By Chris Biellier, Seneca Companies
In the last five years we’ve come a long way in understanding the causes and effects of poor fuel quality and maintenance-related issues for the retail and commercial fuel industry. However, we’ve still got a ways to go in terms of a) understanding the impacts of changing fuel chemistry, and b) getting ahead of the problem through a proactive approach to managing fuel quality.
Fuel contamination has a direct impact on a business’s bottom line. When gasoline and diesel fuel users see their equipment maintenance costs increasing and liability claims mounting, they’ve reached a point where they can no longer turn their back and look away.
I often use this analogy: If you’ve got symptoms of the flu, you take medicine to cut it off at the pass. But if you ignore the symptoms, you become unwell and drag yourself off to the doctor as the virus sets in.
As a petroleum industry and environmental solutions provider to the fuel retail industry, our customers started approaching us with questions regarding problems with fuel quality about four or five years ago. They could see the maintenance effects of fuel contamination such as blocked filters, slow flow pumps, failing components and evidence of corrosion on varying scales, but, understandably, weren’t aware of the underlying causes.
Anticipating this growing issue, we began to offer fuel restoration solutions by partnering with Leighton O’Brien, using their patented fuel polishing technology to treat the root causes of poor quality fuel and its effects as a result of changing fuel chemistry.
Let me explain.
Since the introduction of ethanol and ultra-low sulfur diesel (ULSD) about a decade ago, a growing number of diesel and gasoline storage tanks and dispensing systems have experienced unusual and accelerated corrosion and bacteria problems. What might have taken 10 or 20 years previously was showing up in as little as 30 to 60 days.
Then in 2012, a key industry research piece called the Battelle Study attributed mild steel corrosion from enhanced microbial activity in systems storing and dispensing ULSD and a correlation with the impact of ethanol cross contamination. Another common material fouling filters is a metallic coffee ground substance. Subsequently this problem has led to costly repair, blocking or slow flow or volume delivery pre-set errors.
At first, many in the industry wanted to blame ULSD for these corrosion problems or bacteria accumulation in the tank bottoms because the problem began to emerge about the same time the industry switched over to ULSD. But ULSD is not corrosive by itself, rather it’s the bacteria that forms that creates the issue. As mentioned previously, investigations found traces of ethanol in ULSD. Ethanol by itself isn’t corrosive but when combined with water in the fuel, it becomes the ‘food source’ that’s conducive to the growth of bacteria. This bacteria converts (oxidizes) ethanol into acetic acid, which is highly corrosive to mild carbon steel.
As it turns out, the switch to ULSD happened about the same time gasoline manufacturers started putting ethanol into gasoline. Trace amounts of ethanol-blended gasoline would get into the diesel fuel as delivery tankers switched from one product to the next – known as “switch loading.” This cross contamination, even in small amounts, affects fuel quality.
Ethanol and water have one thing in common: they love each other, more so than gasoline and diesel fuel. When ethanol-entrained diesel fuel is discharged from a tanker into a ULSD UST with bottom water, the ethanol will migrate to the water at the bottom of the tank. Again, it’s the water in both diesel fuel and ethanol that creates the process.
This has led to the growing realization that the fuels we use today have much different compatibilities, don’t play nice with one another and both don’t like water.
This is not to bash ethanol. It’s here to stay and for good reason from an environmental standpoint. Not every UST in the country is experiencing the same level of corrosion or biomass accumulation. However, UST operators who address the water issue quickly have less problems.
A Preventative Maintenance Approach
The ULSD and ethanol-blended fuel corrosion problem is a lot like a three-legged stool – those legs being an energy source (the ethanol), acetobacter (which is everywhere) and water. You can’t do much about the first two but you can monitor and remove enough water from the equation to defeat the problem.
By not transferring the ethanol from the diesel fuel to the water phase, you starve the acetobacter of the moisture and energy it needs to grow and multiply. Even if there’s no cross contamination from ethanol, diesel fuel with the presence of any amount of water creates a petri dish for bacteria to form and accumulate in the tank bottoms. Over time it will be drawn up the system to the dispensers, creating flow issues.
Until the industry comes up with definitive solutions to these problems, visual observation and testing should be a regular part of your maintenance schedule. This includes fuel polishing if the problem exists. Quarterly inspections of your UST are best, semi-annually at least. Even if you’ve got fiberglass tanks, the pipes and fittings are typically steel.
You should also periodically look at the riser tube, joints and threads. If you see rust, you’ve got a problem. Also check your fuel filters. If you see material that resembles coffee grounds, you may have a corrosion issue. Look for rust on the dispenser filter faceplates and if your filters have them, look at any steel springs. You’ll typically see sediment in the filter media. To determine if it’s rust, just pass a magnet over it.
ULSD is a very stable fuel, but if ethanol from switch loading is accumulating in the water phase of the tank and the acetobacter is converting the ethanol to acetic acid, then you need to address the water.
If you see or suspect corrosion, you need to get your fuel tanks tested. If they do test positive, you need to take some corrective measures, possibly adding biocides to your fuel storage, removing the bottom water from the tank and filtering the entire contents all the way to the dispensing nozzle.
Biocides will kill the bugs, but to keep them from coming back you need to nail the problem at the source by keeping water out of your fuel.
The fuels today are here to stay. By taking a preventative ‘flu shot’ approach, you’re preserving the health of your tank system and ensuring the quality of your fuel while keeping your maintenance budget, sales and brand intact.
Chris Biellier is Vice President of Seneca’s Environmental Services, Remediation and Waste Solutions divisions. With 30 years of experience, Chris is one of the industry’s foremost experts on environmental, waste management, remediation and preventative maintenance issues and solutions. Seneca Companies is a large petroleum construction, service and distribution provider and is a valued PEI distributor of Leighton O’Brien’s patented fuel cleaning and polishing services. Seneca Companies has nine physical branch locations throughout the Midwest, Southern and Mountain regions, with a service area spanning over 12 states and growing.
