Catalyst nickel/molybdenum/alumina

The promoting action of cobalt on the activity for hydrodesulfurization has been shown already in the pioneering work of Byrns, Bradley and Lee (14). This promoting action might be linked with the sulfiding step, since the actual catalyst is the sulfided form of cobalt- or nickel-molybdenum-alumina. Voorhoeve and Stuiver (15) and Farragher and Cossee (16) demonstrated the promoting action for the unsupported Ni-WS2 system. Their intercalation model was based on these experiments. 

Nickel Promoted Catalysts. Nickel containing catalysts are known to be sensitive for too high temperatures. The Dutch patent 123195 (17) claims that active nickel-molybdenum-alumina catalysts are obtained, when nickel is impregnated first. The calcination is critical however. According to this patent, catalysts calcined at 480 are twice as active as catalysts, calcined at 650°C. 

The reappearance of Brdnsted acid sites has been observed for the high calcined nickel-molybdenum-alumina catalysts. The presence of a nickel aluminate phase has been concluded from the reflectance spectra. The second Lewis band (1612 cm l) has a very low intensity, in comparison with the cobalt containing catalysts of a same composition and after the same calcination conditions. 

The catalyst was 100 ml of American Cyanamid HDS-3A, a 1/16-inch diameter extrudate of nickel-molybdenum-alumina. It was diluted with inert, granular alpha-alumina to provide a bed depth of 18 inches in the middle section of a 0.96-inch ID vertical reactor with a 5/16-inch OD internal thermocouple well. The catalyst was progressively more dilute toward the top of the bed to minimize exothermic temperature effects, and end sections were packed with alpha-alumina to provide for preheat and cooling zones. 

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. 

J.F. Kriz, J. Monnier, and M. Ternan, Nickel - molybdenum - alumina catalysts Effects of doping with fluoride and lithium and changes in particulate size when applied to bitumen hydroproceasing, Preprints, llth Can. Symp. Catal 11 (1990) 201 210 ... 

Nickel - molybdenum - alumina catalysts doped with fluoride and/or lithium, AlChE Symp. Ser, Tar Sand and Oil Upgrading, (eds S S. Shih and c.M- Oballa) (submitted for publication). 

Natural gas contains both organic and inorganic sulfur compounds that must be removed to protect both the reforming and downstream methanol synthesis catalysts. Hydrodesulfurization across a cobalt or nickel molybdenum—zinc oxide fixed-bed sequence is the basis for an effective purification system. For high levels of sulfur, bulk removal in a Hquid absorption—stripping system followed by fixed-bed residual clean-up is more practical (see Sulfur REMOVAL AND RECOVERY). Chlorides and mercury may also be found in natural gas, particularly from offshore reservoirs. These poisons can be removed by activated alumina or carbon beds. 

The catalyst for the second stage is also a bifimctional catalyst containing hydrogenating and acidic components. Metals such as nickel, molybdenum, tungsten, or palladium are used in various combinations and dispersed on sofid acidic supports such as synthetic amorphous or crystalline sihca—alumina, eg, zeofites. These supports contain strongly acidic sites and sometimes are enhanced by the incorporation of a small amount of fluorine. 

The predominant process for manufacture of aniline is the catalytic reduction of nitroben2ene [98-95-3] ixh. hydrogen. The reduction is carried out in the vapor phase (50—55) or Hquid phase (56—60). A fixed-bed reactor is commonly used for the vapor-phase process and the reactor is operated under pressure. A number of catalysts have been cited and include copper, copper on siHca, copper oxide, sulfides of nickel, molybdenum, tungsten, and palladium—vanadium on alumina or Htbium—aluminum spinels. Catalysts cited for the Hquid-phase processes include nickel, copper or cobalt supported on a suitable inert carrier, and palladium or platinum or their mixtures supported on carbon. 

In direct liquefaction, coal is heated in the presence of hydrogen and a catalyst such as cobalt-molybdenum or nickel-molybdenum on alumina to give a greater yield of high-quality hydrocarbons than that produced by pyrolysis. This hydrogenation process has been demonstrated in several 50- to 250-ton-per-day plants. 

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... 

Reflection spectra for the MoNi-153 catalysts are shown in Figure 10. The 480°C calcined catalyst shows the characteristic absorption band (25) of octahedrally coordinated nickel ions. The 650°C calcined catalyst shows the characteristic spectrum of nickel aluminate. These reflection spectra indicate that the nickel ions migrate from the catalyst surface into the alumina, as has been observed also for the cobalt-molybdenum-alumina catalysts. 

The molybdate surface layer in the molybdenum-alumina samples is characterized by the presence of BrGnsted acid sites ( 1545 cm- ) and one type of strong Lewis acid sites (1622 cm l). Cobalt or nickel ions are brought on this surface on impregnation of the promotor. The absence of BrtSnsted acid sites is observed for both cobalt and nickel impregnated catalysts, calcined at the lower temperatures (400-500°C). Also a second Lewis band is observed at 1612 cnrl.The reflection spectra of these catalysts indicate that no cobalt or nickel aluminate phase has been formed at these temperatures. This indicates that the cobalt and nickel ions are still present on the catalyst surface and neutralize the Brdnsted acid sites of the molybdate layer. These configurations will be called "cobalt molybdate" and "nickel molybdate" and are shown schematically in Figure 11a. 

In summary, fixed-bed processes have advantages in ease of scaleup and operation. The reactors operate in a downflow mode, with liquid feed trickling downward over the solid catalyst concurrent with the hydrogen gas. The usual catalyst is cobalt/molybdenum (Co/Mo) or nickel/molybdenum (Ni/Mo) on alumina (A1203) and contain 11-14% molybdenum and 2-3% of the promoter nickel or cobalt. The alumina typically has a pore volume of 0.5 ml/g. The catalyst is formed into pellets by extrusion, in shapes such as cylinders (ca. 2 mm diameter), lobed cylinders, or rings. 

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. 

There have been a considerable number of papers reporting the properties of sulphur-resistant methanation catalysts, i.e., catalysts which can operate successfully in significant partial pressures of H2S. Most of these report work using catalysts containing vanadium, molybdenum, and such metals. However, attempts have been made to find nickel-based catalysts containing suitable additives to allow them to operate in such atmospheres. For example, Bartholomew and Uken115 have compared the deactivation behaviour of a range of nickel catalysts in 10 p.p.m. H2S. They found that nickel boride catalysts and Raney nickel materials deactivated more slowly than did unsupported nickel and alumina-supported nickel. They attributed this improvement to two factors ... 

Catalysts help customers comply cost-effectively with clean-air regulations. Hydrocarbons, carbon monoxide, and nitrogen oxides can be removed using supported precious metal catalysts. Organic sulfur compounds are converted to H2S using nickel/molybdenum or cobalt/molyb-denum on alumina catalysts. Sulfur can be recovered in a Claus process unit. The Claus catalytic converter is the heart of a sulfur recovery plant. 

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. 

Catalyst Screening Results. A comparison of the catalysts performance is given in Table VIII. Shell 214, (nickel-molybdenum (Ni-Mo)) on alumina, is the best among the five types of catalysts tested with Shell 244, Co-Mo on alumina being nearly as good. It achieved high removal of heteroatoms with the least hydrogen consumption. The... 

A nickel-molybdenum on alumina catalyst in the form of 4-in. spheres is... 

Hydrotreating catalysts are usually alumina supported molybdenum based catalysts with cobalt or nickel promotors. By 1990, the demand for hydrotreating catalysts is expected to reach 80,000,000 pounds annually (1). The increased demand for these catalysts and the limitations on the availability and supply of the active metals increase the urgency to develop effective catalyst regeneration techniques. 

The usual catalysts are based on cobalt, nickel, molybdenum and tungsten sulfides, generally combined and deposited on alumina. The most widely used formula is a composite sulfide of molybdenum and colbalt oo alumina. Run length and catalyst life are longer than those of tbe catalytic systems employed in brst step hydrogenation, Le. 6 to 12 months and 3 to 5 years, and the regeneration method is identical... 

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