1 reply to this topic

[SP500]

Distillation Column Vs Multiple Flash Separation Stages?

Edited by SP500, 02 January 2017 - 08:27 AM.

[sgkim]

Hi SP500,

 

To compare one system with the other, bases and configurations shall be made first and then compare the cost and benefits.  

 

Distillation employs 'fractional distillation' at a minimal cost by applying multiple fractionating 'stages' stacked vertically and by providing single condenser with one reflux pump and one reboiler on the bottom.  Liquid flows from top stage to bottom, and vapors flows reversely; no additional pump, blower, reboiler, or condenser is required for the whole system. 

 

As distillation usually requires multiple number of distillation stages, the flashing may also require the similar number of flashing stage.  Flashing,  however, requires for every stage, a heater(boiler), a pump for liquid transfer, a condenser, and a transfer pump (and/or blower) to the next stage.   For multi-stage flashing, equipment cost and utility consumption would become much higher than distillation.  

 

Being the same quality and quantity of product from the same mixture, distillation seems much less costly than flashing.  What's the configuration of the multi-stage flashing, and how come you guess that flashing can be more beneficial and preferable ?

 

~Stefano