Vehicular Emission Ratios of VOCs in a Megacity Impacted by Extensive Ethanol Use: Results of Ambient Measurements in São Paulo, Brazil
The São Paulo Metropolitan Area (SPMA) is a megacity with 20 million people and over 8 million vehicles. Over the past decade a large increase in biofuel usage, more notably ethanol by light-duty vehicles, has made Brazil, and in particular São Paulo, a unique case worldwide. This study presents the...
| Autores: | , , , , , |
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| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2015 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositório: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/413541 |
| Acesso em linha: | http://hdl.handle.net/10261/413541 https://api.elsevier.com/content/abstract/scopus_id/84943377837 |
| Access Level: | Acceso aberto |
| Palavra-chave: | VOCs http://metadata.un.org/sdg/3 http://metadata.un.org/sdg/9 Ensure healthy lives and promote well-being for all at all ages Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation |
| Resumo: | The São Paulo Metropolitan Area (SPMA) is a megacity with 20 million people and over 8 million vehicles. Over the past decade a large increase in biofuel usage, more notably ethanol by light-duty vehicles, has made Brazil, and in particular São Paulo, a unique case worldwide. This study presents the first assessment of emission ratios of a selected group of volatile organic compounds (VOCs) relative to carbon monoxide (CO) under ambient conditions. The VOCs studied here include aromatics such as benzene (1.03 pptv/ppbv CO), toluene (3.10 pptv/ppbv CO) and Oxygenated VOCs such as methanol (5.39 pptv/ppbv CO), acetaldehyde (3.93 pptv/ppbv CO), acetone (3.59 pptv/ppbv CO), methyl ethyl ketone (1.42 pptv/ppbv CO), and others. Despite the specificity of the fuel composition, emission ratios were in surprisingly close agreement with other megacities in Europe or in North America. Such results include species whose emission factors have been previously reported to decline (e.g., benzene) or increase (e.g., acetaldehyde) with ethanol usage. Furthermore, diurnal profiles and temperature analysis aid separating the primary anthropogenic, secondary or biogenic components of the species studied here. This study shows that a significant fraction of ethanol in gasoline blends does not result in a well-defined trend in VOC emission profile and certainly motivates further studies. |
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