Hydrogen sulfide catalytic decomposition

Decomposition of hydrogen sulfide. Mo 2 catalytic pellets packed on the shell side of the reactor. 

Thiochromans and thiochroman 1,1-dioxides are readily prepared from the corresponding thiochroman-4-one by catalytic hydrogenation in acetic acid/perchloric acid or via the Wolff-Kishner and Clemensen methods. Thermal decomposition of 21 produced thiochroman in 85% yield. Thiochroman and isothiochroman occur in petroleum, and the completely saturated analog of the former (1-thiadecalin) was obtained from propenyl 1-cyclohexenyl ketones in the presence of hydrogen sulfide and sodium acetate in ethanol. 

In this configuration, the membrane is selective to some reactants or products and the catalyst may be placed on the membrane surface or near the pore entrance such as catalytic electrodes attached to solid electrolytes or a platinum layer on the surface of a vanadium membrane as the catalyst for thermal decomposition of hydrogen sulfide [Edlund and Pledger, 1993]. Solid or liquid catalysts have been attached to membranes or their pores. It has been mentioned previously that this configuration can also be used to control the addition of a reactant through the membrane pores from the other side of the membrane where the second reactant is introduced. 

A combination of controlled atmosphere electron microscopy and flow reactor techniques have been used to investigate the influence of hydrogen sulfide on the catalytic activity of cobalt. Changes in the behavior of cobalt were monitored by the use of probe reactions which are sensitive to the chemical nature of the catalyst surface. These included graphite gasification in oxygen and hydrogen, and carbon deposition from decomposition of hydrocarbons. 

Fukuda K, Doklya M, Kameyama T, Kotera Y (1978) Catalytic decomposition of hydrogen sulfide. Ind Eng Chem Fundam 17 4... 

Kaloidas VE, Papayarmakos NG (1991) Kinetic studies on the catalytic decomposition of hydrogen sulfide in a tubular reactor. Ind Eng Chem Res 3(X2) 345... 

Hydrogen sulfide has potentially high economic value if both sulfur and hydrogen can be recovered. Due to thermodynamic constraints, thermal catalytic decomposition is a good candidate for membrane reactor application. Silica membranes appear more suitable than noble metal membranes which are affected by chemical attack by hydrogen sulfide. ... 

Catalytic desulfurization of straight-run naphthas with bauxite or fuller s earth was once widely used, and the comparison of octane numbers of Table 10-1 is based on such processes. Vaporized gasoline was passed through the catalyst at about 750 F, and the hydrogen sulfide produced from the decomposition of mercaptans, sulfide, and disulfides was frac tionated or washed from the product. 

Intermediate 37 can be transformed into ( )-thienamycin [( )-1)] through a sequence of reactions nearly identical to that presented in Scheme 3 (see 22— 1). Thus, exposure of /(-keto ester 37 to tosyl azide and triethylamine results in the facile formation of pure, crystalline diazo keto ester 4 in 65 % yield from 36 (see Scheme 5). Rhodium(n) acetate catalyzed decomposition of 4, followed by intramolecular insertion of the resultant carbene 3 into the proximal N-H bond, affords [3.2.0] bicyclic keto ester 2. Without purification, 2 is converted into enol phosphate 42 and thence into vinyl sulfide 23 (76% yield from 4).18 Finally, catalytic hydrogenation of 23 proceeds smoothly (90%) to afford ( )-thienamycin... 

Although the exchange of the hydroxyl hydrogen in methanol with deuterium in various deuterium compounds such as deuterium oxide and deuterium sulfide has been reported 1-3) and the preparation of methanol-d (CH3OD) by the saponification of esters and decomposition of Grignard reagent with deuterium oxide has been described 4 6), the catalytic exchange of deuterium gas with methanol over Adams platinum catalyst has not been previously studied. 

---