It is no secret the damage unchecked fuel systems incur due to microbial contamination. Product loss, liability increases and Microbial Influenced Corrosion (MIC). MIC is responsible for significant financial cost. According to NACE International, corrosion within the fuel industry accounts for over $7 Billion in annual losses.
We will be discussing the adverse roll microorganisms play in damaging fuel systems. The following summary is meant to be an overview. Please note that this is not an attempt to cover every aspect, but only highlight major problems found today in fuel systems. Let’s start with the basics.
There are three microorganisms commonly found in fuel systems: algae, bacteria and fungi. Algae when found in fuel does not appear to be a major contributor to fuel system damage when compared to bacteria and fungi. Yeast and molds are the most common fungi found. Fungi often observed in the water-fuel interfaces on the bottom of tanks form a thick membrane or film evident in bottom samples. Bacteria are single-cell microorganisms found everywhere. Three broad types are relevant to the fuel industry: aerobes, anaerobes and facultative anaerobes.
Aerobic bacteria require oxygen to survive. Oxygen found commonly in water-fuel interfaces and condensation provide a ready source. Anaerobic bacteria cannot tolerate oxygen and will likely die; others can remain dormant. The most common and damaging anaerobe found in fuel systems is Sulphate Reducing Bacteria (SRB). We will talk about this specifically in later posts. Facultative anaerobes can survive in both oxygen and anoxic (without oxygen) environments.
The most important thing to realize is that no one single microbe is causing the problems associated with fuel contamination and fuel system damage. Microbes work in consortia (communities working together). Biodeterioration (the detrimental change to materials due to bioorganic activity) results from microbes working together. Over the next few months, our posts will describe in more detail how microbes interact, contaminate fuel and damage fuel systems.
Fuel quality is critical. So is the equipment designed to maintain it. At the heart of Dixon’s cleaning and filtration equipment is its Tri-lobe impeller-pump design which provides amazing pressure and vacuum performance during cleaning and filtration. One of the most challenging applications for a pump is lifting fluid from below the inlet of the pump. Dixon’s pump runs dry long enough to create the vacuum needed to lift or pull through long lengths of pipe. And don’t worry about dry run issues. We have astounding dry run capability. We have run our pump dry for 21 days with no change in performance or evidence of damage. Best of all it will not burn up like our competitors. Self-priming is easy and our pump can lift fluid 30 feet.
Why are these important factors for filtration equipment? The challenge of filtering fuel in tanks deep underground or high above ground can make filtration impractical or almost impossible. Dixon’s filtration equipment can overcome many of the challenges associated with suction and lift as a result of its unique design. Check out our videos and see for yourself. Contact us about our superior cleaning and filtration products at 1-800-874-8976 or email Patrick Eakins at email@example.com for more information and pricing.
If you are planning on attending PEI at NACS in Atlanta October 1-4, please come by booth 5141
With a major hurricane set to make landfall next week, tensions are up and readiness activities are well underway. One the of most important and often overlooked preparations is a simple generator fuel quality check. Do you know what is in your tank? In recent years, the statistics remain the same – bad fuel accounts for 75% or generator failures during an emergency. It is not too late to check your fuel quality. Get a bottom sample and make sure it is clean and clear. Make this a priority before bad fuel becomes a serious liability. Call Dixon Pumps at 1-800-874-8976 for advise on how to be prepared.
Fuel contamination and dirty tanks are a reality for tank owners today. Poor fuel quality is responsible for rising costs for tank and fuel system owners.
Liability issues caused by microbial influenced corrosion abound. The tank owner is faced with skyrocketing maintenance costs and liabilities that were not a problem a decade ago. Contaminated fuel attributes to the corrosion issue, part of the larger global corrosion problem costing over $2.5 trillion dollars each year. Corrosion represents the single largest expense in the US economy, 6.2% GDP. Today’s tank owners are having trouble coming to grips with the cost of bad fuel. Separating fact from fiction will help identify an acceptable solution to dirty tanks and contaminated fuel.
Fiction often begins with the idea that tank and fuel cleaning is too expensive. Fact exposes the truth – you cannot afford to have dirty tanks and fuel. The rising cost of equipment, maintenance and liability issues are all attributed to contaminated fuel. The cost benefit of clean tanks and fuel far outweigh the cost to clean.
Fiction includes believing your tanks and fuel are clean. Fact – almost 75% of fuel sampled contain moderate to serious contamination. Exposing the dangers of blind belief that your tanks are clean is a necessary step to taking appropriate action. A fuel sampler is an investment worth making. Monitoring devices and water finding paste can fail. The most effective way to determine what is in your tank is to take a bottom sample.
Helping tank owners peel away fact from fiction is key to reducing the costs associated with contaminated tanks and fuel. Identifying cost effective options to clean and maintain tanks will help owners to take the necessary steps to fuel quality management and tank maintenance. Call Dixon Pumps at 1-800-874-8976 or check out our Online Store where you can order a fuel sampler and much more.
The Effects of Dirty Fuel
As fuel ages, it degrades. Contaminants accelerate fuel degradation. Water is the most damaging contaminant and is attributed to a host of chain reactions. When water is present, microbes can grow. They commonly find their home in emulsified and free water. Microbes do not colonize easily in dissolved water. However, dissolved water does effect the stability of fuel causing accelerated aging. The pictures above show serious contamination in diesel fuel. The water found at the bottom of the tank contained a high level of microbial growth, a direct result of the contamination. Bacteria and fungi (including yeast and mold) will grow wherever water is found. Most of these microorganisms are aerobic – meaning they require oxygen to live and grow. Water supplies the need.
While there are other types of microbes – anaerobic and facultative anaerobes – aerobics are the primary ones found in fuels. Anaerobic microbes do not require oxygen to survive and facultative anaerobes can live in both oxygen and non-oxygen environments. While rarer, they are sometimes found. Aerobic microbes require very little water to multiply. Small areas of condensation on a tank wall can sustain a colony of aerobes. This microbial contamination causes biodeterioration of fuel. As fuel deteriorates, a layer of biofilm forms at the fuel/water interface in the bottom of the tank. Biomass colonies can also form and suspend within the fuel layer, especially when biofuel is present.
Microbes feed off hydrocarbons. They are often referred to as hydrocarbon utilizing microorganisms or Humbugs. As they eat the fuel, they produce an acidic byproduct. The acid settles to the bottom of the tank, remains suspended in the fuel and forms an acidic vapor in the fuel system raising the acidic content of the fuel system and causing microbial influenced corrosion (MIC). One of the most prevalent acids found is acetic acid caused by Acetobacter bacteria. They generate acetic acid from ethanol. Due to cross-contamination of fuels, ethanol is found in most fuel types including diesel allowing for the reproduction of Acetobacter and the production of acetic acid.
Acid formation accelerates the decomposition of fuel especially biodiesel. The molecules of biodiesel are predominantly fatty acid methyl esters (FAME). Its breakdown usually happens slowly unless water is present. The chemical breakdown of FAME by water (hydrolysis) is accelerated in an acidic environment. As a result biodiesel has a very short shelf life.
Most problems can be minimized with a fuel quality management program. Regular fuel sampling and immediate water removal when found. A Fuel Quality Management Program helps to identify contamination problems long before they reach the level seen in the photos above. Contact Dixon Pumps for help with contamination control at 1-800-874-8976 or find additional information at our CleanFuel website.
Where Does Contamination Come From?
Fuel contamination comes from many sources including product aging, the environment, microbial infection, transportation and fuel system deficiencies. The image above showing the fuel supply chain from refining to end user demonstrates many places where contamination is likely to occur.
At every point in the transportation of fuel contamination is a concern, compounded by the growing demand for cleaner fuels. Once fuel is refined, it often goes into temporary storage prior to being conveyed to a terminal. Delivery might include pipeline, ship, barge, tanker or rail car before arriving at terminal storage. Fuels may be allowed to settle prior to being shipped to its next destination. Settling is important as it permits contaminants to fall out and be pumped off. However, if settling time is not provided contaminants are likely to be transferred to the next location. Tankers transfer fuels from terminals to intermediate storage or end users. This might include additional storage or directly into equipment.
Many of the components of a fuel distribution center are made up of low to mild carbon steel. Tanks, pipes and pumps are very susceptible to corrosion. Rust and metal particulates are often carried downstream to the end user. Water always presents a problem. Throughout the distribution system water can be transferred along with fuel. Even pipeline cleaning, called pigging can attribute to higher contamination levels. Even when filtration is a part of the distribution chain, it may not be adequate.
Of the contamination studies, most agree that particulate and water contamination serve to be ongoing challenges. Biofuels tend to test dirtier than non-biofuel samples. On average, a tank that receives 8,000 gallons of fuel a week can gain as much as 35 pounds of particulate contamination per year. This does not include the potential for water contamination. Much of the filtering done through dispensers – especially retail – proves to be inadequate for providing fuel that meets today’s engine cleanliness requirements.
For more information check out Dixon’s CleanFuel website or call us at 1-800-874-8976.