Question

Lubricating oil, which has been used is re-refined as per sets mentioned below.
A. Removal of impurities and dehydration.
B. Blending and product finishing.
C. Segregation and collection.
D. Base oil recovery and distillation.
Choose the correct answer from the options given below:

• A. B, C, A, D
• B. D, A, B, C
• C. C, A, D, B
• D. A, B, C, D

Hint:

In industrial process sequencing, always look for the "raw material input" (Collection) as the first step and the "final product output" (Finishing/Blending) as the last step.

Answer 1

The Correct Option is C

Concept: Re-refining is the process of recycling used oil into new base oil by removing impurities, water, and additives. It follows a logical industrial workflow from collection to finished product.

Step 1: Evaluate the sequence.

• C (Segregation and collection): The first step is the collection of used oil and separating it from other wastes.
• A (Removal of impurities and dehydration): The collected oil is filtered and heated to remove physical debris and water.
• D (Base oil recovery and distillation): The oil is distilled (often under vacuum) to separate the heavy base oil from light ends and contaminants.
• B (Blending and product finishing): Finally, additives are blended back into the recovered base oil to meet modern performance standards.

Step 2: Final Order.
The correct logical order of operations is C $\rightarrow$ A $\rightarrow$ D $\rightarrow$ B.