Petroleum Refinery Engineering

Q1:

Waxes present in petroleum products

A can be separated out by distillation.

B are not soluble in them.

C crystallise out at low temperature.

D decrease their viscosity.

ANS:C - crystallise out at low temperature.

Waxes present in petroleum products typically crystallize out at low temperatures. Here's why:

  1. Nature of Waxes: Waxes are high-molecular-weight hydrocarbons that solidify at relatively high temperatures compared to other components in petroleum products. They are composed mainly of long-chain saturated hydrocarbons.
  2. Crystallization: When the temperature of a petroleum product containing waxes decreases, these waxes tend to crystallize out of the liquid phase. This phenomenon is due to their molecular structure and the intermolecular forces that promote solidification under specific temperature conditions.
  3. Separation and Solubility: Waxes are generally not soluble in the liquid phase of petroleum products at typical operating temperatures. While they can be separated by processes like solvent extraction or filtration, distillation is typically not effective for separating waxes due to their high boiling points and tendency to solidify rather than vaporize.
  4. Effect on Viscosity: The presence of waxes in petroleum products, especially at higher temperatures, can contribute to increased viscosity. However, at lower temperatures, their crystallization can lead to a decrease in fluidity and flow characteristics, affecting product handling and performance.
Therefore, waxes in petroleum products crystallize out at low temperatures rather than being separated by distillation or dissolved in the liquid phase, highlighting their unique behavior and impact on product properties.



img not found
img

For help Students Orientation
Mcqs Questions

One stop destination for examination, preparation, recruitment, and more. Specially designed online test to solve all your preparation worries. Go wherever you want to and practice whenever you want, using the online test platform.