Why is H2SO4 used in the contact process for sulfuric acid production?

[gracy]

I have a doubt please look at this video
At time 1:54 to 2:00 and from time 3:24 to 3:29 After looking at video at time i have mentioned ,one will find that H2SO4 is itself used in this process so my question is what's the point in making H2SO4 by this method,as the method itself requires H2SO4.What's the net advantage when we are using H2SO4 (along with many other chemical compounds such as SO2,V2O5)and then producing the same?

 

[DrDu]

If I remember correctly, H2SO4 is used as a solvent. There is a net production of H2SO4 in that process as the acid serving as solvent can be recycled.

 

[gracy]

If I remember correctly, H2SO4 is used as a solvent. There is a net production of H2SO4 in that process as the acid serving as solvent can be recycled.

OK one more question how impurities in SO2 and o2 reduces the efficiency of V2O5 (used as catalyst) in this process?

 

[DrDu]

They get adsorbed on the catalys thus hindering the reactants to react at the surface.

 

[gracy]

They

they means impurities ,right?

at the surface.

at the surface of catalyst V2O5 ,right?

 

[DrDu]

Yes, yes

 

[gracy]

If I remember correctly, H2SO4 is used as a solvent. There is a net production of H2SO4 in that process as the acid serving as solvent can be recycled.

OK this explains only about when H2SO4 is used as a solvent but what about when H2SO4 is used as spray?look at this in the video At time 1:54 to 2:00 .how can this be recycled?

 

[DrDu]

There are tons of information readily available on the net. Which ones did you check besides this video?

 

[gracy]

There are tons of information readily available on the net. Which ones did you check besides this video?

I have checked and http://en.wikipedia.org/wiki/Contact_process and http://chemwiki.ucdavis.edu/Physical_Chemistry/Equilibria/A._Chemical_Equilibria/The_Contact_Process and http://www.bbc.co.uk/schools/gcsebitesize/science/triple_ocr_gateway/how_much/equilibria/revision/2/ and my textbook.

 

[gracy]

There are tons of information readily available on the net. Which ones did you check besides this video?

So i have searched a lot but such type of in depth questions (as my post 7)can only be answered here.That's why i request you to answer my post 7.
Regards.

 

[DrDu]

The sulfuric acid is used to dissolve the SO3 formed which yields oleum. The latter is diluted to form H2SO4 again. So where is the problem?

 

[gracy]

The sulfuric acid is used to dissolve the SO3 formed which yields oleum. The latter is diluted to form H2SO4 again. So where is the problem?

That's what the problem is,We are using H2SO4 to produce H2SO4 what's the net advantage?

 

[DrDu]

That you get more H2SO4 than you put in.

 

[gracy]

According to your post 2 that H2SO4 is recycled again,right?

 

[DrDu]

Yes, but obviously not all of it.

 

[gracy]

Yes, but obviously not all of it.

And H2SO4 when used as spray consume very less amount of H2SO4 as compared to high yield of end product H2SO4,right?

 

[Borek]

Acid used in the process is not consumed, it is still present in the final product.