THREE WAY CATALYTIC SIMULATION OF ENGINE-OUT EXHAUST EMISSION

Presently Three Way Catalytic Converters (3WCC) are important after treatment devices mounted in the exhaust system of the engines to reduce harmful engine-out emissions. The experimental prediction of catalytic converter performance is time consuming and requires a lot of experimentation and large experimental set-up. In this paper, numerical simulation has been carried out for prediction of emission reduction. CHEMKIN 4.1 software is a powerful tool for solving complex chemical kinetics problems. Catalytic conversions of NOx, CO, and unburned hydrocarbons are numerically modeled by the Pt/Rh catalyst surface mechanisms in CHEMKIN 4.1. In the present work, exhaust emissions data of 2500 cc, spark ignition dedicated natural gas engine has been used to set dynamic inlet conditions for simulation. The simulation results show the conversion of unburned hydrocarbons (C3H6) and CO is, almost complete at the temperature of 709~710 K while 80% NOx is converted whereas it remains constant for higher temperature. These pollutants arrive at optimum conversion in about 93 sec.