Protecting Your Emergency Fuel For Future Use
For those in charge of buying, storing and maintaining fuels, it’s important to ensure that the quality of whatever backup stored fuels to be used in an emergency are protected and maintained. This means the stored fuel combusts properly, doesn’t create black smoke and adverse emissions, the fuel does not leave deposits inside of the engine, and the engines themselves are able to maintain load and run as well as they should.
If these emergency backup stored fuels are not ready for use at the exact time that they're needed, then the consequences of such a problem are amplified. When a hurricane hits in Florida or a tornado happens in the south of the Midwest, public and private sector entities assume the diesel or biodiesel or ethanol fuels set aside for storage will successfully perform their roles in power generators, emergency management equipment and other vehicles that perform the duties called for in the relevant emergency management action plan.
Whatever kind of fuel you use in whatever capacity, there are certain things that you as a fuel manager can do to ensure that the stored fuel is going to continue to be ready to use when you need them the most.
Stability - Making Sure The Fuel “Stays Together”
No matter if you use fuel in an emergency vehicle or cleanup heavy duty equipment or a backup generator, if the fuel quality is not within specification when it is needed, then the vehicle or engine is not going to run properly or it may not even run at all. This concept is really about molecules in the fuel reacting and changing, creating end products in the fuel that change its condition. When you hear about formation of fuel oxidation, gums, varnishes and fuel sludge, they’re really talking about parts of the diesel fuel mixture that used to be soluble in solution with the fuel blend, but which have undergone chemical reactions to form substances that are heavy enough to fall out as sludge. These heavier sludge molecule formations don’t burn very well when they are used by the engine.
The fuel's tendency to resist these kind of changes to its condition speaks to the property of the fuel known as Stability. For stored fuel, it starts out in the best condition possible, and you don’t want that to change. The best way to blunt or resist this change is through the addition of a fuel stabilizer. Fuel stability treatments work to stop the chemical reactions at their source to keep these substances from forming.
Of the common fuels in the marketplace – ethanol, diesel, bio diesel - these all have some common storage quality issues that can all be addressed with simple solutions. So we will take some time to examine some of the common issues that are inherent to the preservation of these fuels – to ensure they’re ready for action when you and your business or group are faced with important action. Understanding the root causes of these changes of fuel quality in storage is the first step in setting up a fuel care protocol (or reexamining an existing one) that will ensure that you’re as prepared as possible for when you need to respond to an emergency in the quickest and best means possible.
Diesel fuel is still the most common backup fuel stored in the United States. The diesel fuel in use today is not exactly like the diesel fuel that was in use 10 or 15 or 20 or more years ago. The big difference between diesel fuels now and diesel fuels then is the level of sulfur allowed in the diesel fuel. This difference stems from requirements introduced to the Clean Air Act around the year 1990, which ushered in big changes on the removal of sulfur from the fuel. In the old days, diesel fuel could contain as much as 5000 ppm of sulfur. The Clean Air Act mandated a dramatic reduction in that sulfur content from 5000 ppm to 500 ppm. That's about a 90% reduction. Later, the amount of sulfur was reduced even more drastically, from 500 ppm to just 15 ppm sulfur allowed in on road diesel fuel. This new cleaner fuel is known as ultra-low sulfur diesel (ULSD) and it’s the only kind of diesel you can use for virtually all on-road vehicles and engines.
What does this mean for fuel storage for emergency management? The biggest initial fears over ULSD were its potential lubricity problems. These fears have been allayed due to the addition of biodiesel and the development of lubricity enhancers. So they don't worry as much about that any more.
However, there are other problems these fuels do have. Many emergency management professionals are not aware that the the change in the fuel brought about by the removal of sulfur from diesel fuel makes that diesel fuel far more likely to see bacteria, fungus, and other microbial infestation problems emerge in storage. They used to think it was because “sulfur is toxic” to microbes, but that’s not necessarily the case. Microbes have the ability to grow in higher sulfur fuels, though they do not like it near as much. The big issue for microbial growth in ULSD is the capping of the aromatic content. Microbes don’t like to consume aromatic hydrocarbons for fuel, they prefer the other, aliphatic hydrocarbons. And today’s ULSD fuels are higher in aliphatic hydrocarbons, which means less inhibiting of microbial growth. Fuels management professionals now find that they're far more likely to have a microbial infestation problem with contemporary ULSD diesel fuels.
Take the removal of sulfur and aromatics, add water accumulation in storage, and you have a perfect recipe for the faster degrading of stored fuel quality. Water plays several roles in the destruction of stored fuel quality. The accumulated water builds up in fuel storage tanks that are vented to the outside. Every fuel management professional knows it is common practice to have at least some water sitting at the bottom of every storage tank. This water increases the possibility of microbial growth in that stored fuel. If you have a layer of water interfacing with a layer of diesel fuel, microbes will have access to all the things that they need to grow and thrive inside of a fuel storage tank. Microbes that infest storage tanks produce acids and corrosive substances as a result of their biological processes. These biological byproducts accelerate the breakdown of the quality of the diesel fuel just as you would expect an acid to do. They also promote corrosion of the inside of the storage tank, especially if biofilms have been formed.
Most fuel storage professionals have a protocol to control water in tanks. There are water coalescers, filters and centrifuges that can allow for the removal of significant amounts of water from tanks. There are also highly effective fuel treatment options, such as those manufactured by Bell Performance, that will absorb significant amounts of water and cause it to be locked into the diesel fuel for combustion.
Biodiesel blends such as 2% or 5% biodiesel are more and more common in municipalities and organizations who face state, local and federal mandates to increase the volume of biofuels that they use in public vehicles. Higher levels of government are always happy to issue requirements dictating the behaviors of the entities below them.
Not only this, but biodiesel fuel users are also taking advantage of its natural lubricating properties, which can restore all of the lubricity properties of the diesel fuel that were lost when the sulfur was reduced by over 98%. A blend of as little as 2% biodiesel methyl ester into an in-spec diesel fuel base will restore all of the lost lubricity from the removal of the sulfur. This keeps these principalities from having to purchase additional lubricity additives from their fuel suppliers. So it is a win – win situation for them. They get a high lubricating diesel fuel blend, and they get to claim a certain number of gallons of renewable biofuels used towards the mandate that are seeping down from further up the political food chain.
But for all of its great qualities, there are some caveats that come with biodiesel, even when the percentage of biodiesel in the blend is less than 5%. Biodiesel has proven to be an excellent food for microbes to feast upon. A B2 or a B5 biodiesel blend faces a greater possibility of these problematic infestations of microbes developing over time. Coupled with the ongoing issue of water condensation buildup in the storage tank, when these factors come together at the same time, you get a perfect breeding ground for microbial infestation.
When this does develop, the only way to get rid of it is by applying a biocide. Removing water won’t kill microbes, but biocides will. Using a biocide treatment is the only thing that will kill and eliminate the problem. There are not many biocides commercially available because the regulations for bringing a biocide to market are very strict indeed. That's why you can't find very many on the store shelves.
Ethanol blends, in the grand history of fuels storage use for emergency management, are relatively new player on the horizon. The story has been told many times before. Ethanol addition into gasoline became common around 2005 and 2006 when a previous fuel additive called MTBE was phased out of the national gasoline supply because of fears of it contaminating groundwater. Ethanol became the substitute for fulfilling the role of being an oxygenate. Oxygenates add more oxygen to a gasoline mixture, and that causes the gasoline to burn with fewer harmful emissions that affect urban air-quality. Addition of oxygenates to the gasoline supply is mandated by the EPA through the Clean Air Act.
Cities and municipalities find that they can do the same thing with ethanol fuels that they can do with biodiesel - that is, use their ethanol fuel usage as a credit towards the number of gallons they are required to use annually of renewable fuels.
Ethanol fuels often garner more attention regarding their issues, perhaps due to their widespread use among consumers in the US. Unlike diesel, ethanol blends are more sensitive to storage problems, possibly because gasoline, being highly refined, is more sensitive. Ethanol blends have a higher propensity to dissolve water, which may seem like it's attracting water. This poses significant problems for stored ethanol fuel blends. The dissolved water accelerates oxidative degradation and microbial infestation in ethanol fuels, and can trigger phase separation. Phase separation occurs when ethanol blends like 5%, 10%, or 15% absorb atmospheric water. Once the absorbed water exceeds the blend's tolerance, it causes the ethanol to separate from the gasoline. This results in a mixture of water and ethanol at the bottom, with the remaining gasoline on top, impacting the fuel's effectiveness and potentially causing engine issues. This highlights the importance of proper storage and maintenance, especially when dealing with ethanol blends, to ensure they remain viable and safe for use.
This is bad news for a couple of reasons. One, when the ethanol undergoes phase separation and falls out, it strips many of the important components that contribute to that gasoline having a high octane rating. This loss of octane rating is related to the practice of fuel blenders and refineries using the ethanol to increase the octane rating of the gasoline blend. Ethanol has a very high octane rating, something that racing drivers notice very well. Refineries know that they can take a low octane gasoline and add high-octane ethanol to end up with an 87 octane mixture. Or an 89 or 91 or 93 octane-rated gasoline. Ethanol is, per-unit, cheaper than gasoline, which means they save money doing this.
But if the blend undergoes phase separation, and the ethanol drops out of the gasoline mixture, what’s behind is, at best, the same low octane and poor quality rated gasoline they started with. At worst it's an even lower octane fuel than they started with because the ethanol has carried away some of the vital organic components that were already in the gasoline and which were making up a portion of the fuel’s octane rating.
Important measures for protecting fuel quality
Fuel management professionals often utilize quality fuel additives to address or mitigate fuel-related problems cost-effectively. Here's what to consider:
1. Fuel Stabilizers: The foremost solution to fuel degradation. Diesel fuel stabilizers, comprised of various chemistries, tackle different degradation aspects. Antioxidants halt chemical reactions causing fuel quality to deteriorate over time. Metal deactivators counteract catalytic effects certain metals have on degradation reactions. Dispersants maintain heavy polymer molecules dispersed in the fuel, delaying their reaction to form larger molecules. A good diesel stability treatment, added to fresh fuel, is a crucial tool for managers.
2. Biocide: Essential for combating microbial contamination in storage tanks or systems. Although there's industry debate on preventative maintenance doses of biocide, it's advisable to treat microbial issues as they arise, which is more efficient and cost-effective. Semi-annual microbial testing, like ATP, is inexpensive and aids in timely intervention. Effective biocide chemistries like Bellicide and ClearKill are available.
3. Water Control Ingredients: Vital for managing water buildup in stored diesel and ethanol fuels. Bell Performance offers products like DFS Plus and Ethanol Defense for water absorption in fuels, and multifunction treatments like Dee-Zol, which besides water control, also enhance combustion and detergency.
Employing these measures can significantly lessen fuel-related issues, ensuring fuel remains in a usable state, especially crucial for emergency scenarios where fuel readiness is paramount.