PERFORMANCE OF 1,5 Nm3/h HYDROGEN GENERATOR BY STEAM REFORMING OF n-DODECANE FOR NAVAL APPLICATIONS

The conversion of liquid hydrocarbons into an hydrogen rich product gas is a central process step in fuel processors for auxiliary power units (APUs) for naval applications [1]. Diesel, together with gasoline, is the preferred fuel for these applications [2]. The CNR-ITAE has developed an hydrogen generator by steam reforming (SR) of n-dodecane (n-C12H26) as surrogate of diesel, with a maximum hydrogen production of 1.5 Nm3/h. The prototype is based on integrated packed bed catalytic tubular reactor which is coupled with heat exchanger, static mixer, water-dodecane and recycle reservoirs, manual/automatic valves, pressure regulators/transducers, flow meters, and ancillaries (Fig.1). The unit has been engineered, focusing every single component and the integration of system, to meet the requirements of small size and volume, improving thermal/mass transfer and system efficiency. This study discusses the performance testing of the hydrogen generator using a Rh-based commercial catalyst. Experiments were performed varying the steam to carbon (S/C) molar ratio from 1.5 to 2.5, under a gas hourly space velocity (GHSV) increasing up to 24000 h-1. In all the experimental conditions, high conversion of n-dodecane and no carbon deposition phenomena, were observed. H2/CO ratio increased from 3.0 to 4.5 by increasing the added steam and the reformate composition was of an acceptable level to be sent to a Solid Oxide Fuel Cell (SOFC).