[Q&A] 3/21/2017

Answer: The main components of liquefied petroleum gas are propane and butane, which are hydrocarbons containing three and four carbon atoms respectively; they are commonly referred to as C3 and C4 compounds. Both are flammable substances. Depending on their composition, its boiling point range at normal temperature and pressure is from -42.7°C to -0.5°C. As a liquid turns into a gas, its volume increases by about 250 times, while absorbing a large amount of heat. (1) Flammability and explosiveness. Liquefied petroleum gas can burn, occurring in two forms: stable combustion and explosion. When liquefied petroleum gas leaks and continues to burn when exposed to fire, this phenomenon is called steady combustion. When liquefied petroleum gas leaks, it mixes with air to form an explosive mixture (with an explosion limit of approximately 2%–9%), and when exposed to a fire source, it explodes, usually generating a powerful shock wave and high temperatures. (II) Heavier than air. The gas relative density of liquefied petroleum gas is 1.5 to 2, and its specific gravity is 1.5 to 2 times that of air. Due to its high density, in the event of a leak, liquefied petroleum gas will accumulate in low-lying areas or drift across the ground; once it reaches an explosive concentration, it will explode upon contact with a fire source. (III) Thermal expansion. The liquid density of liquefied petroleum gas decreases as the temperature rises, while its volume increases. Its coefficient of volume expansion for liquids is greater than that of gasoline and kerosene, and it is 10 to 16 times that of water. Therefore, the filling volume of cylinders filled with liquefied petroleum gas must be strictly controlled; otherwise, as the temperature rises, the cylinders are highly likely to burst. (IV) Low ignition energy. The ignition temperature of liquefied petroleum gas is around 430°C to 460°C, which is lower than that of other flammable gases; it requires less ignition energy, and a single spark is sufficient to ignite it. (5) Toxicity. Liquefied petroleum gas has low toxicity; at a concentration of 1% in the air, it is safe for humans to be in that environment for 10 minutes. When the concentration in the air reaches 10%, a person exposed to this environment for 2 minutes will **. (VI) Chargeability. Liquefied petroleum gas is prone to generating static electricity during storage and transportation; the faster the flow rate, the more likely static electricity will be produced. (7) Corrosivity. Liquefied petroleum gas is corrosive to containers, pipes, rubber hoses, seals, etc.

Main components: ethylene, ethane, propane, propylene, butane, butylene, etc. Highly flammable; when mixed with air, it can form explosive mixtures. There is a risk of combustion and explosion in the presence of heat sources and open flames. It undergoes violent chemical reactions upon contact with fluorine, chlorine, and the like. Its vapor is heavier than air, allowing it to spread over considerable distances at lower levels; it will catch fire and reignite when exposed to a source of flame.

The main components are butene, propylene, butane, and propane； Its characteristics include flammability and explosiveness, being heavier than air but lighter than water, expanding when heated, having a low ignition temperature and a narrow explosive range, as well as being toxic and corrosive with a high calorific value

The main components are propane, propylene, butane, and butene. It is flammable and explosive; during vaporization, it absorbs a large amount of heat, which can easily cause frostbite to parts of the body that come into contact with it

The main components of liquefied petroleum gas are propane, propylene, butane, and butene

Low-carbon alkanes such as methane are flammable and explosive; they represent clean energy sources

Mainly carbon tiers 3 and 4, with a small amount of carbon tiers 2 and 5; cryogenic, volatile, and flammable

Main characteristics of liquefied petroleum gas: Liquefied petroleum gas refers to hydrocarbon compounds obtained from oil and gas fields as well as during petroleum distillation processes; these compounds are gases at normal temperature and pressure. This hydrocarbon compound is mainly a mixture of low-molecular-weight hydrocarbons such as propane, butane, propylene, and butene, with small amounts of impurities as well. Depending on its components, its boiling point range at normal temperature and pressure is from -42.7°C to -0.5°C. As a liquid turns into a gas, its volume increases by about 250 times, while absorbing a large amount of heat. (1) Flammability and explosiveness. Liquefied petroleum gas can burn, occurring in two forms: stable combustion and explosion. When liquefied petroleum gas leaks and continues to burn when exposed to fire, this phenomenon is called steady combustion. When liquefied petroleum gas leaks, it mixes with air to form an explosive mixture (with an explosion limit of approximately 2%–9%), and when exposed to a fire source, it explodes, usually generating a powerful shock wave and high temperatures. (II) Heavier than air. The gas relative density of liquefied petroleum gas is 1.5 to 2, and its specific gravity is 1.5 to 2 times that of air. Due to its high density, in the event of a leak, liquefied petroleum gas will accumulate in low-lying areas or drift across the ground; once it reaches an explosive concentration, it will explode upon contact with a fire source. (III) Thermal expansion. The liquid density of liquefied petroleum gas decreases as the temperature rises, while its volume increases. Its coefficient of volume expansion for liquids is greater than that of gasoline and kerosene, and it is 10 to 16 times that of water. Therefore, the filling volume of cylinders filled with liquefied petroleum gas must be strictly controlled; otherwise, as the temperature rises, the cylinders are highly likely to burst. (IV) Low ignition energy. The ignition temperature of liquefied petroleum gas is around 430°C to 460°C, which is lower than that of other flammable gases; it requires less ignition energy, and a single spark is sufficient to ignite it. (5) Toxicity. Liquefied petroleum gas has low toxicity; at a concentration of 1% in the air, it is safe for humans to be in that environment for 10 minutes. When the concentration in the air reaches 10%, a person exposed to this environment for 2 minutes will **. (VI) Chargeability. Liquefied petroleum gas is prone to generating static electricity during storage and transportation; the faster the flow rate, the more likely static electricity will be produced. (7) Corrosivity. Liquefied petroleum gas is corrosive to containers, pipes, rubber hoses, seals, etc.