Kinetic Features of the Hydrogen Sulfide Sorption on the Ferro-Manganese Material

• Main Authors: Elizaveta Cheremisina, Olga Cheremisina, Maria Ponomareva, Viktor Bolotov, Alexander Fedorov
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: Metals
• Subjects: chemisorption; hydrogen sulfide; ferromanganese material; kinetics; activation energy; heterogeneous catalysis
• Online Access: https://www.mdpi.com/2075-4701/11/1/90

The kinetics of hydrogen sulfide sorption by the surface of a ferromanganese material containing in its composition a mixture of iron (II) and (III) oxides FeO × Fe₂O₃, takanelite (Mn, Ca) Mn₄O₉ × 3H₂O and quartz SiO₂, and which is samples of unrefined ferromanganese ore, was studied in this work. Sorption rate constant and activation energy constant values were calculated. The catalytic effect of iron (III) oxide was established, the presence of which in natural material contributes to a decrease in the H₂S sorption activation energy. Based on the results of X-ray phase and chromatographic analysis methods, a chemical (redox) reaction of the conversion of hydrogen sulfide into elemental sulfur and H₂O was revealed. The overall process rate is expressed in terms of the physical sorption stage and chemical transformation of the components; the influence of the rate of the third stage—reaction products desorption—on the overall rate of the process is taken into account. The limiting stage of the process is determined—a chemical reaction. The relation between the heat and the activation energy of the chemical transformation is used according to the Bronsted—Polanyi rule for catalytic processes. It was found that with an increase in the chemisorption heat, the activation energy of the chemisorption stage decreases and, as a consequence, its rate increases. The sorption process parameters were calculated—the Fe₂O₃ coverage degree with the initial substances and reaction products providing the maximum sorption rate, which can be a criterion for evaluating the catalytically active sites of the catalyst surface for carrying out catalytic reactions.