Continuing our discussion about diesel fuel quality, the issue of diesel fuel contamination is a constant bug in the ear of fuel handling professionals, especially with how today's fuels are so much more prone to microbial contamination. Fuel is an investment that needs to be protected. Contamination of the fuel causes its value to go down by reducing the ability of the fuel to provide the work it normally provides through combustion in an engine.
We start by recognizing that more and more entities are mixing biodiesel into their regular diesel fuel supplies. This increases the instances of harmful fuel contamination. Biodiesel oxidizes and breaks down more easily in the presence of oxygen. The reactions with the oxygen form peroxide that eventually forms acids in the fuel, leading to gums and resins forming. Once you have gums and resins in the fuel, you get the problem of blocked fuel filters.
Water is another contaminant that is more prevalent with biodiesel than conventional diesel. People think that ethanol is the only biofuel with appreciable water issues, but that is not so. Biodiesel users can find their biodiesel blends absorbing more water than usual, which precipitates out of the solution upon temperature changes. Once you have an accumulated water layer, you have the potential for contamination with microbial colonies. And that brings a whole new problem for diesel and biodiesel users.
So we have the presence of biodiesel, and we have the fuel's affinity for water. Combine those two things with the change in the fuel's composition out of the refinery (fewer aromatic molecules), and the result is that today's fuels develop microbial contamination much more easily. This microbial contamination contributes to diesel fuel contamination not only through microbial breakdown of the fuel but also through contamination by biomass secretions from the microbes.
The remedies for fuel contamination are not rocket science. We've done blog posts on them before, but since it's a major problem for users, it's always useful to repeat the information sometimes. When fuel handlers are surveyed on the issue of preventing fuel contamination issues, the common suggestions are usually the best:
To prevent the likelihood of microbe, water, or particulate contaminant problems from being passed on to you, the user. A reputable fuel distributor who turns over a higher fuel volume is more likely to be on top of preventing these problems.
Tanks need maintenance to keep their integrity. You can treat the fuel to prevent water accumulation, but no fuel additive can overcome a rusty tank that allows rainwater to leak into the fuel inside after every storm.
This helps minimize the development of condensation.
When moving fuel, run it through a fuel filtration system.
Regular fuel testing for microbes and water will help you stay on top of stored fuel problems. Tanks should be dipped monthly to monitor water phase levels. Biocides should be used every 90 days to prevent microbial contamination, a serious and costly problem if left unchecked.