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 firstname.lastname@example.org for more information and pricing.
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.
Tank cleaning and fuel polishing are two different processes. The question often asked, “Which one is better?” Are there any advantages to one over the other? Cost can be a determining factor as well as site downtime, if any. Tank cleaning is generally more expense. It usually requires fuel be removed and a chemical agent applied during cleaning. Once the tank cleaning process is completed, the old contaminated fuel is filtered back into the tank or new fuel is delivered. Either way the costs are higher than simply polishing fuel in place.
Opponents on either side of the cleaning and filtration industry will argue their points, but the solution is often determined by cost of service and downtime. Let’s be honest, for many tank owners cleaning versus polishing is a matter of economics. If the only economically feasible solution is to polish the fuel – then do it. It is better than leaving contaminated fuel in the tank. Ignoring the problem will only increase the cost of ownership.
However, there are times when a tank is so contaminated that it requires a tank cleaning with pressure and chemicals. Having been in the field cleaning tanks and filtering fuel for years, I have found around 20% of the tanks serviced needed tank cleaning in addition to fuel polishing.