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What is the downside of using biodiesel?
- A slight increase in NO2 emissions
over petroleum diesel may be experienced, especially with older engines.
These NO2 emissions can be eliminated with the use of a catalytic converter.
- Biodiesel does not store
well for periods of time as it will separate, congeal and in
general break down while
in storage. Biodiesel without preservatives or biocides has a shelf life of 6
months in ideal conditions. In a B20 mix save for pre-existing tank
contamination or petrol contamination the shelf life is slightly higher.
- Biodiesel is subject to algae growth
as water accelerates microbial growth and is naturally more prevalent
in biodiesel fuels than in petroleum-based diesel fuels. Care must be
taken to remove water from fuel tanks. A special algaecide for diesel can be
added to the fuel to inhibit algae growth.
- Biodiesel
has viscosity problems of B100 in cold climates.
- 100%
biodiesel and higher percentage biodiesel blends can cause a variety of engine
performance problems, including:
- filter plugging,
injector choking: Filter plugging and injector choking may be caused early
after the conversion to biodiesel due to its cleaning properties.
- piston ring sticking and
breaking, a tendency for top rings to become stuck: This is not urban myth but
biodiesel and 100% vegetable oil are frequently confused.
- elastomer seal swelling and
hardening/cracking: Older engines are much more susceptible to this.
- severe engine lubricant
degradation.
- Because
biodiesel varies based on manufacturing process and the source materials used,
elastomer compatibility with biodiesel remains unclear; therefore, when
biodiesel fuels are used, the condition of seals, hoses, gaskets, and wire
coatings should be monitored regularly.
- Especially at low ambient temperatures, biodiesel is thicker than conventional
diesel fuel, which limits its use in certain geographic areas. This can be
solved through the use of winterizing agents also used in petroleum based
diesel fuel or, if practical, you can store the biodiesel in a warm location or
heat the fuel tank.
- The biodiesel you use must be free of
all foreign material!
- A
consortium of diesel fuel injection equipment manufacturers (“FIE
Manufacturers”) issued a position statement concluding that blends greater
than B5 (5% biodiesel 95% petroleum diesel) can cause reduced product service
life and injection equipment failures. According to the FIE Manufacturers’
Position Statement, even if the B100 (100% biodiesel) used in a blend and
meets one or more specifications, “the enhanced care and attention required to
maintain the fuels in vehicle tanks may make for a high risk of non-compliance
to the standard during use.” As a result, the FIE Manufacturers disclaim
responsibility for any failures attributable to operating their products with
fuels for which the products were not designed.
- There is
limited information on the effect of neat (100%) biodiesel and biodiesel
blends on engine durability during various environmental conditions. More
information is needed to assess the viability of using these fuels over the
operational life and operating periods typical of heavy-duty engines such as
generators.
- Lubricant degradation
has been noted. The use of B100 or high percentage biodiesel blends may cause
severe engine lubricant degradation. We have been advised by Diesel engine
manufacturers that more frequent oil change intervals are recommended if a
high percentage mix (+B20) biodiesel is used.
- There
are several reasons causing B100 biodiesel to have a greater tendency than
petroleum diesel to get into the oil pan. B100 has about 50% higher viscosity
than petroleum diesel, when the injectors atomize the thicker fuel,
larger droplets form. Droplet size is affected by several properties
including surface tension, specific gravity, and viscosity.
- Biodiesel is a good solvent and can be corrosive. It will dissolve rubber and
some plastics, remove paint, oxidize aluminum and other metals, and it has
been reported to destroy asphalt and concrete if spills were not cleaned
quickly. Keep it off items you care about.
Fuel Injection Equipment (FIE)
Manufacturers
The following is paraphrased
and cannot be directly attributed to the Fuel Injection Equipment Manufacturers.
They feel that the
following problems are attributed to high concentrations of renewable fuels and
thus are the reason to not use them above B5:
- Fuel system seal failures
- Particulate filter clogging
prior to injector pump
- Fuel injector blockage,
resulting in poor atomization.
- Dilution and polymerization
of engine oil
- Injector pump failures due
to poor viscosity oil in cold climates
- Increased injection pressure
- Corrosion of fuel system
components
- Poor long term storage
ability of biofuel
The FIE is unwilling to
recommend a higher than B5 concentration without the inclusion of the following
specifications in an international standard:
- Exclusion of SVO
- High concentrations of
methanol in fuel
- NaOH or KOH particles
in the fuel
- Water content
- Glycerin content
- Free fatty acids
- High viscosity at low
temperatures
- Maximum fuel shelf
life (Organic Acids, Oxidation)
- Iodine Value
- Total Acid Number
Quote from a commercial Biodiesel Manufacturer
Biodiesel is new to them [Manufacturers]
with 50,000 new suppliers ranging from individuals who call fryer grease
biodiesel to high quality true methyl ester biodiesel manufacturers. Engine
Manufacturers have little to no way to tell if the fuel has damaged an
engine unless it's apparent. On a purely business perspective it makes no sense
to endorse biodiesel. They (think they) know what they have with diesel fuel and
it (they think) offers more reliability. Why introduce a substance that is
different into there engines.
From the FAQ on the www.cat.com website
Q: What is
Caterpillar’s position on the use of alternative diesel fuels in Cat engines?
A: New emissions
standards are driving the use of alternative diesel fuels. While ultra-low
sulfur diesel (ULSD) is
the fuel of the future, other
fuels like biodiesel and water-emulsified diesel fuels do have some risk.
Contact your
local Cat Dealer for more
information.
US EPA Act (EPACT) -
Canadians! help me and find Equivalent information and I'll post it for others!
The
Energy Policy Act of 2005
What the Energy Bill Means to You
The Energy Policy Act of
2005 (EPACT), signed by President Bush on August 8, 2005, offers consumers and
businesses federal tax credits beginning in January 2006 for purchasing
fuel-efficient hybrid-electric vehicles and energy-efficient appliances and
products. Most of these tax credits remain in effect through 2007.
...
Biodiesel/Alternative Fuels
Small producer biodiesel and
ethanol credit. This credit will benefit small agri-biodiesel producers by
giving them a 10 cent per gallon tax credit for up to 15 million gallons of agri-biodiesel
produced. In addition, the limit on production capacity for small ethanol
producers increased from 30 million to 60 million gallons. This is effective
until the end of 2008.
Credit for installing
alternative fuel refueling property. Fueling stations are eligible to claim a
30% credit for the cost of installing clean-fuel vehicle refueling equipment,
(e.g. E85 ethanol pumping stations). Under the provision, a clean fuel is any
fuel that consists of at least 85% ethanol, natural gas, compressed natural gas,
liquefied natural gas, liquefied petroleum gas, or hydrogen and any mixture of
diesel fuel and biodiesel containing at least 20% biodiesel. This is effective
through December
What does the US Military do or say
about Biodiesel?
Due to minimal cold flow data using
animal-tallow biodiesel blendstock, the tallow-based biodiesel isn't permitted
for use in the current military specification. The specification currently
used by DESC requires only virgin soy or grape seed methyl-ester blend stocks,
but the military hopes to approve yellow greases in the near future.
In the absence of a national
standard, the US military has developed its own specifications for B20 biodiesel
blends. B20 meeting the requirements has been approved for use in Army engines
and vehicles other than combat and tactical vehicles. The basic specification is
defined in the “Commercial Item Description: Diesel Fuel, Biodiesel Blend (B20)”
[CID-A-A-59693A, 15 Jan 2004], according to which B20 shall consist of 20±1 %
(by vol.) of biodiesel conforming to ASTM D 6751 and a balance of No 2-D or 1-D
diesel fuel conforming to ASTM D 975 or to the military specification A-A-52557.
The standard further specifies a number of properties and test methods for the
B20 blend.
The US Navy reported to be the
world's largest consumer of diesel is now manufacturing some of its own
biodiesel at at Naval Base Ventura County (NBVC). The US military is reported
to be one of the largest users of B20.
The
military bans biodiesel for tactical military vehicles, even under current
military fuel specs.
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