When properly used, cold filter plugging point (CFPP) additives change the shape and size of wax crystals so they can pass through fuel system filters at lower ambient temperatures than without the use of these additives.
A wax anti-settling additive (WASA) can prevent wax from settling if used in the additive package. WASA additives disperse the treated wax so it stays suspended in the fuel and does not settle on the bottom of the tank. The CFPP temperature is now more reliable due to the WASA component.
A caveat of diesel fuel additives and CFPP treatment: TIME
The longer a treated fuel sits in a “Slow Moving Tank” at low temperatures, the more likely gravity will promote the settling of wax at the bottom of the tank.
The increased wax density overwhelms filters on startup (the fuel pick-up is normally on the bottom of the tank). Fuel filter plugging will occur at a temperature higher than the CFPP temperature.
Testing MethodsFuel Testing is of extreme importance. To evaluate wax settling performance in CFPP additives, a treated and untreated fuel sample is cooled to sub-zero temperatures. The sample sits undisturbed and time-lapse photos are taken. The resulting photos show the rate at which wax settles and visually indicate the reliability of the given additive at a selected treat rate.
When concerned about a critical application, i.e. such as a state DOT bid or another requirement that has a hard CFPP target to meet and penalties associated with non-attainment of the target CFPP, one should look for the additive products that provide the best protection from settling.
When should I start testing my fuels to prepare for winter?
I get this question often. No matter the time, my answer is always “right now.” Sure it may be too early to determine a range of where the cloud point for the fuel will be all winter, but other factors play into being successful with a cold winter.
One of the most significant negative contributors to winter issues is moisture. Water freezes at 32°F, so too much moisture in fuel can cause problems at temperatures well above the typical cloud point of the fuel.
By testing in fall before we get into the winter months, we can determine the moisture level in the tanks and respond early to potential issues. For example, elevated moisture levels can indicate a water bottom and lead to plugged filters, iced filters, corrosion, and microbial growth.
It is much easier to fix an issue before it causes significant problems than waiting to find out you have moisture issues and trying to fix them with freezing ambient temperatures. When in doubt, it is always a good idea to take a sample. More information never hurts.
What’s up with “Modern Fuel”?: Fuel Characterization
Fuels are constantly changing, and as a result, effective fuel treatment must adjust accordingly. However, the solutions are not so simple. To correctly identify the proper treatment program, more thorough testing methods are needed. For instance, testing for n- paraffin distribution can significantly help to classify different fuel sources.
Some fuels that we encounter today do not react to winterization the same as they did in the past; we classify these fuels as “hard to treat.” To deal with “hard to treat” fuels effectively, a better and more in-depth understanding of the specific fuel properties is needed.
Diesel is composed of about 75% saturated hydrocarbons. Historically, typical refined ultra-low sulfur diesel would have an even distribution of n-paraffin carbon chains gradually increasing and peaking around C-16 to C-20, then gradually decreasing. Therefore, gaining a better understanding of refining tendencies is instrumental in creating effective treatment programs.
This example of n-paraffin wax distribution diagrams shows the variability between different sources of fuel.
The “n-Paraffin Content” graphic shows variations that often occur between other fuels. For example, the blue fuel contains higher concentrations of smaller n-paraffins than the orange fuel. Conversely, the n-paraffins mainly contained in the orange fuel are larger (to the right). This higher concentration of longer n-paraffins causes this fuel to be more difficult to treat for cold weather operability effectively.
Summary: Wax content varies significantly from refinery to refinery throughout the USA. Determining the proper fuel treatment protocol varies from region to region and fuel to fuel. These characterization programs allow a better understanding of fuels in the different areas and how they react to treatment.
Winterization Treatment Options
Blend with Kerosene or #1 Diesel
Blending with #1 dilutes the overall wax content in fuel and therefore reduces the cloud point. #1 blending offers a certain amount of protection by thinning out n-paraffin wax content and lowering the cloud point of the base fuel. Blending with #1 is useful but costly. The use of #1 is most effective when combined with proper winter additive chemistry.
Blend with Anti-Gel
Anti-gel additive modifies the shapes of wax crystals as they cool to allow them to pass through fuel filters at temperatures below their cloud point. In some fuels, traditional anti-gel is very useful for winterization, however many other modern fuels require additional chemistry.
Blend with Anti-Gel and Wax Anti-Settling Agents (WASA)
If fuels sit static for long durations in cold temperatures at or below the cloud point, wax particles start to become denser and fall to the bottom of equipment/storage tanks. The combination of both Anti-Gel and WASA modifies the shapes, sizes, and densities of wax crystals to prevent gelling and Wax Fallout.
Blend with #1 Diesel, Anti-Gel, and WASA
The use of all three above methods together is most effective because it dilutes the amount of wax with #1 fuel while also using winter additive chemistry to prevent gelling and wax fallout. Keep in mind that blending #1 from the same hard-to-treat #2 blendstock can produce diminishing returns. Fuel testing is beneficial to observe fuel characteristics and determine the proper treatment methods.
Modern fuel refining processes and new crude sources have resulted in harder-to-treat fuels. Most fuels today contain irregular or unpredicted concentrations of n-paraffin waxes and require additional methods to test and treat for cold weather operability effectively. Higher levels of anti-gel and WASA are commonly needed, and often the use of #1 fuel is also necessary.
Fuel Additive Facts to Know
1) Determining a fuel’s cloud point is the most critical first piece of information that we must know to create a proper winter treatment program.
2.) CFPP does not predict the temperature to which a fuel “is good.” You may better understand CFPP as an indication of whether additives are effectively attacking the waxes and whether a fuel source is harder to treat than usual. We can use a combination of CFPP and cloud point to help figure out where the exact operability temperature will be, but there are still other factors that come into place (filter size, filter cleanliness, tank exposure, engine, and fuel system design and requirements, etc…)
3.) When undisturbed treated fuel is subjected to a prolonged duration of frigid temperatures (i.e., cold weekend) at or below the fuel cloud point, the heavier waxes fall out and gather at the tank bottom near the fuel inlet. On the first morning back, restart becomes a battle as the settled wax gets pulled through the fuel system. ET Products counteracts this issue with a proprietary Wax Anti-Settling Agent that works by normalizing the size and density of these wax crystals, so they don’t fall out to the bottom of the tank. We are proud to purport a scientific approach, followed by lab testing and field successes that prove our chemistry.
Cetane is a massive buzzword in the fuel industry. Ask almost anybody what they are looking for in a premium diesel, and cetane is sure to be one of the first words brought up. However, many times, the benefits they are looking for are derived from a premium detergent if you dig deeper.
While cetane is still essential to aid in combustion efficiency and cold starts, it doesn’t typically provide the benefits that the end-user has in mind. Historically, horsepower and fuel economy are associated with cetane. However, equipment changed from mechanically driven, large engine parts to smaller, electronically driven components. Cetane isn’t the most critical factor in restoring horsepower or improving fuel economy. Read more about cetane and cetane numbers here.
Today’s engines and injectors are designed to work on a precise amount of fuel injected in a series of sprays through tiny openings. Premium detergents keep the injectors clean (or clean up if a premium detergent has never been used) from deposits to allow optimal fuel injection sprays. This extends the life of the injectors, but it also restores horsepower and improves fuel economy to new engine performance levels.
In addition to engine components becoming smaller and electronically driven, the way diesel fuel is being refined has also increased the need for a premium detergent. As sodium and calcium come into contact with corrosion inhibitors used in the pipelines, carboxylate soaps/salts are formed. Premium detergent is required to keep these deposits from causing issues in equipment and fuel performance.
All fuel can hold a certain amount of moisture in suspension. But, when moisture exceeds the saturation point, it drops out of the fuel. This is how tank bottoms and other free water separates in storage tanks. Why is this concerning?
Moisture can be the cause of several issues such as microbial growth (commonly referred to as “bugs” or “algae”), icing, dilution of fuel, poor engine performance or damage, corrosion, rust, and more.
Unfortunately, water separators and tank drainage are not realistic or effective solutions to prevent moisture issues independently. Because of this, ET Products recommends the implementation of a moisture control plan. This plan can both identify and prevent large amounts of moisture from building up in fuel tanks.
Using a moisture control agent throughout the year can prevent moisture build-up before it becomes a problem. In addition to this, we have also developed moisture monitoring programs through our laboratory that can identify problematic conditions before they become an issue.
In Spring, we need to be aware of substantial temperature swings that could increase moisture-related issues in fuel tanks. Tank maintenance programs using a combination of fuel cleaning, tank maintenance, and biocide products are instrumental in solving moisture-related issues (caused by microbial growth) and preventing the recurrence of future problems.
When temperatures change, warm air loses its ability to hold as much water vapor. This results in condensation and causes water accumulation. Freezing and thawing temperatures also lead to water in storage tanks (i.e. water can seep into cracks and crevices and expand as it freezes, leading to openings that can let water in). As end-users get moving this Spring, they should pay extra attention to moisture levels in tanks. When care is needed, additional levels of moisture control will help to suspend and remove moisture.
It is good to have a plan in place to deal with potential moisture-related issues and prevent future occurrences.
What is microbial growth? How can it be mediated?
Microbial growth (commonly referred to as bugs or algae) goes hand in hand with high moisture levels. When conditions are right for growth to occur, these microorganisms thrive and can cause a wide range of issues in fuel storage tanks and vehicles.
These organisms use fuel as a food source, but they also need water to become active. As water saturates out of fuel and settles to the bottom, it turns into a breeding ground for microbial growth to flourish.
Proper treatment with biocides and tank cleaning chemicals can help ensure that customers’ tanks are clear of bacteria-related issues.
A common indicator for microbial issues is a slowed fuel flow caused by filter plugging.
Clogged filters often become coated with and contain dark slimy substances in the filter media.
Many microbial growth forms also cause damaging corrosion causing a host of other problems. By far, the most common shared element between all types of microbial growth is the presence of a water bottom in the tank where the growth is occurring.
No matter how it appears, microbial growth can be very frustrating to end-users.
Tank Maintenance Programs
Tank maintenance programs are great for keeping microbial growth at bay and ensuring that fuel storage tanks are in good shape.
Typical tank maintenance programs include fuel cleaning additives. These additives can help maintain tank cleanliness and housekeeping operations ensuring that tanks do not allow in water and moisture. A tank maintenance program can also offer fuel testing to better understand your fuel.
Tank maintenance programs are not a new concept, but the need for tank maintenance programs is evolving and more important. Modern fuels are susceptible to a wide array of issues in storage, so taking steps to ensure that fuels are kept fresh and in good condition is extremely important. Moisture contamination is a constant threat that can result in operational shutdowns if not recognized and dealt with early on.
When bringing vehicles into a service department for possible mechanical failure, mechanics often initially blame fuel for the issues. Having a history of monthly fuel quality analysis is a great way to help dispel guilt and get on the faster track of finding the cause of the issue at hand.
The benefits experienced by a tank maintenance program are wide-reaching. They can go a long way in securing existing business and attracting new business because of the additional advantage you provide customers.
Moisture and Tank Maintenance
The prevention of moisture accumulation is one of the most important aspects of tank maintenance programs. Customers with fuel storage usually depend on their fuel to work properly when called upon, but they do not take the time to inspect their tanks regularly. Taking a few minutes every month to make sure that there are no leaks, cracks, or other failures can go a long way in preventing future fuel issues. Click here for our checklist.
Water enters the fuel supply chain in multiple ways, including condensation, contamination during transport, leaks, and careless handling. The routine removal of this moisture prevents water accumulation and helps prevent ice formation, bacterial and fungal growth (“bugs”), oxidation, and corrosion.
All fuels contain a volume of dissolved moisture that is removed with fuel as it is burned during combustion. ET’s Moisture Control technology attaches to moisture and allows it to be burned off in the engine as regular dissolved moisture. This process prevents the formation of tank water bottoms that can lead to a variety of issues.
Basic Tank Maintenance Tips
Storage Tanks · Use a tank maintenance additive that will prevent the accumulation of moisture and disperse and remove contaminants · Pump out or drain moisture and contaminants at least semi‐annually. · Use desiccant vent breathers to remove water vapor from the air as it enters tanks · Understand whether tanks are level to identify where water bottoms will accumulate · Double-check fill caps and venting for leaking. · Inspect tanks for cracks, holes, leaks, or loose fittings and caps · Keep snow and water away from fill areas · Sample and test fuel annually · Use an effective biocide treatment semi-annually · Glycol ethers (moisture control agent) act as a co‐solvent for water and can help reduce water accumulation and enhance fuel’s ability to hold water in the solution and can help remove moisture from the entire system
ET Products can help determine the proper intervals to treat with an effective biocide to mitigate microbial growth before it multiplies
Vehicle Equipment Tanks · As you enter the cold / winter season, change your fuel filter with a new clean filter of appropriate size · Drain off all water from water separators daily · Make sure fuel caps fit tightly and do not leak · Minimize condensation by topping off tanks at the end of runs.
Fuel refiners are constantly working to improve methods to optimize output and improve profitability. Even though changes in refining methods and new sources of crude stock can be economically advantageous, they routinely require further characterization for cold weather operations, i.e., more extensive lab testing and treatment response.
Weather-related failures could often occur at higher than expected temperatures in addition to those that come with the extreme cold. Sometimes these issues arise even when users presumably treat fuel properly for the winter. If you use #2 diesel and live in regions north of the yellow areas in the map below, then you’ve probably experienced issues with diesel fuel-operability(wax separation, icing, gelling).
We now know that traditional winter treatment methods are not always effective in modern fuels but answering why is not always simple. To correctly identify the proper treatment program, the user should utilize more thorough and comprehensive testing methods. For instance, testing for n-paraffin distribution can greatly help to classify different fuel sources. Diesel is composed of about 75% saturated hydrocarbons.
Traditionally, typical refined ultra-low sulfur diesel would have an even distribution of n-paraffin carbon chains gradually increasing and peaking around C-16 to C-20, then gradually decreasing. The n-paraffin wax distribution diagrams to the right show the variability between different sources of fuel. Understanding your fuel is essential to determine the best cold weather fuel additive treatment options.
The n-Paraffin Distribution Plot 1 shows contrast in a traditional fuel (blue) vs. a recently obtained fuel (red). The recently obtained fuel shows a significant increase in wax content starting at n-C15 level and after. In this case, the higher concentration (red bars) of n-paraffin waxes and the longer carbon chains (to the right) cause this to be more difficult to deal with in cold weather.
After running several n-paraffin distribution content curves (as seen above), it was found that fuel wax content varied greatly from sample to sample across the US.
Therefore, determining the proper fuel treatment protocol varies from region to region and fuel to fuel. Understanding how the fuel you handle reacts to treatment will help determine the proper winterization method(s).
Additive Treatment Options
1. Blend with Kerosene or #1 Diesel
Diluting the overall wax content. Blending with kerosene or #1 diesel will offer you a certain amount of protection by thinning out n-paraffin wax content and lowering the base fuel’s cloud point. Though blending with #1 can be effective, it is also a costly option. The use of #1 is most effective when combined with proper winter additive chemistry.
2. Blend with Anti-gel Additive
As diesel fuel cools, wax particles (n-paraffins) start to bond together and grow larger. As they grow, they can eventually become so large that they will not fit through fuel filters resulting in filter plugging. When fuel blends with anti‐gel, the anti‐gel will modify the wax particles’ shape and size to prevent growth. This modification will help your fuel flow through filters at lower temperatures than untreated fuel. See Image 1 for Wax Modification with Cold Flow Improver (CFI Treated Fuel).
3. Blend with Anti-gel and Wax anti-settling Additives (WASA)
As fuels sit static for long durations in cold temperatures at or below the cloudpoint, wax particles can start to become denser and fall to the bottom of equipment/storage tanks. The combination of both Anti-Gel and WASA modifies the shapes, sizes, and densities of wax crystals to prevent gelling and Wax Fallout. See Image 2 for Wax Modification with WASA and Cold Flow Improver (CFI Treated Fuel).
4. Blend with Anti-gel, WASA, and #1
The use of all three above methods together is most effective because it dilutes the amount of wax with #1 fuel while also using winter additive chemistry to prevent gelling and wax fallout. Keep in mind that blending #1 from the same hard-to-treat #2 blendstock can produce diminishing returns. In this situation, competent fuel testing can help to determine proper responses and ratios.
Many factors, including modern fuel refining processes and new crude sources, result in harder-to-treat fuels nationwide. These fuels contain varying or unpredicted concentrations of n-paraffin waxes and require additional methods to test and treat cold weather operability effectively. Higher concentrations of anti-gel and WASA are commonly needed, and often the use of #1 fuel is also necessary.
Fuel Additive Facts to Know
1. The CFPP temperature is not the only measure of a fuel’s cold flow performance.
Do not focus 100% on the CFPP. As many now have seen, operability failures almost always occur before reaching a CFPP test number. You may better understand CFPP as an indication of whether additives effectively attacking the waxes and whether a fuel source is harder to treat than normal.
3. When the difference between Cloud Point and CFPP is not as expected in a treated fuel, it indicates further testing or analysis be completed for best recommendations of cold flow additives and or blending.
NOTE: WASA does not typically affect the CFPP testing performance but can greatly improve operability.