Reforming Performances

Matsukata, M., Matsushita, T., and Ueyama, K., A circulating fluidized bed CH4 reformer Performance of supported Ni catalysts, Energy Fuels, 9, 822,1995. 

Benefits of Modern Catalyst Pellet Design on Reformer Performance... 

The overall effect of catalyst pellet geometry on heat transfer and reformer performance is shown in the simulation results presented in Table 1. The performance of the traditional Raschig ring (now infrequently used) and a modern 4-hole geometry is compared. The benefits of improved catalyst design in terms of tube wall temperature, methane conversion and pressure drop are self-evident. 

Demonstrations of the scale-up, development, and integration of hardware with real materials of construction must focus on the robustness of the parallel flow in multiple-cell reactors. The issues of cell blockage, hydrocyclone performance, and NOx reformer performance must be addressed. 

The reformer performance is shown in Table 2. The fuel for the original reactor was a 50 wt % mixture of methanol and water. For the higher-efficiency reactor and the system that included carbon monoxide cleanup, the fuel mixture was 60 wt % methanol in water. " The efficiency was calculated using the following equation ... 

The validity of these assumptions will be demonstrated by KINPTR s ability to predict the wide range of commercial reformer performance and feedstock with no additional parameters. 

Figure 2.86 Isooctane steam reformer performance. At constant residence time the hydrogen selectivity is not affecteded by decreasing the S/C ratio while the isooctane conversion is lowered [135] (by courtesy of S. P. Fitzgerald).

A more normal shutdown sequence would first flush the fuel cell, reformer, and scrubber with nitrogen or C02 (if it is safe for the cell design). This step is followed by a slow bleed of air and nitrogen to repassivate the fuel cell and reformer under temperature control. If this is not done gradually, the reformer can reach temperatures high enough to violate its containment (meltdown) and become unrecoverable. The reformer performance does decrease after this treatment, but over 90% of its capacity can be retained. Similar problems are present when reforming the fuel cells themselves. 

F.W. Hohmann, Improve Steam Reformer Performance , Hydrocarbon Processing, [3] 71-74 (1996). 

Zhang, L., Wang, X., Tan, B., and Ozkan, U.S. Effect of preparation method on structural characteristics and propane steam reforming performance of Ni-Al203 catalysts. Journal of Molecular Catalysis A Chemical, 2009, 297 (1), 26. 

Le Goff, P. Pike, M. Increasing semi-regenerative reformer performance through catalytic solutions. Presented at the 3rd European Catalyst Technology Conference, Euro Petroleum Consultants (EPC) Amsterdam, Feb 2002. 

Rajesh, 1. K., Gupta, S. K., Rangaiah, G. P. and Ray, A. K. (2000). Multi-objective optimization of steam reformer performance using genetic algorithm, Ind. Eng. 

Identify the effects of major constituents, additives, and impurities in petroleum-based fuels on reformer performance... 

Continue evaluations of new MEA materials for optimal reformate performance and longevity. 

HAD A, K., Improvements of Reforming Performance of a Nuclear Heated Steam Reforming Process, Report JAERI-Research-96-054, Japan Atomic Energy Research Institute (1996) (in Japanese). 

HOFFMANN, P., (Ed.), Hydrogen Fuel Cells Letter 12 (1997) November. HOHMANN, F.W., Improve Steam Reformer Performance, Hydrocarbon Processing 75 (1996) March 71-74. 

Figure 5 Metrics of reformer performance for various temperatures and relative catalyst weights. Note that due to deactivation effects, higher temperature operation is actually less productive. Wall Temperature 240"C, 260"C., 280°C---------...

Metallic membranes, (Pd-Ag) alloys, are typically used for separation of H2, either as an unsupported foil or a supported thin film. In these membranes, the hydrogen transport is by adsorption and atomic dissociation on one side of the membrane, dissolution in the membrane, followed by diffusion, and finally desorption (on the other side). Due to the H2 dissociation step, H2 separation is driven by a transmembrane difference of the square roots of the hydrogen partial pressures. The preparation technologies of both unsupported and supported Pd-Ag membranes are well developed and such membranes are commercially available. Since the membrane reformer performance is limited by separation capability, optimization of membrane permeability is one of the important issues. 

Rgure 12.16a and b shows the test results of temperature dependence of reforming performance at the hydrogen permeation side pressure of 0.1 MPa and 0.04 MPa. 

The reforming performance is plotted in terms of the product hydrogen flux, the hydrogen recovery and the conversion. The conversion is much... 

Nishu T (2009), Reforming performance of hydrogen production module based on membrane on catalyst . Proceedings of 9th International Conference on Catalysis in Membrane Reactors, Lyon, France. 

Sulfur. Sulfur commonly exists as mercaptans, disulfides, or thiophenes in reformer feeds (Fig. 4). Mercaptans and disulfides are significantly more reactive than thiophene during hydrotreating (4). Sulfur contamination results in poisoning of the platinum metal. Studies have shown that the sulfur reacts with the platinum, changing the reactivity of the platinum in a manner more extensive than a simple blocking of metal sites (5). Typical maximum allowable concentrations of sulfur are 0.5 ppm or less. With proper hydrotreating, levels of 0.2-0.3 wt. ppm are reached and these lower levels are beneficial to reformer performance. 

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