Desulfurization Behavior of Fe–Mn-Based Regenerable Sorbents for High-Temperature H₂S Removal

Abstract

A series of Fe−Mn-based sorbents with different Fe/Mn mole ratios was prepared via coprecipitation for the hightemperature removal of H 2 S. Performance tests were carried out at 1123 K in a fixed-bed reactor, indicating that metallic Fe and MnO were the active components of the Fe−Mn-based sorbents in the hot gas. Single Fe-based sorbents exhibited a low desulfurization efficiency and effective sulfur capacity. The addition of manganese (Fe/Mn mole ratios less than 8:2) considerably improved the desulfurization efficiency and effective sulfur capacity of the Fe-based sorbents. In the first sulfidation test, effective sulfur capacities of 20.71, 20.72, and 20.14 g S/(100 g sorbent) were obtained for Mn7Fe3, Mn5Fe5, and Mn3Fe7, respectively. During five sulfidation−regeneration cycles, Mn7Fe3, Mn5Fe5, and Mn3Fe7 were stable, maintaining high activities and sulfur capacities, and reduced the amount of H 2 S to a few ppmv. After sulfidation, the sulfided sorbents could easily be regenerated with 2% O 2 in N 2 at 1123 K to obtain SO 2 and S 2 . The elemental sulfur recovery rate increased with the decrease of manganese content. Characterization with XRD, SEM, and BET showed that Fe−Mn-based sorbents kept stable structures during successive sulfidation−regeneration cycles.

Selective catalytic oxidation of H 2 S to elemental sulfur over titanium based Ti–Fe, Ti–Cr and Ti–Zr catalysts

“…In the work of Zeng et al, FeeMn based sorbents with different mole ratios were prepared by coprecipitation method and their sulfur retention capacities were determined at high temperature desulfurization (850 C). They reported zero effective sulfur capacity of Fe sorbent at high temperature desulfurization [42]. In this work, H 2 S sorption was completed within a time period of about 10 min with TieFe catalyst.…”

Recent Advances in Functionalized Mesoporous Silica Frameworks for Efficient Desulfurization of Fuels

“…Hydrodesulfurization (HDS) is one of the conventional methods to desulfurize fuel in refineries where organic sulfur is converted to H2S employing transition metal catalysts loaded on alumina substrates. Low cost transition metal oxides of Mn, Zn, Fe, Co, and Mo act as active components of these catalysts due to their high thermal stability [4][5][6][7][8][9]. However, energy demanding operating conditions involving high temperatures and pressures, low octane/cetane values, and selectivity towards simple refractory sulfur compounds in comparison to more complex aromatic species makes this process less efficient and makes room for new alternatives.…”

Hot Coal Gas Desulfurization Using Regenerable ZnO/MCM41 Prepared via One-Step Hydrothermal Synthesis

“…The gasification of coal, petroleum coke, biomass, and their mixture is one key technique for clean utilization of these resources. , However, the release of gasous sulfur species such as hydrogen sulfide and carbonyl sulfide is inevitable during the gasification process . H 2 S does damage to the pipeline and gas turbine. − It also causes poisoning of catalyst used in the subsequent chemical synthesis. − In addition, it leads to pollution when released into air. Therefore, the removal of H 2 S is necessary prior to utilization of gasification products either as fuel gas or as synthesis gas. − The techniques of removing H 2 S involve wet and dry desulfurization.…”

“…H 2 S does damage to the pipeline and gas turbine. − It also causes poisoning of catalyst used in the subsequent chemical synthesis. − In addition, it leads to pollution when released into air. Therefore, the removal of H 2 S is necessary prior to utilization of gasification products either as fuel gas or as synthesis gas. − The techniques of removing H 2 S involve wet and dry desulfurization. The former is mainly used for rough desulfurization.…”