Study on Thermoneutral Reforming catalyst with liquid hydrocarbon fuels and combustion engine exhaust gas

Abstract

Growing environmental demand and need for higher efficiency vehicles has triggered immense interest in hydrogen utilization for transportation applications. Hydrogen or hydrogen rich gas will provide positive effects on the internal combustion engine's performance through improving overall fuel combustion efficiency and thus reducing CO2 emission. The invention of an efficient and appropriate on-board hydrogen generation method will lead to the development of a new low emission vehicle. A reforming catalyst system that can offer high activity, stability and selectivity is needed to develop such an on-board process. In this study, the Thermoneutral Reforming (TNR) catalyst system was selected as it was designed to promote the hydrogen spillover properties that achieve an extraordinarily high reaction rate and a low deactivation rate. The study was conducted in a fixed-bed micro-reactor unit using heavy naphtha, commercial gasoline, and hydrotreated diesel fuels. The system involves the reaction of steam, air, and fuel to produce hydrogen rich gas in presence of TNR catalyst. This reaction will require a considerable amount of steam. Consequently, a large water tank is needed on board the vehicle to provide enough steam. This issue was addressed by using the engine's exhaust gas which contains a considerable amount of water vapor that can eliminate or reduce the need for a large water tank on the vehicle. Also, it can provide part of the heat required for a diesel engine. In this case, the process will involve hydrogen rich gas generation by direct catalytic interaction of hydrocarbon fuels with gasoline and diesel engine exhaust gases in the TNR catalyst system.