Ethylene is produced by steam cracking. Its primary use is as raw material for the manufacture of polyethylene. It is also used as raw material for ethylbenzene (precursor to styrene), ethylene dichloride (precursor to PVC) and ethylene glycol, among many other applications.
Propylene is the second most important starting product in the petrochemical industry after ethylene. Its primary use is as raw material for the manufacture of polypropylene. It is also used for the production of important chemicals such as propylene glycol, propylene oxide, cumene, butyraldehyde, acrylic acid, isopropyl alcohol, acrylonitriles and epoxy resins.
Mixed C4 is a by-product of the steam cracking process. It is primarily used as feedstock in Butadiene Extraction Units (BTD) to recover 1,3-butadiene and other 4-carbon chemicals. One main application of the products is in the manufacture of industrial rubber which is used for tires.
Pyrolysis Gasoline (commonly known as Pygas) is a naphtha-range, high aromatics by-product of the steam cracking process. It is commonly used as feedstock in BTX (Benzene, Toluene and Xylene) extraction units or as a blending component for gasoline.