[mariouma]

Hi Everyone,

I found this old exam, and I am not able to resolve it. Maybe they are missing some info??

Here's the text, maybe some can tell me how to proceed with this kind of questions .
Thanks


"In a Petrochemical factory hydrocarbons for cracking are transported by pipes.The pressure and the temperature in the pipes are kept at 5atm and 56 C respectively.

Calculate the maximum quantity of pentane that can be added to an equimolar mixture of propane and n-butane without causing condensation".

[SABRY]

1. Obtain the k-values for each components at conditions
2. Ensure pressure in absolute unit
3. Select basis of your calculation e.g 100 mol/h of C3/C4 mixture
4. Assume G mol/h of pentane added
5. Compute the composition of each components (yi)
6. Sum the ratio yi/ki-values
7. determine G where the sum in step 6 equal 1
8. Use goalseek in EXCEL to solve, if you have one. Otherwise use trial and error
9. If you cannot find k-values use vapor pressure where k = VP/Total pressure
10. Item 9 only for ideal case but may be good enough for you.
11. What important is not the exact answer, but the method used to show your understanding of the subject matter.