Articles
and Links to useful diesel maintenance issues
Diesel Fuel
Quality is a Question Not a Guarantee
From Ground
Support Magazine, March 2005
When it
comes to the "acceleration" of diesel fuel quality, it just
doesn't compare to the diesel engines it's supposed to "rev"
up.
Diesel engine
designs striving to increase engine performance have made
great advancements in engine fuel delivery to the combustion
chamber. Today's diesel engine is quieter, smoother and more
powerful. But today's diesel engine owners are overlooking
one important factor. The quality of today's diesel fuel has
not advanced at the same rate as the engine improvements.
Diesel fuel
begins to deteriorate as soon as it is produced. Within 30
days of refining, all diesel fuel regardless of brand, goes
through a natural process called re-polymerization and
oxidation. This process forms varnishes and insoluble gums
in the fuel by causing the molecules of the fuel to lengthen
and bond together. These components now drop to the bottom
of the fuel tank and form asphaltene also known as diesel
sludge. The fuel begins to turn dark in color, smell bad and
in most cases causes engines to smoke. The engines smoke
because some of these clusters in the early stages are small
enough in size to pass through the engine filtration and
into the combustion chamber. As these clusters increase in
size, only part of the molecule gets burned. The rest goes
out the exhaust as unburned fuel and smoke. With increases
in cluster size they begin to reduce the flow of fuel by
clogging filters. The filters only address the symptom and
not the cause. Read
more
Advanced
Fundamentals - Magnetic Fuel Conditioning Technology
From boatdiesel.com
June 2003
By Gary Morgan
The
questions continue to the forum... "When I opened the
drains on my Racor filters, there was molasses that came
out the bottom. Is this a byproduct of diesel fuel, or does
it come from some other source?" And another... "I
have a black fine sediment in my diesel fuel that I sent
to the lab and it came back negative for algae. I could
install Algae X magnets, but if it is not algae in the fuel
will Algae X help?" Clearly there are many boaters
impacted by fuel related problems.
This
is the third in a series of articles on fuel related problems
associated with diesel engines. In two previous articles
I have outlined the problem of sedimentation in diesel fuel
[Fundamental Biology and Chemistry for Diesel Owners] and
principles of filtration applied to diesel engines [More
Fundamentals - The Case for Multi-Step Filtration].
Read more
Is
Magnetic Fuel Conditioning Technology for Real?
From boatdiesel.com
June 2003
by Gary Morgan
With the realization that skepticism often accompanies new
technology, I can only suggest to the skeptical reader that
when the U. S. Department of Energy, the Society of Petroleum
Engineers, and the U. S. Navy all publish data on Magnetic
Fuel Conditioning Technology, it must do something. I hope
this paper provides guidance for those desiring to try the
technology, and increases their level of success. Read
more
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Mr. Morgan began his career as Senior Research Scientist
at Pfizer Medical Systems, where he developed X-ray generation
and measurement systems for Computerized Axial Tomography.
He served as Director of Research and Development at Pacific
Scientific, and Chief Research Scientist at Triton Thalassic
Technologies. The holder of five (5) U.S. Patents for Optical
Particle Counters and Excimer Light Sources, his professional
biography is included in Who's Who in Science & Engineering
and Who's Who in America. Mr. Morgan is an avid boater on
the Chesapeake Bay and mid-Atlantic coast. His ancestral
heritage traces back to the early settlers of Tangier Island,
Virginia one of the Chesapeake's most colorful and productive
waterman communities.
Diesel
Fuel Essentials
This article was originally published on SailNet in November,
2000.
Magnetic Biocides... Liquid biocides are the most
hazardous of diesel fuel additives. True, they kill all
the life forms in the tank, but they kill everything else
they touch as well. The carcasses left behind sink to the
bottom of the tank and will eventually clog filters. Sludge
at the bottom of the tank should be handled as special toxic
waste, which can cause difficult disposal problems.
Most
cruisers use their boat's auxiliary engine often, and if
so, they probably won't need to install a recirculation
pump. For those whose boats sit unused for prolonged periods,
having such a device is a good idea.
Several
companies have developed magnetic "bug zappers"
to address these problems. Bacteriologists found that single-celled
organisms have an electrical potential and that disruption
of their delicate electrical balance causes the cell to
sicken and die, sometimes even bursting the cell wall. By
routing the fuel next to a strong, permanent magnet, or
series of magnets, cell reproduction can generally be halted,
the existing micro organisms killed, and the cells themselves
may even be shredded.
It
is clear that the fuel must be circulated through these
units and over the magnetic field to be effective. For work
boat or charter vessel engines that are run often, this
presents no difficulty. Diesels sitting unused for long
periods of time would need to install a recirculation pump
with diverter valves to occasionally pass all the fuel through
the magnets and other filters—not such a bad idea in
any event.
Complete
article at:
http://www.sailnet.com/collections/articles/index.cfm?articleid=woodto044
Fundamental
Biology and Chemistry for Diesel Owners
by Gary Morgan
The
life expectancy of stored diesel fuel is limited. Depending
on the amount of contaminates, sooner or later stored diesel
fuel will deteriorate. Of the many contributing factors,
there are four main factors responsible for the deterioration
of marine diesel fuels.
These factors include:
* oxidation
* microorganism growth
* corrosion
* sedimentation
Reviewing
briefly the first three factors; oxygen reacts with the
hydrocarbon molecules in the fuel. Oxidation causes
discoloration, formation of particulates, water and gum.
Microorganism growth, primarily bacteria and fungi,
gather at the fuel water interface in the storage tank.
They consume diesel fuel and produce acids and water as
byproducts. Corrosion is caused by microbial growth,
water and voltage potential across storage tank walls. Corrosion
may deteriorate tank walls and releases metals back into
the stored fuel. This action will accelerate the oxidative
reaction.
Sedimentation is a consequence of the fact that marine
fuels are not pure hydrocarbons; they contain inorganic
matter such as grit, clay and sand. These substances, to
some extent, occur in the crude oil and remain in the residual
fuel after refining. In addition, other non-oil soluble
material may enter the fuel during storage and distribution.
These sediments can generally be removed from the fuel by
settlement, centrifuging and filtration, depending in their
density and particle size. Tests methods used to identify
these materials, do not assist in the evaluation of the
fuel regarding long term precipitation of asphaltenes.
Several
studies have confirmed the effects of the factors discussed
above. University of Idaho scientists have conducted tests
to determine the timeline and percentage of degradation
of stored diesel fuel #2. The results from this testing
shows that petroleum diesel fuel #2 degraded 26% after 28
days of storage. Studies conducted by Frankenfeld et.al.
under accelerated storage conditions also proved that sediments
are formed. The formation of these sediments are increased
in the presence of water and dissolved oxygen. [references:
"Fuel Facts" National Biodiesel Board, Jefferson
City, MO; Frankenfeld, J.W. "General Features of Sediment
Formation in Model Fuel System," Ind. Eng. Chem. Prod.
Res. Dev. 1983, 22, 608-614].Read
More
Fuel
Quality
By Brent Doughty
Diesel Injector Service, Lubbock,TX
A
major percentage of all problems with diesel engines are
related to fuel quality. Diesel fuel can sometimes vary
from one shipment to another or from one area to another.
Customers also switch from one fuel vendor to another and
suppliers sometimes change the fuel they are offering. The
three things that vary the most in diesel fuel are cetane,
weight and viscosity.
Cetane
is defined as the susceptibility of the fuel to self ignite.
Acceptable cetane levels are between 40 and 45, however,
very few fuel distributors advertise this since each batch
may be different. Cetane can influence both starting and
combustion roughness of an engine. High altitudes and low
temperatures demand increased cetane number of the fuel.
Read
more
Dec
31, 2002
New rules in works for diesel emissions
Proposal would cut that pollution by 95 percent
ASSOCIATED PRESS
WASHINGTON
- Heavy construction vehicles and other large off-road machinery
will have to meet tougher emissions requirements and use
cleaner diesel fuel under proposals being discussed by the
Bush administration.
The proposed rules would force manufacturers to install
new devices on diesel-powered equipment such as:·
Tractors · Forklifts · Bulldozers ·
Irrigation machinery
The Environmental Protection Agency is expected to send
a proposal to the White House next month on dealing with
pollution from the off-road vehicles, administration officials
said Monday. They said a formal proposal is planned for
the spring, with a final rule to come a year later. Read
more
WHY IS DIESEL EXHAUST AN AIR POLLUTION PROBLEM?
Diesel
exhaust is a mixture containing over 450 different components,
including vapors and fine particles. Over 40 chemicals in
diesel exhaust are considered toxic air contaminants by
the State of California. Exposure to this mixture may result
in cancer, exacerbation of asthma, and other health problems.
Read
more
Technology
Update: The Diesel
By
Dennis Simanaitis
Road and Track Magazine May 2003
High
End? Or Middle of the Barrel?
Both
gasoline and diesel fuel are primarily petroleum products.
There are biofuels of each type, but none has proven feasible
in the large scale. Diesel fuel, like kerosene and jet fuel,
is a middle distillate; gasoline, a lighter, high-end product.
Distressingly
enough, in the old days when lamp and lubricating oils were
the petroleum products in demand, high-end distillates were
dumped into rivers and streams! Today, refineries are optimized
for output, but still not without tradeoffs. The Europeans,
for instance, refine so much diesel fuel that they end up
with a glut of high-end product, some of this gasoline actually
being sent our way. U.S. refineries favor cracking techniques
that get more high-end out of the entire barrel. Ironically,
one byproduct of this is an overproduction of diesel —
but it's the wrong kind of diesel, with indifferent cetane
and too much sulfur.
Just
as octane measures the goodness of gasoline (actually, its
knock resistance), cetane is the diesel's measure of quality.
Briefly, cetane is inversely related to ignition lag; the
higher the cetane, the less lag, the better the fuel. European
diesel fuel is around 55 cetane; ours, more like 42-44.
Sulfur
is the real problem, though, now and with future emissions
controls, here and in Europe. Petroleum crudes vary from
source to source. Benchmark Arab Light, for example, is
a sweet crude (i.e., low in sulfur). Mayan and other Central
American sources are considerably more sour. Refineries
can finesse costs of crude supplies and sulfur removal,
but only so far.
Sulfur
in U.S. diesel fuel averages around 350 parts per million,
500 ppm being not unknown. In Europe, the absolute cap is
300 ppm; average levels are perhaps 175. In fact, Europeans
already have low-sulfur diesel available with a maximum
of 50 ppm, phasing down to 10 by 2005. We have low-sulfur
diesel as well, but only in California. We also have similar
national goals seen as crucial in meeting increasingly stringent
(and immensely complex!) emissions-control standards phasing
in between now and 2007. For example, by June 2006, 80 percent
of U.S. diesel fuel sold by major refineries has a 15-ppm
limit; this, rising to 100 percent by 2010. Read
More
