Sulfur-tolerant hydrogenation

B. Cooper, P. N. Hannerup, and P. Sogaard-Andersen, Reduction of Aromatics in Diesel Using Sulfur-Tolerant Hydrogenation Catalysts, presented at the American Institute of Chemical Engineers Spring Annual Meeting, April 17-21,1994. 

Dr. Woodward I tried to indicate in my paper that in ammonia-hydrogen plant operation, in comparison with several other catalysts in such plants, the methanation catalyst situation is really well under control. Speaking for our company, and I would guess others, it s not a particularly active research area because we have higher priorities in catalyst development. As regards methanation catalysts for SNG, I did not discuss that today and perhaps I should let some other fellows answer first. Sulfur tolerance is one area for future development. 

With tethering technology, immobilized Rh(DiPFc) catalyst, a veiy selective hydrogenation catalyst was developed by Engelhard (26) and Chirotech (27). Rh(DiPFc)(COD)BF4 is one of most interesting homogeneous catalysts due to its chemo-selectivity and sulfur tolerant behavior. The anchored complex y-... 

Kamakoti, P., B.D. Morreale, M.V. Ciocco, B.H. Howard, R.P. Killmeyer, A.V. Cugini, and D.S. Sholl, Prediction of hydrogen flux through sulfur-tolerant binary alloy membranes, Science, 307, 569-573,2005. 

Aguilar L, Zha S, Li S, Winnick J, and Liu M. Sulfur-tolerant materials for the hydrogen sulfide SOFC. Electmchem Solid-State Lett 2004 7 A324—A326. 

There are three major gas reformate requirements imposed by the various fuel cells that need addressing. These are sulfur tolerance, carbon monoxide tolerance, and carbon deposition. The activity of catalysts for steam reforming and autothermal reforming can also be affected by sulfur poisoning and coke formation. These requirements are applicable to most fuels used in fuel cell power units of present interest. There are other fuel constituents that can prove detrimental to various fuel cells. However, these appear in specific fuels and are considered beyond the scope of this general review. Examples of these are halides, hydrogen chloride, and ammonia. Finally, fuel cell power unit size is a characteristic that impacts fuel processor selection. 

Yasuda, H., Sato, T., and Yoshimura, Y., Influence of the acidity of USY zeolite on the sulfur tolerance of Pd-Pt catalysts for aromatic hydrogenation. Catal Today 50,63 (1999). 

The presence of sulfur in the feed is also a problem for conventional steam reforming. If the catalyst is not sulfur tolerant, the sulfur will deactivate it (Rostrup-Nielsen, 1984). If the catalyst is "sulfur tolerant", i.e., able to tolerate small amounts of feed sulfur, the sulfur leaves the process as hydrogen sulfide and is likely to cause unacceptable problems downstream. Furthermore many major natural gas resources are "sour," i.e., contain a large percentage of hydrogen sulfide. 

Methanation as final purification for the raw gas from partial oxidation was proposed by Topsoe [739]. In this case the shift conversion is carried out in two stages with a special sulfur-tolerant shift catalyst followed by removal of hydrogen sulfide and carbon dioxide in an acid gas removal unit. Because of the potential danger of a sulfur break-through causing poisoning, the normal copper - zinc - alumina catalyst is usually not applied, which is surprising as the same risk exists in partial oxidation based methanol plants for the similarly composed methanol catalyst. 

In this study, the fouling characteristics of copper exchanged hydrogen mordenile (CuHM) for NOx rtxluction by NHj is examined to understand the effect of sulfur on the catalytic activity. This paper deals with sulfur tolerance of CullM catalyst for NO... 

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