etüleen

Etüleen, also known as ethylene (ethene), is the simplest alkene and a major industrial chemical. Its formula is C2H4. It is a colorless, flammable gas at room temperature and pressure, with a carbon–carbon double bond that makes it highly reactive in addition reactions. Its reactivity underpins its uses as a building block for numerous materials and chemicals.

Industrially, ethylene is primarily produced by steam cracking of hydrocarbon feedstocks such as naphtha or ethane, followed by purification to remove impurities and moisture; lower-boiling by-products are separated cryogenically. Ethylene readily undergoes polymerization to form polyethylene, one of the most widely produced plastics. It is also a precursor to other important products, including vinyl chloride monomer for PVC and ethylbenzene for styrene production (polystyrene comes from styrene). In addition, ethylene occurs naturally in the environment and is produced by living plants as a gaseous hormone that influences fruit ripening, flower wilting, and leaf abscission.

Safety and regulation: Ethylene is highly flammable and forms explosive mixtures with air at certain concentrations, so handling requires proper ventilation, leak detection, and avoidance of ignition sources. It is typically stored and transported as a compressed gas or cryogenic liquid under pressure.