Chemical fuel is an emulsion composed of water and combustible liquid (oil or fuel). The most commonly used emulsion fuel in industrial production is a water emulsion made by emulsifying diesel and water. The emulsified fuel made of diesel and water can provide more complete combustion and more economical fuel consumption, and at the same time make the waste generated by the burning fuel less discharge.

Since the use of emulsified fuel can reduce the amount of fuel used, it also directly reduces production costs. It also reduces greenhouse gases such as carbon dioxide (CO2), nitrogen oxides (NOx) and sulfur oxides (SOx), so it has attracted people's attention as a highly environmentally friendly new fuel.

The emulsified fuel prepared by ultrasonic emulsification has high stability, so no additional surfactant is needed to stabilize the emulsion. The strong shearing force of ultrasonic equipment is effective for producing stable nanoemulsion. Although the purchase of ultrasonic equipment will result in additional production costs, these costs can usually be offset by revenue due to the reduction in the amount of surfactants required in the emulsification process.