Advantages of using ArvinMeritor’s Plasma Fuel Reformer for desulfating a NOx Adsorber
Navin Khadiya, ArvinMeritor
We present results and a strategy for performing desulfation of the traps using ArvinMeritor’s Plasma fuel reformer. In contrast to vaporized diesel, which requires very high temperatures that fall outside the normal exhaust operating temperatures for diesel engines, desulfation was achieved at temperatures around 350°C using the Plasma Fuel Reformer. This is likely to provide substantial durability benefits for the NOx traps, a major hurdle remaining in the commercialization of that technology. A lower temperature that falls within the normal engine operating range also provides an effective desulfation strategy including the possibility of some desulfation occurring simultaneously with regeneration. We also present experimental results on the fuel reformer including hydrogen yield, soot production, start-up time and durability. The fuel reformer is capable of reaching up to 90% of the theoretically possible hydrogen yield at a range of fuel flow rates when used in conjunction with a downstream catalyst. The soot production is minimal both upstream (<20 mg/m3) and downstream (< 5 mg/m3) of the catalyst, while the start-up time required to reach 90% of the maximum hydrogen output is around 10 seconds. The system has been operated for more than 3000 cycles without any noticeable performance degradation.