Fuel Quality

Most fuel dealers believe that the quality of the fuel they buy and sell is poor.  Most also believe that the quality gets even worse when that fuel is stored for months or years.  Let’s look at what really happens with storage of No. 2 distillate ‘ heating oil or diesel fuel ‘ and see how that affects fuel quality.

First, let me say that I am not a fan of the specifications for our fuels today.  I gave a paper at Oilheat Visions in Providence in 2006, making the case for a better specification for our heating oil ‘ and especially regarding its stability.  Most of the movers and shakers in our industry were at that conference and heard ‘ or at least sat in the room ‘ during my presentation.

There has been no movement to improve the quality of our heating oil other than to reduce sulfur levels in a few locations, and to introduce B2 Bioheat in a couple of states.  The ASTM specification for heating oil still has no meaningful requirement for stability of the fuel.

Speaking of fuel stability – this was a real problem during the ’70s and ’80s, and continues to be a problem with some high-sulfur No. 2 fuel – especially if blended with light cycle oils by the fuel wholesaler.  Unstable fuel forms microscopic particles of solid fuel that make the fuel look darker.  You may have run across fuel oil that no longer looks like bright, clear red fuel, but more like coffee.  Sometimes these particles clump together and settle out, making what looks like black river silt in the bottom of a tank.  If the fuel is thermally unstable, it can cause backside coking of nozzles in some systems.  This is still a problem for some of you – though not a big problem.

Should you be using a stabilizer additive to improve your fuel? To stop sludge from fouling your filters, tanks, lines, strainers and nozzles?  Not so fast!  There’s more to this story.

For all the concern about fuel quality and operating problems in oil heat systems, you need to understand that most of those problems are caused not by deficiencies in the fuel itself – but rather by what happens once the fuel leaves the refinery and is transported and stored.  The bottom line: water gets into the fuel and bad things grow in the fuel. That is the primary source of almost all of your system fouling. That is also the reason why pitting corrosion occurs in storage tanks – and why those tanks eventually leak and need replacement.

Wait, you say, that isn’t your problem?  The tank is the homeowner’s problem?  That is exactly what I hear from most fuel oil dealers – and that is one of the things homeowners dislike about oil heat.  We have unwittingly allowed oil heat to be known as the dirty, smelly, and unreliable heating fuel – and we have told the customer that he or she is responsible for that ugly oil tank that one day may leak and require replacement.  No wonder gas and electric marketers are having a field day!

The fact is, oil heat systems have fuel-side operating problems, and oil tanks fail, primarily because water gets into the systems and bad things grow in them.  Perhaps it’s time we wake up to that and start treating to stop those bad things from happening!

Now that we realize that little critters growing in our fuel tanks are our major headache, why not simply kill them with biocides?  There is definitely a place for biocides in fuel systems – but not to defeat sludge, fouling and corrosion.  Why?  Because the critters that cause sludge and corrosion are embedded in their “biomass” (sludge), and biocides simply can’t effectively reach them to make the kill. 

Fortunately we have another way to handle all of this.  In the early ’90s we learned that “filming amines,” chemicals used for decades in industrial water systems to protect against corrosion, can do that and more in fuel systems.  We learned that, by combining two of these useful chemicals, we can dissolve away old sludge, prevent new sludge from forming, clean up dirty fuel systems, and stop the pitting corrosion that leads to storage tanks leaks – all without having to deal with the expense and handling issues of biocides. 

Over the past twenty years we have refined this chemistry, tested, tweaked the formula, and re-tested – and have earned the trust of major users.  This dual filming amine chemistry is now used by homeowners, fuel dealers, heavy equipment operators, tug boat companies, standby generators, navies and coast guards around the world – in short, all those who use No. 2 distillate fuels and who want those systems to operate without problems. 

About the author: Bob Tatnall spent thirty years as a materials engineer with DuPont, specializing in corrosion, linings and coatings. In 1968 he first observed a little-known phenomenon called microbiologically influenced corrosion, or MIC. Fascinated by this destruction of metals and alloys by bacteria, Tatnall spent the rest of his DuPont career learning about how bacteria and other microorganisms interact in different environments. In 1991, he retired from DuPont and became a biocorrosion consultant and developed the sludge-control additives that led to his forming the fuel treatment company Fuel Right. 


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