A three-way catalyst system for a five-stroke engine

This paper presents the results of research on the development of an exhaust gas aftertreatment system for a turbocharged five-stroke engine. This engine was designed and constructed at Cracow University of Technology. A characteristic feature of the five-stroke engine is the use of an additional expansion process to increase overall efficiency. A challenge for a catalytic converter is the fact that it has a low exhaust gas temperature. Two three-way catalytic converters were tested – one with a ceramic support and the second with a metal support. The results of the tests showed that the reactor with a ceramic support obtains an acceptable conversion efficiency starting with an exhaust gas temperature of 280°C. For the metal-support reactor, a few percent increase in torque and a decrease in the brake-specific fuel consumption of the engine was obtained; however, the converter itself did not show signs of operation even with an exhaust gas temperature of over 380°C. The performed analyses highlighted directions of further development works in this area.