Catalytic Converters for Natural Gas Fueled Engines—A Measurement and Control Problem

Three-way catalytic converters proved to have a long-term capacity to effectively reduce the concentration of unwanted compounds in the exhaust gas of engines fueled by natural gas, provided a narrow air-to-fuel-ratio window is maintained. The exhaust-gas sensors hitherto incorporated in the required feedback-control system have an undesirable transfer function and suffer from ageing. This paper therefore advocates the development of an appropriate sensor for carbon monoxide and/or hydrogen to perfect the cleaning system.