An experimental, theoretical and kinetic-modeling study of hydrogen sulfide pyrolysis and oxidation

• DOI: 10.1016/j.cej.2022.136723
• Publication Date: 2022-05-02T15:41:23Z
• Authors: Alessandro Stagni; Suphaporn Aruntha...; Luna Pratali Maffei; Olivier Herbinet; Frédérique Battin...; Tiziano Faravelli
• Keywords: Sulphur oxides; Jet-stirred reactor; Hydrogen sulfide; ab initio; [CHIM.GENI] Chemical Sciences/Chemical engineering; Flow reactor; 01 natural sciences; [CHIM.THEO] Chemical Sciences/Theoretical and/or physical chemistry; Ab initio; 0103 physical sciences; detailed kinetics; Detailed kinetics

Hydrogen sulfide chemistry has recently undergone a renewed interest due to the current energy transition, requiring proper treatment of such impurities in sources like shale gas or biogas. Moreover, lower-temperature, diluted conditions considered nowadays for reducing pollutant emissions require wider-range development and validation pyrolysis oxidation mechanisms. In this work, was addressed through an experimental campaign carried out three reactor facilities, namely jet-stirred two flow reactors. A wide range operating could thus be covered, terms equivalence ratios under lean (0.018≤Φ≤0.5), temperatures (400K≤T≤2000K) residence times (0.1s≤τ≤2s). The mole fractions reactants (H2S, O2), products (SO2, H2O) intermediates (H2) were measured. parallel, kinetic mechanism H2S developed by including latest available rates on sulfur chemistry, which added core H2/O2 module, previously validated. Such included re-evaluation selected key reaction steps, identified via sensitivity analysis. Results showed general agreement measurements with predictions: case pyrolysis, thermal decomposition (H2S + M = H2 S M) as sole controlling step: critical choice rate had made, significant disagreement among literature rates. Concerning oxidation, H-abstraction from O2 found major bottleneck at lowest temperatures, HO2 becoming abstractor, too, very conditions. At higher role played instead SH SH), acting reverse direction providing radicals, boosting process.