In petroleum products, mercaptans (thiols) are sulfur-containing compounds. Which combined statement best describes mercaptans in fuels and LPG practice?

Introduction / Context:
Mercaptans (also called thiols) are organosulfur compounds with a sulfur-hydrogen functional group bonded to carbon. They have strong odors and specific impacts on refining, product quality, and safety practices, particularly in LPG odorization.

Given Data / Assumptions:

• Mercaptans have relatively low boiling points compared to heavier sulfur species.
• Gasoline octane quality is sensitive to certain sulfur species that can poison catalysts and alter combustion chemistry.
• LPG is naturally odorless and is odorized to aid leak detection.

Concept / Approach:

Refiners aim to remove sulfur for environmental and performance reasons. However, controlled addition of specific mercaptans to LPG is standard for safety, while high mercaptan levels in gasoline are avoided to maintain octane and prevent corrosion or catalyst issues.

Step-by-Step Solution:

Verification / Alternative check:

Process units like Merox convert mercaptans to disulfides for sweet gasoline. Product specifications limit sulfur and mercaptan content to protect performance and emissions.

Why Other Options Are Wrong:

Each single statement is correct but incomplete; the option combining them reflects the comprehensive truth.

Common Pitfalls:

Assuming all sulfur behaves the same across products; overlooking that odorization is deliberate in LPG but not desired in gasoline.

Final Answer:

All of the above statements are correct