Evaluation of NH3-Slip from Diesel Vehicles Equipped with Selective Catalytic Reduction Systems by Neural Networks Approach
Abstract:Selective catalytic reduction systems for nitrogen oxides reduction by ammonia has been the chosen technology by most of diesel vehicle (i.e. bus and truck) manufacturers in Brazil, as also in Europe. Furthermore, at some conditions, over-stoichiometric ammonia availability is also needed that increases the NH3 slips even more. Ammonia (NH3) by this vehicle exhaust aftertreatment system provides a maximum efficiency of NOx removal if a significant amount of NH3 is stored on its catalyst surface. In the other words, the practice shows that slightly less than 100% of the NOx conversion is usually targeted, so that the aqueous urea solution hydrolyzes to NH3 via other species formation, under relatively low temperatures. This paper presents a model based on neural networks integrated with a road vehicle simulator that allows to estimate NH3-slip emission factors for different driving conditions and patterns. The proposed model generates high NH3slips which are not also limited in Brazil, but more efforts needed to be made to elucidate the contribution of vehicle-emitted NH3 to the urban atmosphere.
 C. D. R. Souza, S. D. Silva, M. A. V. Silva, M. A. D’Agosto, A. P. Barboza, “Inventory of conventional air pollutants emissions from road transportation for the state of Rio de Janeiro”. Energy Policy, vol. 53, pp. 125 135, 2013.
 R. Suarez-Bertoa, P. Mendoza-Villafuerte, F. Riccobono, M. Vojtisek, M. Pechout, A. Perujo, C. Astorga, “On-road measurement of NH3 emissions from gasoline and diesel passenger cars during real world driving conditions”. Atmospheric Environment, vol. 166, pp. 488 497, 2017.
 DENATRAN – Departamento Nacional de Trânsito (National Department of Traffic), 2016. Frota de Veículos – 2016 (Vehicle Fleet - 2016). Brazil. Available at: http://www.denatran.gov.br/index.php/estatistica/261-frota-2016 (accessed on: Jul.2017).
 H. Dias, B. V. Bertoncini, M. L. M., Oliveira, S. A. Cavalcante, E. Lima, “Analysis of Emission Models Integrated with Traffic Models for Freight Transportation Study in Urban Areas”. International Journal of Environmental Technology and Management, vol. 20, pp. 60, 2017.
 M. L. M., Oliveira, C. M., Silva, R. Moreno-Tost, T. L. Farias, A. Jiménez-López, E. Rodríguez-Castellón, “Modelling of NOx emission factors from heavy and light-duty vehicles equipped with advanced aftertreatment systems”. Energy Conversion and Management, vol. 52, pp. 2945 2951, 2011.
 C. M. Silva, G. A. Gonçalo, T. L. Farias, J. M. Mendes-Lopes, “A Tank-to-Wheel Analysis Tool for Energy and Emissions Studies in Road Vehicles”. Journal Science for the Total Environment, vol. 367, pp. 441 447, 2006.
 Franco, V., Posada Sanches, F., German, J. & Mock, P. “Real-world exhaust emissions from modern diesel cars, Part 2” (Tech. Report: The International Council on Clean Transportation, www.theicct.org, Washington, DC, 2014).
 M. L. M. de Oliveira, C. M. Silva, R. Moreno-Tost, T. L. Farias, A. Jiménez-López, E. Rodríguez-Castellón, “A Study of Copper Exchanged Mordenite Natural And ZSM-5 Zeolites as SCR-NOx Catalysts for Diesel Road Vehicles: Simulation by Neural Networks Approach”. Applied Catalysis B: Environmental, vol. 3-4, pp. 420 429, 2009.
 USEPA, 2004. National Emission Inventory – Ammonia Emissions from Animal Husbandry – Draft Report. US Environmental Protection Agency, Washington, D.C. Jan. 30, 2004.
 Reche, C., Viana, M., Karanasiou, A., Cusack, M., Alastuey, A., Artiñano, B., Revuelta, M.A., López-Mahía, P., Blanco-Heras, G., Rodríguez, S., Sánchez de la Campa, A.M., FernándezCamacho, R., González-Castanedo, Y., Mantilla, E., Tang, Y.S., Querol, X., 2015. Urban NH3 levels and sources in six major Spanish cities. Chemosphere 119, 769-777.
 D. C. Carslaw, G. Rhys-Tyler, “New insights from comprehensive on-road measurement of NOx, NO2, and NH3 from vehicle emission remote sensing in London, UK”. Atmospheric Environment, vol. 81, pp. 339 347, 2013.
 DieselNet, 2016. Emission Standards. Summary of worldwide engine emission standards. Available at: (accessed on: Oct. /20/2017).
 http://www.mma.gov.br/estruturas/163/_arquivos/proconve_163.pdf, acess. in nov. (2017).
 D. R. Cassiano, J. Ribau, F. S. A. Cavalcante, M. L. M. Oliveira, C. M. Silva, “On-board monitoring and simulation of flex fuel vehicles in Brazil”. Transportation Research Procedia, vol. 14, pp. 3129 3138, 2016.
 K. Wipke, M. Cuddy, S. Burch, “ADVISOR 2.1: A User Friendly Advanced Powertrain Simulation Using a Combined Backward/Forward Approach”. IEEE Transactions on Vehicular Technology, vol. 48, pp. 1751, 1999.
 E. M. Faghihi, A.H. Shamekhi, “Development of a neural network model for selective catalytic reduction (SCR) catalytic converter and ammonia dosing optimization using multi objective genetic algorithm”. Chemical Engineering Journal, vol. 165, pp. 508 516, 2010.
 G. A. Gonçalves, T. L. Farias, C. M. Silva, “Comparison of Diesel and Natural Gas Urban Buses Energy Efficiency and Environmental Performance”. Clean Air, pp. 27 30, 2005.
 V. Franco, F. P. Sánchez, J. German, P. Mock, “Real-World Exhaust Emissions from Modern Diesel Cars”. 2014 International Council on Clean Transportation. Access in September of the 2017 http://www.theicct.org/.
 T. J. Wallington, J. L. Sullivan, M. D. Hurley. “Emissions of CO2, CO, NOx, HC, PM, HFC-134a, N2O and CH4 from the global light duty vehicle fleet”. Meteorologische Zeitschrift, Vol. 17, No. 2, 109-116 (2008).
 A. D., B. K. Mandal. “Biodiesel Production and its Emissions and Performance: A Review”. International Journal of Scientific & Engineering Research, Vol. 3, Issue 6, (2012).
 EERE Information Center. • www.eere.energy.gov, acess. in Nov. 2017.
 C. A. Alves, A. I. Calvo, D. J. Lopes, T. Nunes, A. Charron, M. Goriaux, P. Tassel, and P. Perret. Emissions of Euro 3-5 Passenger Cars Measured Over Different Driving Cycles. World Academy of Science, Engineering and Technology International Journal of Environmental and Ecological Engineering Vol:7, No:6, 2013.