Hydrogen sulfide, partial pressure and

The effect on catalyst activity of process variables such as LHSV, temperature, hydrogen partial pressure, hydrogen sulfide partial pressure and gas/oil ratio can be predicted by a suitable kinetic expression. It was found that the expression shown in equation 1 could be used to describe the kinetics of CoMo and NiMo catalysts for very deep desulfurization of diesel. ... 

Ferrari, M. Maggi, R. Delmon, B. Grange, P. (2001). Influences of the hydrogen sulfide partial pressure and of a nitrogen compound on the hydrodeoxygenation activity of a CoMo/carbon catalyst. /, Catal, 198,47-55, ISSN 00021-9517. 

Solutions of hydrogen sulfide, because of hydrogen-induced cracking. Grades of steel are available for certain ranges of pH and hydrogen sulfide partial pressure. 

Va in. (3 mm) for TEMA Class R,3) exchangers and sour water piping with hydrogen sulfide partial pressures less than 10 psi (0.07 MPa) ... 

Maximum corrosion allowance. Primarily used for wet carbon dioxide equipment when the carbon dioxide partial pressure is less than 4 psf (30 kPa) and for sour water equipment when the hydrogen sulfide partial pressure exceeds 10 psi (70 kPa)... 

Pure component studies indicate the rate of mercaptan formation is sufficiently rapid at hydrotreating conditions compared to the saturation step which lead to alkane [8]. The exothermic reversible reaction, which shifts to the left at higher hydrogen sulfide partial pressure, is also dependent on temperature, feedstock type, total sulfiir, partial pressure of hydrogen and alkenes, space velocity and catalyst type. Furthermore the size of the reactor affect the balance between the kinetic sulfur removal and alkene saturation [9]. 

The hydrogen flux produced by exposure to aqueous hydrogen sulfide containing environments can be categorized based on the hydrogen sulfide partial pressure. The effect of solution pH produced by the combined effect of certain soluble corrosive gases (i.e., hydrogen sulfide and carbon dioxide) is also important. 

Because of the wide spectrum of potentially severe environments for SCC of CRA, rank ordering of alloy susceptibility has become one of comparing SCC resistance under fixed stress conditions as a function of environmental variables such as temperature, hydrogen sulfide partial pressure, pH, chloride concentration, and the presence or absence of free sulfur. Selection of a CRA for a specific use requires finding SCC-resistant materials whose environmental limits, as defined by this matrix of environmental data, are beyond the expected environmental limits of the specific use. 

FIGURE 9.7 Hydrogen and Hydrogen sulfide partial pressures as functions of reactor length at400°C, 6.9 MPa, and LHSV = 1 h". ... 

The optimum use of hydrodesulfurization catalysts requires a relatively high hydrogen partial pressure, and it is therefore necessary to introduce with the feedstock quantities of hydrogen that are considerably greater than required on the basis of stoichiometric chemical consumption. In all cases, process economics dictate that unused hydrogen should be recycled after it has been partially (or completely) freed from hydrogen sulfide that was produced in the previous pass. 

At W/F = 0, which is equal to the initial rate (r0), the above derivative reduces to CD. The best values of C and D were obtained by a gradient search using a digital PDP-9 computer. Mezaki and Kittrell (6) have demonstrated that this expression is a convenient and relatively nondiscriminating way to extrapolate to zero conversion. The range of partial pressures (torr) of reactants used were hydrogen sulfide, 4-22, and sulfur dioxide, 2-22. 

Rate constants for hydrogen sulfide removal from moist air in the presence of methane were estimated by Meeyoo and coworkers [124] using the dependence of the reaction on the partial pressures of reactants. The partial pressure of water varied from 0.9 to 2.2%, the hydrt en sulfide partial pressure was in the range from 0.5 to 2.2 kPa and the oxygen pressure from 2 to 22 kPa. Using apparent rate law... 

Figure 11.10 PDMS permeability of CO2 upon exposure to wet mixed gas at different water partial pressures. Reprinted with permission from lournal of Membrane Science, The effect of hydrogen sulfide, carbon monoxide and water on the performance of a PDMS membrane in carbon dioxide/nitrogen separation by Colin Scholes, Sandra Kentish and...

The fluids encountered are traditionally classified as sweet or sour environments. Sweet environments are those containing no hydrogen sulfide, but large amounts of carbon dioxide can be present. Sour environments are those containing significant amounts of hydrogen sulfide (total pressure >65 PSIA, or 4 bar, and H2S partial pressure >0.05 PSIA, or 0.003 bar). 

The equilibrium solubility of hydrogen sulfide in sulfolane and in the Sulfinol-D solvent, as a function of partial pressure, is shown in Figure 14-20 (Dunn et al., 1964). For compari-... 

Calculate —rr (the rale of disappearance of thiophene) and the partial pressures of thiophene, hydrogen, hydrogen sulfide, butenes (total), and butane in the effluent. You may assume that the ideal gas laws are valid. 

SolubiHty of carbon dioxide in ethanolamines is affected by temperature, amine solution strength, and carbon dioxide partial pressure. Information on the performance of amines is available in the Hterature and from amine manufacturers. Values for the solubiHty of carbon dioxide and hydrogen sulfide mixtures in monoethanolamine and for the solubiHty of carbon dioxide in diethanolamine are given (36,37). SolubiHty of carbon dioxide in monoethanolamine is provided (38). The effects of catalysts have been studied to improve the activity of amines and provide absorption data for carbon dioxide in both mono- and diethanolamine solutions with and without sodium arsenite as a catalyst (39). Absorption kinetics over a range of contact times for carbon dioxide in monoethanolamine have also been investigated (40). 

A 1.0-L reaction vessel at 90CC contains 8.00 g of sulfun hydrogen, and hydrogen sulfide gases with partial pressures of 6.0 atm and 0.40 atm, respectively, at equilibrium ... 

Carbon Dioxide Removal. Aside from contained carbon dioxide which is removed from syngas when absorbing hydrogen sulfide, the total carbon dioxide produced in the methanation system is removed by conventional absorption in a single-stage operation in which the volume of gas to be treated is minimum and the partial pressure of the carbon dioxide is maximum. 

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