Carbonyl sulfide, absorption

Danckwerts PV, Sharma MM. The absorption of carbon dioxide into solutions of alkalis and amines (with some notes on hydrogen sulfide and carbonyl sulfide). The Chemical Engineer 1966 (July-Aug) 244—280. 

COMBISULF A process for removing sulfur compounds from the gases from combined-cycle power plants with integrated coal gasification. Carbonyl sulfide is removed by catalytic hydrolysis, hydrogen sulfide is removed by selective absorption in aqueous MEDA, and the sulfur is recovered from both processes by a modified Claus unit. Developed by Krupp Koppers and first operated in Spain in 1996. See PRENFLO. 

The carbonyl sulfide calculations were not as straightforward as the 2D nitrous oxide work. One issue is that the transition involves three transition dipoles to various states, whereas in nitrous oxide the absorption is dominated by a single transition. The calculation for OCS only considered a single transition. In addition the quality of the potential energy surfaces was not as high, and the 2D approximation not as good, for OCS relative to NNO. An illustration of this is that the predicted OCS spectrum has a maximum at 214 nm while the experimental spectrum has a maximum at 223 nm. In comparison the difference in peak location for NNO was only 3 nm. 

The Rectisol process [667], [707], [711]-[715] seems to be the prime choice in partial oxidation plants. The process, invented by Lurgi and developed further by Linde, operates with chilled methanol, a cheap and readily available solvent, in which carbon dioxide, hydrogen sulfide and carbonyl sulfide (COS) are readily soluble at low operating temperatures of below - 30 °C. The Henry absorption coefficient for H2S is about six times higher than for C02-... 

In almost all of the gas-phase kinetic-mechanistic studies on sulfur atom reactions made to date, the source has been the in situ photolysis of carbonyl sulfide (COS). The reasons for this choice are not far to seek. Carbonyl sulfide is a stable, readily available gas. Its absorption spectrum is located in a convenient spectral region and the carbon monoxide formed in the photodissociation provides an excellent internal monitor for sulfur atom production. 

The photo-oxidation products of carbon disulfide in the laboratory were identified as carbon monoxide, carbonyl sulfide, sulfur dioxide, and a polymer that adhered to the sides of the reaction vessel (Heicklen et al. 1971). Although carbon disulfide absorbs light at wavelengths between 280 and 350 nm, dissociation does not occur under environmental conditions because of low molar absorptivity (Atkinson et al. 1978 Wood and Heicklen 1971) and direct photolysis of carbon disulfide in the atmosphere does not appear to be significant. EPA (1978a) stated that the information available indicated that carbon disulfide is relatively persistent in the atmosphere. For the atmospheric oxidation of carbon disulfide to sulfur dioxide, carbonyl sulfide, and carbon monoxide, the half-life was estimated to be about 12 days. 

According to Wine et al. (1981), electronically excited carbon disulfide is rapidly produced in the troposphere from absorption of solar photons. This excited carbon disulfide reacts with oxygen on a time scale of 1-2 weeks to yield carbonyl sulfide, the predominant sulfur-containing compound in the... 

Catalytic hydrogenation of the sulfur dioxide, carbonyl sulfide, and carbon disulfide in the tail gas to reform hydrogen sulfide, which is subsequently recovered by absorption. 

Sulfur in syngas appears as hydrogen sulfide (H2S) and (to a very small degree) carbonyl sulfide (COS). If the process selected for sulfur removal is not effective in COS capture (e.g., Selexol), then COS is typically hydrolyzed to H2S in a catalytic bed at about 200 °C to enhance sulfur removal. H2S is selectively removed from syngas in the acid gas removal (AGR) unit by means of absorption into solvents that have... 

Molina, L.T., Lamb, J.J., Molina, M.J. Temperature dependent UV absorption cross sections for carbonyl sulfide. Geophys. Res. Lett. 8, 1008-1011 (1981)... 

Al-Ghawas, H. A., Ruiz-Ibanez, G., and Sandall, O. C., 1988, Absorption of Carbonyl Sulfide in Aqueous Methj ldiethanolamine, presented at the Spring National Meeting of the AIChE, New Orleans, LA, March 1-10. 

One of the first applications of RQMC was to the rotational dynamics of carbonyl sulfide (OCS) molecules solvated in helium clusters, for cluster sizes (tV = 3,10) [42]. This and related work, described shortly, rest on the absorption spectrum given by the Fourier transform of the reptilian imaginary time electric dipole correlation function. Similarly, the optical activity is extracted from the autocorrelation of the molecular orientation vector. This work by Moroni and coworkers and/or Boroini and co-workers was closely followed by several other investigations of rotational dynamics in doped clusters, summarized as follows ... 

Carbonyl sitlfide may be formed ditring natural gas treatment by the reaction of hydrogen sitlfide and carbon dioxide and this can be difficult to remove completely using zinc oxide alone. This is not a problem if a bed of cobalt molybdate catalyst is included in the desulfurizer. It has been shown that lead oxide is an efficient absorbent of earboityl sulfide so the natural lead oxide impurity in some zinc oxides may promote absorption, espeeially if traees of water vapour are present to hydrolyze the carbonyl sulfide. 

In the present study, we synthesized in zeolite cavities Co-Mo binary sulfide clusters by using Co and Mo carbonyls and characterized the clusters by extended X-ray absorption fine structure (EXAFS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and high resolution electron microscopy (HREM). The mechanism of catalytic synergy generation in HDS is discussed. 

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