By Nicole Cornell, Client Services Associate
As winter fades away and spring ushers in warmer temperatures, it’s time for diesel fuel storage tank owners to consider an essential maintenance task: testing diesel fuel in tanks. Fluctuations in temperature and humidity impact the stability and composition of diesel fuel. These fluctuations can cause an increase in water contamination, microbial growth, and sludge formation.
Water Contamination
As temperatures start to increase, water that used to be ice is now melting and dissolving into the fuel itself. Additionally, the fluctuations in temperatures between the warm days and cool evenings will increase condensation inside diesel fuel tanks. This is because the warm air will carry the moisture into the tank, which will then condense on the cool metal surfaces. Draining diesel tanks will help remove some of that water – at least the water that is settled on the bottom of the tank. However, water also dissolves into the fuel and that likelihood increases with increasing temperature until the fuel reaches saturation. Water in diesel can promote microbial growth, accelerate fuel oxidation, and increase corrosion. To help reduce the amount of water present, it is recommended to use preventative measures like maintenance, sealing, and installation of water absorbing filters.
Microbial Growth
Microorganisms such as bacteria, fungi, and yeast thrive in environments with suitable temperature, moisture, and nutrients. During the winter, some micoorganisms enter dormancy to withstand the harsh conditions. As temperature rises during the spring and summer, these dormant microorganisms can resume their metabolic activity and growth. This resurgence often leads to rapid increase in microbial populations within diesel fuel tanks, leading to contamination and biofilm formation. The consequences of this can include clogged filters, injector fouling, fuel degradation, and corrosion within fuel storage tanks and delivery systems. To decrease microbial contamination, regularly inspect tanks for leaks and corrosion, remove water and debris at bottom of tank, and add biocides as instructed by the manufacturer’s guidelines.
Sludge Formation
Over the winter, it is common to use fuel heaters to prevent diesel fuel from gelling. However, this can also keep the temperatures warm enough to promote microbial growth. Microorganisms can contribute to the formation of insoluble sediment by metabolizing hydrocarbons and producing products that are insoluble in fuel. In addition, some microorganisms will produce acid by-products that will increase rates of diesel fuel degradation, which can also lead to increase sludge formation. Reducing the amount of water present in fuel will help decrease microbial growth, which will then help reduce sludge formation. This is especially important for biodiesels as they are more susceptible to water contamination and microbial growth.
Mitigating Risks Through Testing
Water contamination, microbial growth, and sludge formation are all factors that can decrease the life of your fuel, cause equipment damage, or even halt operations. There are many comprehensive tests that can provide you information on how to mitigate these risks. Depending on what is being observed in the fuel can help determine which tests should be performed:
*not offered as individual test (comes in test package)
Having a more pro-active maintenance plan can extend the life of fuel and equipment and reduce equipment down time. If you are interested in learning more about how Fluid Life can support you and your team, reach out to our reliability specialists.