Hydrolysis of carbonyl sulfide

S. Elliot, E. Lu, F.S. Rowland (1989). Rates and mechanisms for hydrolysis of carbonyl sulfide in natural waters. Environ. Sci. Technol., 23,458-461. 

Carbonyl sulfide is hydrolyzed almost quantitatively to hydrogen sulfide and carbon dioxide and better than 99% removal can be achieved. Carbon disulfide is hydrolyzed in two steps— first to carbonyl sulfide and hydrogen sulfide, followed by hydrolysis of the carbonyl sulfide to hydrogen sulfide and carbon dioxide. The two-step reaction is slower than the simple hydrolysis of carbonyl sulfide with the result that only about 75 to 85% carbon disulfide removal is obtained under normal operating conditions. 

Huisman, H. M., 1994, The Hydrolysis of Carbonyl Sulfide, Carbon Disulfide and Hydrogen Cyanide on Titania Catalysts, Ph.D. Dissertation, Univ. of Utrecht, The Netherlands, October. 

As can be seen, the reaction in equation 13-9 is the same as that in equation 13-6, which represents the hydrolysis of carbonyl sulfide. The first reaction, equation 13-9, was studied within the temperature range of 350° to 600°C (662° to 1,112 F) and the second reaction, equation 13-10, at 700° to 900°C (1,292° to 1,652°F). The experimental data were extrapolated over the range of 20° to 1,000°C (68° to 1,832°F) by conventional thermodynamic calculations. The equilibrium constants thus obtained for the reactions in equations 13-5 and 13-6 and the opposite of the reaction in equation 13-10 are shown in Table 13-11. 

Equilibrium Constants for the Hydrolysis of Carbonyl Sulfide and Carbon Disulfide... 

Zhang, Y. Xiao, Z. Ma, J. Hydrolysis of carbonyl sulfide over rare earth oxysuUides. Appl. Catal. B Environ. 2004, 48, 57-63. 

Alternative means for removal of carbonyl sulfide for gas streams iavolve hydrogenation. For example, the Beavon process for removal of sulfur compounds remaining ia Claus unit tail gases iavolves hydrolysis and hydrogenation over cobalt molybdate catalyst resulting ia the conversion of carbonyl sulfide, carbon disulfide, and other sulfur compounds to hydrogen sulfide (25). 

The hydrogen sulfides (H2S, SH-, S2 and their metal complexes) are well known in restricted reducing regions of the world ocean such as anoxic basins (1), but they have traditionally been dismissed as unimportant for, or even nonexistent in, most oxic seawaters 12-41. Several lines of reasoning are now beginning to suggest that sulfides actually do exist in the surface ocean, and enter into a rich metal chemistiy there. Extensive measurements of carbonyl sulfide (OCS) in seawater (5.61 permit the quantification of a mixed layer source, the hydrolysis reactions f7-111... 

Hydrolysis of vinyl sulfides to carbonyl compounds. Corey and Shulman (3, 97) in 1970 fhst reported that vinyl sulfides could be hydrolyzed to ketones with mercuric chloride in aqueous acetonitrile. This method, sometimes in combination with mercuric oxide or calcium carbonate (4, 38, 39), has been widely used. However, recently, Grieco, Cohen, and collaborators have reported that mercuric chloride hydrolysis of vinyl sulfides of type (1) to aldehydes is not generally successful. They have found a very simple solution illustrated for hydrolysis of (2) to n-heptanal (4). 

Sharma, M. M., 1965, Kinetics of Reaction of Carbonyl Sulfide and Carbon Dioxide with Amines and Catalysis by Brmisted Bases of the Hydrolysis of COS, Trans. Faraday Soc., VoL61,p.681. 

Various reaction mechanisms have been proposed for the formation of carbonyl sulfide and carbon disulfide and for their subsequent hydrolysis to hydrogen sulfide and carbon dioxide (Paskall and Sames, 1992). The plant data available indicate that carbonyl sulfide is formed primarily from the reaction between elemental sulfur and carbon monoxide, which in turn are derived from hydrogen suUide and carbon oxides present during combustion of the feed gas in the Claus thermal stage. The production of carlxin disulfide in the thermal stage is usually attributed to the presence of hydrocarbons in the feed gas because carbon disulfide is produced commercially by reacting elemental sulfur with saturated hydrocarbons. The... 

Fiedorow, R. Leaute, R. Dalla Lana, 1. G. A study of the kinetics and mechanism of carbonyl sulfide hydrolysis over alumina. J. Catal. 1984, 85(2), 339-48. 

To effectively remove carbonyl sulfide from a gas stream, special alkaline scmbbiag Hquors are used. These contain sodium aluminate or sodium plumbite, or they are made of alkaUes with a hydrolysis catalyst based on Zn, Fe, Ni, or Cu. Diethanolamine, diglycolamine, or other alkanolamines (qv) mixed with water remove carbonyl sulfide from sour, ie, acid-gas-containing, gas streams (25,26) (see Carbon dioxide). 

The genus Thiobacillus, especially the species T. denitrificans catalyzed the oxidation reactions of hydrogen sulfide yielding soluble hydrosulfide compounds, elemental sulfur, and sulfuric acid. Carbonyl sulfide and carbon disulfide are converted to hydrogen sulfide by hydrolysis. Additionally, they are oxidized to SOx and sulfates via microbial action. The reported oxidation reactions of thiosulfate using nitrate as electron acceptor are ... 

These species are ubiquitous in soil (Kelly and Harrison 1989). In a recent laboratory investigation of the fate of ionic thiocyanate in six different soils, Brown and Morra (1993) concluded that microbial degradation is the primary mechanism for thiocyanate disappearance at or below 30 °C, with carbonyl sulfide proposed as a possible hydrolysis product. Loss of thiocyanate at higher temperatures (50-60 °C) did not appear to result from microbial degradation the observed decreases in thiocyanate concentrations of soil extracts with incubation time at elevated temperatures were postulated to result primarily from increased sorption or increased sorption kinetics, but abiotic catalysis of thiocyanate degradation was also noted as a possible cause. 

Adewuyi, Y.G. and Carmichael, G.R. Kinetics of hydrolysis and oxidation of carbon disulfide by hydrogen peroxide in alkaline medium and application to carbonyl sulfide, Environ. Sci. Technol, 21(2) 170-177, 1987. 

Dihydrothieno[3,4- ]thiophene (131) was prepared by two methods. In the first (Scheme 8), chloromethylation of methyl thiophene-2-carboxylate (132) forms methyl 2,3-bischloromethyl-thiophene-5-carboxylate (133) (85%) cyclization of 133 with sodium sulfide in methanol yields (66%) methyl 4,6-dihydrothieno[3,4-6]-thiophene-2-carboxylate (134). Peroxide oxidation of 134 gives 2-methoxy carbonyl-4,6-dihydrothieno[3,4-6]thiophene 5,5-dioxide (135) and hydrolysis of 134 followed by metaperiodate oxidation furnishes the sulfoxide (91). Thienothiophene (131)23 was produced by hydrolysis and decarboxylation of 134. As indicated above, the sulfoxide (91) was used for the synthesis of thieno[3,4-6]thiophene (3). 

Measured total sulfide levels confirm the major features of the hypotheses of Elliott and coworkers (8-11). in that sulfide seems to exist in remote oxic waters at concentrations approaching nanomolar, sufficient for meaningful metal interactions. The amplitude of the diurnal variation is too strong, however, for carbonyl sulfide hydrolysis to be the primary input, or for direct oxidation by O2 to be the sole sink, and alternate cycling processes are indicated. 

Dithioacetals of aldehydes are sources of carbanions and hence may be used to form new C-C bonds in reactions in which the formerly electron-deficient character of the aldehydic carbon has been reversed. The 1,3-dithianes derived from formaldehyde or a higher aldehyde may be metallated and then alkylated (Scheme 2.27). Hydrolysis of the dithioac-etal is usually carried out in the presence of a thiophilic (sulfur seeking) metal salt such as a mercury salt. The insoluble sulfides cause the equilibrium to move in favour of the parent carbonyl compound. 

Elhott S., Lu E., and Rowland F. S. (1987) Carbonyl sulfide hydrolysis as a source of hydrogen-sulfide in open ocean seawater. Geophys. Res. Lett. 14(2), 131 — 134. 

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