Improving gasoline direct injection (GDI) engine efficiency and emissions with hydrogen from exhaust gas fuel reforming

Abstract

Graphical Abstract AbstractExhaust gas fuel reforming has been identified as a thermochemical energy recovery technology with potential to improve gasoline engine efficiency, and thereby reduce CO2 in addition to other gaseous and particulate matter (PM) emissions. The principle relies on achieving energy recovery from the hot exhaust stream by endothermic catalytic reforming of gasoline and a fraction of the engine exhaust gas. The hydrogen-rich reformate has higher enthalpy than the gasoline fed to the reformer and is recirculated to the intake manifold, i.e. reformed exhaust gas recirculation (REGR).The REGR system was simulated by supplying hydrogen and carbon monoxide (CO) into a conventional EGR system. The hydrogen and CO concentrations in the REGR stream were selected to be achievable in practice at typical gasoline exhaust temperatures. Emphasis was placed on comparing REGR to the baseline gasoline engine, and also to conventional EGR. The results demonstrate the potential of REGR to simultaneously increase thermal efficiency, reduce gaseous emissions and decrease PM formation.

High efficiency dual-fuel combustion through thermochemical recovery and diesel reforming

“…Finally, Fennell et al [36,37] successfully demonstrated the practical feasibility of the concept in a modern, full scale prototype gasoline direct injection (GDI) engine coupled with a reformer. The substantial amount of work reviewed here shows that on-board reforming is a feasible strategy to increase overall system efficiency, which is fuel flexible and crosscompatible between many combustion strategies.…”

Impact of the Biofuels Burning on Particle Emissions from the Vehicular Exhaust

“…Emphasis was placed on comparing REGR to the baseline gasoline engine, and also to conventional EGR. The results demonstrate the potential of REGR to simultaneously increase thermal efficiency, reduce gaseous emissions, and decrease PM formation [34].…”

Butanol-gasoline blend and exhaust gas recirculation, impact on GDI engine emissions

“…In terms of emissions, EGR is reported to improve regulated emissions except for THC, mainly due to the high EGR heat capacity that reduces the HC oxidation rate and may cause engine to misfire when high EGR rates are used [29,31]. The effect of EGR on particle emissions in GDI engines has been also reported.…”