With the development of the petrochemical industry, liquefied petroleum gas (LPG), as a basic chemical raw material and a new type of fuel, has received increasing attention. In chemical production, LPG is a byproduct obtained from the catalytic and thermal cracking of crude oil in oil refineries. The main components of catalytic cracking gas are as follows (%): hydrogen 5-6, methane 10, ethane 3-5, ethylene 3, propane 16-20, propylene 6-11, butane 42-46, butene 5-6, and hydrocarbons containing more than 5 carbon atoms 5-12. It is used to produce synthetic plastics, synthetic rubber, synthetic fibers, and pharmaceuticals, explosives, dyes, and other products.
Liquefied petroleum gas is a colorless, volatile, and flammable liquid obtained by pressurizing and cooling refinery gas or natural gas. When the concentration of LPG in the air reaches a certain range, it will explode upon contact with an open flame. LPG obtained from refinery gas mainly consists of propane, propylene, butane, and butene (which can be a mixture of one or more hydrocarbons), and contains small amounts of pentane, pentene, and trace amounts of sulfide impurities. Oxysulfide is removed by an alcohol amine absorption tower, and sulfides are removed by alkaline washing [1]. Liquefied gas obtained from natural gas (including associated gas from oil fields) is basically free of olefins. The top product of the gasoline stabilization tower in the refinery is liquefied petroleum gas. It can be used as engine fuel, household fuel, and basic organic synthesis raw material.