is a registered trademark name for a bitumen
-based fuel that was developed for industrial use by British Petroleum
(BP) and Petroleos de Venezuela SA (PDVSA). The bitumen occurs naturally and is obtained from the world's largest deposit in the Orinoco Belt in Venezuela
. Reserves are estimated at more than 1.2 trillion barrels
of bitumen, an amount greater than 50% of the world's estimated oil reserves.
Raw bitumen has an extremely high viscosity at ambient temperatures and is unsuitable for direct use in conventional power stations. Orimulsion is made by mixing the bitumen with about 30% fresh water and a small amount of surfactant. The result behaves similarly to fuel oil. An alcohol-based surfactant recently replaced the original phenol-based version; improving the transport properties of the fuel and eliminating the health concerns associated with the phenol group of surfactants.
As a fuel for electricity generation, Orimulsion has a number of attractive characteristics:
- the known reserves of bitumen are very large;
- it is currently priced to be competitive with internationally traded coal;
- it is relatively easy and safe to produce, transport, handle and store;
- it is easy to ignite and has good combustion characteristics;
- it can be used in power stations designed to run on coal or heavy fuel oil, with suitable modification.
Orimulsion is currently used as a commercial boiler fuel in power plants worldwide (e.g.
, and China
Air pollutant control technology that is commonly available can limit emissions from Orimulsion to levels considered "Best Available Control Technology," as defined by the United States Environmental Protection Agency.