An equilibrium analysis of hydrogen production from ethanol-gasoline fuel blends reforming

Abstract

A hydrogen concentration from ethanol-gasoline blends reforming processes plays a role in exhausted gas recirculation (EGR) that enhanced engine performance and aftertreatment system of gasoline direct injection (GDI) engine. An equilibrium model is widely used as a primary tool to determine a level of hydrogen content from reforming process. Thus, in this work, the equilibrium analysis of hydrogen production is investigated using STANJAN program. Three main reactions (Partial Oxidation Reforming (POx), steam reforming (SRM) and autothermal reforming (ATR)) are studied here. Three commercial ethanol-gasoline blends are studies here (E10, E20 and E85). The effect of reaction temperature, steam to fuel ratio (S/F) and oxygen to fuel ratios (O2/F) are investigated. The results show that the optimum condition for POx is achieved at O2/F ratio of 3 for E10 and E20 and 0.75 for E85. For SRM, the optimum condition for H2 production at temperature 200–500 °C are achieved with S/F ratio of 10–12 for E10 and E20, while E85 can be obtained at S/F ratio of 6–8. Under these conditions, the maximum hydrogen yield (∼30 vol%) are reached with temperature 500 °C. In case of ATR, the highest H2 yield (approximately 25 vol%) is achieved at temperature 500 °C with S/F ratio of 8 for E10 and E20 fuels and 4 for E85 fuel. The highest H2 yields from real exhausted gas reforming are 42 to 55 % vol. Thus, this possibility of on-board hydrogen production via gasoline - ethanol fuel blends reforming operates in GDI engine.