Liquefied petroleum gas is also known as LP gas, propane, or butane, depending on the mixture and the region of the world. This gas or collection of gases is a highly flammable mixture of hydrocarbon gases. It’s typically used as fuel for cooking equipment, vehicles, and heating appliances. It is beginning to be used more and more as an aerosol as well as a refrigerant. In the past, chlorofluorocarbons were the preferred gases for these uses, but they have been found to damage the ozone layer.
When they are used for vehicles, they are referred to collectively as autogas.
Varieties
LP gas has to be mixed under certain conditions for certain applications, so that it always performs at a high level of efficiency. Usually, the gases contain a mix of both propane and butane, but in different amounts depending on the manufacturer and requirements. In the northern hemisphere, LP gas that is used during the winter contains a majority of propane. In the summer, the mixes contain a majority of butane. That’s because propane and butane have different responses to heat. Propane is more stable in cold temperatures, whereas butane remains stable at much higher temperatures.
Creation
LP gas is created using several different processes and refining mixtures depending on the location where it will be used. LPG gas in QLD is going to have different proportions than it would in the United States, for example, but it will be pretty similar.
LP gas is created by refining “wet natural gas” or petroleum. It is almost completely created from fossil fuels. When companies discover liquid petroleum, natural gas is usually built up in the cavity as well. In the past, companies used to release the natural gas and just burn it off. This was extremely wasteful, and now, many processes have come about to find a use for it. The first commercial products utilising natural gas appeared in 1912.
The natural gas is refined to a point where it is only its constituent hydrocarbons.
Properties
LP gas has a boiling point that is below room temperature, which simply means that it is a gas. The gas is kept in a liquid state in one of two ways—temperature or pressure. In certain circumstances, LP gas can be kept liquid if it’s kept cold enough. If you remember your high school chemistry class, cold temperatures slow down molecular activity, which turns gases into liquids and liquids into solids. The more common way to keep it a liquid is to pressurise it. That’s why you buy LP gas in thick steel containers with pressurised valves. The gas is a liquid in the container, but as soon as you turn on your gas grill or your forklift, the pressure is slowly released, and the liquid reverts to flammable gas.
Unlike some other gases, LP gas is heavier than air. That means it will sink and settle into low spots. This is particularly dangerous when the mixture of LP gas in the air reaches explosive areas. That’s why it’s so important to buy your LP gas from respectable sources with high safety levels.