Resumo

SANHUEZA, Eugenio. Potential emissions of Kyoto and Non-Kyoto climate active compounds in the production of sugarcane ethanol. INCI [online]. 2009, vol.34, n.1, pp.008-016. ISSN 0378-1844.

Sugarcane ethanol is the most commercially developed liquid biofuel. The potential emissions of Kyoto and non-Kyoto Protocol climate active compounds in the production of sugarcane ethanol in agricultural lands are evaluated herein. Various scenarios are considered, such as low or high N₂O emission from N-fertilizers, inclusion or not of pre-harvest burning, uncontrolled or controlled emissions in bagasse based boilers, and 20 or 100 years time horizons in GWPs. The CO₂ emitted in ethanol fuel combustion is recycled during sugarcane "re-growing" and does not count as greenhouse gas. However, even though many uncertainties remain, the available information allows estimating that CO₂-eq emissions are very large when ethanol production is based on pre-harvest burning and there is non-controlled particle emission in boilers. In these scenarios, compared with the combustion of equivalent amounts of gasoline, higher CO₂-eq emission would take place. Halting sugarcane field burning would not be sufficient to revert the situation, especially in a 20-years time horizon. Only when more environmental friendly procedures are applied, a significant saving of CO₂-eq emissions occurs at 20 and 100-years horizon scenarios. In all scenarios, non-Kyoto Protocol compounds make an important net contribution. Therefore, if a real evaluation of climate active compounds emissions is to be reached, it would be crucial to include these compounds in life cycles studies. To reduce uncertainties, especially of non-Kyoto compounds, additional research is needed.

Palavras-chave : Bagasse Combustion; Black Carbon; Global Warming; GWPs; Non-Kyoto Compounds; Sugarcane Ethanol.