Orimulsion® spill modelling in marine environments

Orimulsion, a fuel product developed in Venezuela and transported to markets by ocean going tankers, is an emulsion composed of about 70% bitumen (a heavy hydrocarbon) and 30% water to which a surfactant has been added. It has the potential to serve as an inexpensive alternative to Fuel Oil No. 6, an energy source presently used to heat large industrial and electric utility boilers throughout the world. gh Orimulsion is a heavy hydrocarbon fuel, its behavior in marine environments is quite different than that observed for oil. When spilled, Orimulsion rapidly separates in the affected water body into a dissolved fraction that contains an emulsifier and a suspended fraction that contains bitumen (a viscous asphalt like material). The bitumen does not have the cohesive properties exhibited by oil spilled into water, rather it forms a “cloud” of individual bitumen particles. Under prolonged quiescent conditions the bitumen particles can rise to the surface in sea water or sink to the bottom in fresh water. However, in either case, an increase in the energy state of the water can rapidly remix the bitumen into the water column. s paper, the status of modeling Orimulsion spills in marine environments is discussed. The physical and chemical processes that would take place in an Orimulsion spill are examined and incorporated into the design of the model ORI_SLIK, a fate and transport model for marine environments.