How Fractional Distillation Works
Ever wondered how we get petrol for cars from thick black crude oil? It's all about fractional distillation! This process splits crude oil into useful products by heating it and separating the components.
The process begins by heating crude oil to high temperatures (around 350°C). When heated, different parts of the crude oil turn into vapours at different temperatures. The shorter chain hydrocarbons (like those in petrol) have lower boiling points, so they vapourise first and rise to the top of the fractionating column.
Meanwhile, the longer chain hydrocarbons (like those in diesel and bitumen) have higher boiling points. They vapourise last and stay near the bottom of the column. As the vapours rise through the column, they cool and condense at different heights depending on their boiling points.
Remember this: Temperature decreases as you move up the fractionating column! The top is cool (about 25°C) while the bottom remains hot (around 350°C).
The whole process works because different hydrocarbons have different properties. Those with fewer carbon atoms require less energy to boil, while those with more carbon atoms need more energy to break their stronger bonds.
