Distillation:
1. The first step is to heat the fuel oil to very high temperatures in a distillation column, which separates different components of the oil based on their boiling points. The lighter components, such as petrol, vaporise and rise to the top of the column, while heavier components remain at the bottom.
Hydrotreating:
2. The vaporised petrol undergoes hydrotreating to remove impurities, including sulphur and nitrogen compounds, which can affect the quality and performance of the petrol. This process involves reacting the petrol with hydrogen in the presence of a catalyst.
Catalytic Reforming:
3. To improve the octane number and increase the petrol's resistance to knocking, a process called catalytic reforming is carried out. This involves passing the petrol vapour over a catalyst, usually containing platinum or zeolite, at high temperatures and pressure, causing molecular changes to improve the quality of the petrol.
Blending:
4. The reformed petrol may be further blended with other components, such as octane boosters, additives, and specific blending stocks, to achieve the desired specifications and performance characteristics.
Distillation:
5. After blending, the final step involves distillation again to separate the different components of the blended mixture and collect the petrol fraction within the desired boiling range.
It's important to note that the refining process is highly sophisticated, and the exact steps and technologies involved can vary depending on the specific characteristics of the fuel oil and the desired end product. Additionally, environmental regulations and considerations play a significant role in modern refining processes to minimise the impact on the environment.
