Mar 20, 2017 | by Kathy Hudson
Biodiesel as an Alternative Fuel for Generators: Can it do more Harm than Good?
In recent years, alternative fuel sources have seen a rise in popularity. Biodiesel—a renewable fuel made from vegetable oil, plant oil, animal fat, or waste from cooking oil—appears to be an attractive alternative to standard diesel fuel. The production of biodiesel decreases waste, while the use of biodiesel is known to decrease harmful environmental emissions. When it comes to selecting a fuel source for your industrial generator, transitioning from traditional diesel to biodiesel may seem like the most environmentally-friendly and cost-effective decision. However, there are a number of potentially destructive side effects of using biodiesel that need to be taken into consideration when choosing the right fuel for your generator.
Biodiesel is a natural solvent. It breaks down and releases deposits of residue that have accumulated in the fuel system. The particles collect in the fuel filter, shortening its lifespan. A clogged filter restricts fuel flow, which can lead to engine failure if the engine is unable to draw enough fuel to continue running normally.
The corrosive properties of biodiesel may also destroy certain components of older, used generators. Hoses, seals, and gaskets made of rubber or rubber-like materials are likely to be softened and degraded by biodiesel. Glues, some plastics, and paint are also susceptible to biodiesel corrosion.
Biodiesel is thicker than standard diesel. Because of this, atomization in the fuel injector results in the formation of larger droplets. Greater droplet size can clog the injection system in the engine. If deposits form on the injector nozzle, the fuel flow and spray pattern are compromised, decreasing the performance of the generator and possibly leading to engine failure.
Contact with Water
Biodiesel absorbs more water than standard diesel. Increased water content causes a decrease in lubricity, and without sufficient lubrication, the engine’s lifespan will be shortened. In addition to the negative impact on generator performance, the water found in biodiesel accelerates corrosion and encourages microbial growth.
At low temperatures—sometimes as high as 40°F—biodiesel will gel and then solidify as it continues to cool. Because biodiesel can be made from a variety of sources, it is difficult to know at what temperature a specific type of biodiesel will begin to gel.
While the shelf life for traditional diesel is 12 to 18 months, the shelf life for biodiesel is only 6 months. This can pose a problem for standby generators that are rarely used.
Many manufacturer’s warranties are voided if biodiesel is used in equipment that was designed for standard diesel.
Biodiesel is made from a variety of sources, and each one has different properties that may affect the performance of your generator in a number of ways. While the American Society for Testing and Materials has standardized the production of biodiesel, there is no guarantee that the use of biodiesel will leave your generator running efficiently.
As with all decisions regarding the operation of industrial equipment, it is important to take into consideration both the potential advantages and disadvantages of choosing one type of fuel over the other. Ultimately, proper use, regular observation, and routine maintenance will help ensure a long life for your industrial generator.