Article pubs.acs.org/est
Effectiveness of Selective Catalytic Reduction Systems on Reducing Gaseous Emissions from an Engine Using Diesel and Biodiesel Blends Guilherme C. Borillo,† Yara S. Tadano,‡ Ana F. L. Godoi,† Simone S. M. Santana,† Fernando M. Weronka,† Renato A. Penteado Neto,§ Dennis Rempel,§ Carlos I. Yamamoto,∥ Sanja Potgieter-Vermaak,⊥ Johannes H. Potgieter,# and Ricardo H. M. Godoi*,† †
Environmental Engineering Department, Federal University of Paraná, Curitiba, Paraná 81531-980, Brazil Mathematics Department, Federal University of Technology Paraná, Ponta Grossa, Paraná 84016-210, Brazil § Vehicle Emissions Laboratory, Institute of Technology for Development (LACTEC), Curitiba, Paraná 80210-170, Brazil ∥ Chemical Engineering Department, Federal University of Paraná, Curitiba, Paraná 81531-970, Brazil ⊥ Division of Chemistry and Environmental Science, School of Science and the Environment, Manchester Metropolitan University, Manchester M15 6HB, United Kingdom # School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg 2000, South Africa ‡
ABSTRACT: The aim of this investigation was to quantify organic and inorganic gas emissions from a four-cylinder diesel engine equipped with a urea selective catalytic reduction (SCR) system. Using a bench dynamometer, the emissions from the following mixtures were evaluated using a Fourier transform infrared (FTIR) spectrometer: low-sulfur diesel (LSD), ultralow-sulfur diesel (ULSD), and a blend of 20% soybean biodiesel and 80% ULSD (B20). For all studied fuels, the use of the SCR system yielded statistically significant (p < 0.05) lower NOx emissions. In the case of the LSD and ULSD fuels, the SCR system also significantly reduced emissions of compounds with high photochemical ozone creation potential, such as formaldehyde. However, for all tested fuels, the SCR system produced significantly (p < 0.05) higher emissions of N2O. In the case of LSD, the NH3 emissions were elevated, and in the case of ULSD and B20 fuels, the non-methane hydrocarbon (NMHC) and total hydrocarbon of diesel (HCD) emissions were significantly higher.
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INTRODUCTION There is an urgent and pressing need to further understand effects of control systems on emissions from diesel (and gasoline) vehicles. Global pressure to meet emission standards lead to the development and use of new engine technologies and alternative fuels, such as ultralow-sulfur diesel (ULSD) and biodiesel blends. Emissions depend upon a variety of factors, such as engine technology, maintenance, emission control technology,1 and type and quality of the employed fuel. Besides the greenhouse gas pollutants with global warming potential, it is widely known that engine exhaust systems also produce organic gases that have an impact on photochemical ozone and the formation of other secondary pollutants. Among different gases emitted by diesel engines, nitrogen oxides (NOx) are one of the major threats to the environment, and therefore, emissions of those have been widely investigated.2−5 NOx suppression strategies consist of combustion controls, such as selective catalytic reduction (SCR) systems, using a urea solution as the reducing agent, a well-established technique of stationary diesel engines.6−8 Biodiesel seems to be a promising alternative, because it can be used in diesel engines without major modifications,9 reducing several pollutant emissions, qualitatively and quantitatively.10−14 The use of biofuels and fuel © XXXX American Chemical Society
blends, in combination with exhaust after-treatment systems as a means of mitigating emissions, are promising and, therefore, the topic of this investigation. New standard guidelines are being established worldwide concerning heavy-duty diesel engine emissions, aiming mostly at the simultaneous reduction of particles and NOx (Euro V and Euro VI regulations in Europe and 40 Code of Federal Regulations 86.007-11).15 The current Brazilian standards are equivalent to the Euro V emission standards. Those standards were promulgated in January 1, 2012, as the seventh stage of the Program to Control Vehicular Air Pollution (PROCONVE, in Portuguese). To achieve the Brazilian air quality guidelines, the sulfur content of diesel fuels was reduced to be less than
