Refining of petroleum is carried out using which one of the following techniques?

Refining of petroleum is primarily carried out using fractional distillation [4]. Crude petroleum is a complex mixture of various hydrocarbons with different boiling points [2]. In a refinery, the crude oil is heated to high temperatures, causing it to vaporize. These vapors pass through a fractionating column where they separate into different 'fractions' based on their specific boiling points [1]. Lighter fractions like petrol or gasoline condense at higher levels of the column, while heavier fractions like diesel and bitumen are collected lower down [3]. Other techniques like evaporation are used for solid-liquid mixtures like salt in water, while a separating funnel is used for immiscible liquids like oil and water. Sublimation is reserved for solids that transition directly to gas [2]. Therefore, fractional distillation is the standard industrial method for refining crude oil [4].

Sources

1. [1] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 27: Fuel and Power > Oil Refining > p. 269
2. [4] https://www.britannica.com/science/distillation
3. [2] INDIA PEOPLE AND ECONOMY, TEXTBOOK IN GEOGRAPHY FOR CLASS XII (NCERT 2025 ed.) > Chapter 5: Mineral and Energy Resources > Petroleum > p. 59
4. [3] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 8: Energy Resources > Oil Refineries of India > p. 15