Sulfur nickel

The residual portion of feedstocks contains a large concentration of contaminants. The major contaminants, mostly organic in nature, include nickel, vanadium, nitrogen, and sulfur. Nickel, vanadium, and sodium are deposited quantitatively on the catalyst. This deposition poisons the catalyst permanently, accelerating production of coke and light gases. 

Dong J, Zha S, and Liu M. Study of sulfur-nickel interaction using Raman spectroscopy. In Singhal SC, Mizusaki J, editors. Proceedings of the Ninth International Symposium on Solid Oxide Fuel Cells (SOFC-IX), Pennington, NJ The Electrochemical Society, 2005 2005(07) 1284-1293. 

Wang JH and Liu M. Computational study of sulfur-nickel interactions A new S-Ni phase diagram. Electrochem Commun 2007 9 2212-2217. 

A feasibility study on the application of H-NMR petroleum product characterization to predict physicochemical properties of feeds and catalyst-feed interactions has been performed. The technique satisfactorily estimates many feed properties as well as catalyst-feed interactions to forecast products yield. There are, however, limitations that have to be understood when using the H-NMR method. The technique, in general, is not capable either to estimate the level of certain contaminants such as nitrogen, sulfur, nickel, and vanadium when evaluating feed properties or the effect of these contaminants on products yields while testing catalyst-feed interactions. 

Petroleum is a diverse mixture of hydrocarbons—chemical combinations of primarily hydrogen and carbon. Complete combustion of hydrocarbons yields the end products of carbon dioxide (C02) and water (H20). However, incomplete combustion results in a composite mixture of other products such as C02, H20, carbon monoxide (CO), and various oxygenated hydrocarbons. Since burning petroleum consumes air, nitrogen compounds are also formed. In addition, other elements are associated with hydrocarbon compounds such as sulfur, nickel, and vanadium. 

Nickel ranks twenty-fourth in elemental abundance in the earth s crust. It is found in ores, where it is combined mainly with arsenic, antimony, and sulfur. Nickel metal, a silver-white substance with high electrical and thermal conductivities, is quite resistant to corrosion and is often used for plating more active metals. Nickel is also widply used in the production of alloys such as steel. 

Samples. Table I lists the six residua studied and their sulfur, nickel, vanadium, and weight percent asphaltenes data. The Arabian Light is a vacuum (1000 + °F) residuum, while the other five are atmospheric (650 -f °F) residua. The samples were analyzed as received from the refinery distillation tower. 

Treatment of Raw Data. The method of Lagrange multipliers was used to normalize the experimental weight, sulfur, nickel, and vanadium data. A best fit of the experimental data subject to the constraints of 100% recoveries was obtained, using weighting factors determined by the analytical precision of each measurement. 

The size distributions of the sulfur- and metal-containing molecules were determined by summing the individual cut size distributions weighted by the fraction of total sulfur (or metal) in that cut. Equation 4 defines the mean size for the distribution where x is sulfur, nickel, or vanadium. 

Table IV lists the overall mean sizes and the mean sizes for the sulfur-, nickel-, and vanadium-containing molecules obtained for duplicate determinations on an Arabian Light vacuum asphaltene performed two years apart. The precision of the measurements shows the reproducibility of this technique.

Since residuum hydroprocessing involves both demetallation and desulfurization reactions, the residuum metal and sulfur-containing molecules and their sizes are important. As shown in Table V and illustrated in Figure 5 for the Arabian Light vacuum asphaltene, the sulfur, nickel, and vanadium compounds for the asphaltene from any given residuum have similar sizes ... 

The INCO, Thompson plant in Manitoba, Canada, electrolyzes 240 kg sulfide anodes in a sulfate-chloride electrolyte. The approximate composition of the electrolyte is 60 g L x Ni2+, 95 g L 1 SC>42, 35 g L 1 Na+, 60 g L 1 Cl-, and 16 g L 1 H3BO4, and the temperature is 60 °C. Nickel, cobalt, and copper dissolve from the anode, while sulfur, selenium, and the noble metals form an insoluble sludge or slime, from which they can be recovered. The anode sludge contains 95% elemental sulfur, sulfide sulfur, nickel, copper, iron, selenium, and precious metals. Nickel is deposited on to pure nickel starting sheets. The anode cycle is 15 days and the cathode cycle is 5 to 10 days. Electrolysis is carried out at a current density of 240 A m-2 giving a cell voltage of 3 to 6 V [44, 46]. 

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],... 

Inhibitor Mol. wt. Platinum catalyst Relative toxicity per g.-atom a X 10 of sulfur Nickel catalyst Relative toxicity per g.-atom a X lO" of sulfur ... 

The presence of sulfur, combined or elementary, has a great influence on the course of a reaction carried out over nickel catalysts. A reaction which either proceeds at a greater rate or more selectively over nickel catalysts in the presence of sulfur is said to be promoted and a reaction which is retarded or which proceeds less selectively is said to be poisoned. It is convenient to speak of these sulfurized nickel catalysts collectively as nickel sulfide catalysts. 

Many types of ECSCs have yet another advantage, that is, their environmental safety. The fact is that, for example, billions of lithium batteries are thrown to garbage dumps or buried in the earth and pollute the environment after their lifecycle is over. Thus, such toxic elements as lithium, fluorine, sulfur, nickel, and so on are released. As opposed to this, the widespread types of ECSCs with carbon electrodes and aqueous electrolytes are quite environment-friendly, that is, practically safe. 

Nickel, with a relative abundance in the Earth s crust of 70 mg/kg, is twice as abundant as copper, and the Earth s inner core is supposedly made of a Ni-Fe alloy (see Section 13.2). Nickel never occurs free in nature but only as an alloy with iron in certain meteorites. However, due to its chalcophile geochemical character, like copper, most nickel occurs primarily as minerals in combination with arsenic, antimony, and sulfur. Nickel is mined from two types of ore deposits primary nickel-bearing sulfide orebodies and secondary nickel-bearing laterite deposits. 

Petroleum is a mixture of hydrocarbons— chemical combinations of hydrogen and carbon. When burned completely, the hydrocarbons should yield only water (H2O) and carbon dioxide (CO2). When the burning is incomplete, carbon monoxide (CO) and various oxygenated hydrocarbons are formed. Since most burning uses air, nitrogen compounds also exist. In addition, there are other elements associated with the hydrocarbons in petroleum such as sulfur, nickel, and vanadium, just to name a few. 

In the following sections, the simulation of hydrotreating of heavy petroleum carried out at moderate reaction conditions in a bench-scale reactor is performed by means of a heterogeneous model, particularly for removing sulfur, nickel, and vanadium. The capability of prediction of the reactor model is also tested under conditions different from those used to determine the model parameters. Experimental information about the effect of temperature, space velocity, and pressure in a wide range of values is used to develop the kinetic model parameters. Particular emphasis is given on detailed explanations of how to determine all the parameters of the developed model. 

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