As a domain expert in the field of chemical engineering with a focus on energy sources and their properties, I'm often asked about the specifics of various fuels. Liquefied Petroleum Gas (LPG) is a common topic of interest due to its widespread use in both domestic and commercial settings. Let's delve into the details regarding the freezing point of LPG.
LPG is a mixture of hydrocarbon gases, primarily consisting of propane and butane, which are compressed into a liquid form for storage and transportation. The properties of LPG, including its freezing point, are crucial for its safe and efficient use.
The freezing point of a substance is the temperature at which it transitions from a liquid to a solid state. For LPG, this can vary slightly depending on the exact composition, but generally, the freezing point of the propane component is more relevant because it has a lower freezing point than butane. Propane, which is a major component of LPG, has a freezing point of approximately -187°C (-306.6°F) under atmospheric pressure. However, this value can change with variations in pressure, which is a common scenario when LPG is stored and used.
The statement that LPG turns back into a gas at a very low temperature of -42°C (-43.6°F) seems to be a bit misleading. What actually happens at this temperature is not the freezing point but rather the boiling point of LPG under atmospheric pressure. At this temperature, LPG can boil and turn from a liquid to a gas. This is why LPG is often stored under pressure; it keeps the gas in a liquid state at higher temperatures, facilitating easier storage and transportation.
It's important to note that the melting point and freezing point are technically the same thing; they both refer to the temperature at which a substance changes from a solid to a liquid (melting point) or from a liquid to a solid (freezing point). The provided information about the melting/freezing point of propane at -188°C appears to be a slight error, as the accepted value for the freezing point of pure propane is closer to -187°C.
In summary, the freezing point of LPG, specifically propane, is around -187°C (-306.6°F) under standard atmospheric pressure. The temperature of -42°C (-43.6°F) mentioned is actually the boiling point where LPG transitions from a liquid to a gas, not the freezing point. Understanding these properties is essential for the proper handling and use of LPG to ensure safety and efficiency in its applications.

read more >>

LPG is stored under pressure, as a liquid, in a gas bottle. It turns back into a gas by 'boiling' into gas vapour. This happens at the very low temperature of -42--C. LPG (propane) melting point/freezing point is at -188 --C.May 5, 2018read more >>