The hidden costs of biofuels
Taken from the ABC Science News Website
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Judy Skatssoon
ABC Science Online
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Tuesday, 27 September 2005
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Are biofuels all they're cracked up to be? (Image:iStockphoto)
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Concerns that the health and environmental impacts of biofuels haven't
been properly examined have arisen following a recent Australian
government report and a pledge to promote their use.
The Report of the Biofuels Taskforce to the Prime Minister
released last week found that the government's own targets on producing
biofuels, namely ethanol and biodiesel, aren't being met.
And
the Australian government has promised to do more to reach its target
of producing 350 megalitres of biofuels a year by 2010.
But not everyone agrees that biofuels are the hoped-for magic bullet as an alternative to fossil fuels.
One of them, environmental engineer and pollution expert Dr Robert Niven of the University of New South Wales in Sydney, says his research shows ethanol may increase groundwater contamination and photochemical smog.
"It's
sort of entered the mythology," he says of the claimed benefits of
ethanol, admitting his findings about air pollution, published in Renewable and Sustainable Energy Reviews this year, came as a surprise.
The ethanol debate
Ethanol,
which is distilled from sugar or grains, can be used on its own or
added to petrol to increase combustion efficiency and cut back
emissions.
Niven says the report glosses over the environmental consequences of ethanol.
He says ethanol can increase corrosion of underground petrol storage tanks, leading to increased leakage.
And
once a leak has occurred the ethanol prevents biodegradation of the
petroleum because the microbes that normally attack the petrol go for
the ethanol instead.
"These effects work against the ability of the natural environment to restore itself," he says.
Niven
also says ethanol produces higher volatile emissions through
evaporation and more nitrogen oxide emissions compared with fossil
fuels.
Together these produce photochemical smog, or ground
level ozone, the cause of the "brown haze" that sometimes shrouds
Australia's most populous city Sydney.
Reducing greenhouse gas emissions?
CSIRO
Low Emissions Transport leader Dr David Lamb says ethanol may help
society "escape from the tyranny of oil", but its benefits in terms of
reducing greenhouse gas emissions, in particular carbon dioxide (CO2),
are small in the scheme of things.
"We measure the CO2 used in fertilising the crop, plus transportation, plus machinery, plus when you burn it in the car," says.
"We
add that up and offset it against the CO2 absorbed by the sugar cane
when it's growing and the answer is it's a little bit favourable."
And while he says he hasn't seen anything to suggest ethanol increases particulates in exhaust more tests are needed.
He
says every litre of fossil fuel burnt puts 2.3 kilograms of CO2 into
the atmosphere, which translates to an average of 4.3 tonnes of CO2 for
every car in the world, every year.
 | Some research suggests ethanol may contribute to photochemical smog (Image: Reuters/Carlo Cortes) |
The
government's target for biofuel production, which adds up to 0.1% of
the fuel used in transportation in Australia each year, is a mere drop
in the ocean and would make a negligible difference in terms of health
or environment, he says.
"If you're getting a marginal
improvement in one tenth of one per cent of the oil ... you'd certainly
not be able to measure it in terms of population health," he says.
"And let's not kid ourselves that this is going to solve the global warming problem."
Biodiesel
Biodiesel,
a green replacement for diesel, is produced by converting the
triglycerides in products like tallow and cooking oils into highly
oxygenated compounds.
Dr Len Humphreys is the chief executive
officer of the Australian Biodiesel Group, which has the country's
largest biodiesel plant. The plant produces biodiesel from animal fat
from abattoirs and used cooking oil from local food outlets.
Located
on the Central Coast in New South Wales, it can producing 44 million
litres of biodiesel a year, Humphreys says, and the company is building
a second, bigger plant, in Queensland.
Humphreys says
biodiesel is clean-burning, gentle on engines and releases less
polyaromatic hydrocarbons, such as benzene, than diesel.
Niven agrees, saying biodiesel is "less of a problem" than ethanol.
Humphreys
also says the report is inclusive about the health implications of
biofuels. But he says it's "commonsense" that reducing particulate
emissions will entail health benefits.
Market protectionism?
Lamb
says the major stumbling blocks to the introduction of ethanol are the
big oil companies, who want to protect their markets.
But the
corporate affairs manager of Caltex, Richard Beattie, says the company
is already Australia's biggest biofuels marketer and is planning to
expand biofuels production to help the government achieve its goals.
He says it's consumers, not oil companies, who need to be convinced that ethanol won't wreck their cars.
"The only significant problem with ethanol is consumer confidence in the product," he says.
According to the report, these concerns are unfounded, as long as you've got a new car and don't put in too much ethanol.
"The taskforce concludes that almost all post-1986 vehicles can operate satisfactorily on E10 [10% ethanol]," it says.
The future of biofuels will be on the agenda this week at a meeting between the government and Australian oil company heads.
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