Production and use of fuel ethanol in Brazil - BAFF

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B4. Ethanol use: effect on vehicle and GHG
(Greenhouse Gas) emissions
B4.1.
What are the environmental benefits associated
with the use of ethanol?
Ethanol is a fuel produced from renewable sources and has low carbon content
what makes possible the mitigation of greenhouse gases (GHG). These two features
attach strategic importance to it in the struggle against the intensification of the
Greenhouse Effect, as well as its effects on the global climate change, and put the
product in line with the principles of sustainable development (see item B4.5).
Compared to oil and its by-products, it features low toxicity and high biodegradability,
which are factors of paramount importance in events of accidental spillage and
leakage of fuel on seashores, soils and surface and underground waters. This means
that in the case of accidents the environmental impacts of ethanol will be substantially
lower and the restoration of the environment will be much faster compared to what
goes on in the case of fossil fuels.
Due to its high octane rating ethanol has been successfully replacing toxic leadbased
anti-knock additives. In terms of atmospheric emissions the use of ethanol
contributes to the reduction of such important pollutants as carbon monoxide (CO),
sulphur oxides (SOx), particulate matter (PM) and several toxic organic compounds,
such as benzene, toluene, xylene and 1-3 butadiene. In addition, several studies
indicate that the total emissions (volatile compounds and exhaust gas) show a lesser
potential for formation of photochemical smog than those of gasoline.
B4.2.
Is the emission of aldehydes due to the use of
ethanol a problem?
As a matter of fact the incomplete burning of ethanol in engines gives rise to
aldehyde emissions, especially acetaldehyde. However, a fact that is not mentioned
too often is that any other fuels that can be used in automotive applications
(gasoline, diesel, natural gas, liquefied petroleum gas, vegetable oils, biodiesel and
methanol – generate aldehydes as well often in worse conditions. It’s just a matter
of remembering that fossil fuels generate large amounts of formaldehyde, a
substance that is much more harmful than acetaldehyde to living creatures and the
B. Sugar-cane and ethanol production: environmental aspects