7 replies to this topic

HOME-ASSIGNMENT

Q. 35% acetic acid-water solution is to be extracted countercurrently in a Packed Tower to 98% acetic acid concentration.
You can use any solvent, but you have to justify for doing the same.

Soln.

Using IsopropylEther as the extracting solvent.
(Im using it as the Equilibrium Data is available in Mass-Transfer Operations by Robert E. Treybal. No concrete reson for justification)

The number of equilibrium stages required can be calculated.

Plzz help me how to proceed further.

Just want a brief outline of the major steps involved in designing of the Equipment.

plzz help me out.....

Mr. Art Montemayor
Could you please...??

[JEBradley]

Speaking on behalf of Mr. Art Montemayor!!!!

First of all - That's a whole semester's work from university (design of Liq-Liq extraction columns) we can't regurgitate it all now!!!

You should be able to find out how to design the column from numerous books - Perry's, Coulson & Richardson, Smith McCabe Harriot, JK Rowling, or the Trybal book that you have. You could even ask your lecturer fror his recommendation.

For starters though, you will probably need to know the flowrate of the incoming 35% acetic acid mix. Also, when you say you have equilibrium data, do you mean you have something like K=c1/c2 or are you using a triangular diagram??

The solvent has to preferentially dissolve one component over the other so on that count your fine. You will then have to investigate some other aspects - such as health and safety (benzene used to be a common solvent), environment (local EA controls over proposed solvent) and cost.

I dont want to sound rude but most of the books I glanced at have worked examples of these problems - have a stab at it then tell us what youve done at which specific point is causing you difficulties.

Mr. JEBradley

Thanks a lot for replying..!
Well regarding the semester work, we are done with design of heat exchangers and distillation columns in the previous semester. In this semester its the design of liquid-liquid extraction equipments. So yes, i am a starter with the design of liquid-liquid extraction equipments.

Equilibrium data- I have x,y v/s wt. fraction IsopropylEther.
where x= wt. fraction acetic acid in water layer
y= wt. fraction acetic acid in IsopropylEther layer

I am using rectangular coordinates.

Consulting Perry's Handbook and Treybal for solving the problem. And will soon bother you again. And your reply did give me a direction for the solution.
Hope you would assist me..!
Thanks!

[JEBradley]

Thanks

You may also want to check out the cheresources info:

http://www.cheresour...xtraction.shtml

[Padmakar Katre]

Dear,

In addition to the above link on Che Here I am giving some links for liquid-liquid extraxtion I hopw it

will help to proceed in your academic project.

http://vienna.che.ui...oj/Snrtem~1.pdf

http://www.ddpsinc.c...files/pp50.html

http://rigzone.com/s...ct.asp?p_id=248

http://www.qvf.com/e...ents/P150e0.pdf

And at the last I am giving you a link from where you can download the live demonstration

Version of acetic acid extraction by isopropyl ether.

http://demonstration...IsopropylEther/


Njoy....

Regards,

Padmakar Katre

[JEBradley]

That was freaky looking at those links - I used to work for DDPS/QVF and JC Godfrey and M Slater were my lecturers at university!!

Good links though

hi Mr. Padmakar S Katre

Well what i can say is just.................THANKS A LOTTTTTTT.....!!!!!!!
Its just incredible. The design part ....i think my problem is solved.

Well some senior persons might not be happy as there is direct solution given over there. There is hot topic where stress is being given on learning "art of problem solving" by some of the senior members. Well, i had no intention of getting the solution as it is. But i cannot overlook this now.

Thanks.