Sulfur load design

Some sulfur dioxide concentrating systems can be designed to accept gases with fluctuating volumes and sulfur loadings. The sulfur dioxide is either physically or chemically bound in a solid or liquid medium in... 

According to the Eq. (32), the rate of conversion of H2S is influenced by the partial pressures of H2S, H2O, SO2, O2, the mass of the sulfur loaded on the catalyst and the reaction temperature. This equation can be used in designing a commercial fixed-bed reactor for one stage oxidation of hydrogen sulfide. 

The unit was designed for a nitrogen flow rate of 200 scfm at 20 psig with an H2S concentration in the sour gas of 4,(X)0 ppmv. However, after being put into service, the H2S concentration of the nitrogen stream increased to between 10,000 and 20,000 ppmv. After some design modifications, the unit has operated satisfactorily at the new sulfur loading and removes over 40 tons of sulfur annually. 

Sulfur Compounds. Various gas streams are treated by molecular sieves to remove sulfur contaminants. In the desulfurization of wellhead natural gas, the unit is designed to remove sulfur compounds selectively, but not carbon dioxide, which would occur in Hquid scmbbing processes. Molecular sieve treatment offers advantages over Hquid scmbbing processes in reduced equipment size because the acid gas load is smaller in production economics because there is no gas shrinkage (leaving CO2 in the residue gas) and in the fact that the gas is also fliUy dehydrated, alleviating the need for downstream dehydration. 

Reductive alkylation is an efficient method to synthesize secondary amines from primary amines. The aim of this study is to optimize sulfur-promoted platinum catalysts for the reductive alkylation of p-aminodiphenylamine (ADPA) with methyl isobutyl ketone (MIBK) to improve the productivity of N-(l,3-dimethylbutyl)-N-phenyl-p-phenylenediamine (6-PPD). In this study, we focus on Pt loading, the amount of sulfur, and the pH as the variables. The reaction was conducted in the liquid phase under kinetically limited conditions in a continuously stirred tank reactor at a constant hydrogen pressure. Use of the two-factorial design minimized the number of experiments needed to arrive at the optimal solution. The activity and selectivity of the reaction was followed using the hydrogen-uptake and chromatographic analysis of products. The most optimal catalyst was identified to be l%Pt-0.1%S/C prepared at a pH of 6. 

The stability and permeability of a mix are not sufficient criteria to reflect how a material will perform under the repeated loads generated by traffic. Therefore, any mix design selection process should include an examination of the material s fatigue resistance. Figure 5 shows the relationship between sulfur content and fatigue life for some SAS mixtures at two strain levels [15]. These tests were run at constant stress in third point flexure. Both curves go through a maximum at a sulfur content of 14 percent. 

Scavenger processes are used only for trace sulfur removal and are in many cases not suitable for in-situ regeneration. They are typically designed with two or more vessels operating in a lead/lag mode. When the scavenger material reaches the end if its useful life, it must be removed from the vessel and anew charge loaded in. 

Another variation being demonstrated is the combustion of RDF in a dedicated boiler as a principal fuel. Normally the boiler is of spreader-stoker design with some consideration given to the use of fossil fuels such as high sulfur coal as a load leveler and steam production stabilizer. 

When tested in the four-ball machine, solutions of sulfur in petroleum oils of moderate viscosity or in white oil raise the critical load for the onset of severe, destructive wear, which is designated as "antiseizure" action in the technological idiom of the four-ball test. Davey [54] found a significant increase in the critical initial seizure load from 834 N (85 kg) for a petroleum base oil to 1275 N (130 kg) for elemental sulfur dissolved in the oil. Sakurai and Sato [55] observed a 3.2-fold increase in the load-wear index (mean Hertz load) for a 0.5 weight-percent solution of elemental sulfur relative to that of the uncompounded white oil. The load-wear index is a specialized result of the four-ball test that can be taken as indicative of the average antiseizure behavior of the lubricant. Mould, Silver and Syrett [56] reported a load-wear index ratio of 3.08 for 0.48% sulfur in white oil relative to that of the solvent oil, and also an increase in the initial seizure load from 441 N to 637 N (45 kg to 65 kg) and in the 2.5-second seizure-delay load from 490 N to 833 N (50 kg to 90 kg). 

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