I. Basic knowledge of liquefied petroleum gas (LPG), source and composition of LPG.
Liquefied petroleum gas (LPG) refers to oil and gas fields and the tail gas in the process of petroleum distillation and the by-products of chemical production. It is composed of a variety of hydrocarbons, mainly by propane, butane, propylene, butene and other low molecular hydrocarbon mixture, also contains a small amount of impurities, commonly known as carbon three carbon four.LPG, abbreviated as LPG or LPG for short, is a liquid mixture of propane (C3H8) and butane (C4H10), which is mainly composed of propane (C3H8) and butane (C4H10), and usually stored under pressure or low temperature. It is usually accompanied by a small amount of propylene (C3H6) and butene (C4H8), as well as a small amount of alkane (C5H12) and pentene (C5H) 10) and other components, is a clean gas energy, mainly used for catering, civil and industrial and commercial combustion needs and such as gasoline additives, synthetic plastics, rubber, fiber and production of medicine, explosives and other chemical deep processing needs.
II. Why does a liquefied petroleum gas (LPG) tank trailer truck explode and cause so much damage?
Liquefied petroleum gas (LPG) is a gaseous by-product of petroleum catalytic cracking, liquefied after pressure and cooling, and stored in cans in the form of colorless volatile liquid. They are mainly propane and butane, which generally contain more than 60%. Once the tanks, valves and pipeline rupture, liquefied petroleum gas, meets the air will get back in the gas phase, in general, propane and butane “flash point” and “spontaneous combustion point” are very low, flash point is 104 ℃ – propane, butane flash point is – 60 ℃, volatile in the air after reaching a certain concentration range, electrostatic or fire explosion would happen the first time.
The ignition temperature of LPG is lower than that of other fuels, generally between 430℃ and 460℃. The explosion limit is narrow, 1.5%-9.5%, and the lower limit of explosion is lower than other gas, so the risk is relatively large, sporadic electric spark can cause combustion and explosion. Therefore, in the storage and transportation of such dangerous chemicals as liquefied petroleum gas (LPG), the high pressure resistant storage vessels used, the safety awareness of transportation and storage personnel, and the safety accessories of tank trucks (including safety valves, valve sealing gaskets, weld quality, compressive strength, etc.) are all required. However, the reality is that due to the high maintenance and management costs in the later stage, production enterprises often do not pay much attention to end-product management based on cost and other factors. Therefore, transportation enterprises need to constantly strengthen management, strictly in accordance with the normative operation, and strengthen the safety education and emergency drills of management and transportation personnel.