I have a solution containing glucose and some sulfuric acid. I want to distill out the sulfuric acid to then reuse it for other purposes. The problem is the presence of glucose in the solution. I'm afraid that, when increasing the temperature, the sulfuric acid will dehydrate glucose to carbon and other compounds - something that I don't want to happen. Would distillation cause such a reaction?

And in case it would - are there any other methods to extract the sulfuric acid?

  • $\begingroup$ I don't know your equipment, but the boiling point of sulphuric acid is > 300 °C. $\endgroup$ Feb 9 '14 at 14:35
  • $\begingroup$ Is there a specific reason you want to recover that sulphuric acid? Ultimately it'd be much simpler, cheaper, and less energy intensive to simply discard it (after proper neutralization) and use new sulphuric acid. $\endgroup$ Feb 9 '14 at 15:41
  • $\begingroup$ I used the sulfuric acid for hydrolysis of starch and as it is a catalyst, it would be better to recover it? Or is that more expensive than using new sulfuric acid? $\endgroup$
    – user2117
    Feb 9 '14 at 17:01
  • 2
    $\begingroup$ Sulphuric acid is one of the cheapest chemicals of the world. Don't recycle. $\endgroup$
    – ssavec
    Feb 9 '14 at 18:15

As above, your labor all by itself (even if you are grad student) is worth more than the sulfuric acid. As a pedagogic exercise, run the solution down a strong anion exchange resin washed OH-. Only glucose comes out. Recover the sulfuric acid by displacing it with phosphoric acid.


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