Emission source apportionment and photochemical production of ethanol in the lower troposphere

• Grant number: 15/07950-0
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: August 01, 2015
• End date: November 30, 2015
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Principal Investigator: Maria Lúcia Arruda de Moura Campos
• Grantee: Fernanda Furlan Giubbina Bernardi
• Supervisor: Robert Jonh Kieber Jr.
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Institution abroad: University of North Carolina Wilmington (UNCW), United States
• Associated to the scholarship: 13/13482-3 - Behavior of organic and inorganic species dissolved in the rainwater of Ribeirão Preto: a city in a sugarcane producing region that is rapidly changing, BP.DR

Abstract

There is an increasing demand of ethanol fuel due to the need to minimize the dependence on oil and diminish greenhouse gases emissions to the atmosphere. Currently almost half the Brazilian light duty fuel is ethanol. This percentage will almost certainly increase in the future with the projected production of cellulosic ethanol in Brazil. From 2005 to 2010, the generation of ethanol has tripled in the U.S. which recently approved the use of a 15% blend ethanol fuel (E15) in light duty vehicles. Ethanol blended fuels lead to much higher emissions of uncombusted ethanol and aldehydes to the atmosphere compared to gasoline engines. Ethanol is a precursor of acetaldehyde and peroxyacetyl nitrate which both affect human health at relatively low concentrations. Emission of this chemically labile alcohol has important ramifications for a variety of fundamentally important atmospheric processes including the oxidizing capacity of the troposphere, air pollution, aerosol formation, and greenhouse radiative forcing. The largest emissions of ethanol to the global atmosphere has been attributed to biogenic activities, however, these models have great uncertainties because of the lack of knowledge on emission sources. This project aims to better understand the sources of ethanol to the lower troposphere (biogenic and anthropogenic), and the mechanisms of its formation and removal. The large solubility of gas phase ethanol allows this study to be performed in atmospheric water vapor and in rainwater samples. These samples will be collected in Ribeirão Preto - SP, where sugar cane plantation and processing is the main economic activity and in the coastal city of Wilmington, North Caroline located in the eastern United States. The analytical approach will be to determine the isotopic relationship between 13C and 12C that differentiates anthropogenic and direct plant emissions. A solar simulator will be used to determine ethanol photochemical production in natural rainwater. Dr. Robert Kieber from the University of North Carolina Wilmington arrived in our laboratory at USP-Ribeirão Preto in March 2015 where he will stay 4 months as part of a Fulbright scholarship USA/CAPES. Dr. Kieber and his working team have more than 25 years of rainwater composition data at their Wilmington site and have extensive experience in the isotopic and structural elucidation of organic matter from a variety of different environmental matrices. He is already working with Fernanda Bernardi in Brazil, and is very supportive of this project. This is a unique opportunity for the Ph.D. student to interact with a well stablished group in the USA, which has so many common interest with the Brazilian group. Moreover, the student will work with techniques that she would not have the opportunity to experience in Brazil which will be of great importance to her academic career. (AU)