Catalyst nickel/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... 

N ickel-chromium-molybdenum (tungsten) alloys Nickel—molybdenum alloys Nickel-molybdenum catalysts Pb Mo6S8... 

A favorable combination of valence forces of both components seems to be the basic principle of the nickel-molybdenum ammonia catalyst. It has been found (50) that an effective catalyst of this type requires the presence of two solid phases consisting of molybdenum and nickel on the one hand and an excess of metallic molybdenum on the other. Similar conditions prevail for molybdenum-cobalt and for molybdenum-iron catalysts their effectiveness depends on an excess of free metal, molybdenum for the molybdenum-cobalt combination and iron for the molybdenum-iron combination, beyond the amounts of the two components which combine with each other. A simple explanation for the working mechanism of such catalysts is that at the boundary lines between the two phases, an activation takes place. In the case of the nickel-molybdenum catalyst, the nickel-molybdenum phase will probably act preferentially on the hydrogen and the molybdenum phase on the nitrogen. 

SELECTIVE HYDROGENaT IDA Or CITAhL IN THE LIQUID PHASE OVER UNSUPPORTED NICKEL-MOLYBDENUM CATALYSTS Ni rto. ... 

LDG segregation of catalyst by vanadium level has been studied extensively. A test performed on a nickel-molybdenum catalyst is summarized in Table 4. In this test case the vanadium level on the lightest fraction was less that a third of that on the heaviest fraction. Surface area and compacted bulk density correlated with the level of vanadium contamination. Most importantly, it was shown... 

Relative Volume HDS Activity As Compared to the Fresh Nickel/ Molybdenum Catalyst. 

Feedstock Purification. In feedstock purification, mainly desulfurization, adsorption on active carbon was replaced by catalytic hydrogenation over cobalt-molybdenum or nickel-molybdenum catalyst, followed by absorption of the H2S on ZnO pellets with formation of ZnS. By itself this measure has no direct influence on the energy consumption but is a prerequisite for other energy saving measures, especially in reforming and shift conversion. 

A cyclone outside the moving-bed catalytic colnmn serves to sort only catalyst particles of a desired size among the catalyst particles dropped to the lower portion. A nickel-molybdenum catalyst regenerator with an air injector serves to regenerate the catalyst transferred from the cyclone and the regenerated catalyst is then returned to the moving-bed catalytic cracker [29],... 

The effectiveness of catalysts A and B to desulfurize SRN and blend naphtha was investigated and the results are shown in Table 4. Figure 4, which shows the performance of catalyst A, illustrates that it is easier to desulfurize SRN than blend naphtha. The results also confirmed higher HDS performance with blend naphtha than SRN with both catalysts. This could be due to the refractive material in the hydrocracked fraction of the blend naphtha. With blend naphtha and catalyst A the minimum total sulfur ofO.69 ppm was obtained at 320°C, while with SRN the minimum was 0.37 ppm at 300°C. Above these temperatures, the occurrence of H2S-alkene recombination reactions increased the total sulfur. Nickel-molybdenum catalysts are known to reduce recombination reactions by hydrogenating alkenes. Higher temperatures and very active catalysts can cause cracking at the reactor outlet allowing alkenes production[13],... 

The Role of Promoter Atoms in Cobalt-Molybdenum and Nickel-Molybdenum Catalysts... 

Selective oxidation of propane into oxygenated compounds over promoted nickel-molybdenum catalysts... 

Nickel - molybdenum catalysts were prepared by coprecipitation to obtain a significant surface area ( 5-50 mV )- The preparation procedure was an optimisation of the procedure proposed by Mazzocchia [3,4] and Schrader [5], (3NiMo04 was obtained after a thermal treatment of a phase at 700°C in oxygen for 1 h. Nevertheless this P transition was reversible and occurred below 300°C [3], In order to compare all the (Ni-Mo) samples, we used a molar ratio RA = a M0O3 / (a M0O3 + a NiMo04)... 

All the XRD analysis of nickel-molybdenum catalysts with 0chemical analysis and the specific surface areas (BET) are also given. 

Relative Rates of Disappearance of Nonthiophenic Sulfur-Containing Aromatic Compounds over Nickel-Molybdenum Catalyst at 340°C and 70 Atm... 

FIGURE 8.18 Reactivities for the HDN of selected basic nitrogen heterocyclic compounds at 376°C and 136 atm over sulfided nickel-molybdenum catalyst. 

Quantitative microanalysis performed by STEM/EDX showed that the two metals are evenly distributed over graphite leaflets. Graphite as support does not modify the selectivities of the catalysts we prepared nickel chromium catalysts have to be chosen in order to obtain citronellal whereas nickel molybdenum catalysts have to be preferred for the production of citronellol. 

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