Dehydration of ethanol (1 Viewer)

[Loz_metalhead]

Well one of the processes of obtaining ethanol from glucose is dehydration...wouldnt produce ethene...im so confused.

6. Dehydration: The alcohol will then pass through a dehydration system where the remaining water will be removed. The equation is: CH3CH2OH * C2H4 + H2O. Catalysts such as sulfuric acid, phosphoric acid or heated ceramic solids can be used to catalyse the reaction.

I added in the equation...I really don think thats right.

 

[insert-username]

This is a different dehydration. The dehydration of ethanol produces ethene, correct. That process removes one water molecule from each ethanol molecule. However, the dehydration of glucose to get ethanol is slightly different - in the fermentation process, this dehydration is simply getting rid of the excess water to leave just the ethanol. The water is not being removed from the ethanol molecule; the ethanol is mixed with the water (a la I pour ethanol into a jug and then I pour water into the jug as well). The water is being removed from the mix.


I_F

 

[Loz_metalhead]

Yeh I thought it would be something like that...do you know where I could find an equation for it?

 

[insert-username]

You won't need an equation for it. It's basically like evaporating an aqueous copper sulfate solution to get copper sulfate crystals - no chemical change involved. Just mention it as a part of the process.


I_F

 

[Loz_metalhead]

Yeh ok. I need an equation though...hmm...I already have the main equation for ethanol from glucose.

 

[insert-username]

You won't need an equation. The only one you might need is the one you already have - ethanol from glucose. From my understanding, this is all you need on that point:

6. Dehydration: The alcohol will then pass through a dehydration system where the remaining water will be removed.

You could probably substitute in evaporation for dehydration.


I_F

 

[Loz_metalhead]

It says I need equations..not just the fermentation one. The teacher gave us the marking guideline.

 

[insert-username]

The only other equations that you might need are glucose from CO₂ and H₂O (which I think is 6CO₂ (g) + 6H₂O (l) -> C₆H₁₂O₆ (s) + 6O₂ (g), not sure here), and the burning of ethanol (C₂H₅OH (l) + 3O₂ (g) -> 2CO₂ (g) + 3H₂O (l)), which produces CO₂ and H₂O which can then make more glucose, to make more ethanol, etc. You won't need one on the removal of water.


I_F