The petroleum fraction that is used in heating furnaces in industries is

Analysis

The question asks for the specific petroleum fraction used primarily as fuel for heating furnaces in industrial settings. To answer this, we must look at the boiling point ranges and the typical applications of the various fractions obtained from the fractional distillation of crude oil.

Concept Explanation

When crude oil is refined, it is separated into different fractions based on their boiling points. Each fraction has a specific use:

• Gasoline (Petrol): Used primarily as fuel for internal combustion engines (cars).
• Kerosene (Paraffin): Used for domestic heating, cooking, and as jet fuel.
• Diesel Oil (Gas Oil): Used as fuel for heavy-duty engines (trucks, buses, trains) and, crucially, as a fuel for industrial heating furnaces and boilers.
• Lubricating Oil: Used to reduce friction in machinery and engines.

Step-by-Step Solution

1. Evaluate Gasoline: While highly flammable, it is too volatile and expensive for large-scale industrial furnace heating.
2. Evaluate Kerosene: It is used for heating, but it is generally reserved for domestic purposes (stoves/lamps) and aviation.
3. Evaluate Diesel Oil: Diesel oil has a higher boiling point than gasoline and kerosene. It provides a high energy density, making it the standard choice for industrial burners, furnaces, and large boilers where sustained, high-temperature heat is required.
4. Evaluate Lubricating Oil: This is a thick, viscous substance used for lubrication, not as a fuel for combustion.

Comparing these, diesel oil is the fraction specifically processed and marketed for industrial heating applications.

Conclusion

The petroleum fraction used in heating furnaces in industries is diesel oil.

Exam Tip: Remember the order of fractions from the top of the fractionating column to the bottom: Refinery gases → Gasoline → Kerosene → Diesel → Lubricating oil → Bitumen. As you go down the column, the molecules get larger, the boiling point increases, and the substances become more viscous (thicker).