Oxidation of Reduced Sulfur Species: Carbon Disulfide

Abstract

A detailed chemical kinetic model for oxidation of CS 2 has been developed, on the basis of ab initio calculations for key reactions, including CS 2 + O 2 and CS + O 2 , and data from literature. The mechanism has been evaluated against experimental results from static reactors, flow reactors, and shock tubes. The CS 2 + O 2 reaction forms OCS + SO, with the lowest energy path involving crossing from the triplet to the singlet surface. For CS + O 2 , which yields OCS + O, we found a high barrier to reaction, causing this step to be important only at elevated temperatures. The model predicts low temperature ignition delays and explosion limits accurately, whereas at higher temperatures it appears to overpredict both the induction time for CS 2 oxidation and the formation rate of [O] upon ignition. The predictive capability of the model depends on the accuracy of the rate constant for the initiation step CS 2 + O 2 , which is difficult to calculate due to the intersystem crossing, and the branching fraction for CS 2 + O, which is measured only at low temperatures. The governing reaction mechanisms are outlined on the basis of calculations with the kinetic model. ■ INTRODUCTIONOff-gases containing carbon disulfide (CS 2 ) are produced together with other sulfur containing compounds such as H 2 S from a range of industrial processes, including the Claus process 1−3 and production of viscous fibers, 4 and in gasification of coal 5 and biomass. 6 Similar to H 2 S and the oxidation product SO 2 , carbon disulfide is toxic and harmful to the environment. Efficient treatment of the sulfur containing off gases becomes a bottleneck in these processes as strict emission requirements must be met. Hence, knowledge of the CS 2 oxidation mechanism is important. Investigations have shown that CS 2 / O 2 mixtures are able to autoignite at low temperature and low pressure 7−13 under conditions of negligible self-heating. Two explosion limits have been reported in the literature, 7−9 and studies have been carried out to determine the effect upon the limits with a change in surface conditions and addition of inert gases. The induction times range from a few seconds to several minutes. 9,11,14 At higher temperatures, CS 2 oxidation has been investigated in flow reactors, 2,15 shock tubes, 16−18 and laminar premixed flames. 19−23 Much of the high-temperature work has been motivated by interest in the CO laser. CS 2 /O 2 flames form CO with its vibrational population inverted, facilitating production of a CO flame laser.Previous studies of the reaction mechanism of carbon disulfide oxidation have mostly been restricted to fuel-lean, dry conditions. 17,18,20,24,25 No reported chemical kinetic models are found to satisfactory describe experimental data across a wider range of mixture composition, temperature, and pressure as the mechanism is complex and accurate kinetic data have been unavailable for several important reactions. The objective of the present study is to develop a detailed chemical kinetic model for oxidation of...

An Exploratory Flow Reactor Study of H2S Oxidation at 30–100 Bar

“…In addition to SH + O 2 discussed above, reactions of HSO, SO, S, and HSS with O 2 should be considered. The rate constants for the chain branching steps SO + O 2 and S + O 2 are well established , but values for HSO + O 2 and HSS + O 2 are more uncertain.…”

“…Ozone is much more reactive than molecular oxygen and may promote reaction. Following other recent studies on low‐temperature sulfur chemistry , we include an O 3 reaction subset with rate constants mostly from Atkinson et al . Ozone may interact with the O/H radical pool or react with sulfur species, primarily H 2 S or SH.…”

Fluorescent Detection of Carbon Disulfide by a Highly Emissive and Robust Isoreticular Series of Zr-Based Luminescent Metal Organic Frameworks (LMOFs)

“…Carbon disulfide (CS2) is a highly volatile neurotoxic species produced in the manufacturing of viscose rayon fibers, the production of agricultural pesticides, as a vulcanizing accelerant, and as a chemical by-product of syngas produced from biomass [18][19][20]. CS2 is a nonpolar organic solvent that can dissolve a wide range of chemicals; however, it is also known to cause atherosclerosis and coronary artery disease [21].…”

Experimental and computational studies of the kinetics of the reaction of hydrogen atoms with carbon disulfide

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