Presulfiding, partial

Pressure gap, effect on catalysis, 28 71,72 Presulfiding, partial, 31 194—196 Primary reaction products in cobalt catalysis, 32 330-333, 336-337... 

The objective of the present work is to evaluate the effect of a wide range of process or reaction variables— reaction temperature, hydrogen partial pressure, catalyst loading, and reaction time—on hydrodesulfurization and hydrogenation of filtered liquid product (coal-derived liquid) obtained from the coal dissolution stage in the presence of a commercial presulfided Co-Mo-Al catalyst. The selectivity for desulfurization over hydrogenation (Se) is used to rate the effectiveness of the above mentioned process variables. Se is defined as the fraction of sulfur removal per unit (g) of hydrogen consumed, that is,... 

Effect of Partial Presulfiding (Fixed Bed) on Activity I Selectivity Properties of Ni/Al203 and CojAI1Oi Catalysts at 500 K, 1 atma,h... 

Based on the results of Dalla Betta and co-workers, it is clear that the steady-state activity of a completely sulfur-poisoned Ni or Ru methanation catalyst is 102-104 times lower than that of the fresh catalyst. However, a typical industrial methanation process would more probably involve a catalyst only partly poisoned by sulfur. Bartholomew and co-workers (23, 113, 157) attempted to assess how sulfur poisoning of only a portion of the catalyst would affect its activity/selectivity properties in fixed-bed and fluidized-bed reactors. Data in Table XII show the effects on specific activity and product distribution of partially presulfided Co/A1203 and Ni/Al203 catalysts in a fixed bed. Catalysts were presulfided with 10 ppm H2S at 725 K, and reaction was carried out with sulfur-free feedgas. Corresponding data are listed in Table XIII for catalysts partially presulfided and then studied in a fluidized-bed reactor under the same conditions. The decrease in H2 uptake... 

SPARG A process for the C02 reforming of methane, producing carbon monoxide and hydrogen, using a partially presulfided nickel catalyst. Developed by Haldor Topsoe in the 1990s for the direct reduction of iron ore, but not commercialized. 

NaY (Katalistiksj Si/Al=2 56) was used as a starting material for preparation of NH, K, Cs exchanged samples and three series of stab.lliJed Y-zeolites. Nickel was introduced before molybdenum by ion-exchange from Wi(NO )2 solution. Molybdenum was incorporated into the zeolite by sublimation of Mo(CO) in hydrogen stream at room temperature. Sulfided and non-sulfided Mo Y and Ni-Mo-Y samples were characterized with XRD, ND sorption capacity and FTIR spectroscopy. Each sample (0.25 g. 0.5-1 mm grains) was partially decarbonylated at 425 K before the WGS reaction and next presulfided with 1 2 vo1 %)/H2 mixture at 675 K, Catalysts after pre-... 

El-Dahshan ME, Whittle DP and Stringer J, Effect of presulfidation on the oxidation behavior of Co-based alloys. Part I. Presulfidation at sulfur partial pressures above the dissociation pressure of cobalt sulfide. 

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