Mol % in feed Boiling Melting Soluble in Soluble in Molecule point (C) Point (C) water benzene
Naphtalene 12 218 80.2 yes yes
Ethylene glycol 18 197 -11.5 yes no
Ethyl benzene 32 136.2 -95 no yes
Styrene 38 145.2 -30.6 no yes
Separate this into four essentially pure product streams. Indicate the separation technology you choose and the sequence of the separation steps.
The answer that I came up with :
N, EG, EB, S -EXTRACTION w/ water--> we get two streams which are :
the first stream : EB,S --DISTILLATION--> we get two streams, one contains EB and another contains S
the second stream : water + N + EG -EVAPORATION-> we get two streams, #1 is water and #2 is N + EG
Do EXTRACTION with benzene to the second stream which contains N,EG. The results are two streams, #1 contains EG and #2 is benzene + N.
My questions are :
* Is my answer correct?
The heuristic that I should follow are :
- if the feed is already in two phases, use a mechanical separation technology. If it's in single phase, first consider equilibrium-based separation
- for equilibrium-based separation, consider differences in boiling pt, melting pt, solubility in common solvents, and binding to solid surface
-avoid adding foreign material as possible
- remove corrosive/hazardous material early
- separate out components present in the greatest quantity first
- save difficult separations for last
-operate at temperatures and pressures as close to ambient as possible. Prefer T above ambient to below.
* How to separate benzene and naphtalene ? I don;t havae any idea how to answer this one.
That's all. Sorry if this post is very long. I really hope someone could help. Thanks.