John Frederick Pignon

Thermochemical recovery technology for improved modern engine fuel economy – part 1: analysis of a prototype exhaust gas fuel reformer

Exhaust gas fuel reforming has the potential to improve the thermal efficiency of internal combustion engines, as well as simultaneously reduce gaseous and particulate emissions. This thermochemical energy recovery technique aims to reclaim exhaust energy from the high temperature engine exhaust stream to drive catalytic endothermic fuel reforming reactions; these convert hydrocarbon fuel to hydrogen-rich reformate. The reformate is recycled back to the engine as Reformed Exhaust Gas Recirculation (REGR), which provides a source of hydrogen to enhance the engine combustion process and enable high levels of charge dilution; this process is especially promising for modern gasoline direct injection (GDI) engines. This paper presents a full-scale prototype gasoline reformer integrated with a multi-cylinder GDI engine. Performance is assessed in terms of the reformate composition, the temperature distribution across the catalyst, the reforming process (fuel conversion) efficiency and the amount of exhaust heat recovery achieved.

On-board thermochemical energy recovery technology for low carbon clean gasoline direct injection engine powered vehicles:

Exhaust gas fuel reforming is a catalytic process that reclaims exhaust energy from the high temperature engine exhaust stream to drive catalytic endothermic fuel reforming reactions; these convert hydrocarbon fuel to higher enthalpy hydrogen-rich gas known as reformate. This technique has the potential to improve the thermal efficiency of internal combustion engines, as well as to simultaneously reduce gaseous and particulate emissions. This study demonstrates a novel, prototype exhaust gas fuel reformer integrated with a modern, turbocharged, 4-cylinder gasoline direct injection engine and analyses the effects on engine performance, combustion characteristics and emissions. The results suggest that exhaust gas fuel reforming raises the engine fuel efficiency through a combination of: exhaust energy recovery; improved engine thermal efficiency; and enhanced combustion at highly dilute operation, which considerably reduces NOx emissions by up to 91% and improves engine fuel consumption by up to 8%. The presence of hydrogen and exhaust gas diluents in the combustion charge also reduces particle formation for lower total particulate matter emissions (up to 78% and 84% for number and mass, respectively).