Kerosene improvement by Edeleanu extraction Raw kerosene has a smoke point of 15 mm. After dearomatisation using liquid SO2 extraction (Edeleanu process), to what typical smoke point value may it increase?

Introduction / Context:
Smoke point is a classic indicator of kerosene burning quality. Lower aromatic content generally yields a higher smoke point, signifying a cleaner, less sooty flame. The Edeleanu process selectively extracts aromatics from kerosene using liquid sulphur dioxide at low temperature, improving combustion characteristics.

Given Data / Assumptions:

• Feed kerosene smoke point: 15 mm (raw).
• Treatment: Edeleanu dearomatisation with liquid SO2.
• We seek the typical improved smoke point after such extraction.

Concept / Approach:
Because aromatics foster soot formation, removing them increases smoke point. Industrial and exam-style benchmarks commonly cite post-extraction smoke points in the mid-20 mm region for a previously 15 mm sample, depending on cut severity and extraction ratio. Thus, a rise to about 25 mm is a realistic and widely taught result.

Step-by-Step Solution:

Verification / Alternative check:
Refining texts link aromatic extraction (Edeleanu or similar) to smoke-point uplift; product specs often require >20 mm for better burning fuels, consistent with an increase to ~25 mm.

Why Other Options Are Wrong:

• 10 / 5: Lower than the raw 15 mm; extraction should raise, not reduce, smoke point.
• 100: Unrealistically high for kerosene; far above normal specification ranges.

Common Pitfalls:
Interpreting smoke point as directly measuring aromatics; it is an indirect combustion metric improved by lowering aromatics.

Final Answer:
25