Petroleum chemical industry, abbreviated as petrochemical industry. Generally refers to the chemical industry that uses petroleum and natural gas as raw materials. The scope is very broad and there are many products. Crude oil undergoes cracking (cracking), reforming and separation to provide basic raw materials such as ethylene, propylene, butene, butadiene, benzene, toluene, xylene, naphthalene, etc. From these basic raw materials, various basic organic raw materials such as methanol, formaldehyde, ethanol, acetaldehyde, acetic acid, isopropanol, acetone, phenol, etc. can be produced.