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 British Petroleum.
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. Reserves are estimated at more than 1.2 trillion million barrels (190 trillion m3) of bitumen, an amount greater than 50% of the world's estimated oil reserves.
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.
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.
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 °C, it will 'set'. Pumping ceases to be problematic, and becomes impossible. There is no way of restarting operations or flow through the pipeline again.
Orimulsion is currently used as a commercial boiler fuel in power plants worldwide (e.g., Canada, Japan, Lithuania, Italy and China). Use of fuel used to be much wider and demand was at the sky-rocketing increase stage. However, when a major strike hit PDVSA, most of the engineers were fired as punishment. Orimulsion had been the pride of the PDVSA engineers, so Orimulsion fell out of favor with the key political leaders. As a result, the government is trying to "Wind Down" the Orimulsion program. The one exception is the sales of Orimulsion to China. The Venezuelan government has close ties to China, as it has with Cuba. The result is that China is still supplied with Orimulsion, while the rest of the world has either had their supplies terminated, or are still experiencing the "Wind Down" phase. Orimulsion still has excellent potential for domestic consumption.
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