Selective Partial Oxidation of Hydrogen Sulfide by the BrOx Cycle

Abstract

Neutralization of the toxic gas hydrogen sulfide is an important step in almost every natural gas processing plant. A novel method for the conversion of hydrogen sulfide is a combination of bromination and oxidation reactions (BrOx). The first of those, the bromination of hydrogen sulfide, is investigated experimentally. An analysis of the potential by‐products reveals that their formation during the reaction can be excluded. Furthermore, a parameter study showed that reaction yields of up to 94 % are achievable by suitable reaction conditions.

Experimental Splitting of Hydrogen Sulfide by Halogens for Application in Reaction Cycles

“…Various studies have already been carried out on the halogenation of hydrogen sulfide. This publication itself is a follow up to preliminary tests and first measurements published in 2019 [18]. Since then, the experimental setup has been extensively improved, allowing for more numerous and more precise measurements.…”

“…In this series of experiments, the yield was investigated instead of the conversion, since the reactant Br 2 cannot be analyzed; it dissolves in the liquid sulfur inside the separator and does not reach the analysis vial. This series of experiments is based on the previously published results [18] and, since the plant was generally fine-tuned a lot, partially repeats them in order to compare both generations.…”

“…A thermodynamic calculation was performed for bromination and chlorination to look more accurately at previous observations about the exothermicity of the reactions [18,22]. At atmospheric pressure and above 445 °C, sulfur is present in gaseous molecular form from S 2 to S 8 with varying proportions depending on the temperature, which must be considered when calculating enthalpy and entropy.…”

“…The layout of the plant for hydrogen sulfide chlorination is displayed in Fig. 3, the flowsheet for the bromination plant was previously published [18]. Chlorine (99.8 %, Linde) and hydrogen sulfide (99.5 %, Linde) are supplied by gas cylinders and diluted by the inert gases argon (Ar, 99.996 %, Messer) and nitrogen (N 2 , 99.5 %, Messer), with which the reactant bottle attachments can also be flushed before and after the experiments to avoid corrosion.…”