The increase in the number of motorcycles in large Brazilian cities is due to several factors such as traffic, low cost, mobility, few parking lots and the low efficiency of public transportation, becoming an important factor in air quality deterioration. In this context, vehicle emissions monitoring is essential to understand the contribution to air pollution as a whole. In this scenario, the emissions were sampled on a motorcycle dynamometer test bench and analyzed by gas chromatography and on-line analyzers according to the EC/97/24 standard (European Commission). Emissions from motorcycles using commercial gasoline (with 22% of ethanol) were used in combination with meteorological data and ambient air pollutants for Rio de Janeiro City (Brazil) during the Winter of 2011, using the trajectory model OZIPR (Ozone Isopleth Package for Research) and the chemical model SAPRC99 (State-wide Air Pollution Research Centre) to assess the impact on the ozone formation in the troposphere of Rio de Janeiro for the next several years. The results indicate that ozone levels will exceed the established limits by national legislation within three years. The study also showed that pollutant emission rates stay in agreement with emissions recommended by the Brazilian legislation for all phases. The increase in ozone concentration occurs due to high emissions of reactive volatile organic compounds in an atmosphere with high levels of nitrogen oxides (NOx). Given this scenario, additional measures are necessary to manage emissions from mobile sources in the future.

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The increased number of motorcycles in the large Brazilian cities is due to several factors such as traffic, low cost, mobility, few parking lots and low efficiency of public transportation, making it an important factor in air quality deterioration. In this context, vehicle emissions monitoring is essential to understanding the contribution on air pollution. Emissions of two representative motorcycles using gasohol (gasoline with 22% of ethanol) were evaluated on a dynamometer test bench and analyzed by gas chromatography mass spectrometry and on-line analyzers according to the EC/97/24 standard. Emission data obtained in combination with meteorological data and ambient air pollutants for the city of Rio de Janeiro (Brazil) during the winter of 2011, using the trajectory model OZIPR and chemical model SAPRC to assess the impact on the ozone forming potential in the troposphere of Rio de Janeiro city for the next years. The results indicate that ozone levels will exceed the established limits by national legislation within three years. The increase in ozone concentration occurs due to high emissions of reactive volatile organic compounds in an atmosphere with high levels of nitrogen oxides. Given this scenario, additional measures are necessary for the management of emissions from mobile sources.

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While criteria pollutants have established emission limits for motorcycles in Brazil, aldehydes limits have not been established and conclusive studies have not been found in the existing literature, despite the growing number of motorcycles using flex fuel in Brazil. This work presents results for the emissions of criteria pollutants, such as carbon monoxide, hydrocarbons and nitrogen oxides, acetaldehyde and formaldehyde. The motorcycle was tested with 22, 61, and 100% of ethanol in gasoline blends. Fourier transform infrared (FTIR) and high performance liquid chromatography (HPLC) were used to determine the pre-and post-catalytic converter emissions. Aldehyde emissions directly increased with the ethanol content in the fuel blend. The tailpipe aldehyde emissions for 22, 61, and 100% of ethanol in gasoline were 3.9, 8.5, and 38.8 mg km -1 , respectively. These results demonstrated that aldehyde emissions in motorcycles are not negligible, and higher emissions are observed during the cold phase of the engine. Keywords: vehicular, emission, aldehyde, motorcycle, flex fuel IntroductionThe internal combustion engines will remain, in the coming years, the main propulsion system for vehicles. Thus, the impact on the environment by emissions from mobile sources assumes great importance, mainly in urban centers. [1][2][3] In Brazil, concern over vehicular emissions is not new. In 1986, the Control Program of Air Pollution from Motor Vehicles (PROCONVE) was created, and PROCONVE imposed a schedule to gradually reduce pollutant emissions for light and heavy vehicles. 4,5 With regard to motorcycles, legislation for emission control is newer, and in 2002, the Control Program of the Air Pollution by Motorcycles and Similar Vehicles (PROMOT) was created in Brazil. In countries with a tradition in the control of vehicle emissions such as the United States and European countries, legislation was established in the early 1960s and 1970s, respectively, 6,7 and the establishment of limits for motorcycle emissions has been established since 1990, 8 with a marked restriction from 1999. 9 However, the Brazilian legislation basically considered compounds legislated by the European Union.The emission of aldehydes is relevant to the Brazilian context, 10,11 being legislated for vehicles in terms of total emissions since 1992. 12 The basis for this control was due to the Brazilian automotive energy matrix, where fuel differs from other countries by the addition of ethanol to gasoline and its use in the hydrated form. The use of ethanol has many advantages such as a renewable fuel, generation of less carbon monoxide, hydrocarbons and particulates, and higher octane numbers compared to gasoline, which leads to an increase in the engine compression ratio, promoting greater efficiency and engine power. Disadvantages stand out because of its lower calorific value and the increased emissions of carbonyl compounds, especially aldehydes. 13,14 Because of the relationship between aldehyde emissions and the use of ethanol as a fuel, 10,15-1...

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In urban environments, vehicle emissions are the main source of hydrocarbons (HC) which contribute to formation of tropospheric ozone. Since individual HC exhibit a wide range of ozone formation reactivity, speciated analyzes are necessary to assess the overall impact of vehicle exhaust emissions. Flex-fuel represents more than 90% of the light duty vehicle sales in Brazil. In this project, sampling and analytical methods were implemented and optimized for determination of speciated HC (C 4 -C 12 ). Three flex-fuel vehicles (PROCONVE L4, L5 and L6) were tested, with both gasoline (E22) and ethanol (E100). Vehicle exhaust samples were obtained during emissions testing with FTP75 drive cycle (according to ABNT/NBR 6601) for each of the three phases: cold start, stabilized and hot start. The exhaust was collected in Tedlar bags and transferred to electropolished stainless steel canisters. HC were analyzed using thermal desorption and gas chromatography with a mass spectrometry detector. The analytical procedure was based on Method TO-15 (US EPA). Quantification was performed using a standard reference mixture that covered the entire concentration range of the samples. Using gasoline, E22, experimental emission values for phase 1 were 0.037, 0.017 and 0.019 g HC (C 4 -C 12 ) km -1 for PROCONVE L4, L5 and L6 vehicles, respectively. Average MIR values (specific reactivity) for exhaust phase 1 were 3.04, 3.03 and 2.27, respectively, for PROCONVE L4, L5 and L6 vehicles. Weighted Maximum Incremental Reactivity (MIR) and Ozone Formation Potential (OFP) values, for C 4 -C 12 fraction, were approximately in the intervals 2.00-2.76 and 0.013-0.099, respectively. Aromatic organic compounds in the exhaust of ethanol tests were < 1 ppmC for all phases and vehicles. Results suggest that these compounds are not due to the combustion of ethanol and their contribution for total HC (C 4 -C 12 ) reactivity was considered negligible. A new method will be implemented in future tests to determine the low HC fraction (C 2 and C 3 ) by chromatography. Speciated HC emission data may be useful for technical discussions about the ozone formation potential using Brazilian fuels.

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