Cobalt molybdenum

Thiophene [110-02-17, C H S, and dibenzothiophene [132-65-OJ C22HgS, are models for the organic sulfur compounds found in coal, as well as in petroleum and oil shale. Cobalt—molybdenum and nickel—molybdenum catalysts ate used to promote the removal of organic sulfur (see Coal CONVERSION... 

The conversion of CO to CO2 can be conducted in two different ways. In the first, gases leaving the gas scmbber are heated to 260°C and passed over a cobalt—molybdenum catalyst. These catalysts typically contain 3—4% cobalt(II) oxide [1307-96-6] CoO 13—15% molybdenum oxide [1313-27-5] MoO and 76—80% alumina, JSifDy and are offered as 3-mm extmsions, SV about 1000 h . On these catalysts any COS and CS2 are converted to H2S. Operating temperatures are 260—450°C. The gases leaving this shift converter are then scmbbed with a solvent as in the desulfurization step. After the first removal of the acid gases, a second shift step reduces the CO content in the gas to 0.25—0.4%, on a dry gas basis. The catalyst for this step is usually Cu—Zn, which may be protected by a layer of ZnO. 

Metals can be precipitated from the Hquid or gas phase. For example, nickel ammonium carbonate gives nickel powder when subjected to hydrogen in an autoclave. Copper, cobalt, molybdenum, and titanium powders can also be formed by precipitation. 

In addition, molybdenum has high resistance to a number of alloys of these metals and also to copper, gold, and silver. Among the molten metals that severely attack molybdenum are tin (at 1000°C), aluminum, nickel, iron, and cobalt. Molybdenum has moderately good resistance to molten zinc, but a molybdenum—30% tungsten alloy is practically completely resistant to molten zinc at temperatures up to 800°C. Molybdenum metal is substantially resistant to many types of molten glass and to most nonferrous slags. It is also resistant to hquid sulfur up to 440°C. 

The head of the femoral component then articulates with an ion-bombarded, HDPE, high walled, acetabular liner which fits iato a screwed ia, machined, titanium, chromium—cobalt—molybdenum or vanadium—aluminum metallic alloy hydroxyapatite-coated acetabular shell/cup. Each of the separate parts of the modular system for total hip arthroplasty is manufactured ia several different sizes. 

The first iron—nickel martensitic alloys contained ca 0.01% carbon, 20 or 25% nickel, and 1.5—2.5% aluminum and titanium. Later an 18% nickel steel containing cobalt, molybdenum, and titanium was developed, and still more recentiy a senes of 12% nickel steels containing chromium and molybdenum came on the market. 

By adjusting the content of cobalt, molybdenum, and titanium, the 18% nickel steel can attain yield strengths of 1380—2070 MPa (200,000—300,000 psi) after the aging treatment. Similarly, yield strengths of 12% nickel steel in the range of 1035—1380 MPa (150,000—200,000 psi) can be developed by adjusting its composition. 

Cobalt—molybdenum alloys are used for the desulfurization of high sulfur bituminous coal, and cobalt—iron alloys in the hydrocracking of cmde oil shale (qv) and in coalhquefaction (6). 

Ammonia production from natural gas includes the following processes desulfurization of the feedstock primary and secondary reforming carbon monoxide shift conversion and removal of carbon dioxide, which can be used for urea manufacture methanation and ammonia synthesis. Catalysts used in the process may include cobalt, molybdenum, nickel, iron oxide/chromium oxide, copper oxide/zinc oxide, and iron. 

The virgin naphtha feed after having been hydrofined over a cobalt molybdenum catalyst to remove sulftir compounds passes through the Powerformer. After stabilization, the aromatics are recovered by extracdon with... 

Catalysts used in hydrotreatment (hydrodesulfurization, HDS) processes are the same as those developed in Germany for coal hydrogenation during World War II. The catalysts should be sulfur-resistant. The cobalt-molybdenum system supported on alumina was found to be an effective catalyst. 

Trickle-bed operation is the oldest and the most commonly used its development is described in a recent publication (VI). Cobalt-molybdenum catalysts may be used at a temperature of 360°C and a pressure of 57 atm for the hydrogenation of straight-run gas oils. 

Gas-liquid fluidization is employed in the H-Oil process developed in the United States (H6). Cobalt-molybdenum catalyst particles of -in. diameter may be used at a reaction pressure of 100 atm or more and a temperature of about 400°C (V4). 

The compounds of the t/block elements show a wide range of interesting properties. Some are vital to life. Iron is an essential component of mammalian blood. Compounds of cobalt, molybdenum, and zinc are found in vitamins and essential enzymes. Other compounds simply make life more interesting and colorful. The beautiful color of cobalt blue glass, the brilliant greens and blues of kiln-baked pottery, and many pigments used by artists make use of d-block compounds. 

Iron, nickel, cobalt, molybdenum, and tungsten powders produced by the pyrolysis of the respective metal carbonyl (see Ch. 3).P 1... 

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. 

Systematic assessment of alumina-supported cobalt-molybdenum nitride catalyst Relationship between nitriding conditions, innate properties and CO hydrogenation activity... 

Computerized IR Studies of Cobalt-Molybdenum-Aluminum Oxide HydrodesuUurization Catalysts... 

Delmon, B. "Recent Approaches To The Anatomy and Physiology of Cobalt Molybdenum Hydrodesulfurization Catalysts" in preprints of Third International Conference on the Chemistry and Uses of Molybdenum, Univ. of Michigan, Ann Arbor, 1979 (Climax Molybdenum Company). 

Minaev, V. Z. Zaidman, N. M. Spirina, G. A., et al., Effect of Pore Structure of Alumina-Cobalt-Molybdenum Catalyst on Activity and Stability in Hydrodesulfurization of Heavy Feedstocks. Chemistry and Technology of Fuels and Oils, 1975. 11(6) pp. 436-39. 

Chonglun F., Piron D.L., Paradis R, Hydrogen evolution on electrodeposited nickel-cobalt-molybdenum in alkaline water electrolysis, Electrochim. Acta, 39(18), 2715-2722,1994. 

Autofining A fixed-bed catalytic process for removing sulfur compounds from petroleum distillates. This process uses a conventional cobalt/molybdenum hydrodesulfurization catalyst but does not require additional hydrogen. Developed by The Anglo-Iranian Oil Company in 1948. 

BASF/Scholven A pretreatment process for benzole, the product formed by hydrogenating hard coal. The benzole is hydrogenated at 300 to 400°C using a molybdenum or cobalt/molybdenum catalyst. The product is a mixture of aromatic hydrocarbons, suitable for separation by a variety of physical processes. The process was invented by BASF in 1925 and adopted by Scholven-Chemie in 1950. Eleven plants in France and Germany subsequently adopted the process. 

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