Chemical to mix with water to increase evaporation rate.

[Ray H]

Hi all,

I have a process where we currently use a 50/50 mixture of water and isopropanol, and am looking to replace the isopropanol with something less flammable and toxic. The purpose of the isopropanol is simply to increase the evaporation rate of the mixture so it dries up quickly after a certain point in the process.

Does anyone have any ideas? One improvement would be to replace the isopropanol with denatured alcohol so it would be less toxic, but I'd preferably like to remove the fire hazard as well.

Thanks

 

[georgeverghese]

In my operating days in the mid 80s', we used perchloro ethylene as a cleaning agent for degreasing O2 compressors internals, not only for its degreasing ability, but also for removing any residual moisture.
But I see there are some HSE concerns with this solvent now - see if this suits your purpose and if your HSE folks will allow this with some procedural caveats.

 

[MortenA]

The use of Tetrachloroethylene is regulated many places but i dont know if it will work the same way as isopropnol work in the describe process? I assume that what you have is a solid with water in it - you then "wash" the sludge with the isopropnol and remove the bulk og the water/isopropanol liquid (by filtration). What you then have is a sludge with a little water and mostly isopropanol. The isopropanol has a much higher vapor pressure at your process temperature (and lower heat of evaporation) and will thus dry much faster? In the lab we did the same with acetone. But thats probably not a recommendable replacement. I dont think that Tetrachloroethylene mixes well enough with water to help in this process?

What you could use was a kind of vacuum drying or a fluid bed type dryer?

 

[Compositepro]

If the OP explained the purpose of his process he might get better responses. I do not feel like playing 20 questions.

 

[25362]

Look for a low-boiling azeotrope with no environmental risks. In any case, condense and collect the condensate for safe disposal.

 

[Ray H]

Thanks for the responses everyone,

This mixture is used as an light lubricant, where it is critical that the solution dries up quickly after application and does not leave a residue. I looked through some azeotrope data for water and did not find something that would work for my application.

I also came across some water-based VOC free vanishing oils, which might work for this use case.