Hi mohd,
Distallation pros:
-purified substances
-mass balance possible
-clarified product (usually)
-hydrocracking possibilities
-can be batch or continuous feed
Distallation cons:
-expensive
-only boiling point separation
-higher temperature valves, seals, etc
-fouling of distiller with variable feedstocks
-energy intensive
-insulation required for increasing efficiency
I hope this helps you,
Eugene