Search

Abstract: The purpose of this paper is to describe the benefits of sugar cane ethanol in Brazil, appointing the productivity of this type of fuel based on hectares of plantation, its carbon dioxide cycle and the contribution to reduce the greenhouse effect. In the following step the uses of ethanol for hydrogen production by steam reforming is analyzed and some comparison with natural gas steam reforming is performed. The sugar cane industry in Brazil, in a near future, in the hydrogen era, could be modified according to our purpose, since besides the production of sugar, and ethylic and anhydric alcohol, Brazilian sugar cane industry will also be able to produce biohydrogen. Fuel cells appear like a promising technology for energy generation. Among several technologies in the present, the PEMFC (proton exchange membrane fuel cell) is the most appropriate for vehicles application, because it combines durability, high power density, high efficiency, good response and it works at relatively low temperatures. Besides that it is easy to turn it on and off and it is able to support present vibration in vehicles. A PEMFC''s problem is the need of noble catalysts like platinum. Another problem is that CO needs to be in low concentration, requiring a more clean hydrogen to avoid fuel cell deterioration. One part of this paper was developed in Stockholm, where there are some buses within the CUTE (clean urban transport for Europe) project that has been in operation with FC since January 2004. Another part was developed in Guaratinguetá, Brazil. Brazil intends to start up a program of FC buses. As conclusion, this paper shows the economical analysis comparing buses moved by fuel cells using hydrogen by different kinds of production. Electrolyze with wind turbine, natural gas steam reforming and ethanol steam reforming. [Copyright &y& Elsevier]

Abstract: This article aims to investigate the introduction, sustenance and consolidation of bioethanol in Brazil. It presents an analysis of its introductory stage, from the first decades of the 20th century until the early 1970s, when, in a second stage, additional measures allowed for its consolidation and maturity, under the widely known Proalcool. The paper presents a historical reinterpretation of the policies, mechanisms and instruments adopted in both stages, aiming to highlight the economical and political links. It is concluded that the interests of the agrarian elites, operating at the political level, and the fuel supply crisis during Second World War were basic during the first stage, to sustain a productive and logistic capacity and maintain ethanol alive as an automotive fuel. It is also concluded that the launching of Proalcool represented a transition combining the interests of the sugarcane agribusiness, burdened by the drop in sugar prices, and the need to equilibrate the balance of payments due to the oil shocks of the 1970s. Ethanol supply shocks harmed its credibility and its commercial consolidation was only possible through the introduction of flex-fuel vehicles with expectations strongly relying on climate change mitigation actions. [Copyright &y& Elsevier]