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Fuel Breakdown By-Products
Least understood is the natural process whereby organic fuels break down. Diesel and other fuels are naturally unstable, and actually less stable today due to modern refining techniques (catalytic cracking) that are designed to produce more fuel per barrel. Most major oil companies have documented on their Web sites that 6 to 12 months is the useful shelf life for their products, but the deterioration process starts as soon as the products leave the refinery.
This fuel breakdown is a process where agglomerating hydrocarbon chains bond together to create larger clusters. These larger compounds, present even in what visibly appears as clear and bright fuel, do not burn as efficiently. This incomplete combustion robs fuel economy, leaves carbon deposits on injectors and raises emissions, often with visible smoke and soot.
As the process continues, with even larger compounds being formed, the fuel begins to appear “dirty.” Eventually it progresses to forming sludge that falls to the bottom of the tank. This clotting fuel is the material that is commonly clogging fuel filters and shutting down generators. Often it may happen when a tank gets low and new fuel is poured in, agitating the sludge and dispersing throughout the fuel, releasing the threat that had been lying dormant. Or maybe the new fuel delivery came from such an agitated tank upstream in the supply line.
The Bottom of the Barrel
Water and tank sludge, of course, drop to the bottom of the tank, and a too-often overlooked but critical concern is that any tank cleaning be done properly by getting to the bottom of the tank. Access is frequently a limiting factor, but an inspection port can be installed to alleviate this problem. Similarly, when installing a recirculating conditioning and filtration system, the pickup tube into the tank is optimized when near the bottom (not using the fuel system’s draw, which is several inches higher to avoid the very substances you wish to collect).
Take the Test
Any generator that is in a critical application ought to be a candidate for a routine fuel testing service, probably on a quarterly basis. All the talk about fuel quality means little if you don’t have a benchmark to measure from. Be sure to get your samples from both a midpoint and the bottom of the tank.
Put Fuel Maintenance into the Vocabulary
Too often, fuel condition is overlooked, mostly out of ignorance of the issue. When that happens, the extreme of fuel removal, replacement, and possibly extensive tank cleaning or even tank replacement, is the cost. That is, if you’re lucky and didn’t have a generator failure in a real emergency situation. Only the business in question can determine the cost in the case of a total failure. But, generally, they wouldn’t have a generator if total power loss was an acceptable outcome.
It is crucial that disaster-planning professionals become aware of the need for a fuel maintenance routine to assure the survival of critical systems in the event of an emergency. PEI members are perfectly positioned to advance this educational effort. It can also represent a value-add service, as well as potential source of revenue and profits. Perhaps most important, you will be participating in raising overall organizational survivability and reducing the human suffering and loss of life in the midst of the worst of catastrophes.
Contaminant | Source | Effects | Solution |
Water | Condensation, Leaks, Fuel delivery | Combustion/Injector problems, Corrosion, Saturates filters, Supports microbial growth at bottom of tank | Fix flawed tanks, Water eliminators, Periodic tank cleaning, Automated conditioning and filtration system, Some additives can deal with small (normal) quantities |
Microbial Growth | Arrives through air or water, Requires water to thrive | Multiplies and produces waste matter, Clogs filters, By-product is corrosive | Biocide – only if highly advanced state, Periodic tank cleaning, Automated conditioning and filtration system |
Particulate Matter | Faulty tank breather, Tank corrosion, Fuel delivery, Tank installation | Abrasive wear and tear | Filtration through: Periodic tank cleaning, Automated conditioning and filtration system |
Fuel Breakdown By-Products (most tank sludge) | Natural deterioration process of all organic fuels, Accelerated by heat, temp changes, pressure, presence of water | Incomplete combustion, Carbon deposits on injectors, Poor fuel economy, High emission levels (often visible smoke and soot), Filter clogging | Process reversal through conditioning in some: Tank cleaning systems, Automated conditioning and filtration system, Chemical breakdown with additives |