Exhaust gas fuel reforming for IC Engines using diesel type fuels

Control of NO_x and Particulate Matter (PM) emissions from diesel engines remains a significant challenge. One approach to reduce both emissions simultaneously without fuel economy penalty is the reformed exhaust gas recirculation (REGR) technique, where part of the fuel is catalytically reacted with hot engine exhaust gas to produce a hydrogen-rich combustible gas that is then fed to the engine. On the contrary to fuel cell technology where the reforming requirements are to produce a reformate with maximized H₂ concentration and minimized (virtually zero) CO concentration, the key requirement of the application of the exhaust gas fuel reforming technique in engines is the efficient on-demand generation of a reformate with only a relatively low concentration of hydrogen (typically up to 20%). In order to design an optimized practical engine-reformer system, an experimental study of the effects of the oxygen-to-carbon atomic ratio in the reactor input gas mixture (O/C), the reactor input fuel chemical power and the reactor gas hourly space velocity (GHSV) on the reforming process was carried out using ultra low sulphur diesel (ULSD) and gas-to-liquid (GTL) fuel. Calculations of theoretical equilibrium reformate compositions were also performed.