Forensic Studies on Spent Catalytic Converters to Examine the Effect of Diesel and B100 Pongamia Biodiesel on Emissions

The ever-increasing demand for transport is sustained by fossil fuel-based internal combustion (IC) engines fitted with catalytic converters (CCs) while alternative options and fuels are still emerging. Biodiesel seems to be a potential alternate to diesel, but the formation of NOx and smoke are major issues. This study aimed to explore the effect of B100 Pongamia biodiesel on the performance of CCs and to assist the designers of compression ignition engines. This study included a comparison of deposits on the catalytic converter (CC) in the cases of diesel fuel and biodiesel. Forensic examination of the spent CCs after 250 h was performed by characterization using SEM/EDS. The amount and composition of the deposits were compared for the diesel and biodiesel, and the effectiveness of the CC. The study revealed that the efficiency of the CC increased in biodiesel. The amount of soot and deposits was greater at the engine side of the spent CC with diesel, including the atomic percentage (At. %) of C, while the minimum deposits and C At. % in the spent CC were at the exhaust side with biodiesel. Oxygen content in the deposits was greater in biodiesel. The efficiency and effectiveness of the CC increased with the biodiesel.