Many things happen within the downstream sector of the oil and gas industry, but what makes it so important is that it’s the most physically felt sector on a consumer level. The fuel you put in your car, the asphalt itself, every single piece of plastic you touch, and even some pharmaceutical ingredients present today are all the result of the ever expanding downstream, with the petrochemical industry one of its leading contributors.
On a more technical side, the petrochemical industry deals primarily with two main hydrocarbon groups: olefins (like ethylene and propylene) and aromatics (like benzene, toluene, and xylenes). These substances are usually byproducts of the refining process.
Just as an example, naphtha (a heavy material which refineries produce while transforming crude oil into motor fuels), can be fed into a steam cracker which breaks own the hydrocarbon bonds into lighter molecules like ethylene (C2) and propylene (C3), which can be later agglomerated to form giant molecules containing very long chains of carbon atoms called polymers. These polymers are the base substances for the plastic manufacturing industries.
Schematic depicting typical petrochemical plant processing
Apart from plastics, the petrochemical industry is responsible for many other principle end-use products including:
So how is working at a petrochemical plant like?
As a petrochemical engineer, you’ll probably work on monitoring and developing processes like catalytic cracking to break down the complex organic substances found in crude oil to much simpler (and more useful) materials.
This will require cooking up more creative approaches synthesizing new materials, combining different elements and developing new processes that ultimately make modern life easier, safer, and more efficient in product and resource consumption.
The typical tasks of engineers in a petrochemical plant include: