Question

describe steam distillation and it's advantages and limitations

Answer 1

Steam distillation is a special type of distillation (a separation process) for temperature sensitive materials like natural aromaticcompounds.

Notice that in the presence of water, phenylamine (or any other liquid which is immiscible with water) boils well below its normal boiling point. This has an important advantage in separating molecules like this from mixtures.

ADVANTAGE: Normal distillation of these liquids would need quite high temperatures. On the whole these tend to be big molecules we are talking about. Quite a lot of molecules of this sort will be broken up by heating at high temperatures. Distilling them in the presence of water avoids this by keeping the temperature low.

That's what steam distillation achieves.

LIMITATION: Steam distillation has the disadvantage of having a higher initial cost for investment in the equipment needed to execute the process successfully. You'll need some initial training in order to operate the equipment, and you must take care in conducting the process because you're working with high temperatures, a heat source, pressurized containers and volatile oils. A final hidden cost to the process is the cost of maintaining and repairing your equipment.