Nickel-tungsten catalysts

The isooctane feed was pulsed at frequencies of from 0.001 to 0.5 Hz at a pulse duration of 2 ms corresponding to a gaseous isooctane feed of 4.2 cm per pulse. At the maximum pulse frequency of 0.5 Hz, 480cm min isooctane were therefore fed to the reactor along with a nitrogen flow at 200 cm min. The S/C ratio was set to 1 and the O/C ratio to 0.64, corresponding to autothermal conditions. Up to 98% conversion could be achieved over a rhodium/ceria catalyst. Nickel/tungsten and... 

Hy-C Cracking A hydrocracking process. The catalyst is nickel/tungsten on alumina. Developed by Cities Service Research and Development Company and Hydrocarbon Research. 

Alloying the nickel of the anode to improve tolerance for fuel contaminants has been explored. Gold and copper alloying decreases the catalytic activity for carbon deposition, while dispersing the anode with a heavy transition metal catalyst like tungsten improves sulfur resistance. Furthermore, ceria cermets seem to have a higher sulfur tolerance than Ni-YSZ cermets [75],... 

Hydrotreating also produces some residuals in the form of spent catalyst fines, usually consisting of aluminum silicate and some metals (e.g., cobalt, molybdenum, nickel, tungsten). Spent hydrotreating catalyst is now listed as a hazardous waste (K171) (except for most support material). Hazardous constituents of this waste include benzene and arsenia (arsenic oxide, AS2O3). The support material for these catalysts is usually an inert ceramic (e.g., alumina, AI2O3). 

In addition to the successful reductive carbonylation systems utilizing the rhodium or palladium catalysts described above, a nonnoble metal system has been developed (27). When methyl acetate or dimethyl ether was treated with carbon monoxide and hydrogen in the presence of an iodide compound, a trivalent phosphorous or nitrogen promoter, and a nickel-molybdenum or nickel-tungsten catalyst, EDA was formed. The catalytst is generated in the reaction mixture by addition of appropriate metallic complexes, such as 5 1 combination of bis(triphenylphosphine)-nickel dicarbonyl to molybdenum carbonyl. These same catalyst systems have proven effective as a rhodium replacement in methyl acetate carbonylations (28). Though the rates of EDA formation are slower than with the noble metals, the major advantage is the relative inexpense of catalytic materials. Chemistry virtually identical to noble-metal catalysis probably occurs since reaction profiles are very similar by products include acetic anhydride, acetaldehyde, and methane, with ethanol in trace quantities. 

Equation (305) describes the ammonia synthesis rate not only on iron catalysts, but also over molybdenum catalyst (105), tungsten (106), cobalt (95), nickel (96), and other metals (107). Equation (300) describes ammonia decomposition on various metals (provided that there is enough H2 in the gas phase). 

Hydrogenation tests made on the 600°-1000°F heavy gas oil from in situ crude shale oil showed that a nickel-molybdenum-on-ahimina catalyst was superior to either cobalt-molybdenum-on-alumina or nickel-tungsten-on-alumina catalysts for removing nitrpgen from shale oil fractions. This nickel-molybdenum-on-alumina catalyst was used in the preparation of the synthetic crude oil. A high yield of premium refinery feedstock whose properties compared favorably with those of a syncrude described by the NPC was attained by hydrogenating the naphtha, light... 

Two Chevron catalysts were evaluated ICR 106 (containing nickel, tungsten, silica, and alumina) and ICR 113 (containing nickel, molybdenum, silica, and alumina) Although ICR 113 is somewhat less active than ICR 106, it is also a less expensive catalyst and, therefore, may be the catalyst of choice for cases in which lower severities of hydrogenation are needed. 

Two proprietary Chevron catalysts were used in different pilot plant simulations of the syncrude hydrotreater ICR 106 and ICR 113. The ICR 106 catalyst contains nickel, tungsten, silica, and alumina and the ICR 113 catalyst contains nickel, molybdenum, silica, and alumina. An equal volume of inert, nonporous alumina was placed on top of the catalysts. This alumina served as a preheating zone. These catalysts operated satisfactorily for over one-half year (4000 hours) with the Illinois H-Coal syncrude. 

Authentic and synthetic solvent-refined coal filtrates were processed upflow in hydrogen over three different commercially available catalysts. Residual (>850°F bp) solvent-refined coal versions up to 46 wt % were observed under typical hydrotreating conditions on authentic filtrate over a cobalt-molybdenum (Co-Mo) catalyst. A synthetic filtrate comprised of creosote oil containing 52 wt % Tacoma solvent-refined coals was used for evaluating nickel-molybdenum and nickel-tungsten catalysts. Nickel-molybdenum on alumina catalyst converted more 850°F- - solvent-refined coals, consumed less hydrogen, and produced a better product distribution than nickel-tungsten on silica alumina. Net solvent make was observed from both catalysts on synthetic filtrate whereas a solvent loss was observed when authentic filtrate was hydroprocessed. Products were characterized by a number of analytical methods. 

Catalyst Evaluation. Commercial nickel-molybdenum (Ni-Mo) and nickel-tungsten (Ni-W) catalysts were evaluated with this feedstock. The Ni-Mo catalyst was HDS-3A from American Cyanamid and the Ni-W catalyst was Ketjenfine HC-5 from Armak Company. Both were extrudate types supported on alumina and silica-alumina, respectively. The run conditions for the Ni-W evaluation run are shown in Table VII for selected samples. Pressure, liquid feed rate, and hydrogen feed rates were held as nearly constant as possible only the temperature was changed. 

Hydrotreating of the pyrolyzer stripper bottoms was carried out over a commercial nickel-tungsten on silica-alumina hydrotreating catalyst at 300°C, a liquid hourly space velocity of 1.5 h 13.4 MPa total pressure, and 880 standard cubic meters once-through H2 per cubic meter of feed. At these conditions, cracking of the feed was minimal. 

Various industrial processes have been developed to convert heavy crude oils into transport fuels [3,4], Most of those in use are based on residual cracking or on hydroprocessing over cobalt-molybdenum, nickel-molybdenum or nickel-tungsten based catalysts [3], Given the nature of the feed and the severity of the processing, it is not surprising that catalyst deactivation is a major problem. 

For the three model aromatic compounds—benzene, naphthalene, and anthracene7—naphthalene underwent hydrotreatment over sulfided nickel/tungsten catalyst at 340°C/70 bar H2 to the corresponding monoaromatic (tetralin) an order of magnitude faster than benzene saturates to cyclohexane (Table 8.3). 

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