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The term "diesel fuel" (DF) generally refers to any fuel for a compression
ignition engine. Most commercial DF is made from petroleum and
is often called petrodiesel. There are also non-petroleum types of such
fuel, such as biodiesel.
Crude oil naturally contains some sulfur, a portion of which is
converted to
sulfate particulates in the exhaust and contribute to so-called
particulate matter (PM) emission. To reduce PM and to enable some
advanced
emissions control devices for better air quality, many countries set
the limits to sulfur content of DF. Particularly, in US
starting in June, 2006, EPA required at least 80% of the on-highway DF to be Ultra-Low Sulfur Diesel (also called ULSD or S15),
with maximum sulfur level of 15 parts per million (ppm). Gas pump may
still sell DF with 500 ppm sulfur until December 2010. In US by
2014 DF for all categories of equipment has to be ULSD. Note that
in European Union and Japan ULSD means less then 10ppm sulfur.
Older engines should work normal on ULSD with just a small reduction of
efficiency. However, newest engines with advanced pollution-control
technology designed for ULSD, may be damaged by fuel with high sulfur
content.
DIESEL GENERATOR
USES
DGs are widely used in places where grid is not available or
as emergency power source
for home or business if the grid fails. Depending on size, they can be
used for small loads,
such as electric tools, and for large loads like factories, commercial
buildings, and hospitals. Automatic
standby systems are widely used as an emergency backup
source in hospitals, fire and police stations because DG is the
only type of gensets that can reach rated power within ten seconds of a
grid failure. They are also used in remote locations in hybrid off-grid solar
systems as an auxiliary power source. Portable DGs are popular
on jobsites because they typically have 2-3 times longer life then
gasoline-powered models.
The chart below summarizes basic advantages and disadvantages of DG.
| PROs |
CONs |
The
most reliable and maintenance-free of all types: no ignition systems,
carburetors, nor spark plugs (just regular oil and filter changes);
Lowest fuel consumtion (typically it would burn half the amount of fuel
that would be required for a same-size gasoline generator);
The fuel can be stored in large tanks (up to 2 years with fuel
preservatives), it is less flammable then other fuels and is the safest
fuel to store |
The
most expensive type;
The fuel not be available during wide spread blackouts;
The fuel contains paraffin waxes that become solid at freezing
temperatures- needs low temperature operability additives;
High engine's emissions and unpleasant odor |
In short, diesel-powered gensets are more reliable and have
higher efficiency than the gensets
running on other types of fuel, but they cost more.
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