Production and use of fuel ethanol in Brazil - BAFF

environment. Studies conducted in Brazil by the São Paulo state’s environmental
agency CETESB (www.scielo.br/pdf/rsp/v39n3/en_24804.pdf) with diesel vehicles
show that emissions of aldehydes from those vehicles can be up to 40 times as
high as those from vehicles running exclusively on ethanol. In Brazil and other
countries aldehyde emissions have been successfully controlled with the help of
catalytic converters, which for years have been standard equipment for emission
control.
Air quality surveys in regions where ethanol has been in use, either straight or in
blends with gasoline do not show that the aldehyde emissions resulting from the use
of that fuel have caused problems.
B4.3.
Is it true that the use of ethanol-gasoline blends
increases NOx emissions?
The NOx (nitrogen oxides) emissions from a fleet of gasoline-fueled vehicles
can increase slightly when using gasoline blends with up to 10 percent ethanol.
The observed increase is usually around 1 percent, on average. Not only is that
variation of little significance, it is also lower than that observed for vehicles that
are converted for running on natural gas or equipped with diesel engines, the use of
which has been promoted as environment-friendly in many countries, but the NOx
emissions from which can be more 200 percent higher than those of equivalent
vehicles running on gasoline.
B4.4.
Does the addition of ethanol to gasoline cause
volatile compound emissions?
Even though ethanol is a low-volatility fuel, five times less volatile than gasoline,
it has the effect of increasing volatility in the blend with gasoline. The magnitude
of the increase in such emission basically depends on the ethanol content of the
blend and the gasoline composition. This characteristic, which can actually be
positive in temperate zones because it makes cold starts easier, has been the
subject of a lot of discussion due to the allegation that favors the permeability of
the fuel into components made from some types of rubber and plastic, resulting
in increased volatile compound emissions. It is important to note that this effect
can be minimized by adjusting the gasoline composition for the intended ethanol
content of the blend.
B. Sugar-cane and ethanol production: environmental aspects
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