New Delhi: Crude oil comes out of the ground as a thick mixture of different hydrocarbons. It cannot be used in vehicles or homes in its raw form. Before it reaches consumers, it goes through large industrial refineries where it is broken down and cleaned into fuels and other usable products.
The process is based on the fact that different components of crude oil boil at different temperatures. Inside a refinery, crude oil is heated to very high temperatures, often above 400 degrees Celsius, until it turns into vapour. This vapour is then sent into tall distillation towers.
These towers are designed with a temperature difference from bottom to top. The bottom stays hot while the top is cooler. As vapour rises, it cools at different levels and separates into different products based on weight and boiling point.
Light components condense first and form petrol. Medium-weight fractions turn into kerosene, while heavier parts settle lower in the tower and form diesel and other heavy fuels.
How much petrol comes from crude oil
According to the US Energy Information Administration, one barrel of crude oil contains about 159 litres. From this, refineries produce around 19 to 20 gallons of petrol, which equals roughly 72 to 76 litres.
In simple terms, 1 litre of crude oil produces about 0.45 to 0.48 litres of petrol. This number can change slightly depending on the quality of crude oil and the type of refinery.
Diesel and kerosene output
Diesel is a heavier fuel compared to petrol and is collected from the middle section of the distillation tower. One barrel of crude oil produces about 11 to 12 gallons of diesel, which comes to around 42 to 45 litres.
This means 1 litre of crude oil gives roughly 0.26 to 0.28 litres of diesel. Diesel is mainly used in trucks, buses and heavy machinery.
Kerosene, which is also known as jet fuel in refined form, is collected from another section of the process. From one barrel of crude oil, refineries produce about 4 to 5 gallons of kerosene or similar fuel.
This equals roughly 0.10 to 0.12 litres per litre of crude oil. It is used in cooking stoves, lamps and aviation fuel.
What happens after distillation
After basic separation, refineries carry out additional processes to improve fuel output. Heavy oil fractions are further broken down to produce more petrol and diesel. Impurities such as sulphur are removed to make fuels cleaner and more suitable for engines and the environment.
These additional steps help increase efficiency and ensure that different fuel types meet international standards.
More than just fuel
Crude oil is not only used for petrol, diesel and kerosene. It also plays an important role in making plastics, medicines, road construction materials like tar and many other industrial products.
In some cases, the total output volume after refining becomes slightly higher than the original crude oil volume due to processing methods and added components.
Global supply and impact
Most countries import crude oil and refine it domestically. India is one of the major importers, and a large share of its crude oil comes from Gulf countries. Much of this supply passes through the narrow shipping routes called the Strait of Hormuz.
Any disruption in these routes has a direct impact on international oil prices and supply chains. Recent geopolitical tensions in the region have also raised concerns about energy security across the world, affecting both crude oil movement and fuel costs.
