| The conventional base metal particulate catalyst used to produce hydrogen should be questioned due to its chemical and physical limitations (as further discussed in this thesis). These chemical and physical limitations compromise the durability and longevity of the catalyst system. They can also contribute to a less economically sound system when evaluated over an extended period of time. Due to the exothermic nature of a typical base metal particulate catalyst used in hydrogen production, such as NiO/áAl2O3, a reduction step is required. This in turn adds safety concerns and precautions to every startup of fresh catalyst (which additionally compromises the economic feasibility of the system). These safety risks add complexity to planning and documentation, all of which are greatly time-consuming and demanding of personnel.;Precious metal monolith washcoat catalyst allow for an alternative that results in smaller systems and greater efficiencies. Data was collected to better understand the corresponding advantages of precious metal washcoat catalyst versus that of conventional base metal particulate catalyst. These advantages include higher space velocities, greatly improved heat transfer or temperature profile, smaller sized equipment (specifically reactors), the lack of an activation step, safer discharge, improved and eased operations, significantly less routine maintenance, less down time, the ability to quickly recover well from upsets, longer catalyst lifespan (resulting in less frequent catalyst change-outs), and other benefits that are described in this paper. These advantages were determined by a variety of studies, including: the fresh activity of different metal-loaded catalysts and their relative weight percent, the effect of sulfur poisoning on the conversion of methane, a comparison of the temperature profiles for base metal and precious metal catalyst systems, a comparison of aged vs. fresh precious metal catalyst performance, the operational conditions attainable post start-stop cycles, and the reactivity of precious metal catalysts at two distinct space velocities. |
