Hi,
I am trying to renovate old laboratory apparatus for the study of the hydrodynamics of countercurrent liquid-liquid flow through a packed column. Not for research, but rather education and didactics, as part of general course on various aspects of basic unit processes (Chemical Engineering lab).
While it was once operated using water and tetrachloromethane, since that time new legal regulations were introduced and the former was deemed too toxic to use in such configuration (it isn't standing in the fume hood and is rather impossible to move it there). New question arose - whether replace this apparatus with something else,, or maybe just change the second liquid. We have quite a bit of ideas, but I decided it wouldn't be bad if I will also move the discussion here, and maybe somebody will catch up.
After that general introduction to a topic, the final question is just the same as above: can anyone recommend some non-toxic liquid, that is not miscible with water in considerable proportions and with comparable dynamic viscosity (or just quite low)?
I am open to various suggestions.
PS.
We thought about, for example, some kind of vegetable oil as non-polar phase, as they are cheap and readily available. However, they are also quite viscous in comparison with water and prone to ageing. While first isn't big problem, we could just buy the pump well-adjusted for handling oils, the second issue is quite a nuisance.
Krzysztof,
I believe there are alternatives which can be safer.
Regarding liquid-liquid emulsions, Matthias Kraume (TU Berlin) has tested different oils when he was looking for Toluene alternatives.
See attached file. There are different oils & their physical properties.
Best regards.
Not fully sure, what about paraffin oil, the density almost in range 850 to 900 kg/m3, and the viscosity is low as well, and still up too you mate.
Dear Mounir,
I will surely take a look. Thank you very much for such rapid response (and sorry for my late answer).
Dear Ammar,
parrafinic oil was something we have also considered, however since the time I asked my question, I was occupied with my other duties as technician, so as for now things haven't got any further.
I am grateful for suggestions you both have given me, and for sure I will give some kind of feedback what finally happened in that regard.
Cheers,
Paraffin oil has a dynamic viscosity 100 times greater than water. I would look for the right liquid among the esters. There are many. Some of them are non-toxic and have a much lower dynamic viscosity than oils (sometimes lower then water). In general, they poorly dissolve in water. Regards,
PS. Tak blisko i tak daleko. MG
Dear Colleague, Have the nice days.
Your problem may be solving by silicon oils, their density and viscosity are too different for making a appropriate choise. Some are volatile liquids and others are dance and viscous. Direct H.C. solvents can be toxical..... Correctly what is the experiment and conditions of this procedures? H.C. with low molecular weight are volatile and haves high vapor pressure, but very low viscosity.They have the toxicity when inhalling. The any one with high MW is viscous liquid with low fluidity. See you again. With my Best Regards. Dr.Tunçer Mutlu
Ethyl, methyl and other acetic and formic acid monoesters are appropriate like biofuel, but it must to insight their B.P. and octane indexes. Not only vegetable oils , waste burned edible oils from kitchen and fats are a good raw materials. The direct converting of oils to the hydroxyl derivatives can be performing without alcohol aditions!
See You Again.
With My Best Regards
Dr. Tunçer Mutlu(Chem.Eng)
How about ionic liquids? Ionic liquids usually have high thermal stability, low flammability, electrical conductivity, and the ability to solvate various organic and inorganic compounds. You may have a try.
And Alfa chemistry offers a variety of ionic liquids with different properties to choose from.
https://www.alfa-chemistry.com/products/ionic-liquids-148.htm
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