248 Environmental Biotechnology
and to improve the biodegradability of the conventional diesel component of a
blended fuel. Various studies have concluded that biodiesel exhaust is generally
less harmful to both human health and the planet. Specifically, it contains sig-
nificantly lower levels of polycyclic aromatic hydrocarbons (PAHs) and nitrited
polycyclic aromatic hydrocarbons (nPAHs), which is of great importance, since
both groups have been identified as potential carcinogens. In laboratory tests,
PAHs were reduced by between 75–85 % (excepting benzo(a)anthracene for
which the figure was around 50%) and nPAHs were also dramatically lessened.
Most of the targeted nPAH compounds were present only as traces, while the
highest levels reported, 2-nitrofluorene and 1-nitropyrene, were found to repre-
sent a 90% reduction over typical conventional diesel releases. Objective views
of the performance of a ‘new’ fuel depend on such information and the National
Biodiesel Board was congratulated by representatives of the House Energy and
Power subcommittee for being the first industry to complete the rigorous health
effects testing of the Clean Air Act.
It is not entirely without irony that in 1894, when Rudolf Diesel invented the
engine which bears his name, he produced a design specifically suitable for a
range of fuels, including coal dust and vegetable oil, as well as the petroleum
product which is automatically associated with the device. In many respects,
the current resurgence of interest in the potential of a fuel source so deeply
rooted in diesel’s origins might almost be described as a retrograde step in the
right direction.
External regional considerations
As stated at the outset, biodiesel is a product derived by the application of
chemistry to material of biological origin and is not, thus, biotechnological in the
truest sense. It does, however, illustrate very well the influence of local modality
as one of the recurrent themes of the sector. For a time, use of biodiesel in the
USA was confined to certain niche markets, principally because relatively low
conventional fuel prices and the contemporarily high cost of vegetable oil made
wider uptake unattractive. However, the impact of the legislative requirement for
alternative fuel in the Energy Policy Act of 1992 (EPACT) has led to a major
upsurge in usage, especially amongst bus operators and hauliers, for whom it is
the most cost-effective option available.
In Europe, by contrast, the economic and environmental benefits may be less
clear cut. The UK’s Royal Commission on Environmental Pollution’s major
report,Energy and the Changing Climate, published in June 2000, largely ignored
biodiesel, concentrating its attention more on farmed energy crops for use in
combined heat and power stations. Of biomass crops for vehicle fuel, it was
much less enthusiastic. Its examination of European Union funded research on
oilseed rape as a raw material for biodiesel led it to identify quality control issues
and conclude that the actual production of biodiesel is polluting, and is ineffi-
cient in terms of both energy and cost. The economics aspect is a major one.