost of storing the battery’s electricity makes this option economically viable only in some situations.
When LPG is used to fuel an internal combustion engine, it is often referred to as autogas or autopropane. It has been used in some countries as a gasoline alternative to spark ignition engines since the 1940s. In some countries, there are additives in fluids that increase engine life, and the ratio of butane to propane is quite strictly maintained in LPG fuels.
Two recent studies examined LPG thermal fuel blends and found that smoke emissions and fuel economy were reduced, but hydrocarbon emissions increased. The study was divided into CO emissions, one found a significant increase and the other a slight increase at low engine loads but a significant decrease at high engine loads.
The advantages are that it is non-toxic, non-corrosive and does not contain tetraethyl lead or any additives, and has a high octane rating (102-108 RON depending on local specifications). It burns cleaner than gasoline or heating oil and is very free of the particles it contains.
LPG has a lower energy density per liter than gasoline or heating oil, resulting in higher equivalent fuel consumption. Many governments tax LPG lower than gasoline or heating oil, which helps offset the higher consumption of LPG than gasoline or heating oil.
However, in many European countries, these tax breaks are often offset by much higher annual taxes for LPG cars than for petrol or diesel cars. Propane is the third most widely used motor fuel in the world. According to estimates for 2013, more than 24.9 million vehicles worldwide are powered by propane gas. More than 25 million tonnes (more than 9 billion US gallons) are used each year as automotive fuel.
LPG is a device for providing off-grid cooling, usually using a gas absorption chiller.
Blended of pure dry propane (refrigerant designation R-290) and isobutane (R-600a), the “R-290a” blend has negligible ozone depletion potential and very low global warming potential and can serve as a functional replacement for R-12. , R-22, R-134a, and other chlorofluorocarbon or hydrofluorocarbon refrigerants in conventional stationary refrigeration and air conditioning systems.
Such substitutions are widely prohibited or discouraged in automotive air conditioning systems because of the significant risk of fire or explosion from the use of flammable hydrocarbons in systems originally designed to carry non-flammable refrigerants.
Suppliers and advocates of hydrocarbon refrigerants oppose the ban on the grounds that such incidents are very few compared to the number of hydrocarbon-filled vehicle air conditioning systems. A special test conducted by a University of New South Wales professor accidentally tested the worst-case scenario of a sudden and complete release of refrigerant into the passenger compartment, followed by subsequent ignition.
He and several other people in the car suffered minor burns to their faces, ears, and hands, and several people around had lacerations from the shattered passenger window. No serious injuries.
Chlorofluorocarbons (CFCs) were once widely used as fuels, but since the Montreal Protocol came into force in 1989, they have been replaced in almost every country due to the negative impact of CFCs on the earth’s ozone layer.
The most common substitutes for CFCs are mixtures of volatile hydrocarbons, typically propane, n-butane, and isobutane. Dimethyl ether (DME) and methyl ethyl ether are also used. They all have the disadvantage that they are flammable.
Nitrous oxide and carbon dioxide are also used as blowing agents to promote food products (eg whipped cream and cooking spray). Medical aerosols such as asthma inhalers using hydrofluoroalkanes (HFA): HFA 134a (1,1,1,2,-Tetrafluoroethane) or HFA 227 (1,1,1,2,3,3,3-Heptafluoropropane), or a combination of the two.
Recently, liquid hydro-fluoro olefin (HFO) propellants have been widely used in aerosol systems because of their relatively low vapor pressure, low global warming potential (GWP), and non-flammable. Hand pump sprayers can also be used as an alternative to stored propellants.