Hey folks -
this is an area where I have a little experience. Full disclosure up front: I am working with a company that is building next-gen fuel filtration and polishing systems for any size fuel storage
sites (1000l to 400,000l and more). We are actively dealing with this in many industries, including marine
, on a daily basis.
Most of the comments thus far are mostly correct from a technical standpoint- but there are a few changes that have occurred in the fuel manufacturing and distribution chain around the world that have moved the goal posts and dramatically complicated matters.
In short - Diesel
fuel today ain't what it was only a few short years ago.
The (government mandated) move to ULSD (below 15 ppm sulphur) removed much of the lubricity inherent in diesel
. Without lubricity, engines don't run for long, so additives are put back into the fuel to bring lubricity back up. these additives are all members of the surfactant family
, and change the chemistry of the blend, bringing with them the ability to absorb and attract more water
. they also change what's called the interfacial tension in the fuel molecules. This has a significant effect on the ability of water
to exist in emulsion in the fuel, and makes it almost impossible to filter out using traditional absorptive (racor and equiv type) filters. Even big-ship centrifugal polishing/purifying systems are not removing this water effectively - they also have this issue.
Add to this the (also govt mandated) addition of a certain percentage of bio-sourced fuels, and there is an enormously variable new source of both water and other contaminants. the Fatty Methyl Esters (FAME) of bio-sourced fuels are highly unstable and also very hygroscopic; increasing both the water content and tendency of the fuels to gel and be less predictable at variable temperatures.
As has been noted, the growth of bacteria in fuel tanks is directly related to water - the bacteria (not algae please...) grows in the water, feeding on the fuel components. biocides do kill the bacteria, but there is still the organic matter that is slushing around in your tank. dead or alive, it still clogs stuff up badly. Another lesser known issue with these bacteria are their byproducts of consumption
- which is acetic (and others) acid. many terrestrial tanks are finding severe corrosion
of metallic components under the new fuels, and so far all indicators are pointing to a high acid concentration near corroded areas- directly as a result of the bacterial byproducts.
The end result is a fuel that can contain a lot
of water in emulsion, which is not being filtered out by almost any of the exiting polishing systems on the market (ask them to show you their SAE J1488 2010 test results... where they measure the ability of a filter to remove emulsified water from ULSD and bioblends... they won't have any). This fuel is radically unstable and can degrade in a matter of months - and folks... this is the fuel we all buy right now, whether we know it or not. it's mandated in most of North America and Europe
. Around here, we're getting anywhere from a 2% to a 10% bio-blend depending on the time of year, but you don't really know because the blenders are allowed to average it over a full year. could be 10% in the summer and 2% or less in winter... you'll never really know unless you test on each fuel delivery
(which is possible - but a simple biofuel test kit is a couple hundred bucks!).
Combine this with modern common rail diesels with very tight tolerances and high injection pressures and almost zero ability to handle either water or sludge and you've got a perfect storm.
What can you do about it? Well of course I'd like to suggest you buy one of our systems - but they are not ready for the non-commercial/recreational market yet... will come soon. They are the only 3rd party certified SAE J1488 (2010) fuel polishing systems on the market that can remove all the emulsified water from new blends of fuel. if you'd like to learn more go to Puritas Energy - Puritas Energy
to read the whole story.
in the meantime (I am dealing with this on my boat too) all you can do is try to burn your fuel reasonably quickly, keep it as dry as possible, use a biocide and have lots of filters handy to change out when the clogs come thru. AND clean your tanks whenever you get the chance.
who knew fuel was so dang complicated? I just wanna burn the stuff!!