Influence of prototype three way catalytic converter on regulated and unregulated emissions from gasoline HCCI/SI engine

Designing automotive catalysts for the effective control of NOx, HC (Hydrocarbon) and CO (Carbon Monoxide) emissions under both lean and stoichiometric engine operation is a challenging task. The research presented in this thesis assesses the performance efficiency of a three-zone prototype catalytic converter in reducing exhaust emissions from a gasoline engine, operating in HCCI (Homogeneous Charge Compression Ignition) and SI (Spark Ignition) mode under lean and stoichiometric conditions. The research was carried out using Jaguar V6 engine operating in SI and HCCI mode using commercial unleaded gasoline fuel. The catalyst efficiency in reducing the three pollutant emissions is closely related to the exhaust gas conditions (e.g. temperature and space velocity), oxygen content and composition i.e. NOx, CO and HC concentrations. As part of this study a quantitative and qualitative analysis of C1-C11 hydrocarbon compounds achieved before and after the catalytic converter. The results show that hydrocarbon species formation in the combustion process and destruction over the catalyst is primarily dependent on the engine operation and combustion mode (i.e. HCCI or SI). Alkane concentrations were found to be higher in the HCCI mode, while alkene species were mainly found in the engine exhaust under SI mode. The analysis showed that the HCCI exhaust contained heavier hydrocarbon species (e.g. toluene, p-exylene, naphthalene and methylnaphthalene) compared to the exhaust from the SI engine operation. Methane, Naphthalene and methylnaphthalene were the most resistant compounds while toluene was the most degradable compound over the catalyst.EThOS - Electronic Theses Online ServiceGBUnited Kingdo