Question

Which of the following statements is true if fuel has a high aniline point?
A.Fuel has low paraffin
B.Fuel has high diesel index
C.Fuel has high aromatics
D.Fuel has low diesel index

Answer 1

To solve this question, we must define the three major parameters mentioned in the question: aniline point, diesel index and paraffin content. Then, we must find a relation between these three parameters to find the correct answer.

Complete Step-by-Step Answer:
Before we move forward with the solution of the given question, let us first understand some important basic concepts.
Aniline point or the “Aniline point temperature” can be understood as the lowest possible temperature at which aniline and the given oil become miscible with each other, that is they form a single phase. If the given fuel sample has low aniline point, then it corresponds to the fact that the fuel contains a high number of aromatic compounds. Lower the value of aniline point, lower would be the quality of the fuel.
Diesel index can be understood as an empirical measure for the given sample of diesel fuel, as the quality of the ignition produced. These measurements are done by keeping parameters like API gravity and aniline point of the fuel under consideration. If the readings for the diesel index are high, then the quality of the ignition of the fuel is also high.
Paraffins in fuels have proven to improve the octane number of the fuel. And higher the octane number of the fuel, better would be its quality. Hence, the relation between these three quantities can be given as:
Aniline point $\alpha$ Diesel index $\alpha$ paraffin content

Hence, a high aniline point would mean that the fuel has a high diesel index and also a higher content of paraffins

Hence, Option C is the correct option

Note: Aniline point is usually used to understand the aromatic character of the oil under consideration. The aniline point serves as an apt reference point for determining the aromaticity of oils consisting of saturated and unsaturated hydrocarbon.