Biodiesel contamination by water

The water can contaminate biodiesel, degrading many of its properties in the process. It is true that biodiesel isn't miscible with water, but this isn't the issue here, the real problem is the fact that it absorbs water at a molecular level.

This is what makes biodiesel significantly more susceptible to water contamination compared to standard petroleum diesel. Once biodiesel gets contaminated by water, removing the water out of is anything but easy because biodiesel can retain up to 20 times more water than regular diesel.

The presence of water in biodiesel can cause damage to your vehicle

 
The presence of the water in biodiesel causes several different problems:

- The presence of water can lead to corrosion of fuel and injector pumps, fuel lines, as well as some other vital parts of the car.
- It can lead to loss of power and harder starting of the car because of its ability to reduce the heat of combustion of the bulk fuel.
- Water can also cause rotting of the filters in the system. Rotten filters can significantly shorten the lifespan of fuel pump.
- Water freezes at low temperatures, and this can result in faster gelling of the residual fuel.
- Water can also cause pitting in the pistons on a diesel engine.
- The presence of water can also accelerate the growth of microbe colonies.

As already said above, removing water out of biodiesel is difficult, meaning that the prevention should always be the first choice. Several techniques have proved to be extremely helpful in preventing water contamination of biodiesel, for instance, having all tank caps in place and in good condition, doing the filling of the tanks at the end of the day to avoid condensation when the temperatures cool overnight, using underground storage tanks, avoiding the prolonged exposure of fuel to light since this can induce algae growth, etc.