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1649584 
Journal Article 
Transient modeling of dual fuel catalytic converter 
Sallamie, N; Kazemeini, M; Badakhshan, A; Soltanieh, M; Estiri, M 
2003 
27 
B2 
291-298 
WOS:000185412600006 
Exhaust gas emissions from mobile sources and its importance in urban pollution have currently attracted lots of interests towards studying on alternative fuel systems for road vehicles usage. One of the best replacements is the natural gas/diesel dual fuel, which offers an alternative to standard compression-ignition diesel engines. In the dual fuel system the primary fuel is natural gas, which may replace as much as 90% of the diesel fuel with a small amount of diesel fuel required ensuring effective ignition. Methane, the main constituent of natural gas, has high combustion efficiency. Dual fuel engines produce lower NOx emissions and fewer particulates. However, at moderate engine loads, lower fuel combustion efficiency leads to significant production of hydrocarbons and carbon monoxide in the exhaust. Therefore, an oxidizing catalytic converter is necessary in the exhaust system to reduce these emissions to an acceptable level.



Based upon experimental data gained with an Isuzu 4BE1 dual fuel engine, a transient two-dimensional model is introduced in this work for the monolithic oxidizing catalytic converter, while at the same time considering chemical reaction and transport phenomena. It is shown that first order kinetics may well fit methane and carbon monoxide catalytic conversion. Furthermore, effectiveness factor is used to describe simultaneous mass transfer and reaction in the catalyst phase. Temperature and composition dependent physical properties are also employed. Predicted steady-state conversions are then compared with experimental data to verify the validity of the model. Finally, some extensions of the model, including the effectiveness factor changes and temperature profiles in the transient state are presented. Ultimately, it is concluded that the model is' properly capable to describe the performance of the converter. 
dual fuel; natural gas; diesel engine; catalytic converter; transient modeling