Orimulsion is a type of liquid fuel that is made from two things – a very thick type of oil called bitumen, and water.
When they mix bitumen and water together, they make a sort of gooey liquid that can be burned like other fuels. But because it takes a lot of energy to produce orimulsion, it's not used as much as other types of fuels like gasoline or diesel.
In some places, people have tried to use orimulsion instead of other fuels because it can be cheaper to produce. But some people worry that using orimulsion could have bad effects on the environment, like polluting the air and water.
So while orimulsion is an interesting fuel option, people are still trying to figure out if it's a good choice for the future.