ANS:B - water from petrol

Removal of water from petrol exemplifies an adsorption unit operation. Explanation:

• Adsorption is a unit operation in which molecules or particles from a fluid phase (the adsorbate) adhere to the surface of a solid material (the adsorbent).
• In the case of removing water from petrol, adsorption can be used to selectively capture water molecules from the petrol. This process typically involves using a solid adsorbent material with a high affinity for water molecules.
• The solid adsorbent material may be activated carbon, silica gel, molecular sieves, or another material chosen for its ability to selectively adsorb water while allowing the petrol to pass through.
• As the petrol passes through the adsorption unit containing the adsorbent material, water molecules are adsorbed onto the surface of the adsorbent, effectively removing them from the petrol stream.
• The purified petrol, now with reduced water content, exits the adsorption unit, while the water-laden adsorbent may be regenerated for reuse or disposed of, depending on the specific process design.
• This application of adsorption is common in the petroleum industry for treating fuels to meet quality specifications by removing impurities such as water, sulfur compounds, or trace contaminants.