Catalytic Oxidation of Hydrogen Sulfide. Influence of Pore Structure and Chemical Composition of Various Porous Substances

Abstract

systems could favor the localization of tellurium either by means of interstitial or substitutional solid solution.The nature of the active sites in oxidative dehydrogenation of 1-butene to butadiene has also been discussed in terms of possible formation of Te==O groups or modification of M-0 groups previously present or even formation of Te==O M e 0 gem groups. AcknowledgmentsWe thank Professor I. Pasquon for encouragement and useful discussion and Italian Consiglio Nazionale delle Ricerche (Rome) for financial support. Literature CitedAbraham, S. C., Reddy, J. M., J. Chem. Phys., 43 (7), 2533 (1965). 413, 180 (1975).Cairati, L., Trifiro. F., Villa, P. L., Italian Patent 25 545 A 74 (July 25, 1974).Courtine, P.. Cord. P. P., Pannetier, G., Daumas, J. C., Montarnal, R., Bull. Soc. Fr., 4816 (1968).(1 966).(1 973). (1975).Received for reuieui M a r c h 16, 1976 Accepted November 14, 1976 The catalytic oxidation of H2S with O2 at 200 OC on various porous materials was investigated. The influence of the pore structure and the chemical composition of the materials on the activity and the selectivity toward the product (sulfur) was studied. It was found that in materials with an average pore diameter between 5 and 10 A the sulfur adsorption is strong. The catalytic activity per square meter of total surface area is approximately proportional to the amount of adsorbed sulfur. In this case the selectivity towardwdfur is high. In materials with larger pores sulfur adsorption is enhanced by the presence of Lewis acid sites and by a hydrophobic surface. For these materials the presence of water in the feed has an activity lowering effect. If iron oxide is present, at 200 OC, SO2 is the main product. This is the case when other group 6-8 metal ions are present. For practical use in an H2S removal process the industrial active charcoals, zeolite NaX, Ti02, and ZrOp are most suitable.

Sewage Sludge-Derived Materials as Efficient Adsorbents for Removal of Hydrogen Sulfide

“…Although the volume of small pores is still available to nitrogen molecules, it is not active in the process of hydrogen sulfide adsorption. This is probably the result of the fouling effect of sulfur or/and sulfuric acid on the catalytic properties of the adsorbents (25,30,31). Similar trends were observed for activated carbons in which even after exhaustion a significant volume of micropores was still available for nitrogen adsorption (14,(21)(22)(23).…”

Effects of addition of Mo on the sulfidation properties of Fe-based sorbents supported on fly ash during hot coal gas desulfurization

“…Fly ash may also pose high reactivity to the sorbents because of its well developed pore structure and greater specific surface area [10,11]. Steijins and Mars [12] studied the influence of pore structure of different substances on their desulfurization performance and found that micropore less than 0.5-1 nm had the highest catalytic activity. In our previous studies [13,14], iron oxides based sorbent supported on fly ash have shown comparably good performance during hot coal gas desulfurization.…”

H2S Adsorption/Oxidation on Materials Obtained Using Sulfuric Acid Activation of Sewage Sludge-Derived Fertilizer

“…Following the arguments presented above, more sulfur is likely adsorbed in the very small pores of this material, and this process is enhanced by changes in the composition of the solid during heat treatment between 800 and 950 • C. Since elemental sulfur is the predominant product of hydrogen sulfide oxidation on activated carbons (17,25,(28)(29)(30)(31) its presence on SCS-950E can be linked to a relatively high content of a highly carbonized (after treatment at 950…”