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

Abstract

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 NO_x 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).