Biodiesel and Ethanol - False Panacea
Source - NewScientist magazine, July 15-21, 2006
It appears that neither biodiesel nor ethanol are truly viable alternatives to the hydrocarbon molecule and it's unfortunate that the current 'hype' in both are leading to a false panacea in the minds of American citizens.
In the battle of the biofuels, biodiesel turns out to be greener than ethanol. Sadly, neither will go very far to replace petrol and deisel in our vehicles, however.
David Tilman at the University of Minnesota in St. Paul and his colleagues have worked out the environmental costs of producing ethanol from maize and biodiesel from soybeans. Their caluculations include the fuel needed to make and run farm machinery, and make pesticides and fertilizers.
Tilman and colleagues found that using ethanol would only reduce greenhouse gas emissions by 12 per cent compared with petrol, while biodiesel reduces emissions by 41 per cent against diesel (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.06046000103).
They caluculate that even if the US turned all its corn and soybeans into biofuel, this would cover less than 5 per cent of current needs.
