Control of NOx and CO in S I Engine Exhaust using Cu-Ion Exchange ZSM-5 with impregnation of Platinum and Palladium 2001-28-0042

The most efficient gas after treatment system envisages the use of Catalytic Converter for oxidizing Carbon monoxide (CO), and reducing the oxides of Nitrogen (NO_x). The exhaust is made to pass through a catalytic bed which catalyses the conversion reactions for the different exhaust gas components.

The Cu-Ion exchanged ZSM-5 Zeolite Catalysts are processed with the impregnation of 0.1% Platinum and 0.1% Palladium in a pellet form 1.5 mm diameter are placed in a catalytic converter for the reduction of CO and NO_x. The combination of catalyst exhibits significant NO_x reduction for a lean air fuel ratio 17.5 and conversion system tested in a commercial Maruti (800 cc) S I engine and some encouraging results are obtained. Maximum conversion efficiencies achieved with Cu-ZSM-5 are 87% NO_x at 440°C and 76% of CO at 450°C.

The design and fabrication of the converter is such that it consists of two parts, namely, casing and catalyst cartridge.

Back pressure developed across the catalytic bed is found to be well within the acceptable limits and power loss due to the back pressure is only 0.25%.