On board Exhaust Gas Reforming of Gasoline Using Integrated Reformer & TWC 2007-24-0078
Producing on-board the hydrogen that is to be used as supplementary fuel by exhaust gas reforming of gasoline shows encouraging results. Extensive research has been done at the University of Birmingham towards on board generation of hydrogen-rich gaseous fuel. Exhaust gas reforming which utilizes water vapor and enthalpy from the hot engine exhaust gas was applied using a compact system of a fuel reformer reactor integrated with the three way catalytic converter (TWC). Such system can be fitted in the limited space close to the engine. The device has been designed and built in concentric shape with the catalytic converter as a core and the reformer in an annular shape outside, to best utilize the waste heat from the catalytic converter. It requires very little extra space beyond the baseline catalytic converter. The split of exhaust gas between the two reactors can be managed using an external valve, whereby 10-20 % of the exhaust from one bank of a V6 engine will enter the reformer when reforming is needed; otherwise all the exhaust gas will flow through the TWC. Gasoline fuel has been introduced to the reactor in gaseous form to achieve more homogenous mixture of fuel and exhaust gas before entering the reformer section. The reformer part was made of metallic monolith of high cell density (900 cells per square inch) coated by proprietary reforming catalyst. The fuel reforming reactor has been tested on-line at several engine operating points without the TWC and at one point with the TWC fitted at its core. It was possible to produce hydrogen concentrations of up to 11% by volume in the reformer products, and hydrogen concentration obtained from the combined fuel reformer / TWC was much higher than that from the annular fuel reformer without the TWC core at comparable engine condition and exhaust gas temperature.