Nigeria shows how water in diesel engines can reduce pollution

Nigeria’s research team showed how mixing small amounts of water into diesel fuel could  reduce harmful emissions and sometimes even improve engine performance.

Based on the research, adding water to diesel—in the form of a carefully formulated water-in-diesel emulsion (WiDE) —can reduce certain harmful emissions and improve thermal efficiency. However, it's not a simple solution, as it can increase other pollutants and presents practical challenges .

How it Works: The "Micro-Explosion"

The benefits come from the unique way water-in-diesel burns. When the emulsion is injected into the hot engine cylinder, the water droplets inside the fuel vaporize rapidly. This causes a "micro-explosion" that breaks the fuel into smaller droplets, leading to more complete combustion .

The Trade-Offs: Emissions and Efficiency

The effects on engine performance and emissions are a mix of positives and negatives.

The Crucial Difference: Emulsion vs. Contaminated Fuel

A key point is that this technology applies to engineered emulsions, not simply pouring water into a fuel tank .

• Water-in-Diesel Emulsion (WiDE): This is a stable, homogeneous mixture created using surfactants (a kind of soap) to suspend tiny water droplets within the diesel. It is produced under controlled conditions and can remain stable for up to 60 days .
• Water Contamination: This is the presence of free, non-emulsified water in the fuel tank. This is a serious problem for diesel engines. It can cause corrosion, promote microbial growth (the "diesel bug"), damage fuel injectors, and reduce engine power .

In short, adding water to diesel can improve certain aspects of emissions and efficiency, but only through the precise science of creating a stable emulsion. It is not a DIY hack and comes with the significant caveat of increasing other harmful pollutants like CO and HC.

By Jamuna Rangachari