Paraffin-base versus asphalt-base crude: compared to asphalt-base crude oil, paraffin-base crude typically yields which of the following?

Introduction:Crude oil “type” influences yields and qualities from atmospheric and vacuum distillation. Paraffin-base (paraffinic) crudes differ from asphalt-base (more naphthenic/aromatic) crudes in product slates and lube oil characteristics. Recognizing these tendencies helps in crude selection and planning downstream processing loads.

Given Data / Assumptions:

• Paraffin-base crudes are richer in normal and isoparaffins and wax.
• Asphalt-base crudes are richer in naphthenes/aromatics and asphaltenes.
• “Straight-run gasoline” refers to the atmospheric distillate without cracking.

Concept / Approach:Paraffin-base crudes generally provide good yields of light distillates (including straight-run gasoline) and produce lube base stocks with high viscosity index after dewaxing. Their straight-run gasoline octane is usually lower than that from more aromatic/naphthenic crudes, but yield in the light range tends to be favorable. Asphalt-base crudes give more heavy ends/asphaltenes and poorer VI lube stocks.

Step-by-Step Solution:Compare light distillate yields: paraffinic → higher straight-run light cuts.Assess octane: paraffinic straight-run octane lower than aromatic-rich crudes (therefore option (b) is false).Evaluate VI: paraffinic crudes → higher VI, so option (c) is false.Lube yield: paraffinic crudes are favorable for lube base stocks; option (d) is false.

Verification / Alternative check:Crude assay comparisons (e.g., paraffinic Pennsylvanian vs. asphaltic Venezuelan) show higher wax/high-VI lube potential and robust light ends from paraffinic crudes, whereas asphaltic crudes skew heavy.

Why Other Options Are Wrong:

• Higher octane straight-run gasoline: aromatics/naphthenes raise octane, so paraffinic straight-run octane is not higher.
• Lower viscosity index lube: paraffinic gives higher VI lube stocks.
• Poorer lube yield: opposite of typical trend.

Common Pitfalls:Confusing “yield” with “quality”; paraffinic crudes may give more light cut yield but require octane upgrading (e.g., reforming) to meet specifications.

Final Answer:Higher yield of straight-run gasoline