tailieunhanh - PLANET EARTH 2011 – GLOBAL WARMING CHALLENGES AND OPPORTUNITIES FOR POLICY AND PRACTICE_2

Tham khảo sách 'planet earth 2011 – global warming challenges and opportunities for policy and practice_2', khoa học tự nhiên, công nghệ môi trường phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 14 The Choice of Biofuels to Mitigate Greenhouse Gas Emissions Rogério Cezar de Cerqueira Leite1 Manoel Regis Lima Verde Leal2 and Luís Augusto Barbosa Cortez3 interdisciplinary Center of Energy Planning University of Campinas 2Brazilian Bioethanol Science and Technology Laboratory 3Faculty of Agricultural Engineering University of Campinas Brazil 1. Introduction The tentatives to use biofuels can be traced back to the years around 1900 when Henry Ford and Rudolf Diesel used ethanol and vegetable oil in their Otto cycle and Diesel cycle engines respectively. With the introduction of oil in the energy scenario as a very cheap option the interest in biofuels dwindled down rapidly and the transport sector was fully dominated by gasoline and diesel. However the idea did not die and biofuels came and went a few times in the mid 1920s ethanol fuel was used in Brazil and in 1931 a Federal Law mandated the blending of 5 ethanol in all imported gasoline used in the country. Since then several biofuels options have been produced and tentatively used in some countries ethanol methanol higher alcohols vegetable oils fat acid methyl ethyl esters biogas and dimethyl ether DME just to mention the main ones. The driving forces behind the use of biofuels are many but can be separated in four groups environmental benefits local and global high oil prices energy security and support to local agriculture. Different countries in different times were drawn by different motivations that changed in time in each case. Looking into the main biofuel programs today it can be seen that USA alcohol program was originally intended to mitigate local pollution problems due to vehicle tail pipe emissions but today is driven by the support to local agriculture energy security and only very recently with the Energy Independence and Security Act of 2007 EISA 2007 it has shown some interest in global warming mitigation with the introduction of minimum greenhouse gas GHG emission reduction limits for .