Formation, prevention and breaking of sea water in crude oil emulsions ‘chocolate mousses’

During the combatting of oil spills, the handling of the stable sea water in crude oil emulsions called ‘chocolate mousses’, either at sea or on the beach, is often a major problem.

A recent laboratory study of the formation and properties of such emulsions revealed the key roles played by asphaltenes and crystallized wax in their stability.

Viscosity measurements showed that mousses with 70% vol. sea water are thixotropic and may solidify after having been pumped into the hold of a salvage vessel or into a storage tank. During a search for novel chemicals for combatting oil spills we found a type of chemical additive that is effective in preventing the formation of mousses, in greatly improving the pumpability of mousses once formed and in decreasing their water content after recovery or during storage. The additive, designated LA 1834, has been tested successfully in the laboratory, on a semi-technical scale in cooperation with the Netherlands State Waterways Board and in the large-scale clean-up operation after a recent oil spill in Greece. The compound keeps oil from dispersing vertically into the water column, when applied to spilled oil or mousse on a sea water surface and holds promise of environmental acceptability.