Sciencemadness Discussion Board

Fractional distillation of WFNA and water in inert gas with H2SO4?

chucknorris - 19-11-2012 at 05:12

Long story short, aside for another process that leaves 68% azeotropic HNO3 as a leftover, is it possible to create chain distillation with fractionating as per following method:

The receiver where the 68% HNO3 flows, has sulfuric acid in it which is preheated to somewhere 200C where the sulfuric acid will remain concentrated. If we flow 68% HNO3 there and it boils over and we boil it with fractionating column, will it distill as an azeotrope or will it separate as 99% WFNA and water? If this doesnt work, is there any way so that the reaction could be made non-stop so that you put 68% HNO3 from other end and receive 99% HNO3 from other end?

hissingnoise - 19-11-2012 at 05:43

Quote:
The receiver where the 68% HNO3 flows, has sulfuric acid in it which is preheated to somewhere 200C where the sulfuric acid will remain concentrated.

On distillation, H2SO4 retains the water present in conc. HNO3!
Better to stick with the tried-and-trusted batch process. IMO . . .
And the azeotrope boils @ 120°C ─ above this, HNO3 decomposition is extensive and water may be forced into the distillate!