An aqueous solution of methanol is to be distilled in a tray column. High pressure steam is available as a source of heat. For a given reflux ratio and overhead composition, two options are being explored; (i) a reboiler is used and (ii) no reboiler is used but steam is fed directly to the bottom of the column. As compared to option (i), in option (ii)

• A. Composition of the residue remains unchanged
• B. More number of trays are required but the residue composition remains unchanged
• C. More number of trays are required and the residue composition is more dilute in methanol
• D. Less number of trays are required

Answer: (D)