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    Development of Fe2O3 based catalysts to control pollutant emissions in diesel engines
    (ELSEVIER SCI LTD, 2017) Reşitoğlu, İbrahim Aslan; Altınışık, Kemal; Keskin, Ali; Yıldırımcan, Saadet; Ocakoğlu, Kasım; Omar, Muhammed Arslan
    Exhaust after treatment systems have become a necessity to eliminate pollutant emissions as required by standard. Nowadays, DOC and SCR are widely used after treatment technologies in diesel vehicles. In this experimental study carried on DOC and SCR systems, two different catalysts as Al2O3-TiO2/Fe2O3 and Al2O3-Pt/Fe2O3 were produced with impregnation method. The catalysts were characterized by Field Emission-Scanning Electron Microscope (FE-SEM), X-ray diffraction (XRD), X-ray fluorescence (XRF) and Brauner-Emmett-Teller (BET). Each catalyst was tested as DOC and SCR in real working state to see the effect of catalyst on pollutant emissions in diesel engine. Results showed that the use catalysts as DOC led to significant decrease in CO, HC, NO and smoke emissions. The exhaust temperature rose up to 50 degrees C after DOC. The use of catalysts in SCR system eliminated NOx emission by high rates. Furthermore; the use of catalysts in emission control systems led to an increase in specific fuel consumption and a decrease in excess air coefficient of engine. (C) 2017 Elsevier Ltd. All rights reserved.
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    The effects of Fe2O3 based DOC and SCR catalyst on the exhaust emissions of diesel engines
    (ELSEVIER SCI LTD, 2020) Reşitoğlu, İbrahim Aslan; Altınışık, Kemal; Keskin, Ali; Ocakoğlu, Kasım
    The effects of Fe2O3 based DOCs (Diesel Oxidation Catalyst) and SCR (Selective Catalytic Reduction) catalysts on the exhaust emissions of diesel engine were investigated in this experimental study. The investigated catalysts, Al2O3 - TiO2/CeO2/Fe2O3 (ATCF) and Al2O3- Nb2O5/CeO2/Fe2O3 (ANCF), were produced with impregnation method and aged for 6 h at 600 degrees C. FE-SEM (Field Emission Scanning Electron Microscopy), XRD (X-Ray Diffraction), XRF (X-Ray Fluorescence) and BET (Brunauer-Emmett-Teller) Surface Area analyzes were carried out to determine the specifications of catalysts. The catalytic performances of the DOCs were tested for the oxidation of CO, HC, PM, NO while SCR catalysts were tested for SCR of NOx using NH3. An individual exhaust system was built up and mounted to the engine for tests of catalysts. An electronic control system and a software were developed to control the SCR system. After the completion of experimental setup, catalysts placed inside the exhaust system were subjected to the engine tests to determine their effects on the exhaust emissions. Tests were carried out under actual working conditions with a single cylinder direct injection diesel engine. In conclusion, the catalysts made significant decrease in pollutant emissions while brake specific fuel consumption (BSFC) increased slightly. ANCF released better conversion efficiency in all pollutant emissions compared to the ATCF. Maximum decreases in CO, HC and NOx emissions, which are resulted from ANCF catalyst, were obtained at a rate of 83.51%, 80.83% and 80.29% respectively.
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    The pollutant emissions from diesel-engine vehicles and exhaust aftertreatment systems
    (SPRINGER, 2015) Reşitoğlu, İbrahim Aslan; Altınışık, Kemal; Keskin, Ali
    Diesel engines have high efficiency, durability, and reliability together with their low-operating cost. These important features make them the most preferred engines especially for heavy-duty vehicles. The interest in diesel engines has risen substantially day by day. In addition to the widespread use of these engines with many advantages, they play an important role in environmental pollution problems worldwide. Diesel engines are considered as one of the largest contributors to environmental pollution caused by exhaust emissions, and they are responsible for several health problems as well. Many policies have been imposed worldwide in recent years to reduce negative effects of diesel engine emissions on human health and environment. Many researches have been carried out on both diesel exhaust pollutant emissions and aftertreatment emission control technologies. In this paper, the emissions from diesel engines and their control systems are reviewed. The four main pollutant emissions from diesel engines (carbon monoxide-CO, hydrocarbons-HC, particulate matter-PM and nitrogen oxides-NOx) and control systems for these emissions (diesel oxidation catalyst, diesel particulate filter and selective catalytic reduction) are discussed. Each type of emissions and control systems is comprehensively examined. At the same time, the legal restrictions on exhaust-gas emissions around the world and the effects of exhaust-gas emissions on human health and environment are explained in this study.