In my last post on the surge of oil prices, I received a comment which made me realise that some of us may not be aware how the rising price of crude oil will impact our daily lives. I decided to post some information on crude oil and catalytic cracking which takes place in a typical oil refinery.

Crude oil is separated into fractions by fractional distillation. The fractions at the top of the fractionating column have lower boiling points than the fractions at the bottom. The heavy bottom fractions are often cracked into lighter, more useful products. All of the fractions are processed further in other refining units. I vaguely remember doing this in school when I was 10 as part of a science experiment. Thank goodness for Wikipedia else I would not be able to look this up myself.

The diagram below, we can see the different by-products of crude oil as it goes through the catalytic cracking process. Click on the thumbnail to see view larger diagram.

Schematic flow diagram

Oil refinery - Wikipedia, the free encyclopedia

In simple layman terms, crude oil is heated to various temperature to extract the different by-products. Heavier by-products like asphalt, bitumen and tar used to pave roads generally need more heat in order to be extracted. On the other hand, petroleum products like gas/LPG (Liquid Petroleum Gas), gasoline/petrol, kerosene/jet fuel, diesel and other fuels have lower boiling points. Products with lower boiling points are lighter and have more value I am assuming because of it’s purity compared to heavier products like asphalt.