Downstream Lambda Sensor Control Optimized to Fuel Blend

The current stringent emissions regulations can be achieved by automakers applying different technologies. One of these recent technologies is the downstream lambda sensor to control catalytic converter oxygen storage. This lambda sensor is installed after the catalytic converter and its response is the oxygen concentration of exhaust gases after the converter compared to ambient. This oxygen content is correlated to the amount of oxygen stored inside the catalytic converter. The stored oxygen is significantly important for the emissions conversion trade of between hydrocarbons, carbon monoxides and nitrous oxides. The ideal stored oxygen is particular to each application and engine operational condition. Besides, the flexible fuel applications must be optimized to control the oxygen stored in catalytic converter according to the fuel blend in tank. Considering the different properties of the fuel blends regarding oxygen resulted from combustion, this paper analyses the representative fuel blend properties that impacts the stored oxygen control in the catalytic converter to optimize conversion efficiency in Brazilian Flexible Fuel Vehicles.