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UPSC Prelims 2021 · Environment · Pollution Files
With reference to furnace oil, consider the following statements: Which of the statements given above are correct?
- It is a product of oil refineries.
- Some industries use it to generate power.
- Its use causes sulphur emissions into environment.
- (a) 1 and 2 only
- (b) 2 and 3 only
- (c) 1 and 3 only
- (d) 1, 2 and 3
Show the answer and explanation
Answer: (d) 1, 2 and 3
All three are true.
Statement by statement
1. ✓ CORRECT Furnace oil is a heavy residue from oil refineries.
2. ✓ CORRECT Industries burn it in boilers and generators for power.
3. ✓ CORRECT It is high in sulphur, so burning it releases SO₂.
The idea
A refinery separates crude oil by boiling point. The light parts come off first: gas, petrol, kerosene, diesel. What is left at the bottom is thick and dark: furnace oil and bitumen. Sulphur and metals collect in this heavy part, so furnace oil is cheap but dirty.
Crude oil is heated → Petrol, kerosene and diesel are drawn off → Heavy residue remains → Sold as furnace oil → Burnt in boilers and generators → Sulphur leaves as SO₂
Elimination technique
All three are plain descriptions with no absolute word. Plain statements of this kind are usually true in Environment PYQs, which points to all three.
Also know
In 2017 the Supreme Court banned furnace oil and petroleum coke in Uttar Pradesh, Haryana and Rajasthan to protect the air of the Delhi region. Petroleum coke is the solid residue of refining and has even more sulphur. The heavy fuel burnt by ships is of the same family.
🔒 Furnace oil & pet coke: high-sulphur fuels; banned in Delhi NCR (2017).