It is a truly sustainable environmentally friendly biofuel and
generates no harmful emissions. It can be used in standard diesel
engines without modifications being required. Its ingredients are
waste cooking oils and fats but it can also be made from organic oil,
rapeseed oil, Soya or other vegetable oils.
In chemical terms, Bio-diesel consists of long chain fatty acids
derived from renewable lipid sources. The lipid (vegetable oil,
animal fat or, as in our process, cooking oil) is treated with a
light alcohol in the presence of a catalyst. This gives two products,
glycerine and Bio-diesel, both of which are bio-degradable and non-
When used in diesel fuel engines, Biodiesel performance is similar to
petroleum-based diesel fuel. Its higher viscosity can be reduced by a
variety of relatively simple processes giving better atomisation in
the injector system and an improved spray pattern.
Fleet managers have found that Biodiesel gives similar operating
performance to conventional diesel fuel and requires no changes in
facilities. This gives it a major advantage over other possible
The waste cooking oil is readily available from our sister company,
Oilco Cooking oils. About 85% of the output is Bio-diesel and the
remaining 15% is glycerine. Naturally occurring micro-organisms
attack and degrade glycerine with no harmful effect. This by-product
can therefore be disposed of without requiring complex
'decontamination' systems or long-distance transport to specialist
Is It Safe ?
Many tests have been carried out on various aspects of the safety of
Bio-diesel and the key points that emerged were :
Its toxicity in water is far lower than the toxicity of petroleum-
based diesel fuel by a factor of between 15 and 200.
Its flash point is much higher than that of petroleum-based diesel
fuel and it is therefore safer to store and to use. The air/fuel
vapour produced by Biodiesel is not explosive.
There is a major reduction of unburned hydrocarbons, carbon monoxide,
and particles (in particular the sulphate fraction is eliminated and
the solid hydrocarbon fraction is greatly reduced). The nitrogen
oxide levels are not significantly changed.
Who Gains ?
We all do.
Indirectly we will all benefit from any move towards a fully
sustainable non-polluting biofuel such as Biodiesel rather than using
the ever-decreasing fossil fuel resources. This combines with the
benefits of nil emissions, and a useful and bio-degradable by-product
in the production process. It has been shown that Bio-diesel has a
far shorter bio-degradation time than standard diesel fuel (and that
a 20% admixture of Bio-diesel significantly reduces the degradation
time for standard diesel).
Direct gains will occur for Companies who use Biodiesel as the nil
emission level will reduce the tax payable on Company vehicles and
many tests have shown no difference in performance. After all, the
first diesel engine was engineered to be run on peanut oil and not
mineral oil. Most car manufacturers recognise Biodiesel as a ‘real’
fuel and will honour warranties as a result.
Another direct gain will come for businesses needing to dispose of
waste cooking oil. Most such waste oil is currently recycled, under
strict controls, in animal feeds and we use about 35,000 litres a
week for making Bio-Diesel. There is a plan to ban the use of waste
oil in animal feeds and, if this occurs, catering and other
industries will be looking for alternative ways of disposing of their
waste. It is therefore likely that our usage will increase to over
100,000 litres a week.
We at Greenstar Biofuels feel that the government should themselves
be introducing Bio-diesel into the market place within the next few
years with a target of 2-3% of total fuel used in the UK, increasing
to 10% in ten years. Quite apart from the cost savings to the
consumer there would be a triple environmental advantage : lower
emission levels, reduced use of the limited petroleum resources and
an efficient disposal system for a waste product. Taken as a whole
this has to be a good political plus point !
Who Loses ?
The taxman. The duty on Bio-diesel is, at the moment, 27p per litre
compared to 47p for diesel. This means that the overall cost should
be less by a few pence per litre
Biodiesel is the first and only alternative fuel to have a complete
evaluation of emission results and potential health effects submitted
to the U.S. Environmental Protection Agency (EPA) under the Clean Air
Act Section 211(b). These programs include the most stringent
emissions testing protocols ever required by EPA for certification of
fuels or fuel additives. The data gathered complete the most thorough
inventory of the environmental and human health effects attributes
that current technology will allow.
EPA has surveyed the large body of biodiesel emissions studies and
averaged the Health Effects testing results with other major studies.
The results are seen in the table below.
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The overall ozone (smog) forming potential of biodiesel is less than
The ozone forming potential of the speciated hydrocarbon emissions
was 67 percent less than that measured for diesel fuel.
Sulfur emissions are essentially eliminated with pure biodiesel.
The exhaust emissions of sulfur oxides and sulfafes (major components
of acid rain) from biodiesel were essentially eliminated compared to
Criteria pollutants are reduced with biodiesel use. Tests show the
use of biodiesel in diesel engines results in substantial reductions
of unburned hydrocarbons, carbon monoxide, and par+iculate matter.
Emissions of nitrogen oxides stay the same or are slightly increased.
Carbon Monoxide -
The exhaust emissions of carbon monoxide (a poisonous gas) from
biodiesel are on average 47 percent lower than carbon monoxide
emissions from diesel.
Particulate Matter -
Breathing particulate has been shown to be a human health hazard. The
exhaust emissions of par+iculate matter from biodiesel are about 47
percent lower than overall particulate matter emissions from diesel.
The exhaust emissions of total hydrocarbons (a contributing factor in
the localized formation of smog and ozone) are on average 67 percent
lower for biodiesel than diesel fuel.
Nitrogen Oxides -
NOx emissions from biodiesel increase or decrease depending on the
engine family and testing procedures. NOx emissions (a contributing
factor in the localized formation of smog and ozone) from pure (100%)
biodiesel increase on average by 10 percent. However, biodiesel's
lack of sulfur allows the use of NOx control technologies that cannot
be used with conventional diesel. Additionally, some companies have
successfully developed additives to reduce Nox emissions in biodiesel
Biodiesel reduces the health risks associated with petroleum diesel.
Biodiesel emissions show decreased levels of polycyclic aromatic
hydrocarbons (PAH) and nitrated polycyclic aromatic hydrocarbons
(nPAH), which have been identified as potential cancer causing
compounds. In Health Effects testing, PAH compounds were reduced by
75 to 85 percent, with the exception of benzo (a) anthracene, which
was reduced by roughly 50 percent. Targeted nPAH compounds were also
reduced dramatically with biodiesel, with 2-nitrofluorene and 1-
nitropyrene reduced by 90 percent, and the rest of the nPAH compounds
reduced to only trace levels.