Designing a Greener Catalytic Converter - A computational study on the use of Aerogels to Improve Performance

Internal combustion engines produce harmful exhaust gases. Catalytic converters are implemented to combat these harmful emissions. Located between the engine and exhaust, the catalytic converter speeds up the reactions that turn the gases leaving the engine into less harmful gases before they enter the atmosphere. To function properly, catalytic converters must reach a certain temperature, known as light-off temperature. Generally it takes two to three minutes for the modern catalytic converter to reach light-off temperature, during which about 70% of the harmful emissions produced are emitted into the atmosphere. To reduce the time to light-off temperature, I studied the thermal effects of using catalytically active aerogels in place of the traditional alumina washcoat used within the catalytic converter. Aerogels unique properties, notably low density and thermal stability, make it an ideal material for this application. I developed a finite-difference model of a flow channel in a catalytic converter and analyzed the thermal response of copper-alumina aerogel compared to alumina washcoat. Using copper-alumina aerogels in place of the alumina washcoat was found to significantly decrease the time to light-off temperature, and therefore reduce the amount of harmful emissions released into the atmosphere.