A crude oil shows a characterization (UOP K) factor of 12.5. Based on this value, how would you classify the crude type?
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AParaffinic
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BNaphthenic
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CIntermediate (mixed)
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DNone of these
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EAromatic-rich
Answer
Correct Answer: Paraffinic
Explanation
Introduction:The UOP K (characterization) factor is a classical single-number crude property indicator linking average boiling point and specific gravity. It is frequently used to infer general crude type and expected product distribution tendencies.
Given Data / Assumptions:
- Reported K factor: 12.5.
- Rule-of-thumb ranges: paraffinic >~12, intermediate ~11.5–12, naphthenic/aromatic <~11.5 (approximate).
- Purpose: qualitative classification, not a precise composition assay.
Concept / Approach:Higher K factors correspond to more paraffinic character (lighter, higher H/C), which typically yields more naphtha and paraffinic fractions; lower K factors indicate more naphthenic/aromatic content, favoring heavier distillates and lube stocks.
Step-by-Step Solution:1) Compare 12.5 with rule-of-thumb thresholds.2) 12.5 lies in the paraffinic/upper intermediate regime.3) Select paraffinic as the best classification.
Verification / Alternative check:Refinery planning practice: Light, paraffinic crudes often show K factors around or above ~12, confirming a paraffinic tendency for 12.5.
Why Other Options Are Wrong:Naphthenic/intermediate: Would imply lower K values near ~11–12.None/aromatic-rich: Not supported by a K factor as high as 12.5.
Common Pitfalls:Treating K as a precise predictor of yields; it is best used comparatively alongside assays and TBP curves.
Final Answer:Paraffinic