How to do demulsification of oil?

What type of oil are you talking about? A vegetable oil? Or a petroleum product? What else is in the emulsion?

Hi Sudhir,

As Artsmith said, you need to define your situation a little more to get really useful answers. But in general an emaulsion is a homogeonous mixture of two (or more) liquid phases.

You won't be able to separate due to density difference, so settling tanks and centrifugation are out.

You may get some success from chromagraphic seperation - but this entirely depends on your specific scenario.

I think the most likely method for achieving a good seperation will be distillation through a good column. As I don't believe the emulsion will have any effect on the differences between the boiling temperature of the liquids.

Hope this helps.

Anthony

I agree with most of your post. As one reply stated it is always helpful to understand as much about the mixture you are dealing with. In addition, one should know what you want to accomplish by breaking the emulsion. What are the species making up the emulsion? I think only then can one adequately address his question. Normally, an emulsion is broken by a combination of chemical treatment & heat, via centrafuge and by distillation. I would definately try to break the emulsion in the lab before I scaled-up.

A vessel with a high electrical field is used in petroleum refining for desalting. The field leads the droplets of water to coalesce and drop to the bottom of the vessel. The Tesaro (nee' Tosco) refinery in Martinez, CA has the largest ones I know of.

If you add salt, it will make the aqueous phase more ionic and could cause separation. You could dilute it with salt water and cause the oil to separate faster. Try these in the lab first! Try gentle stirring of the diluted salted mix briefly, then let it stand.