Fuel Testing and Winter Preparation 2021

When should I start testing my fuels to prepare for winter?

fuel tank moisture control

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.

Marshall Root, Major Account Executive

Winterizing Modern Fuel 2021

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. 

This image has an empty alt attribute; its file name is n-paraffin-content.png

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 DieselBlending 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-GelAnti-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 WASAThe 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.