Define petrolatum in refinery products

Introduction / Context:
Refinery wax and heavy residual streams yield several by-products. Petrolatum is a widely used semisolid product in lubricants, cosmetics, and protective coatings, so recognizing its composition is important for applications and specifications.

Given Data / Assumptions:

• Petrolatum is produced from dewaxed lubricating oil fractions and residuals.
• It appears as a translucent to opaque, jelly-like mass.

Concept / Approach:
Petrolatum (often known by trade names like petroleum jelly) consists of microcrystalline wax dispersed in viscous oil. This composition imparts the semisolid structure at ambient conditions and good occlusive, water-resistant properties. It is distinct from petroleum ether (a light solvent), petroleum coke (a solid carbonaceous residue), and aromatic solvent cuts.

Step-by-Step Solution:

Verification / Alternative check:
Material specifications (e.g., USP white petrolatum) describe melting range and oil content consistent with wax-in-oil matrices.

Why Other Options Are Wrong:

• Petroleum ether is a light, volatile solvent.
• Petroleum coke is a solid carbon product.
• “None” and “aromatic solvent cut” do not match the semisolid composition.

Common Pitfalls:
Confusing petrolatum with paraffin wax; petrolatum contains significant oil, giving a softer, greasier texture.

Final Answer:
A mixture of microcrystalline wax in viscous hydrocarbon liquids