The petrochemical manufacturing process begins with a “feedstock”.
A feedstock is a raw material that is used to make a useful product in an industrial process. Natural gas liquids and naphtha that is created from crude oil during the refining process are used as feedstocks to manufacture a wide variety of petrochemicals.
When using natural gas liquids to create petrochemicals, we separate it into ethane, propane and butanes.
Most people know propane as what you use to power your barbeque and butane as what fuels your lighter. They can also be used as feedstocks to create petrochemicals. Ethane is an important feedstock because its structure is the simplest of the hydrocarbons, and it can be transformed into novel plastics that have remarkable and useful properties.
Ethane is first converted to ethylene using a process called cracking.
Ethane is fed into a large, complex piece of equipment called a cracker. It uses high temperatures to crack the bonds between carbons. Physics then takes over, and the carbons form two bonds (also known as a double-bond) with each other that make a new hydrocarbon molecule called ethylene.
Propane and butane undergo additional processes to make propylene and butylenes (e.g., butadienes).
Propane and butane can be cracked to make propylene and butylenes, the same way ethane is cracked to make ethylene. They can also undergo a newer process that plucks hydrogen atoms from them to form the double-bonds.
Ethylene, propylene and butylenes, along with benzene, toluene and xylenes, are the fundamental building blocks of plastics.
These six petrochemicals can be made into plastics, nylons, polyesters, etc., that are then transformed into items like bicycle helmets, lightweight car bumpers, space suits, medical devices and wind turbines.
Petrochemicals don’t just make plastic; they also enable progress.
These chemicals and the specialty chemicals created from them have special properties that just simply make the products we use better. They make nylon stronger so seatbelts and parachute straps are safer. They make workout clothes sweat resistant. They make cars lighter so they are more fuel efficient.