  orimulsion is a registered trademark name for a bitumen-based fuel that was developed for industrial use by intevep, the research and development affiliate of petroleos de venezuela sa (pdvsa), following earlier collaboration on oil emulsions with bp. ==source of the bitumen== like coal and oil, bitumen occurs naturally and is obtained from the world's largest deposit in the orinoco belt in venezuela. the deposit is estimated to be more than 1,200 billion barrels (190 billion m3) of bitumen, an amount approximately equivalent to the world's estimated proven oil reserves.   ==preparation== raw bitumen has an extremely high viscosity and specific gravity between 8 to 10 api gravity, 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. ==advantages== 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. ==disadvantages== if there is a spill while shipping over water the mixture de-emulsifies and the bitumen drops out of suspension. it is a non-newtonian fluid, and if it is allowed to cool below 30 Â°c, it will 'set'. pumping becomes impossible, and there is no way of restarting operations or the flow through the pipeline again. ==decreasing usage== orimulsion is currently used as a commercial boiler fuel in power plants worldwide (e.g., canada, japan, lithuania, italythe torrevaldaliga nord plant in civitavecch
Petroleum_products