Made available in DSpace on 2014-12-17T14:08:44Z (GMT). No. of bitstreams: 1 RafhaelAH_DISSERT.pdf: 3286080 bytes, checksum: f7d63c2f5fde3101ddffb2cd1417b11d (MD5) Previous issue date: 2011-02-17 / Efforts in research and development of new technologies to reduce emission levels of pollutant gases in the atmosphere has intensified in the last decades. In this context, it can be highlighted the modern systems of electronic engine management, new automotive catalysts and the use of renewable fuels which contributes to reduce the environmental impact. The purpose of this study was a comparative analysis of gas emissions from a automotive vehicle, operating with different fuels: natural gas, AEHC or gasoline. To execute the experimental tests, a flex vehicle was installed on a chassis dynamometer equipped with a gas analyzer and other complementary accessories according to the standard guidelines of emission and security procedures. Tests were performed according to NBR 6601 and NBR 7024, which define the urban and road driving cycle, respectively. Besides the analysis of exhaust gases in the discharge tube, before and after the catalyst, using the suction probe of the gas analyzer to simulate the vehicle in urban and road traffic, were performed tests of fuel characterization. Final results were conclusive in indicating leaded gasoline as the fuel which most contributed with pollutant emissions in atmosphere and the usual gasoline being the fuel which less contributed with pollutant emissions in atmosphere / Nas ?ltimas d?cadas tem se intensificado os esfor?os em pesquisa e desenvolvimento de novas tecnologias para redu??o dos n?veis das emiss?es de gases poluentes na atmosfera. Neste contexto, destacam-se os modernos sistemas de gerenciamento eletr?nico do motor, os novos catalisadores automotivos e a utiliza??o de combust?veis renov?veis que contribuem para o menor impacto ambiental. A presente pesquisa teve como prop?sito a an?lise comparativa das emiss?es gasosas de um ve?culo automotivo, funcionando com diferentes combust?veis: g?s natural, AECH, ou gasolina. Para execu??o dos testes experimentais, um ve?culo flex foi instalado em um dinam?metro de chassi equipado com analisador de gases e demais acess?rios complementares ao atendimento das diretrizes das normas de emiss?o e procedimentos de seguran?a. Os ensaios foram realizados de acordo com as normas NBR 6601 e NBR 7024, que definem o ciclo de condu??o urbano e estrada, respectivamente. Al?m da an?lise dos gases de escapamento no tubo de descarga, antes e ap?s o catalisador, utilizando a sonda de aspira??o do analisador de gases, para simula??o do ve?culo em tr?fego urbano e estrada, foram realizados testes de caracteriza??o dos combust?veis. Os resultados finais foram conclusivos em apontar a gasolina aditivada como o combust?vel que mais contribuiu com as emiss?es de poluentes na atmosfera e a gasolina comum sendo o combust?vel que menos contribuiu com as emiss?es de poluentes na atmosfera