🔍 Key Concepts

• Centrifugal purifiers and what property of oil makes separation from water/contaminants more difficult • The meaning of demulsibility in lubricating oils • How TBN (Total Base Number) and neutralization number relate to acidity/alkalinity, not separation

💭 Think About

• Ask yourself: Which option describes how easily or poorly the oil separates from water when mixed? • Which properties in the choices are mainly about the oil’s chemical ability to neutralize acids, rather than its ability to be physically separated in a purifier? • If an oil tends to form stable emulsions with water, will the centrifuge’s job become easier or harder?

✅ Before You Answer

• Identify which choice directly affects oil–water separation in a centrifuge, not just oil chemistry. • Distinguish between acid/base properties (TBN, neutralization number) and emulsion behavior (separation vs. mixing with water). • Think about whether a low floc point mainly affects wax/solid precipitation at low temperature or continuous separation performance in the purifier.