Demulsifiers

in petroleum production, substances aiding the destruction of emulsions formed from petroleum and water. Upon introducing demulsifiers into an emulsion, they are adsorbed on the surface layer of particles of the dispersed phase (so-called drops), forming around the drops a new layer saturated with demulsifier and of lower mechanical strength. Owing to this, on collision of the drops their coalescence and also the destruction of the emulsion are facilitated. In the USSR the theory of emulsion destruction has been worked out by the school of Academician P. A. Rebinder and in the USA, by I. Langmuir.

The main user of demulsifiers (consuming tens of thousands of tons a year) is the petroleum industry, in petroleum refineries, where demulsifiers are used to dewater and desalt petroleum. In destroying emulsions of the “water in petroleum” type, the demulsifier consumption varies from a few tens to a few hundreds of grams per ton of emulsion. Demulsifiers for destroying “water in petroleum” type emulsions are nonionic surface-active agents whose synthesis is based on ethylene oxide and propylene oxide.