Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations TugboatEng on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
Entrainer for THF/Water distillation
- Thread starter cdev
- Start date
Guest
Do you mean Tetrahydrofuran? Is one species
minimal (say less than 10%) or are they about
the same? Do you want to recover the water or can it be wasted? If mixture is mostly THF then passing it through salt (NaCl) will make a THF layer that is about
2.5% water (The bottom layer is salt water.)
I suppose you mean that pentane would entrain
THF in the top layer of a decanter. I have experience using toluene (more toxic than pentane however).
I would imagine that THF would prefer many organics over water.
minimal (say less than 10%) or are they about
the same? Do you want to recover the water or can it be wasted? If mixture is mostly THF then passing it through salt (NaCl) will make a THF layer that is about
2.5% water (The bottom layer is salt water.)
I suppose you mean that pentane would entrain
THF in the top layer of a decanter. I have experience using toluene (more toxic than pentane however).
I would imagine that THF would prefer many organics over water.
Sorry for my delayed comment. It happens that I adhered to the Eng-Tip forums only of late.
One technical book says that THF and water form an azeotrope with composition sensitive to pressure. So they can be effectively separated in a two-stripping column system operating at two pressures: the atmospheric, taking water as a bottom product using stripping steam as heating medium. The condensed overhead stream from this tower, serves part as reflux, the remainder is sent to the middle section of a pressure tower heated with a reboiler. The bottom stream of this column is pure THF, the top stream is condensed. Part of it is used as reflux and part re-sent to the original blend of THF and water. The pressure tower works at about 7.5 atm.
Although not exactly satisfying your request, I hope this message helps.
One technical book says that THF and water form an azeotrope with composition sensitive to pressure. So they can be effectively separated in a two-stripping column system operating at two pressures: the atmospheric, taking water as a bottom product using stripping steam as heating medium. The condensed overhead stream from this tower, serves part as reflux, the remainder is sent to the middle section of a pressure tower heated with a reboiler. The bottom stream of this column is pure THF, the top stream is condensed. Part of it is used as reflux and part re-sent to the original blend of THF and water. The pressure tower works at about 7.5 atm.
Although not exactly satisfying your request, I hope this message helps.
PierreSTRAUCH
Chemical
A good alternative to the pressure swing distillation will be a combination of a distillation and vapour permeation (pervaporation). At atm. Pressure the azeotrope will be around 94% THF / 6% Water.
90% (10% Water) can be reached with a simple distillation. The dehydration from 90% up to 99.5% is easy by pervaporation.
a general info is available under:
Sites/products_services/pervap.html
Feel free to ask for more info or sizing details.
pierre.strauch@sulzer.com
90% (10% Water) can be reached with a simple distillation. The dehydration from 90% up to 99.5% is easy by pervaporation.
a general info is available under:
Sites/products_services/pervap.html
Feel free to ask for more info or sizing details.
pierre.strauch@sulzer.com
- Status
Similar threads
- Question
